pg_backup_archiver.c

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/*-------------------------------------------------------------------------
 *
 * pg_backup_archiver.c
 *
 *  Private implementation of the archiver routines.
 *
 *  See the headers to pg_restore for more details.
 *
 * Copyright (c) 2000, Philip Warner
 *  Rights are granted to use this software in any way so long
 *  as this notice is not removed.
 *
 *  The author is not responsible for loss or damages that may
 *  result from its use.
 *
 *
 * IDENTIFICATION
 *      src/bin/pg_dump/pg_backup_archiver.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres_fe.h"

#include <ctype.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/wait.h>
#ifdef WIN32
#include <io.h>
#endif

#include "parallel.h"
#include "pg_backup_archiver.h"
#include "pg_backup_db.h"
#include "pg_backup_utils.h"
#include "dumputils.h"
#include "fe_utils/string_utils.h"

#include "libpq/libpq-fs.h"

#define TEXT_DUMP_HEADER "--\n-- PostgreSQL database dump\n--\n\n"
#define TEXT_DUMPALL_HEADER "--\n-- PostgreSQL database cluster dump\n--\n\n"

/* state needed to save/restore an archive's output target */
typedef struct _outputContext
{
    void       *OF;
    int         gzOut;
} OutputContext;

/* translator: this is a module name */
static const char *modulename = gettext_noop("archiver");


static ArchiveHandle *_allocAH(const char *FileSpec, const ArchiveFormat fmt,
         const int compression, bool dosync, ArchiveMode mode,
         SetupWorkerPtrType setupWorkerPtr);
static void _getObjectDescription(PQExpBuffer buf, TocEntry *te,
                      ArchiveHandle *AH);
static void _printTocEntry(ArchiveHandle *AH, TocEntry *te, bool isData);
static char *replace_line_endings(const char *str);
static void _doSetFixedOutputState(ArchiveHandle *AH);
static void _doSetSessionAuth(ArchiveHandle *AH, const char *user);
static void _doSetWithOids(ArchiveHandle *AH, const bool withOids);
static void _reconnectToDB(ArchiveHandle *AH, const char *dbname);
static void _becomeUser(ArchiveHandle *AH, const char *user);
static void _becomeOwner(ArchiveHandle *AH, TocEntry *te);
static void _selectOutputSchema(ArchiveHandle *AH, const char *schemaName);
static void _selectTablespace(ArchiveHandle *AH, const char *tablespace);
static void processEncodingEntry(ArchiveHandle *AH, TocEntry *te);
static void processStdStringsEntry(ArchiveHandle *AH, TocEntry *te);
static teReqs _tocEntryRequired(TocEntry *te, teSection curSection, RestoreOptions *ropt);
static RestorePass _tocEntryRestorePass(TocEntry *te);
static bool _tocEntryIsACL(TocEntry *te);
static void _disableTriggersIfNecessary(ArchiveHandle *AH, TocEntry *te);
static void _enableTriggersIfNecessary(ArchiveHandle *AH, TocEntry *te);
static void buildTocEntryArrays(ArchiveHandle *AH);
static void _moveBefore(ArchiveHandle *AH, TocEntry *pos, TocEntry *te);
static int  _discoverArchiveFormat(ArchiveHandle *AH);

static int  RestoringToDB(ArchiveHandle *AH);
static void dump_lo_buf(ArchiveHandle *AH);
static void dumpTimestamp(ArchiveHandle *AH, const char *msg, time_t tim);
static void SetOutput(ArchiveHandle *AH, const char *filename, int compression);
static OutputContext SaveOutput(ArchiveHandle *AH);
static void RestoreOutput(ArchiveHandle *AH, OutputContext savedContext);

static int  restore_toc_entry(ArchiveHandle *AH, TocEntry *te, bool is_parallel);
static void restore_toc_entries_prefork(ArchiveHandle *AH,
                            TocEntry *pending_list);
static void restore_toc_entries_parallel(ArchiveHandle *AH,
                             ParallelState *pstate,
                             TocEntry *pending_list);
static void restore_toc_entries_postfork(ArchiveHandle *AH,
                             TocEntry *pending_list);
static void par_list_header_init(TocEntry *l);
static void par_list_append(TocEntry *l, TocEntry *te);
static void par_list_remove(TocEntry *te);
static void move_to_ready_list(TocEntry *pending_list, TocEntry *ready_list,
                   RestorePass pass);
static TocEntry *get_next_work_item(ArchiveHandle *AH,
                   TocEntry *ready_list,
                   ParallelState *pstate);
static void mark_dump_job_done(ArchiveHandle *AH,
                   TocEntry *te,
                   int status,
                   void *callback_data);
static void mark_restore_job_done(ArchiveHandle *AH,
                      TocEntry *te,
                      int status,
                      void *callback_data);
static void fix_dependencies(ArchiveHandle *AH);
static bool has_lock_conflicts(TocEntry *te1, TocEntry *te2);
static void repoint_table_dependencies(ArchiveHandle *AH);
static void identify_locking_dependencies(ArchiveHandle *AH, TocEntry *te);
static void reduce_dependencies(ArchiveHandle *AH, TocEntry *te,
                    TocEntry *ready_list);
static void mark_create_done(ArchiveHandle *AH, TocEntry *te);
static void inhibit_data_for_failed_table(ArchiveHandle *AH, TocEntry *te);

static void StrictNamesCheck(RestoreOptions *ropt);


/*
 * Allocate a new DumpOptions block containing all default values.
 */
DumpOptions *
NewDumpOptions(void)
{
    DumpOptions *opts = (DumpOptions *) pg_malloc(sizeof(DumpOptions));

    InitDumpOptions(opts);
    return opts;
}

/*
 * Initialize a DumpOptions struct to all default values
 */
void
InitDumpOptions(DumpOptions *opts)
{
    memset(opts, 0, sizeof(DumpOptions));
    /* set any fields that shouldn't default to zeroes */
    opts->include_everything = true;
    opts->dumpSections = DUMP_UNSECTIONED;
}

/*
 * Create a freshly allocated DumpOptions with options equivalent to those
 * found in the given RestoreOptions.
 */
DumpOptions *
dumpOptionsFromRestoreOptions(RestoreOptions *ropt)
{
    DumpOptions *dopt = NewDumpOptions();

    /* this is the inverse of what's at the end of pg_dump.c's main() */
    dopt->outputClean = ropt->dropSchema;
    dopt->dataOnly = ropt->dataOnly;
    dopt->schemaOnly = ropt->schemaOnly;
    dopt->if_exists = ropt->if_exists;
    dopt->column_inserts = ropt->column_inserts;
    dopt->dumpSections = ropt->dumpSections;
    dopt->aclsSkip = ropt->aclsSkip;
    dopt->outputSuperuser = ropt->superuser;
    dopt->outputCreateDB = ropt->createDB;
    dopt->outputNoOwner = ropt->noOwner;
    dopt->outputNoTablespaces = ropt->noTablespace;
    dopt->disable_triggers = ropt->disable_triggers;
    dopt->use_setsessauth = ropt->use_setsessauth;

    dopt->disable_dollar_quoting = ropt->disable_dollar_quoting;
    dopt->dump_inserts = ropt->dump_inserts;
    dopt->no_publications = ropt->no_publications;
    dopt->no_security_labels = ropt->no_security_labels;
    dopt->no_subscriptions = ropt->no_subscriptions;
    dopt->lockWaitTimeout = ropt->lockWaitTimeout;
    dopt->include_everything = ropt->include_everything;
    dopt->enable_row_security = ropt->enable_row_security;
    dopt->sequence_data = ropt->sequence_data;

    return dopt;
}


/*
 *  Wrapper functions.
 *
 *  The objective it to make writing new formats and dumpers as simple
 *  as possible, if necessary at the expense of extra function calls etc.
 *
 */

/*
 * The dump worker setup needs lots of knowledge of the internals of pg_dump,
 * so It's defined in pg_dump.c and passed into OpenArchive. The restore worker
 * setup doesn't need to know anything much, so it's defined here.
 */
static void
setupRestoreWorker(Archive *AHX)
{
    ArchiveHandle *AH = (ArchiveHandle *) AHX;

    AH->ReopenPtr(AH);
}


/* Create a new archive */
/* Public */
Archive *
CreateArchive(const char *FileSpec, const ArchiveFormat fmt,
              const int compression, bool dosync, ArchiveMode mode,
              SetupWorkerPtrType setupDumpWorker)

{
    ArchiveHandle *AH = _allocAH(FileSpec, fmt, compression, dosync,
                                 mode, setupDumpWorker);

    return (Archive *) AH;
}

/* Open an existing archive */
/* Public */
Archive *
OpenArchive(const char *FileSpec, const ArchiveFormat fmt)
{
    ArchiveHandle *AH = _allocAH(FileSpec, fmt, 0, true, archModeRead, setupRestoreWorker);

    return (Archive *) AH;
}

/* Public */
void
CloseArchive(Archive *AHX)
{
    int         res = 0;
    ArchiveHandle *AH = (ArchiveHandle *) AHX;

    AH->ClosePtr(AH);

    /* Close the output */
    if (AH->gzOut)
        res = GZCLOSE(AH->OF);
    else if (AH->OF != stdout)
        res = fclose(AH->OF);

    if (res != 0)
        exit_horribly(modulename, "could not close output file: %s\n",
                      strerror(errno));
}

/* Public */
void
SetArchiveOptions(Archive *AH, DumpOptions *dopt, RestoreOptions *ropt)
{
    /* Caller can omit dump options, in which case we synthesize them */
    if (dopt == NULL && ropt != NULL)
        dopt = dumpOptionsFromRestoreOptions(ropt);

    /* Save options for later access */
    AH->dopt = dopt;
    AH->ropt = ropt;
}

/* Public */
void
ProcessArchiveRestoreOptions(Archive *AHX)
{
    ArchiveHandle *AH = (ArchiveHandle *) AHX;
    RestoreOptions *ropt = AH->public.ropt;
    TocEntry   *te;
    teSection   curSection;

    /* Decide which TOC entries will be dumped/restored, and mark them */
    curSection = SECTION_PRE_DATA;
    for (te = AH->toc->next; te != AH->toc; te = te->next)
    {
        /*
         * When writing an archive, we also take this opportunity to check
         * that we have generated the entries in a sane order that respects
         * the section divisions.  When reading, don't complain, since buggy
         * old versions of pg_dump might generate out-of-order archives.
         */
        if (AH->mode != archModeRead)
        {
            switch (te->section)
            {
                case SECTION_NONE:
                    /* ok to be anywhere */
                    break;
                case SECTION_PRE_DATA:
                    if (curSection != SECTION_PRE_DATA)
                        write_msg(modulename,
                                  "WARNING: archive items not in correct section order\n");
                    break;
                case SECTION_DATA:
                    if (curSection == SECTION_POST_DATA)
                        write_msg(modulename,
                                  "WARNING: archive items not in correct section order\n");
                    break;
                case SECTION_POST_DATA:
                    /* ok no matter which section we were in */
                    break;
                default:
                    exit_horribly(modulename, "unexpected section code %d\n",
                                  (int) te->section);
                    break;
            }
        }

        if (te->section != SECTION_NONE)
            curSection = te->section;

        te->reqs = _tocEntryRequired(te, curSection, ropt);
    }

    /* Enforce strict names checking */
    if (ropt->strict_names)
        StrictNamesCheck(ropt);
}

/* Public */
void
RestoreArchive(Archive *AHX)
{
    ArchiveHandle *AH = (ArchiveHandle *) AHX;
    RestoreOptions *ropt = AH->public.ropt;
    bool        parallel_mode;
    TocEntry   *te;
    OutputContext sav;

    AH->stage = STAGE_INITIALIZING;

    /*
     * Check for nonsensical option combinations.
     *
     * -C is not compatible with -1, because we can't create a database inside
     * a transaction block.
     */
    if (ropt->createDB && ropt->single_txn)
        exit_horribly(modulename, "-C and -1 are incompatible options\n");

    /*
     * If we're going to do parallel restore, there are some restrictions.
     */
    parallel_mode = (AH->public.numWorkers > 1 && ropt->useDB);
    if (parallel_mode)
    {
        /* We haven't got round to making this work for all archive formats */
        if (AH->ClonePtr == NULL || AH->ReopenPtr == NULL)
            exit_horribly(modulename, "parallel restore is not supported with this archive file format\n");

        /* Doesn't work if the archive represents dependencies as OIDs */
        if (AH->version < K_VERS_1_8)
            exit_horribly(modulename, "parallel restore is not supported with archives made by pre-8.0 pg_dump\n");

        /*
         * It's also not gonna work if we can't reopen the input file, so
         * let's try that immediately.
         */
        AH->ReopenPtr(AH);
    }

    /*
     * Make sure we won't need (de)compression we haven't got
     */
#ifndef HAVE_LIBZ
    if (AH->compression != 0 && AH->PrintTocDataPtr != NULL)
    {
        for (te = AH->toc->next; te != AH->toc; te = te->next)
        {
            if (te->hadDumper && (te->reqs & REQ_DATA) != 0)
                exit_horribly(modulename, "cannot restore from compressed archive (compression not supported in this installation)\n");
        }
    }
#endif

    /*
     * Prepare index arrays, so we can assume we have them throughout restore.
     * It's possible we already did this, though.
     */
    if (AH->tocsByDumpId == NULL)
        buildTocEntryArrays(AH);

    /*
     * If we're using a DB connection, then connect it.
     */
    if (ropt->useDB)
    {
        ahlog(AH, 1, "connecting to database for restore\n");
        if (AH->version < K_VERS_1_3)
            exit_horribly(modulename, "direct database connections are not supported in pre-1.3 archives\n");

        /*
         * We don't want to guess at whether the dump will successfully
         * restore; allow the attempt regardless of the version of the restore
         * target.
         */
        AHX->minRemoteVersion = 0;
        AHX->maxRemoteVersion = 9999999;

        ConnectDatabase(AHX, ropt->dbname,
                        ropt->pghost, ropt->pgport, ropt->username,
                        ropt->promptPassword);

        /*
         * If we're talking to the DB directly, don't send comments since they
         * obscure SQL when displaying errors
         */
        AH->noTocComments = 1;
    }

    /*
     * Work out if we have an implied data-only restore. This can happen if
     * the dump was data only or if the user has used a toc list to exclude
     * all of the schema data. All we do is look for schema entries - if none
     * are found then we set the dataOnly flag.
     *
     * We could scan for wanted TABLE entries, but that is not the same as
     * dataOnly. At this stage, it seems unnecessary (6-Mar-2001).
     */
    if (!ropt->dataOnly)
    {
        int         impliedDataOnly = 1;

        for (te = AH->toc->next; te != AH->toc; te = te->next)
        {
            if ((te->reqs & REQ_SCHEMA) != 0)
            {                   /* It's schema, and it's wanted */
                impliedDataOnly = 0;
                break;
            }
        }
        if (impliedDataOnly)
        {
            ropt->dataOnly = impliedDataOnly;
            ahlog(AH, 1, "implied data-only restore\n");
        }
    }

    /*
     * Setup the output file if necessary.
     */
    sav = SaveOutput(AH);
    if (ropt->filename || ropt->compression)
        SetOutput(AH, ropt->filename, ropt->compression);

    ahprintf(AH, "--\n-- PostgreSQL database dump\n--\n\n");

    if (AH->archiveRemoteVersion)
        ahprintf(AH, "-- Dumped from database version %s\n",
                 AH->archiveRemoteVersion);
    if (AH->archiveDumpVersion)
        ahprintf(AH, "-- Dumped by pg_dump version %s\n",
                 AH->archiveDumpVersion);

    ahprintf(AH, "\n");

    if (AH->public.verbose)
        dumpTimestamp(AH, "Started on", AH->createDate);

    if (ropt->single_txn)
    {
        if (AH->connection)
            StartTransaction(AHX);
        else
            ahprintf(AH, "BEGIN;\n\n");
    }

    /*
     * Establish important parameter values right away.
     */
    _doSetFixedOutputState(AH);

    AH->stage = STAGE_PROCESSING;

    /*
     * Drop the items at the start, in reverse order
     */
    if (ropt->dropSchema)
    {
        for (te = AH->toc->prev; te != AH->toc; te = te->prev)
        {
            AH->currentTE = te;

            /*
             * In createDB mode, issue a DROP *only* for the database as a
             * whole.  Issuing drops against anything else would be wrong,
             * because at this point we're connected to the wrong database.
             * Conversely, if we're not in createDB mode, we'd better not
             * issue a DROP against the database at all.
             */
            if (ropt->createDB)
            {
                if (strcmp(te->desc, "DATABASE") != 0)
                    continue;
            }
            else
            {
                if (strcmp(te->desc, "DATABASE") == 0)
                    continue;
            }

            /* Otherwise, drop anything that's selected and has a dropStmt */
            if (((te->reqs & (REQ_SCHEMA | REQ_DATA)) != 0) && te->dropStmt)
            {
                ahlog(AH, 1, "dropping %s %s\n", te->desc, te->tag);
                /* Select owner and schema as necessary */
                _becomeOwner(AH, te);
                _selectOutputSchema(AH, te->namespace);

                /*
                 * Now emit the DROP command, if the object has one.  Note we
                 * don't necessarily emit it verbatim; at this point we add an
                 * appropriate IF EXISTS clause, if the user requested it.
                 */
                if (*te->dropStmt != '\0')
                {
                    if (!ropt->if_exists)
                    {
                        /* No --if-exists?  Then just use the original */
                        ahprintf(AH, "%s", te->dropStmt);
                    }
                    else
                    {
                        /*
                         * Inject an appropriate spelling of "if exists".  For
                         * large objects, we have a separate routine that
                         * knows how to do it, without depending on
                         * te->dropStmt; use that.  For other objects we need
                         * to parse the command.
                         */
                        if (strncmp(te->desc, "BLOB", 4) == 0)
                        {
                            DropBlobIfExists(AH, te->catalogId.oid);
                        }
                        else
                        {
                            char       *dropStmt = pg_strdup(te->dropStmt);
                            char       *dropStmtOrig = dropStmt;
                            PQExpBuffer ftStmt = createPQExpBuffer();

                            /*
                             * Need to inject IF EXISTS clause after ALTER
                             * TABLE part in ALTER TABLE .. DROP statement
                             */
                            if (strncmp(dropStmt, "ALTER TABLE", 11) == 0)
                            {
                                appendPQExpBuffer(ftStmt,
                                                  "ALTER TABLE IF EXISTS");
                                dropStmt = dropStmt + 11;
                            }

                            /*
                             * ALTER TABLE..ALTER COLUMN..DROP DEFAULT does
                             * not support the IF EXISTS clause, and therefore
                             * we simply emit the original command for DEFAULT
                             * objects (modulo the adjustment made above).
                             *
                             * If we used CREATE OR REPLACE VIEW as a means of
                             * quasi-dropping an ON SELECT rule, that should
                             * be emitted unchanged as well.
                             *
                             * For other object types, we need to extract the
                             * first part of the DROP which includes the
                             * object type.  Most of the time this matches
                             * te->desc, so search for that; however for the
                             * different kinds of CONSTRAINTs, we know to
                             * search for hardcoded "DROP CONSTRAINT" instead.
                             */
                            if (strcmp(te->desc, "DEFAULT") == 0 ||
                                strncmp(dropStmt, "CREATE OR REPLACE VIEW", 22) == 0)
                                appendPQExpBufferStr(ftStmt, dropStmt);
                            else
                            {
                                char        buffer[40];
                                char       *mark;

                                if (strcmp(te->desc, "CONSTRAINT") == 0 ||
                                    strcmp(te->desc, "CHECK CONSTRAINT") == 0 ||
                                    strcmp(te->desc, "FK CONSTRAINT") == 0)
                                    strcpy(buffer, "DROP CONSTRAINT");
                                else
                                    snprintf(buffer, sizeof(buffer), "DROP %s",
                                             te->desc);

                                mark = strstr(dropStmt, buffer);

                                if (mark)
                                {
                                    *mark = '\0';
                                    appendPQExpBuffer(ftStmt, "%s%s IF EXISTS%s",
                                                      dropStmt, buffer,
                                                      mark + strlen(buffer));
                                }
                                else
                                {
                                    /* complain and emit unmodified command */
                                    write_msg(modulename,
                                              "WARNING: could not find where to insert IF EXISTS in statement \"%s\"\n",
                                              dropStmtOrig);
                                    appendPQExpBufferStr(ftStmt, dropStmt);
                                }
                            }

                            ahprintf(AH, "%s", ftStmt->data);

                            destroyPQExpBuffer(ftStmt);
                            pg_free(dropStmtOrig);
                        }
                    }
                }
            }
        }

        /*
         * _selectOutputSchema may have set currSchema to reflect the effect
         * of a "SET search_path" command it emitted.  However, by now we may
         * have dropped that schema; or it might not have existed in the first
         * place.  In either case the effective value of search_path will not
         * be what we think.  Forcibly reset currSchema so that we will
         * re-establish the search_path setting when needed (after creating
         * the schema).
         *
         * If we treated users as pg_dump'able objects then we'd need to reset
         * currUser here too.
         */
        if (AH->currSchema)
            free(AH->currSchema);
        AH->currSchema = NULL;
    }

    if (parallel_mode)
    {
        /*
         * In parallel mode, turn control over to the parallel-restore logic.
         */
        ParallelState *pstate;
        TocEntry    pending_list;

        par_list_header_init(&pending_list);

        /* This runs PRE_DATA items and then disconnects from the database */
        restore_toc_entries_prefork(AH, &pending_list);
        Assert(AH->connection == NULL);

        /* ParallelBackupStart() will actually fork the processes */
        pstate = ParallelBackupStart(AH);
        restore_toc_entries_parallel(AH, pstate, &pending_list);
        ParallelBackupEnd(AH, pstate);

        /* reconnect the master and see if we missed something */
        restore_toc_entries_postfork(AH, &pending_list);
        Assert(AH->connection != NULL);
    }
    else
    {
        /*
         * In serial mode, process everything in three phases: normal items,
         * then ACLs, then matview refresh items.  We might be able to skip
         * one or both extra phases in some cases, eg data-only restores.
         */
        bool        haveACL = false;
        bool        haveRefresh = false;

        for (te = AH->toc->next; te != AH->toc; te = te->next)
        {
            if ((te->reqs & (REQ_SCHEMA | REQ_DATA)) == 0)
                continue;       /* ignore if not to be dumped at all */

            switch (_tocEntryRestorePass(te))
            {
                case RESTORE_PASS_MAIN:
                    (void) restore_toc_entry(AH, te, false);
                    break;
                case RESTORE_PASS_ACL:
                    haveACL = true;
                    break;
                case RESTORE_PASS_REFRESH:
                    haveRefresh = true;
                    break;
            }
        }

        if (haveACL)
        {
            for (te = AH->toc->next; te != AH->toc; te = te->next)
            {
                if ((te->reqs & (REQ_SCHEMA | REQ_DATA)) != 0 &&
                    _tocEntryRestorePass(te) == RESTORE_PASS_ACL)
                    (void) restore_toc_entry(AH, te, false);
            }
        }

        if (haveRefresh)
        {
            for (te = AH->toc->next; te != AH->toc; te = te->next)
            {
                if ((te->reqs & (REQ_SCHEMA | REQ_DATA)) != 0 &&
                    _tocEntryRestorePass(te) == RESTORE_PASS_REFRESH)
                    (void) restore_toc_entry(AH, te, false);
            }
        }
    }

    if (ropt->single_txn)
    {
        if (AH->connection)
            CommitTransaction(AHX);
        else
            ahprintf(AH, "COMMIT;\n\n");
    }

    if (AH->public.verbose)
        dumpTimestamp(AH, "Completed on", time(NULL));

    ahprintf(AH, "--\n-- PostgreSQL database dump complete\n--\n\n");

    /*
     * Clean up & we're done.
     */
    AH->stage = STAGE_FINALIZING;

    if (ropt->filename || ropt->compression)
        RestoreOutput(AH, sav);

    if (ropt->useDB)
        DisconnectDatabase(&AH->public);
}

/*
 * Restore a single TOC item.  Used in both parallel and non-parallel restore;
 * is_parallel is true if we are in a worker child process.
 *
 * Returns 0 normally, but WORKER_CREATE_DONE or WORKER_INHIBIT_DATA if
 * the parallel parent has to make the corresponding status update.
 */
static int
restore_toc_entry(ArchiveHandle *AH, TocEntry *te, bool is_parallel)
{
    RestoreOptions *ropt = AH->public.ropt;
    int         status = WORKER_OK;
    teReqs      reqs;
    bool        defnDumped;

    AH->currentTE = te;

    /* Work out what, if anything, we want from this entry */
    reqs = te->reqs;

    /*
     * Ignore DATABASE entry unless we should create it.  We must check this
     * here, not in _tocEntryRequired, because the createDB option should not
     * affect emitting a DATABASE entry to an archive file.
     */
    if (!ropt->createDB && strcmp(te->desc, "DATABASE") == 0)
        reqs = 0;

    /* Dump any relevant dump warnings to stderr */
    if (!ropt->suppressDumpWarnings && strcmp(te->desc, "WARNING") == 0)
    {
        if (!ropt->dataOnly && te->defn != NULL && strlen(te->defn) != 0)
            write_msg(modulename, "warning from original dump file: %s\n", te->defn);
        else if (te->copyStmt != NULL && strlen(te->copyStmt) != 0)
            write_msg(modulename, "warning from original dump file: %s\n", te->copyStmt);
    }

    defnDumped = false;

    /*
     * If it has a schema component that we want, then process that
     */
    if ((reqs & REQ_SCHEMA) != 0)
    {
        /* Show namespace in log message if available */
        if (te->namespace)
            ahlog(AH, 1, "creating %s \"%s.%s\"\n",
                  te->desc, te->namespace, te->tag);
        else
            ahlog(AH, 1, "creating %s \"%s\"\n", te->desc, te->tag);

        _printTocEntry(AH, te, false);
        defnDumped = true;

        if (strcmp(te->desc, "TABLE") == 0)
        {
            if (AH->lastErrorTE == te)
            {
                /*
                 * We failed to create the table. If
                 * --no-data-for-failed-tables was given, mark the
                 * corresponding TABLE DATA to be ignored.
                 *
                 * In the parallel case this must be done in the parent, so we
                 * just set the return value.
                 */
                if (ropt->noDataForFailedTables)
                {
                    if (is_parallel)
                        status = WORKER_INHIBIT_DATA;
                    else
                        inhibit_data_for_failed_table(AH, te);
                }
            }
            else
            {
                /*
                 * We created the table successfully.  Mark the corresponding
                 * TABLE DATA for possible truncation.
                 *
                 * In the parallel case this must be done in the parent, so we
                 * just set the return value.
                 */
                if (is_parallel)
                    status = WORKER_CREATE_DONE;
                else
                    mark_create_done(AH, te);
            }
        }

        /* If we created a DB, connect to it... */
        if (strcmp(te->desc, "DATABASE") == 0)
        {
            PQExpBufferData connstr;

            initPQExpBuffer(&connstr);
            appendPQExpBufferStr(&connstr, "dbname=");
            appendConnStrVal(&connstr, te->tag);
            /* Abandon struct, but keep its buffer until process exit. */

            ahlog(AH, 1, "connecting to new database \"%s\"\n", te->tag);
            _reconnectToDB(AH, te->tag);
            ropt->dbname = connstr.data;
        }
    }

    /*
     * If it has a data component that we want, then process that
     */
    if ((reqs & REQ_DATA) != 0)
    {
        /*
         * hadDumper will be set if there is genuine data component for this
         * node. Otherwise, we need to check the defn field for statements
         * that need to be executed in data-only restores.
         */
        if (te->hadDumper)
        {
            /*
             * If we can output the data, then restore it.
             */
            if (AH->PrintTocDataPtr != NULL)
            {
                _printTocEntry(AH, te, true);

                if (strcmp(te->desc, "BLOBS") == 0 ||
                    strcmp(te->desc, "BLOB COMMENTS") == 0)
                {
                    ahlog(AH, 1, "processing %s\n", te->desc);

                    _selectOutputSchema(AH, "pg_catalog");

                    /* Send BLOB COMMENTS data to ExecuteSimpleCommands() */
                    if (strcmp(te->desc, "BLOB COMMENTS") == 0)
                        AH->outputKind = OUTPUT_OTHERDATA;

                    AH->PrintTocDataPtr(AH, te);

                    AH->outputKind = OUTPUT_SQLCMDS;
                }
                else
                {
                    _disableTriggersIfNecessary(AH, te);

                    /* Select owner and schema as necessary */
                    _becomeOwner(AH, te);
                    _selectOutputSchema(AH, te->namespace);

                    ahlog(AH, 1, "processing data for table \"%s.%s\"\n",
                          te->namespace, te->tag);

                    /*
                     * In parallel restore, if we created the table earlier in
                     * the run then we wrap the COPY in a transaction and
                     * precede it with a TRUNCATE.  If archiving is not on
                     * this prevents WAL-logging the COPY.  This obtains a
                     * speedup similar to that from using single_txn mode in
                     * non-parallel restores.
                     */
                    if (is_parallel && te->created)
                    {
                        /*
                         * Parallel restore is always talking directly to a
                         * server, so no need to see if we should issue BEGIN.
                         */
                        StartTransaction(&AH->public);

                        /*
                         * If the server version is >= 8.4, make sure we issue
                         * TRUNCATE with ONLY so that child tables are not
                         * wiped.
                         */
                        ahprintf(AH, "TRUNCATE TABLE %s%s;\n\n",
                                 (PQserverVersion(AH->connection) >= 80400 ?
                                  "ONLY " : ""),
                                 fmtId(te->tag));
                    }

                    /*
                     * If we have a copy statement, use it.
                     */
                    if (te->copyStmt && strlen(te->copyStmt) > 0)
                    {
                        ahprintf(AH, "%s", te->copyStmt);
                        AH->outputKind = OUTPUT_COPYDATA;
                    }
                    else
                        AH->outputKind = OUTPUT_OTHERDATA;

                    AH->PrintTocDataPtr(AH, te);

                    /*
                     * Terminate COPY if needed.
                     */
                    if (AH->outputKind == OUTPUT_COPYDATA &&
                        RestoringToDB(AH))
                        EndDBCopyMode(&AH->public, te->tag);
                    AH->outputKind = OUTPUT_SQLCMDS;

                    /* close out the transaction started above */
                    if (is_parallel && te->created)
                        CommitTransaction(&AH->public);

                    _enableTriggersIfNecessary(AH, te);
                }
            }
        }
        else if (!defnDumped)
        {
            /* If we haven't already dumped the defn part, do so now */
            ahlog(AH, 1, "executing %s %s\n", te->desc, te->tag);
            _printTocEntry(AH, te, false);
        }
    }

    if (AH->public.n_errors > 0 && status == WORKER_OK)
        status = WORKER_IGNORED_ERRORS;

    return status;
}

/*
 * Allocate a new RestoreOptions block.
 * This is mainly so we can initialize it, but also for future expansion,
 */
RestoreOptions *
NewRestoreOptions(void)
{
    RestoreOptions *opts;

    opts = (RestoreOptions *) pg_malloc0(sizeof(RestoreOptions));

    /* set any fields that shouldn't default to zeroes */
    opts->format = archUnknown;
    opts->promptPassword = TRI_DEFAULT;
    opts->dumpSections = DUMP_UNSECTIONED;

    return opts;
}

static void
_disableTriggersIfNecessary(ArchiveHandle *AH, TocEntry *te)
{
    RestoreOptions *ropt = AH->public.ropt;

    /* This hack is only needed in a data-only restore */
    if (!ropt->dataOnly || !ropt->disable_triggers)
        return;

    ahlog(AH, 1, "disabling triggers for %s\n", te->tag);

    /*
     * Become superuser if possible, since they are the only ones who can
     * disable constraint triggers.  If -S was not given, assume the initial
     * user identity is a superuser.  (XXX would it be better to become the
     * table owner?)
     */
    _becomeUser(AH, ropt->superuser);

    /*
     * Disable them.
     */
    _selectOutputSchema(AH, te->namespace);

    ahprintf(AH, "ALTER TABLE %s DISABLE TRIGGER ALL;\n\n",
             fmtId(te->tag));
}

static void
_enableTriggersIfNecessary(ArchiveHandle *AH, TocEntry *te)
{
    RestoreOptions *ropt = AH->public.ropt;

    /* This hack is only needed in a data-only restore */
    if (!ropt->dataOnly || !ropt->disable_triggers)
        return;

    ahlog(AH, 1, "enabling triggers for %s\n", te->tag);

    /*
     * Become superuser if possible, since they are the only ones who can
     * disable constraint triggers.  If -S was not given, assume the initial
     * user identity is a superuser.  (XXX would it be better to become the
     * table owner?)
     */
    _becomeUser(AH, ropt->superuser);

    /*
     * Enable them.
     */
    _selectOutputSchema(AH, te->namespace);

    ahprintf(AH, "ALTER TABLE %s ENABLE TRIGGER ALL;\n\n",
             fmtId(te->tag));
}

/*
 * This is a routine that is part of the dumper interface, hence the 'Archive*' parameter.
 */

/* Public */
void
WriteData(Archive *AHX, const void *data, size_t dLen)
{
    ArchiveHandle *AH = (ArchiveHandle *) AHX;

    if (!AH->currToc)
        exit_horribly(modulename, "internal error -- WriteData cannot be called outside the context of a DataDumper routine\n");

    AH->WriteDataPtr(AH, data, dLen);

    return;
}

/*
 * Create a new TOC entry. The TOC was designed as a TOC, but is now the
 * repository for all metadata. But the name has stuck.
 */

/* Public */
void
ArchiveEntry(Archive *AHX,
             CatalogId catalogId, DumpId dumpId,
             const char *tag,
             const char *namespace,
             const char *tablespace,
             const char *owner, bool withOids,
             const char *desc, teSection section,
             const char *defn,
             const char *dropStmt, const char *copyStmt,
             const DumpId *deps, int nDeps,
             DataDumperPtr dumpFn, void *dumpArg)
{
    ArchiveHandle *AH = (ArchiveHandle *) AHX;
    TocEntry   *newToc;

    newToc = (TocEntry *) pg_malloc0(sizeof(TocEntry));

    AH->tocCount++;
    if (dumpId > AH->maxDumpId)
        AH->maxDumpId = dumpId;

    newToc->prev = AH->toc->prev;
    newToc->next = AH->toc;
    AH->toc->prev->next = newToc;
    AH->toc->prev = newToc;

    newToc->catalogId = catalogId;
    newToc->dumpId = dumpId;
    newToc->section = section;

    newToc->tag = pg_strdup(tag);
    newToc->namespace = namespace ? pg_strdup(namespace) : NULL;
    newToc->tablespace = tablespace ? pg_strdup(tablespace) : NULL;
    newToc->owner = pg_strdup(owner);
    newToc->withOids = withOids;
    newToc->desc = pg_strdup(desc);
    newToc->defn = pg_strdup(defn);
    newToc->dropStmt = pg_strdup(dropStmt);
    newToc->copyStmt = copyStmt ? pg_strdup(copyStmt) : NULL;

    if (nDeps > 0)
    {
        newToc->dependencies = (DumpId *) pg_malloc(nDeps * sizeof(DumpId));
        memcpy(newToc->dependencies, deps, nDeps * sizeof(DumpId));
        newToc->nDeps = nDeps;
    }
    else
    {
        newToc->dependencies = NULL;
        newToc->nDeps = 0;
    }

    newToc->dataDumper = dumpFn;
    newToc->dataDumperArg = dumpArg;
    newToc->hadDumper = dumpFn ? true : false;

    newToc->formatData = NULL;

    if (AH->ArchiveEntryPtr != NULL)
        AH->ArchiveEntryPtr(AH, newToc);
}

/* Public */
void
PrintTOCSummary(Archive *AHX)
{
    ArchiveHandle *AH = (ArchiveHandle *) AHX;
    RestoreOptions *ropt = AH->public.ropt;
    TocEntry   *te;
    teSection   curSection;
    OutputContext sav;
    const char *fmtName;
    char        stamp_str[64];

    sav = SaveOutput(AH);
    if (ropt->filename)
        SetOutput(AH, ropt->filename, 0 /* no compression */ );

    if (strftime(stamp_str, sizeof(stamp_str), PGDUMP_STRFTIME_FMT,
                 localtime(&AH->createDate)) == 0)
        strcpy(stamp_str, "[unknown]");

    ahprintf(AH, ";\n; Archive created at %s\n", stamp_str);
    ahprintf(AH, ";     dbname: %s\n;     TOC Entries: %d\n;     Compression: %d\n",
             replace_line_endings(AH->archdbname),
             AH->tocCount, AH->compression);

    switch (AH->format)
    {
        case archCustom:
            fmtName = "CUSTOM";
            break;
        case archDirectory:
            fmtName = "DIRECTORY";
            break;
        case archTar:
            fmtName = "TAR";
            break;
        default:
            fmtName = "UNKNOWN";
    }

    ahprintf(AH, ";     Dump Version: %d.%d-%d\n",
             ARCHIVE_MAJOR(AH->version), ARCHIVE_MINOR(AH->version), ARCHIVE_REV(AH->version));
    ahprintf(AH, ";     Format: %s\n", fmtName);
    ahprintf(AH, ";     Integer: %d bytes\n", (int) AH->intSize);
    ahprintf(AH, ";     Offset: %d bytes\n", (int) AH->offSize);
    if (AH->archiveRemoteVersion)
        ahprintf(AH, ";     Dumped from database version: %s\n",
                 AH->archiveRemoteVersion);
    if (AH->archiveDumpVersion)
        ahprintf(AH, ";     Dumped by pg_dump version: %s\n",
                 AH->archiveDumpVersion);

    ahprintf(AH, ";\n;\n; Selected TOC Entries:\n;\n");

    curSection = SECTION_PRE_DATA;
    for (te = AH->toc->next; te != AH->toc; te = te->next)
    {
        if (te->section != SECTION_NONE)
            curSection = te->section;
        if (ropt->verbose ||
            (_tocEntryRequired(te, curSection, ropt) & (REQ_SCHEMA | REQ_DATA)) != 0)
        {
            char       *sanitized_name;
            char       *sanitized_schema;
            char       *sanitized_owner;

            /*
             * As in _printTocEntry(), sanitize strings that might contain
             * newlines, to ensure that each logical output line is in fact
             * one physical output line.  This prevents confusion when the
             * file is read by "pg_restore -L".  Note that we currently don't
             * bother to quote names, meaning that the name fields aren't
             * automatically parseable.  "pg_restore -L" doesn't care because
             * it only examines the dumpId field, but someday we might want to
             * try harder.
             */
            sanitized_name = replace_line_endings(te->tag);
            if (te->namespace)
                sanitized_schema = replace_line_endings(te->namespace);
            else
                sanitized_schema = pg_strdup("-");
            sanitized_owner = replace_line_endings(te->owner);

            ahprintf(AH, "%d; %u %u %s %s %s %s\n", te->dumpId,
                     te->catalogId.tableoid, te->catalogId.oid,
                     te->desc, sanitized_schema, sanitized_name,
                     sanitized_owner);

            free(sanitized_name);
            free(sanitized_schema);
            free(sanitized_owner);
        }
        if (ropt->verbose && te->nDeps > 0)
        {
            int         i;

            ahprintf(AH, ";\tdepends on:");
            for (i = 0; i < te->nDeps; i++)
                ahprintf(AH, " %d", te->dependencies[i]);
            ahprintf(AH, "\n");
        }
    }

    /* Enforce strict names checking */
    if (ropt->strict_names)
        StrictNamesCheck(ropt);

    if (ropt->filename)
        RestoreOutput(AH, sav);
}

/***********
 * BLOB Archival
 ***********/

/* Called by a dumper to signal start of a BLOB */
int
StartBlob(Archive *AHX, Oid oid)
{
    ArchiveHandle *AH = (ArchiveHandle *) AHX;

    if (!AH->StartBlobPtr)
        exit_horribly(modulename, "large-object output not supported in chosen format\n");

    AH->StartBlobPtr(AH, AH->currToc, oid);

    return 1;
}

/* Called by a dumper to signal end of a BLOB */
int
EndBlob(Archive *AHX, Oid oid)
{
    ArchiveHandle *AH = (ArchiveHandle *) AHX;

    if (AH->EndBlobPtr)
        AH->EndBlobPtr(AH, AH->currToc, oid);

    return 1;
}

/**********
 * BLOB Restoration
 **********/

/*
 * Called by a format handler before any blobs are restored
 */
void
StartRestoreBlobs(ArchiveHandle *AH)
{
    RestoreOptions *ropt = AH->public.ropt;

    if (!ropt->single_txn)
    {
        if (AH->connection)
            StartTransaction(&AH->public);
        else
            ahprintf(AH, "BEGIN;\n\n");
    }

    AH->blobCount = 0;
}

/*
 * Called by a format handler after all blobs are restored
 */
void
EndRestoreBlobs(ArchiveHandle *AH)
{
    RestoreOptions *ropt = AH->public.ropt;

    if (!ropt->single_txn)
    {
        if (AH->connection)
            CommitTransaction(&AH->public);
        else
            ahprintf(AH, "COMMIT;\n\n");
    }

    ahlog(AH, 1, ngettext("restored %d large object\n",
                          "restored %d large objects\n",
                          AH->blobCount),
          AH->blobCount);
}


/*
 * Called by a format handler to initiate restoration of a blob
 */
void
StartRestoreBlob(ArchiveHandle *AH, Oid oid, bool drop)
{
    bool        old_blob_style = (AH->version < K_VERS_1_12);
    Oid         loOid;

    AH->blobCount++;

    /* Initialize the LO Buffer */
    AH->lo_buf_used = 0;

    ahlog(AH, 1, "restoring large object with OID %u\n", oid);

    /* With an old archive we must do drop and create logic here */
    if (old_blob_style && drop)
        DropBlobIfExists(AH, oid);

    if (AH->connection)
    {
        if (old_blob_style)
        {
            loOid = lo_create(AH->connection, oid);
            if (loOid == 0 || loOid != oid)
                exit_horribly(modulename, "could not create large object %u: %s",
                              oid, PQerrorMessage(AH->connection));
        }
        AH->loFd = lo_open(AH->connection, oid, INV_WRITE);
        if (AH->loFd == -1)
            exit_horribly(modulename, "could not open large object %u: %s",
                          oid, PQerrorMessage(AH->connection));
    }
    else
    {
        if (old_blob_style)
            ahprintf(AH, "SELECT pg_catalog.lo_open(pg_catalog.lo_create('%u'), %d);\n",
                     oid, INV_WRITE);
        else
            ahprintf(AH, "SELECT pg_catalog.lo_open('%u', %d);\n",
                     oid, INV_WRITE);
    }

    AH->writingBlob = 1;
}

void
EndRestoreBlob(ArchiveHandle *AH, Oid oid)
{
    if (AH->lo_buf_used > 0)
    {
        /* Write remaining bytes from the LO buffer */
        dump_lo_buf(AH);
    }

    AH->writingBlob = 0;

    if (AH->connection)
    {
        lo_close(AH->connection, AH->loFd);
        AH->loFd = -1;
    }
    else
    {
        ahprintf(AH, "SELECT pg_catalog.lo_close(0);\n\n");
    }
}

/***********
 * Sorting and Reordering
 ***********/

void
SortTocFromFile(Archive *AHX)
{
    ArchiveHandle *AH = (ArchiveHandle *) AHX;
    RestoreOptions *ropt = AH->public.ropt;
    FILE       *fh;
    char        buf[100];
    bool        incomplete_line;

    /* Allocate space for the 'wanted' array, and init it */
    ropt->idWanted = (bool *) pg_malloc(sizeof(bool) * AH->maxDumpId);
    memset(ropt->idWanted, 0, sizeof(bool) * AH->maxDumpId);

    /* Setup the file */
    fh = fopen(ropt->tocFile, PG_BINARY_R);
    if (!fh)
        exit_horribly(modulename, "could not open TOC file \"%s\": %s\n",
                      ropt->tocFile, strerror(errno));

    incomplete_line = false;
    while (fgets(buf, sizeof(buf), fh) != NULL)
    {
        bool        prev_incomplete_line = incomplete_line;
        int         buflen;
        char       *cmnt;
        char       *endptr;
        DumpId      id;
        TocEntry   *te;

        /*
         * Some lines in the file might be longer than sizeof(buf).  This is
         * no problem, since we only care about the leading numeric ID which
         * can be at most a few characters; but we have to skip continuation
         * bufferloads when processing a long line.
         */
        buflen = strlen(buf);
        if (buflen > 0 && buf[buflen - 1] == '\n')
            incomplete_line = false;
        else
            incomplete_line = true;
        if (prev_incomplete_line)
            continue;

        /* Truncate line at comment, if any */
        cmnt = strchr(buf, ';');
        if (cmnt != NULL)
            cmnt[0] = '\0';

        /* Ignore if all blank */
        if (strspn(buf, " \t\r\n") == strlen(buf))
            continue;

        /* Get an ID, check it's valid and not already seen */
        id = strtol(buf, &endptr, 10);
        if (endptr == buf || id <= 0 || id > AH->maxDumpId ||
            ropt->idWanted[id - 1])
        {
            write_msg(modulename, "WARNING: line ignored: %s\n", buf);
            continue;
        }

        /* Find TOC entry */
        te = getTocEntryByDumpId(AH, id);
        if (!te)
            exit_horribly(modulename, "could not find entry for ID %d\n",
                          id);

        /* Mark it wanted */
        ropt->idWanted[id - 1] = true;

        /*
         * Move each item to the end of the list as it is selected, so that
         * they are placed in the desired order.  Any unwanted items will end
         * up at the front of the list, which may seem unintuitive but it's
         * what we need.  In an ordinary serial restore that makes no
         * difference, but in a parallel restore we need to mark unrestored
         * items' dependencies as satisfied before we start examining
         * restorable items.  Otherwise they could have surprising
         * side-effects on the order in which restorable items actually get
         * restored.
         */
        _moveBefore(AH, AH->toc, te);
    }

    if (fclose(fh) != 0)
        exit_horribly(modulename, "could not close TOC file: %s\n",
                      strerror(errno));
}

/**********************
 * 'Convenience functions that look like standard IO functions
 * for writing data when in dump mode.
 **********************/

/* Public */
void
archputs(const char *s, Archive *AH)
{
    WriteData(AH, s, strlen(s));
    return;
}

/* Public */
int
archprintf(Archive *AH, const char *fmt,...)
{
    char       *p;
    size_t      len = 128;      /* initial assumption about buffer size */
    size_t      cnt;

    for (;;)
    {
        va_list     args;

        /* Allocate work buffer. */
        p = (char *) pg_malloc(len);

        /* Try to format the data. */
        va_start(args, fmt);
        cnt = pvsnprintf(p, len, fmt, args);
        va_end(args);

        if (cnt < len)
            break;              /* success */

        /* Release buffer and loop around to try again with larger len. */
        free(p);
        len = cnt;
    }

    WriteData(AH, p, cnt);
    free(p);
    return (int) cnt;
}


/*******************************
 * Stuff below here should be 'private' to the archiver routines
 *******************************/

static void
SetOutput(ArchiveHandle *AH, const char *filename, int compression)
{
    int         fn;

    if (filename)
        fn = -1;
    else if (AH->FH)
        fn = fileno(AH->FH);
    else if (AH->fSpec)
    {
        fn = -1;
        filename = AH->fSpec;
    }
    else
        fn = fileno(stdout);

    /* If compression explicitly requested, use gzopen */
#ifdef HAVE_LIBZ
    if (compression != 0)
    {
        char        fmode[10];

        /* Don't use PG_BINARY_x since this is zlib */
        sprintf(fmode, "wb%d", compression);
        if (fn >= 0)
            AH->OF = gzdopen(dup(fn), fmode);
        else
            AH->OF = gzopen(filename, fmode);
        AH->gzOut = 1;
    }
    else
#endif
    {                           /* Use fopen */
        if (AH->mode == archModeAppend)
        {
            if (fn >= 0)
                AH->OF = fdopen(dup(fn), PG_BINARY_A);
            else
                AH->OF = fopen(filename, PG_BINARY_A);
        }
        else
        {
            if (fn >= 0)
                AH->OF = fdopen(dup(fn), PG_BINARY_W);
            else
                AH->OF = fopen(filename, PG_BINARY_W);
        }
        AH->gzOut = 0;
    }

    if (!AH->OF)
    {
        if (filename)
            exit_horribly(modulename, "could not open output file \"%s\": %s\n",
                          filename, strerror(errno));
        else
            exit_horribly(modulename, "could not open output file: %s\n",
                          strerror(errno));
    }
}

static OutputContext
SaveOutput(ArchiveHandle *AH)
{
    OutputContext sav;

    sav.OF = AH->OF;
    sav.gzOut = AH->gzOut;

    return sav;
}

static void
RestoreOutput(ArchiveHandle *AH, OutputContext savedContext)
{
    int         res;

    if (AH->gzOut)
        res = GZCLOSE(AH->OF);
    else
        res = fclose(AH->OF);

    if (res != 0)
        exit_horribly(modulename, "could not close output file: %s\n",
                      strerror(errno));

    AH->gzOut = savedContext.gzOut;
    AH->OF = savedContext.OF;
}



/*
 *  Print formatted text to the output file (usually stdout).
 */
int
ahprintf(ArchiveHandle *AH, const char *fmt,...)
{
    char       *p;
    size_t      len = 128;      /* initial assumption about buffer size */
    size_t      cnt;

    for (;;)
    {
        va_list     args;

        /* Allocate work buffer. */
        p = (char *) pg_malloc(len);

        /* Try to format the data. */
        va_start(args, fmt);
        cnt = pvsnprintf(p, len, fmt, args);
        va_end(args);

        if (cnt < len)
            break;              /* success */

        /* Release buffer and loop around to try again with larger len. */
        free(p);
        len = cnt;
    }

    ahwrite(p, 1, cnt, AH);
    free(p);
    return (int) cnt;
}

void
ahlog(ArchiveHandle *AH, int level, const char *fmt,...)
{
    va_list     ap;

    if (AH->debugLevel < level && (!AH->public.verbose || level > 1))
        return;

    va_start(ap, fmt);
    vwrite_msg(NULL, fmt, ap);
    va_end(ap);
}

/*
 * Single place for logic which says 'We are restoring to a direct DB connection'.
 */
static int
RestoringToDB(ArchiveHandle *AH)
{
    RestoreOptions *ropt = AH->public.ropt;

    return (ropt && ropt->useDB && AH->connection);
}

/*
 * Dump the current contents of the LO data buffer while writing a BLOB
 */
static void
dump_lo_buf(ArchiveHandle *AH)
{
    if (AH->connection)
    {
        size_t      res;

        res = lo_write(AH->connection, AH->loFd, AH->lo_buf, AH->lo_buf_used);
        ahlog(AH, 5, ngettext("wrote %lu byte of large object data (result = %lu)\n",
                              "wrote %lu bytes of large object data (result = %lu)\n",
                              AH->lo_buf_used),
              (unsigned long) AH->lo_buf_used, (unsigned long) res);
        if (res != AH->lo_buf_used)
            exit_horribly(modulename,
                          "could not write to large object (result: %lu, expected: %lu)\n",
                          (unsigned long) res, (unsigned long) AH->lo_buf_used);
    }
    else
    {
        PQExpBuffer buf = createPQExpBuffer();

        appendByteaLiteralAHX(buf,
                              (const unsigned char *) AH->lo_buf,
                              AH->lo_buf_used,
                              AH);

        /* Hack: turn off writingBlob so ahwrite doesn't recurse to here */
        AH->writingBlob = 0;
        ahprintf(AH, "SELECT pg_catalog.lowrite(0, %s);\n", buf->data);
        AH->writingBlob = 1;

        destroyPQExpBuffer(buf);
    }
    AH->lo_buf_used = 0;
}


/*
 *  Write buffer to the output file (usually stdout). This is used for
 *  outputting 'restore' scripts etc. It is even possible for an archive
 *  format to create a custom output routine to 'fake' a restore if it
 *  wants to generate a script (see TAR output).
 */
void
ahwrite(const void *ptr, size_t size, size_t nmemb, ArchiveHandle *AH)
{
    int         bytes_written = 0;

    if (AH->writingBlob)
    {
        size_t      remaining = size * nmemb;

        while (AH->lo_buf_used + remaining > AH->lo_buf_size)
        {
            size_t      avail = AH->lo_buf_size - AH->lo_buf_used;

            memcpy((char *) AH->lo_buf + AH->lo_buf_used, ptr, avail);
            ptr = (const void *) ((const char *) ptr + avail);
            remaining -= avail;
            AH->lo_buf_used += avail;
            dump_lo_buf(AH);
        }

        memcpy((char *) AH->lo_buf + AH->lo_buf_used, ptr, remaining);
        AH->lo_buf_used += remaining;

        bytes_written = size * nmemb;
    }
    else if (AH->gzOut)
        bytes_written = GZWRITE(ptr, size, nmemb, AH->OF);
    else if (AH->CustomOutPtr)
        bytes_written = AH->CustomOutPtr(AH, ptr, size * nmemb);

    else
    {
        /*
         * If we're doing a restore, and it's direct to DB, and we're
         * connected then send it to the DB.
         */
        if (RestoringToDB(AH))
            bytes_written = ExecuteSqlCommandBuf(&AH->public, (const char *) ptr, size * nmemb);
        else
            bytes_written = fwrite(ptr, size, nmemb, AH->OF) * size;
    }

    if (bytes_written != size * nmemb)
        WRITE_ERROR_EXIT;

    return;
}

/* on some error, we may decide to go on... */
void
warn_or_exit_horribly(ArchiveHandle *AH,
                      const char *modulename, const char *fmt,...)
{
    va_list     ap;

    switch (AH->stage)
    {

        case STAGE_NONE:
            /* Do nothing special */
            break;

        case STAGE_INITIALIZING:
            if (AH->stage != AH->lastErrorStage)
                write_msg(modulename, "Error while INITIALIZING:\n");
            break;

        case STAGE_PROCESSING:
            if (AH->stage != AH->lastErrorStage)
                write_msg(modulename, "Error while PROCESSING TOC:\n");
            break;

        case STAGE_FINALIZING:
            if (AH->stage != AH->lastErrorStage)
                write_msg(modulename, "Error while FINALIZING:\n");
            break;
    }
    if (AH->currentTE != NULL && AH->currentTE != AH->lastErrorTE)
    {
        write_msg(modulename, "Error from TOC entry %d; %u %u %s %s %s\n",
                  AH->currentTE->dumpId,
                  AH->currentTE->catalogId.tableoid, AH->currentTE->catalogId.oid,
                  AH->currentTE->desc, AH->currentTE->tag, AH->currentTE->owner);
    }
    AH->lastErrorStage = AH->stage;
    AH->lastErrorTE = AH->currentTE;

    va_start(ap, fmt);
    vwrite_msg(modulename, fmt, ap);
    va_end(ap);

    if (AH->public.exit_on_error)
        exit_nicely(1);
    else
        AH->public.n_errors++;
}

#ifdef NOT_USED

static void
_moveAfter(ArchiveHandle *AH, TocEntry *pos, TocEntry *te)
{
    /* Unlink te from list */
    te->prev->next = te->next;
    te->next->prev = te->prev;

    /* and insert it after "pos" */
    te->prev = pos;
    te->next = pos->next;
    pos->next->prev = te;
    pos->next = te;
}
#endif

static void
_moveBefore(ArchiveHandle *AH, TocEntry *pos, TocEntry *te)
{
    /* Unlink te from list */
    te->prev->next = te->next;
    te->next->prev = te->prev;

    /* and insert it before "pos" */
    te->prev = pos->prev;
    te->next = pos;
    pos->prev->next = te;
    pos->prev = te;
}

/*
 * Build index arrays for the TOC list
 *
 * This should be invoked only after we have created or read in all the TOC
 * items.
 *
 * The arrays are indexed by dump ID (so entry zero is unused).  Note that the
 * array entries run only up to maxDumpId.  We might see dependency dump IDs
 * beyond that (if the dump was partial); so always check the array bound
 * before trying to touch an array entry.
 */
static void
buildTocEntryArrays(ArchiveHandle *AH)
{
    DumpId      maxDumpId = AH->maxDumpId;
    TocEntry   *te;

    AH->tocsByDumpId = (TocEntry **) pg_malloc0((maxDumpId + 1) * sizeof(TocEntry *));
    AH->tableDataId = (DumpId *) pg_malloc0((maxDumpId + 1) * sizeof(DumpId));

    for (te = AH->toc->next; te != AH->toc; te = te->next)
    {
        /* this check is purely paranoia, maxDumpId should be correct */
        if (te->dumpId <= 0 || te->dumpId > maxDumpId)
            exit_horribly(modulename, "bad dumpId\n");

        /* tocsByDumpId indexes all TOCs by their dump ID */
        AH->tocsByDumpId[te->dumpId] = te;

        /*
         * tableDataId provides the TABLE DATA item's dump ID for each TABLE
         * TOC entry that has a DATA item.  We compute this by reversing the
         * TABLE DATA item's dependency, knowing that a TABLE DATA item has
         * just one dependency and it is the TABLE item.
         */
        if (strcmp(te->desc, "TABLE DATA") == 0 && te->nDeps > 0)
        {
            DumpId      tableId = te->dependencies[0];

            /*
             * The TABLE item might not have been in the archive, if this was
             * a data-only dump; but its dump ID should be less than its data
             * item's dump ID, so there should be a place for it in the array.
             */
            if (tableId <= 0 || tableId > maxDumpId)
                exit_horribly(modulename, "bad table dumpId for TABLE DATA item\n");

            AH->tableDataId[tableId] = te->dumpId;
        }
    }
}

TocEntry *
getTocEntryByDumpId(ArchiveHandle *AH, DumpId id)
{
    /* build index arrays if we didn't already */
    if (AH->tocsByDumpId == NULL)
        buildTocEntryArrays(AH);

    if (id > 0 && id <= AH->maxDumpId)
        return AH->tocsByDumpId[id];

    return NULL;
}

teReqs
TocIDRequired(ArchiveHandle *AH, DumpId id)
{
    TocEntry   *te = getTocEntryByDumpId(AH, id);

    if (!te)
        return 0;

    return te->reqs;
}

size_t
WriteOffset(ArchiveHandle *AH, pgoff_t o, int wasSet)
{
    int         off;

    /* Save the flag */
    AH->WriteBytePtr(AH, wasSet);

    /* Write out pgoff_t smallest byte first, prevents endian mismatch */
    for (off = 0; off < sizeof(pgoff_t); off++)
    {
        AH->WriteBytePtr(AH, o & 0xFF);
        o >>= 8;
    }
    return sizeof(pgoff_t) + 1;
}

int
ReadOffset(ArchiveHandle *AH, pgoff_t * o)
{
    int         i;
    int         off;
    int         offsetFlg;

    /* Initialize to zero */
    *o = 0;

    /* Check for old version */
    if (AH->version < K_VERS_1_7)
    {
        /* Prior versions wrote offsets using WriteInt */
        i = ReadInt(AH);
        /* -1 means not set */
        if (i < 0)
            return K_OFFSET_POS_NOT_SET;
        else if (i == 0)
            return K_OFFSET_NO_DATA;

        /* Cast to pgoff_t because it was written as an int. */
        *o = (pgoff_t) i;
        return K_OFFSET_POS_SET;
    }

    /*
     * Read the flag indicating the state of the data pointer. Check if valid
     * and die if not.
     *
     * This used to be handled by a negative or zero pointer, now we use an
     * extra byte specifically for the state.
     */
    offsetFlg = AH->ReadBytePtr(AH) & 0xFF;

    switch (offsetFlg)
    {
        case K_OFFSET_POS_NOT_SET:
        case K_OFFSET_NO_DATA:
        case K_OFFSET_POS_SET:

            break;

        default:
            exit_horribly(modulename, "unexpected data offset flag %d\n", offsetFlg);
    }

    /*
     * Read the bytes
     */
    for (off = 0; off < AH->offSize; off++)
    {
        if (off < sizeof(pgoff_t))
            *o |= ((pgoff_t) (AH->ReadBytePtr(AH))) << (off * 8);
        else
        {
            if (AH->ReadBytePtr(AH) != 0)
                exit_horribly(modulename, "file offset in dump file is too large\n");
        }
    }

    return offsetFlg;
}

size_t
WriteInt(ArchiveHandle *AH, int i)
{
    int         b;

    /*
     * This is a bit yucky, but I don't want to make the binary format very
     * dependent on representation, and not knowing much about it, I write out
     * a sign byte. If you change this, don't forget to change the file
     * version #, and modify readInt to read the new format AS WELL AS the old
     * formats.
     */

    /* SIGN byte */
    if (i < 0)
    {
        AH->WriteBytePtr(AH, 1);
        i = -i;
    }
    else
        AH->WriteBytePtr(AH, 0);

    for (b = 0; b < AH->intSize; b++)
    {
        AH->WriteBytePtr(AH, i & 0xFF);
        i >>= 8;
    }

    return AH->intSize + 1;
}

int
ReadInt(ArchiveHandle *AH)
{
    int         res = 0;
    int         bv,
                b;
    int         sign = 0;       /* Default positive */
    int         bitShift = 0;

    if (AH->version > K_VERS_1_0)
        /* Read a sign byte */
        sign = AH->ReadBytePtr(AH);

    for (b = 0; b < AH->intSize; b++)
    {
        bv = AH->ReadBytePtr(AH) & 0xFF;
        if (bv != 0)
            res = res + (bv << bitShift);
        bitShift += 8;
    }

    if (sign)
        res = -res;

    return res;
}

size_t
WriteStr(ArchiveHandle *AH, const char *c)
{
    size_t      res;

    if (c)
    {
        int         len = strlen(c);

        res = WriteInt(AH, len);
        AH->WriteBufPtr(AH, c, len);
        res += len;
    }
    else
        res = WriteInt(AH, -1);

    return res;
}

char *
ReadStr(ArchiveHandle *AH)
{
    char       *buf;
    int         l;

    l = ReadInt(AH);
    if (l < 0)
        buf = NULL;
    else
    {
        buf = (char *) pg_malloc(l + 1);
        AH->ReadBufPtr(AH, (void *) buf, l);

        buf[l] = '\0';
    }

    return buf;
}

static int
_discoverArchiveFormat(ArchiveHandle *AH)
{
    FILE       *fh;
    char        sig[6];         /* More than enough */
    size_t      cnt;
    int         wantClose = 0;

#if 0
    write_msg(modulename, "attempting to ascertain archive format\n");
#endif

    if (AH->lookahead)
        free(AH->lookahead);

    AH->lookaheadSize = 512;
    AH->lookahead = pg_malloc0(512);
    AH->lookaheadLen = 0;
    AH->lookaheadPos = 0;

    if (AH->fSpec)
    {
        struct stat st;

        wantClose = 1;

        /*
         * Check if the specified archive is a directory. If so, check if
         * there's a "toc.dat" (or "toc.dat.gz") file in it.
         */
        if (stat(AH->fSpec, &st) == 0 && S_ISDIR(st.st_mode))
        {
            char        buf[MAXPGPATH];

            if (snprintf(buf, MAXPGPATH, "%s/toc.dat", AH->fSpec) >= MAXPGPATH)
                exit_horribly(modulename, "directory name too long: \"%s\"\n",
                              AH->fSpec);
            if (stat(buf, &st) == 0 && S_ISREG(st.st_mode))
            {
                AH->format = archDirectory;
                return AH->format;
            }

#ifdef HAVE_LIBZ
            if (snprintf(buf, MAXPGPATH, "%s/toc.dat.gz", AH->fSpec) >= MAXPGPATH)
                exit_horribly(modulename, "directory name too long: \"%s\"\n",
                              AH->fSpec);
            if (stat(buf, &st) == 0 && S_ISREG(st.st_mode))
            {
                AH->format = archDirectory;
                return AH->format;
            }
#endif
            exit_horribly(modulename, "directory \"%s\" does not appear to be a valid archive (\"toc.dat\" does not exist)\n",
                          AH->fSpec);
            fh = NULL;          /* keep compiler quiet */
        }
        else
        {
            fh = fopen(AH->fSpec, PG_BINARY_R);
            if (!fh)
                exit_horribly(modulename, "could not open input file \"%s\": %s\n",
                              AH->fSpec, strerror(errno));
        }
    }
    else
    {
        fh = stdin;
        if (!fh)
            exit_horribly(modulename, "could not open input file: %s\n",
                          strerror(errno));
    }

    if ((cnt = fread(sig, 1, 5, fh)) != 5)
    {
        if (ferror(fh))
            exit_horribly(modulename, "could not read input file: %s\n", strerror(errno));
        else
            exit_horribly(modulename, "input file is too short (read %lu, expected 5)\n",
                          (unsigned long) cnt);
    }

    /* Save it, just in case we need it later */
    memcpy(&AH->lookahead[0], sig, 5);
    AH->lookaheadLen = 5;

    if (strncmp(sig, "PGDMP", 5) == 0)
    {
        int         byteread;
        char        vmaj,
                    vmin,
                    vrev;

        /*
         * Finish reading (most of) a custom-format header.
         *
         * NB: this code must agree with ReadHead().
         */
        if ((byteread = fgetc(fh)) == EOF)
            READ_ERROR_EXIT(fh);

        vmaj = byteread;

        if ((byteread = fgetc(fh)) == EOF)
            READ_ERROR_EXIT(fh);

        vmin = byteread;

        /* Save these too... */
        AH->lookahead[AH->lookaheadLen++] = vmaj;
        AH->lookahead[AH->lookaheadLen++] = vmin;

        /* Check header version; varies from V1.0 */
        if (vmaj > 1 || (vmaj == 1 && vmin > 0))    /* Version > 1.0 */
        {
            if ((byteread = fgetc(fh)) == EOF)
                READ_ERROR_EXIT(fh);

            vrev = byteread;
            AH->lookahead[AH->lookaheadLen++] = vrev;
        }
        else
            vrev = 0;

        AH->version = MAKE_ARCHIVE_VERSION(vmaj, vmin, vrev);

        if ((AH->intSize = fgetc(fh)) == EOF)
            READ_ERROR_EXIT(fh);
        AH->lookahead[AH->lookaheadLen++] = AH->intSize;

        if (AH->version >= K_VERS_1_7)
        {
            if ((AH->offSize = fgetc(fh)) == EOF)
                READ_ERROR_EXIT(fh);
            AH->lookahead[AH->lookaheadLen++] = AH->offSize;
        }
        else
            AH->offSize = AH->intSize;

        if ((byteread = fgetc(fh)) == EOF)
            READ_ERROR_EXIT(fh);

        AH->format = byteread;
        AH->lookahead[AH->lookaheadLen++] = AH->format;
    }
    else
    {
        /*
         * *Maybe* we have a tar archive format file or a text dump ... So,
         * read first 512 byte header...
         */
        cnt = fread(&AH->lookahead[AH->lookaheadLen], 1, 512 - AH->lookaheadLen, fh);
        /* read failure is checked below */
        AH->lookaheadLen += cnt;

        if (AH->lookaheadLen >= strlen(TEXT_DUMPALL_HEADER) &&
            (strncmp(AH->lookahead, TEXT_DUMP_HEADER, strlen(TEXT_DUMP_HEADER)) == 0 ||
             strncmp(AH->lookahead, TEXT_DUMPALL_HEADER, strlen(TEXT_DUMPALL_HEADER)) == 0))
        {
            /*
             * looks like it's probably a text format dump. so suggest they
             * try psql
             */
            exit_horribly(modulename, "input file appears to be a text format dump. Please use psql.\n");
        }

        if (AH->lookaheadLen != 512)
        {
            if (feof(fh))
                exit_horribly(modulename, "input file does not appear to be a valid archive (too short?)\n");
            else
                READ_ERROR_EXIT(fh);
        }

        if (!isValidTarHeader(AH->lookahead))
            exit_horribly(modulename, "input file does not appear to be a valid archive\n");

        AH->format = archTar;
    }

    /* If we can't seek, then mark the header as read */
    if (fseeko(fh, 0, SEEK_SET) != 0)
    {
        /*
         * NOTE: Formats that use the lookahead buffer can unset this in their
         * Init routine.
         */
        AH->readHeader = 1;
    }
    else
        AH->lookaheadLen = 0;   /* Don't bother since we've reset the file */

    /* Close the file */
    if (wantClose)
        if (fclose(fh) != 0)
            exit_horribly(modulename, "could not close input file: %s\n",
                          strerror(errno));

    return AH->format;
}


/*
 * Allocate an archive handle
 */
static ArchiveHandle *
_allocAH(const char *FileSpec, const ArchiveFormat fmt,
         const int compression, bool dosync, ArchiveMode mode,
         SetupWorkerPtrType setupWorkerPtr)
{
    ArchiveHandle *AH;

#if 0
    write_msg(modulename, "allocating AH for %s, format %d\n", FileSpec, fmt);
#endif

    AH = (ArchiveHandle *) pg_malloc0(sizeof(ArchiveHandle));

    /* AH->debugLevel = 100; */

    AH->version = K_VERS_SELF;

    /* initialize for backwards compatible string processing */
    AH->public.encoding = 0;    /* PG_SQL_ASCII */
    AH->public.std_strings = false;

    /* sql error handling */
    AH->public.exit_on_error = true;
    AH->public.n_errors = 0;

    AH->archiveDumpVersion = PG_VERSION;

    AH->createDate = time(NULL);

    AH->intSize = sizeof(int);
    AH->offSize = sizeof(pgoff_t);
    if (FileSpec)
    {
        AH->fSpec = pg_strdup(FileSpec);

        /*
         * Not used; maybe later....
         *
         * AH->workDir = pg_strdup(FileSpec); for(i=strlen(FileSpec) ; i > 0 ;
         * i--) if (AH->workDir[i-1] == '/')
         */
    }
    else
        AH->fSpec = NULL;

    AH->currUser = NULL;        /* unknown */
    AH->currSchema = NULL;      /* ditto */
    AH->currTablespace = NULL;  /* ditto */
    AH->currWithOids = -1;      /* force SET */

    AH->toc = (TocEntry *) pg_malloc0(sizeof(TocEntry));

    AH->toc->next = AH->toc;
    AH->toc->prev = AH->toc;

    AH->mode = mode;
    AH->compression = compression;
    AH->dosync = dosync;

    memset(&(AH->sqlparse), 0, sizeof(AH->sqlparse));

    /* Open stdout with no compression for AH output handle */
    AH->gzOut = 0;
    AH->OF = stdout;

    /*
     * On Windows, we need to use binary mode to read/write non-text files,
     * which include all archive formats as well as compressed plain text.
     * Force stdin/stdout into binary mode if that is what we are using.
     */
#ifdef WIN32
    if ((fmt != archNull || compression != 0) &&
        (AH->fSpec == NULL || strcmp(AH->fSpec, "") == 0))
    {
        if (mode == archModeWrite)
            _setmode(fileno(stdout), O_BINARY);
        else
            _setmode(fileno(stdin), O_BINARY);
    }
#endif

    AH->SetupWorkerPtr = setupWorkerPtr;

    if (fmt == archUnknown)
        AH->format = _discoverArchiveFormat(AH);
    else
        AH->format = fmt;

    AH->promptPassword = TRI_DEFAULT;

    switch (AH->format)
    {
        case archCustom:
            InitArchiveFmt_Custom(AH);
            break;

        case archNull:
            InitArchiveFmt_Null(AH);
            break;

        case archDirectory:
            InitArchiveFmt_Directory(AH);
            break;

        case archTar:
            InitArchiveFmt_Tar(AH);
            break;

        default:
            exit_horribly(modulename, "unrecognized file format \"%d\"\n", fmt);
    }

    return AH;
}

/*
 * Write out all data (tables & blobs)
 */
void
WriteDataChunks(ArchiveHandle *AH, ParallelState *pstate)
{
    TocEntry   *te;

    for (te = AH->toc->next; te != AH->toc; te = te->next)
    {
        if (!te->dataDumper)
            continue;

        if ((te->reqs & REQ_DATA) == 0)
            continue;

        if (pstate && pstate->numWorkers > 1)
        {
            /*
             * If we are in a parallel backup, then we are always the master
             * process.  Dispatch each data-transfer job to a worker.
             */
            DispatchJobForTocEntry(AH, pstate, te, ACT_DUMP,
                                   mark_dump_job_done, NULL);
        }
        else
            WriteDataChunksForTocEntry(AH, te);
    }

    /*
     * If parallel, wait for workers to finish.
     */
    if (pstate && pstate->numWorkers > 1)
        WaitForWorkers(AH, pstate, WFW_ALL_IDLE);
}


/*
 * Callback function that's invoked in the master process after a step has
 * been parallel dumped.
 *
 * We don't need to do anything except check for worker failure.
 */
static void
mark_dump_job_done(ArchiveHandle *AH,
                   TocEntry *te,
                   int status,
                   void *callback_data)
{
    ahlog(AH, 1, "finished item %d %s %s\n",
          te->dumpId, te->desc, te->tag);

    if (status != 0)
        exit_horribly(modulename, "worker process failed: exit code %d\n",
                      status);
}


void
WriteDataChunksForTocEntry(ArchiveHandle *AH, TocEntry *te)
{
    StartDataPtrType startPtr;
    EndDataPtrType endPtr;

    AH->currToc = te;

    if (strcmp(te->desc, "BLOBS") == 0)
    {
        startPtr = AH->StartBlobsPtr;
        endPtr = AH->EndBlobsPtr;
    }
    else
    {
        startPtr = AH->StartDataPtr;
        endPtr = AH->EndDataPtr;
    }

    if (startPtr != NULL)
        (*startPtr) (AH, te);

    /*
     * The user-provided DataDumper routine needs to call AH->WriteData
     */
    te->dataDumper((Archive *) AH, te->dataDumperArg);

    if (endPtr != NULL)
        (*endPtr) (AH, te);

    AH->currToc = NULL;
}

void
WriteToc(ArchiveHandle *AH)
{
    TocEntry   *te;
    char        workbuf[32];
    int         tocCount;
    int         i;

    /* count entries that will actually be dumped */
    tocCount = 0;
    for (te = AH->toc->next; te != AH->toc; te = te->next)
    {
        if ((te->reqs & (REQ_SCHEMA | REQ_DATA | REQ_SPECIAL)) != 0)
            tocCount++;
    }

    /* printf("%d TOC Entries to save\n", tocCount); */

    WriteInt(AH, tocCount);

    for (te = AH->toc->next; te != AH->toc; te = te->next)
    {
        if ((te->reqs & (REQ_SCHEMA | REQ_DATA | REQ_SPECIAL)) == 0)
            continue;

        WriteInt(AH, te->dumpId);
        WriteInt(AH, te->dataDumper ? 1 : 0);

        /* OID is recorded as a string for historical reasons */
        sprintf(workbuf, "%u", te->catalogId.tableoid);
        WriteStr(AH, workbuf);
        sprintf(workbuf, "%u", te->catalogId.oid);
        WriteStr(AH, workbuf);

        WriteStr(AH, te->tag);
        WriteStr(AH, te->desc);
        WriteInt(AH, te->section);
        WriteStr(AH, te->defn);
        WriteStr(AH, te->dropStmt);
        WriteStr(AH, te->copyStmt);
        WriteStr(AH, te->namespace);
        WriteStr(AH, te->tablespace);
        WriteStr(AH, te->owner);
        WriteStr(AH, te->withOids ? "true" : "false");

        /* Dump list of dependencies */
        for (i = 0; i < te->nDeps; i++)
        {
            sprintf(workbuf, "%d", te->dependencies[i]);
            WriteStr(AH, workbuf);
        }
        WriteStr(AH, NULL);     /* Terminate List */

        if (AH->WriteExtraTocPtr)
            AH->WriteExtraTocPtr(AH, te);
    }
}

void
ReadToc(ArchiveHandle *AH)
{
    int         i;
    char       *tmp;
    DumpId     *deps;
    int         depIdx;
    int         depSize;
    TocEntry   *te;

    AH->tocCount = ReadInt(AH);
    AH->maxDumpId = 0;

    for (i = 0; i < AH->tocCount; i++)
    {
        te = (TocEntry *) pg_malloc0(sizeof(TocEntry));
        te->dumpId = ReadInt(AH);

        if (te->dumpId > AH->maxDumpId)
            AH->maxDumpId = te->dumpId;

        /* Sanity check */
        if (te->dumpId <= 0)
            exit_horribly(modulename,
                          "entry ID %d out of range -- perhaps a corrupt TOC\n",
                          te->dumpId);

        te->hadDumper = ReadInt(AH);

        if (AH->version >= K_VERS_1_8)
        {
            tmp = ReadStr(AH);
            sscanf(tmp, "%u", &te->catalogId.tableoid);
            free(tmp);
        }
        else
            te->catalogId.tableoid = InvalidOid;
        tmp = ReadStr(AH);
        sscanf(tmp, "%u", &te->catalogId.oid);
        free(tmp);

        te->tag = ReadStr(AH);
        te->desc = ReadStr(AH);

        if (AH->version >= K_VERS_1_11)
        {
            te->section = ReadInt(AH);
        }
        else
        {
            /*
             * Rules for pre-8.4 archives wherein pg_dump hasn't classified
             * the entries into sections.  This list need not cover entry
             * types added later than 8.4.
             */
            if (strcmp(te->desc, "COMMENT") == 0 ||
                strcmp(te->desc, "ACL") == 0 ||
                strcmp(te->desc, "ACL LANGUAGE") == 0)
                te->section = SECTION_NONE;
            else if (strcmp(te->desc, "TABLE DATA") == 0 ||
                     strcmp(te->desc, "BLOBS") == 0 ||
                     strcmp(te->desc, "BLOB COMMENTS") == 0)
                te->section = SECTION_DATA;
            else if (strcmp(te->desc, "CONSTRAINT") == 0 ||
                     strcmp(te->desc, "CHECK CONSTRAINT") == 0 ||
                     strcmp(te->desc, "FK CONSTRAINT") == 0 ||
                     strcmp(te->desc, "INDEX") == 0 ||
                     strcmp(te->desc, "RULE") == 0 ||
                     strcmp(te->desc, "TRIGGER") == 0)
                te->section = SECTION_POST_DATA;
            else
                te->section = SECTION_PRE_DATA;
        }

        te->defn = ReadStr(AH);
        te->dropStmt = ReadStr(AH);

        if (AH->version >= K_VERS_1_3)
            te->copyStmt = ReadStr(AH);

        if (AH->version >= K_VERS_1_6)
            te->namespace = ReadStr(AH);

        if (AH->version >= K_VERS_1_10)
            te->tablespace = ReadStr(AH);

        te->owner = ReadStr(AH);
        if (AH->version >= K_VERS_1_9)
        {
            if (strcmp(ReadStr(AH), "true") == 0)
                te->withOids = true;
            else
                te->withOids = false;
        }
        else
            te->withOids = true;

        /* Read TOC entry dependencies */
        if (AH->version >= K_VERS_1_5)
        {
            depSize = 100;
            deps = (DumpId *) pg_malloc(sizeof(DumpId) * depSize);
            depIdx = 0;
            for (;;)
            {
                tmp = ReadStr(AH);
                if (!tmp)
                    break;      /* end of list */
                if (depIdx >= depSize)
                {
                    depSize *= 2;
                    deps = (DumpId *) pg_realloc(deps, sizeof(DumpId) * depSize);
                }
                sscanf(tmp, "%d", &deps[depIdx]);
                free(tmp);
                depIdx++;
            }

            if (depIdx > 0)     /* We have a non-null entry */
            {
                deps = (DumpId *) pg_realloc(deps, sizeof(DumpId) * depIdx);
                te->dependencies = deps;
                te->nDeps = depIdx;
            }
            else
            {
                free(deps);
                te->dependencies = NULL;
                te->nDeps = 0;
            }
        }
        else
        {
            te->dependencies = NULL;
            te->nDeps = 0;
        }

        if (AH->ReadExtraTocPtr)
            AH->ReadExtraTocPtr(AH, te);

        ahlog(AH, 3, "read TOC entry %d (ID %d) for %s %s\n",
              i, te->dumpId, te->desc, te->tag);

        /* link completed entry into TOC circular list */
        te->prev = AH->toc->prev;
        AH->toc->prev->next = te;
        AH->toc->prev = te;
        te->next = AH->toc;

        /* special processing immediately upon read for some items */
        if (strcmp(te->desc, "ENCODING") == 0)
            processEncodingEntry(AH, te);
        else if (strcmp(te->desc, "STDSTRINGS") == 0)
            processStdStringsEntry(AH, te);
    }
}

static void
processEncodingEntry(ArchiveHandle *AH, TocEntry *te)
{
    /* te->defn should have the form SET client_encoding = 'foo'; */
    char       *defn = pg_strdup(te->defn);
    char       *ptr1;
    char       *ptr2 = NULL;
    int         encoding;

    ptr1 = strchr(defn, '\'');
    if (ptr1)
        ptr2 = strchr(++ptr1, '\'');
    if (ptr2)
    {
        *ptr2 = '\0';
        encoding = pg_char_to_encoding(ptr1);
        if (encoding < 0)
            exit_horribly(modulename, "unrecognized encoding \"%s\"\n",
                          ptr1);
        AH->public.encoding = encoding;
    }
    else
        exit_horribly(modulename, "invalid ENCODING item: %s\n",
                      te->defn);

    free(defn);
}

static void
processStdStringsEntry(ArchiveHandle *AH, TocEntry *te)
{
    /* te->defn should have the form SET standard_conforming_strings = 'x'; */
    char       *ptr1;

    ptr1 = strchr(te->defn, '\'');
    if (ptr1 && strncmp(ptr1, "'on'", 4) == 0)
        AH->public.std_strings = true;
    else if (ptr1 && strncmp(ptr1, "'off'", 5) == 0)
        AH->public.std_strings = false;
    else
        exit_horribly(modulename, "invalid STDSTRINGS item: %s\n",
                      te->defn);
}

static void
StrictNamesCheck(RestoreOptions *ropt)
{
    const char *missing_name;

    Assert(ropt->strict_names);

    if (ropt->schemaNames.head != NULL)
    {
        missing_name = simple_string_list_not_touched(&ropt->schemaNames);
        if (missing_name != NULL)
            exit_horribly(modulename, "schema \"%s\" not found\n", missing_name);
    }

    if (ropt->tableNames.head != NULL)
    {
        missing_name = simple_string_list_not_touched(&ropt->tableNames);
        if (missing_name != NULL)
            exit_horribly(modulename, "table \"%s\" not found\n", missing_name);
    }

    if (ropt->indexNames.head != NULL)
    {
        missing_name = simple_string_list_not_touched(&ropt->indexNames);
        if (missing_name != NULL)
            exit_horribly(modulename, "index \"%s\" not found\n", missing_name);
    }

    if (ropt->functionNames.head != NULL)
    {
        missing_name = simple_string_list_not_touched(&ropt->functionNames);
        if (missing_name != NULL)
            exit_horribly(modulename, "function \"%s\" not found\n", missing_name);
    }

    if (ropt->triggerNames.head != NULL)
    {
        missing_name = simple_string_list_not_touched(&ropt->triggerNames);
        if (missing_name != NULL)
            exit_horribly(modulename, "trigger \"%s\" not found\n", missing_name);
    }
}

static teReqs
_tocEntryRequired(TocEntry *te, teSection curSection, RestoreOptions *ropt)
{
    teReqs      res = REQ_SCHEMA | REQ_DATA;

    /* ENCODING and STDSTRINGS items are treated specially */
    if (strcmp(te->desc, "ENCODING") == 0 ||
        strcmp(te->desc, "STDSTRINGS") == 0)
        return REQ_SPECIAL;

    /* If it's an ACL, maybe ignore it */
    if (ropt->aclsSkip && _tocEntryIsACL(te))
        return 0;

    /* If it's a publication, maybe ignore it */
    if (ropt->no_publications && strcmp(te->desc, "PUBLICATION") == 0)
        return 0;

    /* If it's security labels, maybe ignore it */
    if (ropt->no_security_labels && strcmp(te->desc, "SECURITY LABEL") == 0)
        return 0;

    /* If it's a subcription, maybe ignore it */
    if (ropt->no_subscriptions && strcmp(te->desc, "SUBSCRIPTION") == 0)
        return 0;

    /* Ignore it if section is not to be dumped/restored */
    switch (curSection)
    {
        case SECTION_PRE_DATA:
            if (!(ropt->dumpSections & DUMP_PRE_DATA))
                return 0;
            break;
        case SECTION_DATA:
            if (!(ropt->dumpSections & DUMP_DATA))
                return 0;
            break;
        case SECTION_POST_DATA:
            if (!(ropt->dumpSections & DUMP_POST_DATA))
                return 0;
            break;
        default:
            /* shouldn't get here, really, but ignore it */
            return 0;
    }

    /* Check options for selective dump/restore */
    if (ropt->schemaNames.head != NULL)
    {
        /* If no namespace is specified, it means all. */
        if (!te->namespace)
            return 0;
        if (!(simple_string_list_member(&ropt->schemaNames, te->namespace)))
            return 0;
    }

    if (ropt->schemaExcludeNames.head != NULL &&
        te->namespace &&
        simple_string_list_member(&ropt->schemaExcludeNames, te->namespace))
        return 0;

    if (ropt->selTypes)
    {
        if (strcmp(te->desc, "TABLE") == 0 ||
            strcmp(te->desc, "TABLE DATA") == 0 ||
            strcmp(te->desc, "VIEW") == 0 ||
            strcmp(te->desc, "FOREIGN TABLE") == 0 ||
            strcmp(te->desc, "MATERIALIZED VIEW") == 0 ||
            strcmp(te->desc, "MATERIALIZED VIEW DATA") == 0 ||
            strcmp(te->desc, "SEQUENCE") == 0 ||
            strcmp(te->desc, "SEQUENCE SET") == 0)
        {
            if (!ropt->selTable)
                return 0;
            if (ropt->tableNames.head != NULL && (!(simple_string_list_member(&ropt->tableNames, te->tag))))
                return 0;
        }
        else if (strcmp(te->desc, "INDEX") == 0)
        {
            if (!ropt->selIndex)
                return 0;
            if (ropt->indexNames.head != NULL && (!(simple_string_list_member(&ropt->indexNames, te->tag))))
                return 0;
        }
        else if (strcmp(te->desc, "FUNCTION") == 0)
        {
            if (!ropt->selFunction)
                return 0;
            if (ropt->functionNames.head != NULL && (!(simple_string_list_member(&ropt->functionNames, te->tag))))
                return 0;
        }
        else if (strcmp(te->desc, "TRIGGER") == 0)
        {
            if (!ropt->selTrigger)
                return 0;
            if (ropt->triggerNames.head != NULL && (!(simple_string_list_member(&ropt->triggerNames, te->tag))))
                return 0;
        }
        else
            return 0;
    }

    /*
     * Check if we had a dataDumper. Indicates if the entry is schema or data
     */
    if (!te->hadDumper)
    {
        /*
         * Special Case: If 'SEQUENCE SET' or anything to do with BLOBs, then
         * it is considered a data entry.  We don't need to check for the
         * BLOBS entry or old-style BLOB COMMENTS, because they will have
         * hadDumper = true ... but we do need to check new-style BLOB
         * comments.
         */
        if (strcmp(te->desc, "SEQUENCE SET") == 0 ||
            strcmp(te->desc, "BLOB") == 0 ||
            (strcmp(te->desc, "ACL") == 0 &&
             strncmp(te->tag, "LARGE OBJECT ", 13) == 0) ||
            (strcmp(te->desc, "COMMENT") == 0 &&
             strncmp(te->tag, "LARGE OBJECT ", 13) == 0) ||
            (strcmp(te->desc, "SECURITY LABEL") == 0 &&
             strncmp(te->tag, "LARGE OBJECT ", 13) == 0))
            res = res & REQ_DATA;
        else
            res = res & ~REQ_DATA;
    }

    /*
     * Special case: <Init> type with <Max OID> tag; this is obsolete and we
     * always ignore it.
     */
    if ((strcmp(te->desc, "<Init>") == 0) && (strcmp(te->tag, "Max OID") == 0))
        return 0;

    /* Mask it if we only want schema */
    if (ropt->schemaOnly)
    {
        /*
         * In binary-upgrade mode, even with schema-only set, we do not mask
         * out large objects.  Only large object definitions, comments and
         * other information should be generated in binary-upgrade mode (not
         * the actual data).
         */
        if (!(ropt->sequence_data && strcmp(te->desc, "SEQUENCE SET") == 0) &&
            !(ropt->binary_upgrade && strcmp(te->desc, "BLOB") == 0) &&
            !(ropt->binary_upgrade && strncmp(te->tag, "LARGE OBJECT ", 13) == 0))
            res = res & REQ_SCHEMA;
    }

    /* Mask it if we only want data */
    if (ropt->dataOnly)
        res = res & REQ_DATA;

    /* Mask it if we don't have a schema contribution */
    if (!te->defn || strlen(te->defn) == 0)
        res = res & ~REQ_SCHEMA;

    /* Finally, if there's a per-ID filter, limit based on that as well */
    if (ropt->idWanted && !ropt->idWanted[te->dumpId - 1])
        return 0;

    return res;
}

/*
 * Identify which pass we should restore this TOC entry in.
 *
 * See notes with the RestorePass typedef in pg_backup_archiver.h.
 */
static RestorePass
_tocEntryRestorePass(TocEntry *te)
{
    /* "ACL LANGUAGE" was a crock emitted only in PG 7.4 */
    if (strcmp(te->desc, "ACL") == 0 ||
        strcmp(te->desc, "ACL LANGUAGE") == 0 ||
        strcmp(te->desc, "DEFAULT ACL") == 0)
        return RESTORE_PASS_ACL;
    if (strcmp(te->desc, "MATERIALIZED VIEW DATA") == 0)
        return RESTORE_PASS_REFRESH;
    return RESTORE_PASS_MAIN;
}

/*
 * Identify TOC entries that are ACLs.
 *
 * Note: it seems worth duplicating some code here to avoid a hard-wired
 * assumption that these are exactly the same entries that we restore during
 * the RESTORE_PASS_ACL phase.
 */
static bool
_tocEntryIsACL(TocEntry *te)
{
    /* "ACL LANGUAGE" was a crock emitted only in PG 7.4 */
    if (strcmp(te->desc, "ACL") == 0 ||
        strcmp(te->desc, "ACL LANGUAGE") == 0 ||
        strcmp(te->desc, "DEFAULT ACL") == 0)
        return true;
    return false;
}

/*
 * Issue SET commands for parameters that we want to have set the same way
 * at all times during execution of a restore script.
 */
static void
_doSetFixedOutputState(ArchiveHandle *AH)
{
    RestoreOptions *ropt = AH->public.ropt;

    /*
     * Disable timeouts to allow for slow commands, idle parallel workers, etc
     */
    ahprintf(AH, "SET statement_timeout = 0;\n");
    ahprintf(AH, "SET lock_timeout = 0;\n");
    ahprintf(AH, "SET idle_in_transaction_session_timeout = 0;\n");

    /* Select the correct character set encoding */
    ahprintf(AH, "SET client_encoding = '%s';\n",
             pg_encoding_to_char(AH->public.encoding));

    /* Select the correct string literal syntax */
    ahprintf(AH, "SET standard_conforming_strings = %s;\n",
             AH->public.std_strings ? "on" : "off");

    /* Select the role to be used during restore */
    if (ropt && ropt->use_role)
        ahprintf(AH, "SET ROLE %s;\n", fmtId(ropt->use_role));

    /* Make sure function checking is disabled */
    ahprintf(AH, "SET check_function_bodies = false;\n");

    /* Avoid annoying notices etc */
    ahprintf(AH, "SET client_min_messages = warning;\n");
    if (!AH->public.std_strings)
        ahprintf(AH, "SET escape_string_warning = off;\n");

    /* Adjust row-security state */
    if (ropt && ropt->enable_row_security)
        ahprintf(AH, "SET row_security = on;\n");
    else
        ahprintf(AH, "SET row_security = off;\n");

    ahprintf(AH, "\n");
}

/*
 * Issue a SET SESSION AUTHORIZATION command.  Caller is responsible
 * for updating state if appropriate.  If user is NULL or an empty string,
 * the specification DEFAULT will be used.
 */
static void
_doSetSessionAuth(ArchiveHandle *AH, const char *user)
{
    PQExpBuffer cmd = createPQExpBuffer();

    appendPQExpBufferStr(cmd, "SET SESSION AUTHORIZATION ");

    /*
     * SQL requires a string literal here.  Might as well be correct.
     */
    if (user && *user)
        appendStringLiteralAHX(cmd, user, AH);
    else
        appendPQExpBufferStr(cmd, "DEFAULT");
    appendPQExpBufferChar(cmd, ';');

    if (RestoringToDB(AH))
    {
        PGresult   *res;

        res = PQexec(AH->connection, cmd->data);

        if (!res || PQresultStatus(res) != PGRES_COMMAND_OK)
            /* NOT warn_or_exit_horribly... use -O instead to skip this. */
            exit_horribly(modulename, "could not set session user to \"%s\": %s",
                          user, PQerrorMessage(AH->connection));

        PQclear(res);
    }
    else
        ahprintf(AH, "%s\n\n", cmd->data);

    destroyPQExpBuffer(cmd);
}


/*
 * Issue a SET default_with_oids command.  Caller is responsible
 * for updating state if appropriate.
 */
static void
_doSetWithOids(ArchiveHandle *AH, const bool withOids)
{
    PQExpBuffer cmd = createPQExpBuffer();

    appendPQExpBuffer(cmd, "SET default_with_oids = %s;", withOids ?
                      "true" : "false");

    if (RestoringToDB(AH))
    {
        PGresult   *res;

        res = PQexec(AH->connection, cmd->data);

        if (!res || PQresultStatus(res) != PGRES_COMMAND_OK)
            warn_or_exit_horribly(AH, modulename,
                                  "could not set default_with_oids: %s",
                                  PQerrorMessage(AH->connection));

        PQclear(res);
    }
    else
        ahprintf(AH, "%s\n\n", cmd->data);

    destroyPQExpBuffer(cmd);
}


/*
 * Issue the commands to connect to the specified database.
 *
 * If we're currently restoring right into a database, this will
 * actually establish a connection. Otherwise it puts a \connect into
 * the script output.
 *
 * NULL dbname implies reconnecting to the current DB (pretty useless).
 */
static void
_reconnectToDB(ArchiveHandle *AH, const char *dbname)
{
    if (RestoringToDB(AH))
        ReconnectToServer(AH, dbname, NULL);
    else
    {
        if (dbname)
        {
            PQExpBufferData connectbuf;

            initPQExpBuffer(&connectbuf);
            appendPsqlMetaConnect(&connectbuf, dbname);
            ahprintf(AH, "%s\n", connectbuf.data);
            termPQExpBuffer(&connectbuf);
        }
        else
            ahprintf(AH, "%s\n", "\\connect -\n");
    }

    /*
     * NOTE: currUser keeps track of what the imaginary session user in our
     * script is.  It's now effectively reset to the original userID.
     */
    if (AH->currUser)
        free(AH->currUser);
    AH->currUser = NULL;

    /* don't assume we still know the output schema, tablespace, etc either */
    if (AH->currSchema)
        free(AH->currSchema);
    AH->currSchema = NULL;
    if (AH->currTablespace)
        free(AH->currTablespace);
    AH->currTablespace = NULL;
    AH->currWithOids = -1;

    /* re-establish fixed state */
    _doSetFixedOutputState(AH);
}

/*
 * Become the specified user, and update state to avoid redundant commands
 *
 * NULL or empty argument is taken to mean restoring the session default
 */
static void
_becomeUser(ArchiveHandle *AH, const char *user)
{
    if (!user)
        user = "";              /* avoid null pointers */

    if (AH->currUser && strcmp(AH->currUser, user) == 0)
        return;                 /* no need to do anything */

    _doSetSessionAuth(AH, user);

    /*
     * NOTE: currUser keeps track of what the imaginary session user in our
     * script is
     */
    if (AH->currUser)
        free(AH->currUser);
    AH->currUser = pg_strdup(user);
}

/*
 * Become the owner of the given TOC entry object.  If
 * changes in ownership are not allowed, this doesn't do anything.
 */
static void
_becomeOwner(ArchiveHandle *AH, TocEntry *te)
{
    RestoreOptions *ropt = AH->public.ropt;

    if (ropt && (ropt->noOwner || !ropt->use_setsessauth))
        return;

    _becomeUser(AH, te->owner);
}


/*
 * Set the proper default_with_oids value for the table.
 */
static void
_setWithOids(ArchiveHandle *AH, TocEntry *te)
{
    if (AH->currWithOids != te->withOids)
    {
        _doSetWithOids(AH, te->withOids);
        AH->currWithOids = te->withOids;
    }
}


/*
 * Issue the commands to select the specified schema as the current schema
 * in the target database.
 */
static void
_selectOutputSchema(ArchiveHandle *AH, const char *schemaName)
{
    PQExpBuffer qry;

    if (!schemaName || *schemaName == '\0' ||
        (AH->currSchema && strcmp(AH->currSchema, schemaName) == 0))
        return;                 /* no need to do anything */

    qry = createPQExpBuffer();

    appendPQExpBuffer(qry, "SET search_path = %s",
                      fmtId(schemaName));
    if (strcmp(schemaName, "pg_catalog") != 0)
        appendPQExpBufferStr(qry, ", pg_catalog");

    if (RestoringToDB(AH))
    {
        PGresult   *res;

        res = PQexec(AH->connection, qry->data);

        if (!res || PQresultStatus(res) != PGRES_COMMAND_OK)
            warn_or_exit_horribly(AH, modulename,
                                  "could not set search_path to \"%s\": %s",
                                  schemaName, PQerrorMessage(AH->connection));

        PQclear(res);
    }
    else
        ahprintf(AH, "%s;\n\n", qry->data);

    if (AH->currSchema)
        free(AH->currSchema);
    AH->currSchema = pg_strdup(schemaName);

    destroyPQExpBuffer(qry);
}

/*
 * Issue the commands to select the specified tablespace as the current one
 * in the target database.
 */
static void
_selectTablespace(ArchiveHandle *AH, const char *tablespace)
{
    RestoreOptions *ropt = AH->public.ropt;
    PQExpBuffer qry;
    const char *want,
               *have;

    /* do nothing in --no-tablespaces mode */
    if (ropt->noTablespace)
        return;

    have = AH->currTablespace;
    want = tablespace;

    /* no need to do anything for non-tablespace object */
    if (!want)
        return;

    if (have && strcmp(want, have) == 0)
        return;                 /* no need to do anything */

    qry = createPQExpBuffer();

    if (strcmp(want, "") == 0)
    {
        /* We want the tablespace to be the database's default */
        appendPQExpBufferStr(qry, "SET default_tablespace = ''");
    }
    else
    {
        /* We want an explicit tablespace */
        appendPQExpBuffer(qry, "SET default_tablespace = %s", fmtId(want));
    }

    if (RestoringToDB(AH))
    {
        PGresult   *res;

        res = PQexec(AH->connection, qry->data);

        if (!res || PQresultStatus(res) != PGRES_COMMAND_OK)
            warn_or_exit_horribly(AH, modulename,
                                  "could not set default_tablespace to %s: %s",
                                  fmtId(want), PQerrorMessage(AH->connection));

        PQclear(res);
    }
    else
        ahprintf(AH, "%s;\n\n", qry->data);

    if (AH->currTablespace)
        free(AH->currTablespace);
    AH->currTablespace = pg_strdup(want);

    destroyPQExpBuffer(qry);
}

/*
 * Extract an object description for a TOC entry, and append it to buf.
 *
 * This is used for ALTER ... OWNER TO.
 */
static void
_getObjectDescription(PQExpBuffer buf, TocEntry *te, ArchiveHandle *AH)
{
    const char *type = te->desc;

    /* Use ALTER TABLE for views and sequences */
    if (strcmp(type, "VIEW") == 0 || strcmp(type, "SEQUENCE") == 0 ||
        strcmp(type, "MATERIALIZED VIEW") == 0)
        type = "TABLE";

    /* objects that don't require special decoration */
    if (strcmp(type, "COLLATION") == 0 ||
        strcmp(type, "CONVERSION") == 0 ||
        strcmp(type, "DOMAIN") == 0 ||
        strcmp(type, "TABLE") == 0 ||
        strcmp(type, "TYPE") == 0 ||
        strcmp(type, "FOREIGN TABLE") == 0 ||
        strcmp(type, "TEXT SEARCH DICTIONARY") == 0 ||
        strcmp(type, "TEXT SEARCH CONFIGURATION") == 0 ||
    /* non-schema-specified objects */
        strcmp(type, "DATABASE") == 0 ||
        strcmp(type, "PROCEDURAL LANGUAGE") == 0 ||
        strcmp(type, "SCHEMA") == 0 ||
        strcmp(type, "EVENT TRIGGER") == 0 ||
        strcmp(type, "FOREIGN DATA WRAPPER") == 0 ||
        strcmp(type, "SERVER") == 0 ||
        strcmp(type, "PUBLICATION") == 0 ||
        strcmp(type, "SUBSCRIPTION") == 0 ||
        strcmp(type, "USER MAPPING") == 0)
    {
        /* We already know that search_path was set properly */
        appendPQExpBuffer(buf, "%s %s", type, fmtId(te->tag));
        return;
    }

    /* BLOBs just have a name, but it's numeric so must not use fmtId */
    if (strcmp(type, "BLOB") == 0)
    {
        appendPQExpBuffer(buf, "LARGE OBJECT %s", te->tag);
        return;
    }

    /*
     * These object types require additional decoration.  Fortunately, the
     * information needed is exactly what's in the DROP command.
     */
    if (strcmp(type, "AGGREGATE") == 0 ||
        strcmp(type, "FUNCTION") == 0 ||
        strcmp(type, "OPERATOR") == 0 ||
        strcmp(type, "OPERATOR CLASS") == 0 ||
        strcmp(type, "OPERATOR FAMILY") == 0)
    {
        /* Chop "DROP " off the front and make a modifiable copy */
        char       *first = pg_strdup(te->dropStmt + 5);
        char       *last;

        /* point to last character in string */
        last = first + strlen(first) - 1;

        /* Strip off any ';' or '\n' at the end */
        while (last >= first && (*last == '\n' || *last == ';'))
            last--;
        *(last + 1) = '\0';

        appendPQExpBufferStr(buf, first);

        free(first);
        return;
    }

    write_msg(modulename, "WARNING: don't know how to set owner for object type \"%s\"\n",
              type);
}

/*
 * Emit the SQL commands to create the object represented by a TOC entry
 *
 * This now also includes issuing an ALTER OWNER command to restore the
 * object's ownership, if wanted.  But note that the object's permissions
 * will remain at default, until the matching ACL TOC entry is restored.
 */
static void
_printTocEntry(ArchiveHandle *AH, TocEntry *te, bool isData)
{
    RestoreOptions *ropt = AH->public.ropt;

    /*
     * Avoid dumping the public schema, as it will already be created ...
     * unless we are using --clean mode (and *not* --create mode), in which
     * case we've previously issued a DROP for it so we'd better recreate it.
     *
     * Likewise for its comment, if any.  (We could try issuing the COMMENT
     * command anyway; but it'd fail if the restore is done as non-super-user,
     * so let's not.)
     *
     * XXX it looks pretty ugly to hard-wire the public schema like this, but
     * it sits in a sort of no-mans-land between being a system object and a
     * user object, so it really is special in a way.
     */
    if (!(ropt->dropSchema && !ropt->createDB))
    {
        if (strcmp(te->desc, "SCHEMA") == 0 &&
            strcmp(te->tag, "public") == 0)
            return;
        if (strcmp(te->desc, "COMMENT") == 0 &&
            strcmp(te->tag, "SCHEMA public") == 0)
            return;
    }

    /* Select owner, schema, and tablespace as necessary */
    _becomeOwner(AH, te);
    _selectOutputSchema(AH, te->namespace);
    _selectTablespace(AH, te->tablespace);

    /* Set up OID mode too */
    if (strcmp(te->desc, "TABLE") == 0)
        _setWithOids(AH, te);

    /* Emit header comment for item */
    if (!AH->noTocComments)
    {
        const char *pfx;
        char       *sanitized_name;
        char       *sanitized_schema;
        char       *sanitized_owner;

        if (isData)
            pfx = "Data for ";
        else
            pfx = "";

        ahprintf(AH, "--\n");
        if (AH->public.verbose)
        {
            ahprintf(AH, "-- TOC entry %d (class %u OID %u)\n",
                     te->dumpId, te->catalogId.tableoid, te->catalogId.oid);
            if (te->nDeps > 0)
            {
                int         i;

                ahprintf(AH, "-- Dependencies:");
                for (i = 0; i < te->nDeps; i++)
                    ahprintf(AH, " %d", te->dependencies[i]);
                ahprintf(AH, "\n");
            }
        }

        /*
         * Zap any line endings embedded in user-supplied fields, to prevent
         * corruption of the dump (which could, in the worst case, present an
         * SQL injection vulnerability if someone were to incautiously load a
         * dump containing objects with maliciously crafted names).
         */
        sanitized_name = replace_line_endings(te->tag);
        if (te->namespace)
            sanitized_schema = replace_line_endings(te->namespace);
        else
            sanitized_schema = pg_strdup("-");
        if (!ropt->noOwner)
            sanitized_owner = replace_line_endings(te->owner);
        else
            sanitized_owner = pg_strdup("-");

        ahprintf(AH, "-- %sName: %s; Type: %s; Schema: %s; Owner: %s",
                 pfx, sanitized_name, te->desc, sanitized_schema,
                 sanitized_owner);

        free(sanitized_name);
        free(sanitized_schema);
        free(sanitized_owner);

        if (te->tablespace && strlen(te->tablespace) > 0 && !ropt->noTablespace)
        {
            char       *sanitized_tablespace;

            sanitized_tablespace = replace_line_endings(te->tablespace);
            ahprintf(AH, "; Tablespace: %s", sanitized_tablespace);
            free(sanitized_tablespace);
        }
        ahprintf(AH, "\n");

        if (AH->PrintExtraTocPtr != NULL)
            AH->PrintExtraTocPtr(AH, te);
        ahprintf(AH, "--\n\n");
    }

    /*
     * Actually print the definition.
     *
     * Really crude hack for suppressing AUTHORIZATION clause that old pg_dump
     * versions put into CREATE SCHEMA.  We have to do this when --no-owner
     * mode is selected.  This is ugly, but I see no other good way ...
     */
    if (ropt->noOwner && strcmp(te->desc, "SCHEMA") == 0)
    {
        ahprintf(AH, "CREATE SCHEMA %s;\n\n\n", fmtId(te->tag));
    }
    else
    {
        if (strlen(te->defn) > 0)
            ahprintf(AH, "%s\n\n", te->defn);
    }

    /*
     * If we aren't using SET SESSION AUTH to determine ownership, we must
     * instead issue an ALTER OWNER command.  We assume that anything without
     * a DROP command is not a separately ownable object.  All the categories
     * with DROP commands must appear in one list or the other.
     */
    if (!ropt->noOwner && !ropt->use_setsessauth &&
        strlen(te->owner) > 0 && strlen(te->dropStmt) > 0)
    {
        if (strcmp(te->desc, "AGGREGATE") == 0 ||
            strcmp(te->desc, "BLOB") == 0 ||
            strcmp(te->desc, "COLLATION") == 0 ||
            strcmp(te->desc, "CONVERSION") == 0 ||
            strcmp(te->desc, "DATABASE") == 0 ||
            strcmp(te->desc, "DOMAIN") == 0 ||
            strcmp(te->desc, "FUNCTION") == 0 ||
            strcmp(te->desc, "OPERATOR") == 0 ||
            strcmp(te->desc, "OPERATOR CLASS") == 0 ||
            strcmp(te->desc, "OPERATOR FAMILY") == 0 ||
            strcmp(te->desc, "PROCEDURAL LANGUAGE") == 0 ||
            strcmp(te->desc, "SCHEMA") == 0 ||
            strcmp(te->desc, "EVENT TRIGGER") == 0 ||
            strcmp(te->desc, "TABLE") == 0 ||
            strcmp(te->desc, "TYPE") == 0 ||
            strcmp(te->desc, "VIEW") == 0 ||
            strcmp(te->desc, "MATERIALIZED VIEW") == 0 ||
            strcmp(te->desc, "SEQUENCE") == 0 ||
            strcmp(te->desc, "FOREIGN TABLE") == 0 ||
            strcmp(te->desc, "TEXT SEARCH DICTIONARY") == 0 ||
            strcmp(te->desc, "TEXT SEARCH CONFIGURATION") == 0 ||
            strcmp(te->desc, "FOREIGN DATA WRAPPER") == 0 ||
            strcmp(te->desc, "SERVER") == 0 ||
            strcmp(te->desc, "PUBLICATION") == 0 ||
            strcmp(te->desc, "SUBSCRIPTION") == 0)
        {
            PQExpBuffer temp = createPQExpBuffer();

            appendPQExpBufferStr(temp, "ALTER ");
            _getObjectDescription(temp, te, AH);
            appendPQExpBuffer(temp, " OWNER TO %s;", fmtId(te->owner));
            ahprintf(AH, "%s\n\n", temp->data);
            destroyPQExpBuffer(temp);
        }
        else if (strcmp(te->desc, "CAST") == 0 ||
                 strcmp(te->desc, "CHECK CONSTRAINT") == 0 ||
                 strcmp(te->desc, "CONSTRAINT") == 0 ||
                 strcmp(te->desc, "DEFAULT") == 0 ||
                 strcmp(te->desc, "FK CONSTRAINT") == 0 ||
                 strcmp(te->desc, "INDEX") == 0 ||
                 strcmp(te->desc, "RULE") == 0 ||
                 strcmp(te->desc, "TRIGGER") == 0 ||
                 strcmp(te->desc, "ROW SECURITY") == 0 ||
                 strcmp(te->desc, "POLICY") == 0 ||
                 strcmp(te->desc, "USER MAPPING") == 0 ||
                 strcmp(te->desc, "STATISTICS") == 0)
        {
            /* these object types don't have separate owners */
        }
        else
        {
            write_msg(modulename, "WARNING: don't know how to set owner for object type \"%s\"\n",
                      te->desc);
        }
    }

    /*
     * If it's an ACL entry, it might contain SET SESSION AUTHORIZATION
     * commands, so we can no longer assume we know the current auth setting.
     */
    if (_tocEntryIsACL(te))
    {
        if (AH->currUser)
            free(AH->currUser);
        AH->currUser = NULL;
    }
}

/*
 * Sanitize a string to be included in an SQL comment or TOC listing,
 * by replacing any newlines with spaces.
 * The result is a freshly malloc'd string.
 */
static char *
replace_line_endings(const char *str)
{
    char       *result;
    char       *s;

    result = pg_strdup(str);

    for (s = result; *s != '\0'; s++)
    {
        if (*s == '\n' || *s == '\r')
            *s = ' ';
    }

    return result;
}

/*
 * Write the file header for a custom-format archive
 */
void
WriteHead(ArchiveHandle *AH)
{
    struct tm   crtm;

    AH->WriteBufPtr(AH, "PGDMP", 5);    /* Magic code */
    AH->WriteBytePtr(AH, ARCHIVE_MAJOR(AH->version));
    AH->WriteBytePtr(AH, ARCHIVE_MINOR(AH->version));
    AH->WriteBytePtr(AH, ARCHIVE_REV(AH->version));
    AH->WriteBytePtr(AH, AH->intSize);
    AH->WriteBytePtr(AH, AH->offSize);
    AH->WriteBytePtr(AH, AH->format);
    WriteInt(AH, AH->compression);
    crtm = *localtime(&AH->createDate);
    WriteInt(AH, crtm.tm_sec);
    WriteInt(AH, crtm.tm_min);
    WriteInt(AH, crtm.tm_hour);
    WriteInt(AH, crtm.tm_mday);
    WriteInt(AH, crtm.tm_mon);
    WriteInt(AH, crtm.tm_year);
    WriteInt(AH, crtm.tm_isdst);
    WriteStr(AH, PQdb(AH->connection));
    WriteStr(AH, AH->public.remoteVersionStr);
    WriteStr(AH, PG_VERSION);
}

void
ReadHead(ArchiveHandle *AH)
{
    char        tmpMag[7];
    int         fmt;
    struct tm   crtm;

    /*
     * If we haven't already read the header, do so.
     *
     * NB: this code must agree with _discoverArchiveFormat().  Maybe find a
     * way to unify the cases?
     */
    if (!AH->readHeader)
    {
        char        vmaj,
                    vmin,
                    vrev;

        AH->ReadBufPtr(AH, tmpMag, 5);

        if (strncmp(tmpMag, "PGDMP", 5) != 0)
            exit_horribly(modulename, "did not find magic string in file header\n");

        vmaj = AH->ReadBytePtr(AH);
        vmin = AH->ReadBytePtr(AH);

        if (vmaj > 1 || (vmaj == 1 && vmin > 0))    /* Version > 1.0 */
            vrev = AH->ReadBytePtr(AH);
        else
            vrev = 0;

        AH->version = MAKE_ARCHIVE_VERSION(vmaj, vmin, vrev);

        if (AH->version < K_VERS_1_0 || AH->version > K_VERS_MAX)
            exit_horribly(modulename, "unsupported version (%d.%d) in file header\n",
                          vmaj, vmin);

        AH->intSize = AH->ReadBytePtr(AH);
        if (AH->intSize > 32)
            exit_horribly(modulename, "sanity check on integer size (%lu) failed\n",
                          (unsigned long) AH->intSize);

        if (AH->intSize > sizeof(int))
            write_msg(modulename, "WARNING: archive was made on a machine with larger integers, some operations might fail\n");

        if (AH->version >= K_VERS_1_7)
            AH->offSize = AH->ReadBytePtr(AH);
        else
            AH->offSize = AH->intSize;

        fmt = AH->ReadBytePtr(AH);

        if (AH->format != fmt)
            exit_horribly(modulename, "expected format (%d) differs from format found in file (%d)\n",
                          AH->format, fmt);
    }

    if (AH->version >= K_VERS_1_2)
    {
        if (AH->version < K_VERS_1_4)
            AH->compression = AH->ReadBytePtr(AH);
        else
            AH->compression = ReadInt(AH);
    }
    else
        AH->compression = Z_DEFAULT_COMPRESSION;

#ifndef HAVE_LIBZ
    if (AH->compression != 0)
        write_msg(modulename, "WARNING: archive is compressed, but this installation does not support compression -- no data will be available\n");
#endif

    if (AH->version >= K_VERS_1_4)
    {
        crtm.tm_sec = ReadInt(AH);
        crtm.tm_min = ReadInt(AH);
        crtm.tm_hour = ReadInt(AH);
        crtm.tm_mday = ReadInt(AH);
        crtm.tm_mon = ReadInt(AH);
        crtm.tm_year = ReadInt(AH);
        crtm.tm_isdst = ReadInt(AH);

        AH->archdbname = ReadStr(AH);

        AH->createDate = mktime(&crtm);

        if (AH->createDate == (time_t) -1)
            write_msg(modulename, "WARNING: invalid creation date in header\n");
    }

    if (AH->version >= K_VERS_1_10)
    {
        AH->archiveRemoteVersion = ReadStr(AH);
        AH->archiveDumpVersion = ReadStr(AH);
    }
}


/*
 * checkSeek
 *    check to see if ftell/fseek can be performed.
 */
bool
checkSeek(FILE *fp)
{
    pgoff_t     tpos;

    /*
     * If pgoff_t is wider than long, we must have "real" fseeko and not an
     * emulation using fseek.  Otherwise report no seek capability.
     */
#ifndef HAVE_FSEEKO
    if (sizeof(pgoff_t) > sizeof(long))
        return false;
#endif

    /* Check that ftello works on this file */
    tpos = ftello(fp);
    if (tpos < 0)
        return false;

    /*
     * Check that fseeko(SEEK_SET) works, too.  NB: we used to try to test
     * this with fseeko(fp, 0, SEEK_CUR).  But some platforms treat that as a
     * successful no-op even on files that are otherwise unseekable.
     */
    if (fseeko(fp, tpos, SEEK_SET) != 0)
        return false;

    return true;
}


/*
 * dumpTimestamp
 */
static void
dumpTimestamp(ArchiveHandle *AH, const char *msg, time_t tim)
{
    char        buf[64];

    if (strftime(buf, sizeof(buf), PGDUMP_STRFTIME_FMT, localtime(&tim)) != 0)
        ahprintf(AH, "-- %s %s\n\n", msg, buf);
}

/*
 * Main engine for parallel restore.
 *
 * Parallel restore is done in three phases.  In this first phase,
 * we'll process all SECTION_PRE_DATA TOC entries that are allowed to be
 * processed in the RESTORE_PASS_MAIN pass.  (In practice, that's all
 * PRE_DATA items other than ACLs.)  Entries we can't process now are
 * added to the pending_list for later phases to deal with.
 */
static void
restore_toc_entries_prefork(ArchiveHandle *AH, TocEntry *pending_list)
{
    bool        skipped_some;
    TocEntry   *next_work_item;

    ahlog(AH, 2, "entering restore_toc_entries_prefork\n");

    /* Adjust dependency information */
    fix_dependencies(AH);

    /*
     * Do all the early stuff in a single connection in the parent. There's no
     * great point in running it in parallel, in fact it will actually run
     * faster in a single connection because we avoid all the connection and
     * setup overhead.  Also, pre-9.2 pg_dump versions were not very good
     * about showing all the dependencies of SECTION_PRE_DATA items, so we do
     * not risk trying to process them out-of-order.
     *
     * Stuff that we can't do immediately gets added to the pending_list.
     * Note: we don't yet filter out entries that aren't going to be restored.
     * They might participate in dependency chains connecting entries that
     * should be restored, so we treat them as live until we actually process
     * them.
     *
     * Note: as of 9.2, it should be guaranteed that all PRE_DATA items appear
     * before DATA items, and all DATA items before POST_DATA items.  That is
     * not certain to be true in older archives, though, and in any case use
     * of a list file would destroy that ordering (cf. SortTocFromFile).  So
     * this loop cannot assume that it holds.
     */
    AH->restorePass = RESTORE_PASS_MAIN;
    skipped_some = false;
    for (next_work_item = AH->toc->next; next_work_item != AH->toc; next_work_item = next_work_item->next)
    {
        bool        do_now = true;

        if (next_work_item->section != SECTION_PRE_DATA)
        {
            /* DATA and POST_DATA items are just ignored for now */
            if (next_work_item->section == SECTION_DATA ||
                next_work_item->section == SECTION_POST_DATA)
            {
                do_now = false;
                skipped_some = true;
            }
            else
            {
                /*
                 * SECTION_NONE items, such as comments, can be processed now
                 * if we are still in the PRE_DATA part of the archive.  Once
                 * we've skipped any items, we have to consider whether the
                 * comment's dependencies are satisfied, so skip it for now.
                 */
                if (skipped_some)
                    do_now = false;
            }
        }

        /*
         * Also skip items that need to be forced into later passes.  We need
         * not set skipped_some in this case, since by assumption no main-pass
         * items could depend on these.
         */
        if (_tocEntryRestorePass(next_work_item) != RESTORE_PASS_MAIN)
            do_now = false;

        if (do_now)
        {
            /* OK, restore the item and update its dependencies */
            ahlog(AH, 1, "processing item %d %s %s\n",
                  next_work_item->dumpId,
                  next_work_item->desc, next_work_item->tag);

            (void) restore_toc_entry(AH, next_work_item, false);

            /* Reduce dependencies, but don't move anything to ready_list */
            reduce_dependencies(AH, next_work_item, NULL);
        }
        else
        {
            /* Nope, so add it to pending_list */
            par_list_append(pending_list, next_work_item);
        }
    }

    /*
     * Now close parent connection in prep for parallel steps.  We do this
     * mainly to ensure that we don't exceed the specified number of parallel
     * connections.
     */
    DisconnectDatabase(&AH->public);

    /* blow away any transient state from the old connection */
    if (AH->currUser)
        free(AH->currUser);
    AH->currUser = NULL;
    if (AH->currSchema)
        free(AH->currSchema);
    AH->currSchema = NULL;
    if (AH->currTablespace)
        free(AH->currTablespace);
    AH->currTablespace = NULL;
    AH->currWithOids = -1;
}

/*
 * Main engine for parallel restore.
 *
 * Parallel restore is done in three phases.  In this second phase,
 * we process entries by dispatching them to parallel worker children
 * (processes on Unix, threads on Windows), each of which connects
 * separately to the database.  Inter-entry dependencies are respected,
 * and so is the RestorePass multi-pass structure.  When we can no longer
 * make any entries ready to process, we exit.  Normally, there will be
 * nothing left to do; but if there is, the third phase will mop up.
 */
static void
restore_toc_entries_parallel(ArchiveHandle *AH, ParallelState *pstate,
                             TocEntry *pending_list)
{
    TocEntry    ready_list;
    TocEntry   *next_work_item;

    ahlog(AH, 2, "entering restore_toc_entries_parallel\n");

    /*
     * The pending_list contains all items that we need to restore.  Move all
     * items that are available to process immediately into the ready_list.
     * After this setup, the pending list is everything that needs to be done
     * but is blocked by one or more dependencies, while the ready list
     * contains items that have no remaining dependencies and are OK to
     * process in the current restore pass.
     */
    par_list_header_init(&ready_list);
    AH->restorePass = RESTORE_PASS_MAIN;
    move_to_ready_list(pending_list, &ready_list, AH->restorePass);

    /*
     * main parent loop
     *
     * Keep going until there is no worker still running AND there is no work
     * left to be done.  Note invariant: at top of loop, there should always
     * be at least one worker available to dispatch a job to.
     */
    ahlog(AH, 1, "entering main parallel loop\n");

    for (;;)
    {
        /* Look for an item ready to be dispatched to a worker */
        next_work_item = get_next_work_item(AH, &ready_list, pstate);
        if (next_work_item != NULL)
        {
            /* If not to be restored, don't waste time launching a worker */
            if ((next_work_item->reqs & (REQ_SCHEMA | REQ_DATA)) == 0)
            {
                ahlog(AH, 1, "skipping item %d %s %s\n",
                      next_work_item->dumpId,
                      next_work_item->desc, next_work_item->tag);
                /* Drop it from ready_list, and update its dependencies */
                par_list_remove(next_work_item);
                reduce_dependencies(AH, next_work_item, &ready_list);
                /* Loop around to see if anything else can be dispatched */
                continue;
            }

            ahlog(AH, 1, "launching item %d %s %s\n",
                  next_work_item->dumpId,
                  next_work_item->desc, next_work_item->tag);

            /* Remove it from ready_list, and dispatch to some worker */
            par_list_remove(next_work_item);

            DispatchJobForTocEntry(AH, pstate, next_work_item, ACT_RESTORE,
                                   mark_restore_job_done, &ready_list);
        }
        else if (IsEveryWorkerIdle(pstate))
        {
            /*
             * Nothing is ready and no worker is running, so we're done with
             * the current pass or maybe with the whole process.
             */
            if (AH->restorePass == RESTORE_PASS_LAST)
                break;          /* No more parallel processing is possible */

            /* Advance to next restore pass */
            AH->restorePass++;
            /* That probably allows some stuff to be made ready */
            move_to_ready_list(pending_list, &ready_list, AH->restorePass);
            /* Loop around to see if anything's now ready */
            continue;
        }
        else
        {
            /*
             * We have nothing ready, but at least one child is working, so
             * wait for some subjob to finish.
             */
        }

        /*
         * Before dispatching another job, check to see if anything has
         * finished.  We should check every time through the loop so as to
         * reduce dependencies as soon as possible.  If we were unable to
         * dispatch any job this time through, wait until some worker finishes
         * (and, hopefully, unblocks some pending item).  If we did dispatch
         * something, continue as soon as there's at least one idle worker.
         * Note that in either case, there's guaranteed to be at least one
         * idle worker when we return to the top of the loop.  This ensures we
         * won't block inside DispatchJobForTocEntry, which would be
         * undesirable: we'd rather postpone dispatching until we see what's
         * been unblocked by finished jobs.
         */
        WaitForWorkers(AH, pstate,
                       next_work_item ? WFW_ONE_IDLE : WFW_GOT_STATUS);
    }

    /* There should now be nothing in ready_list. */
    Assert(ready_list.par_next == &ready_list);

    ahlog(AH, 1, "finished main parallel loop\n");
}

/*
 * Main engine for parallel restore.
 *
 * Parallel restore is done in three phases.  In this third phase,
 * we mop up any remaining TOC entries by processing them serially.
 * This phase normally should have nothing to do, but if we've somehow
 * gotten stuck due to circular dependencies or some such, this provides
 * at least some chance of completing the restore successfully.
 */
static void
restore_toc_entries_postfork(ArchiveHandle *AH, TocEntry *pending_list)
{
    RestoreOptions *ropt = AH->public.ropt;
    TocEntry   *te;

    ahlog(AH, 2, "entering restore_toc_entries_postfork\n");

    /*
     * Now reconnect the single parent connection.
     */
    ConnectDatabase((Archive *) AH, ropt->dbname,
                    ropt->pghost, ropt->pgport, ropt->username,
                    ropt->promptPassword);

    /* re-establish fixed state */
    _doSetFixedOutputState(AH);

    /*
     * Make sure there is no work left due to, say, circular dependencies, or
     * some other pathological condition.  If so, do it in the single parent
     * connection.  We don't sweat about RestorePass ordering; it's likely we
     * already violated that.
     */
    for (te = pending_list->par_next; te != pending_list; te = te->par_next)
    {
        ahlog(AH, 1, "processing missed item %d %s %s\n",
              te->dumpId, te->desc, te->tag);
        (void) restore_toc_entry(AH, te, false);
    }
}

/*
 * Check if te1 has an exclusive lock requirement for an item that te2 also
 * requires, whether or not te2's requirement is for an exclusive lock.
 */
static bool
has_lock_conflicts(TocEntry *te1, TocEntry *te2)
{
    int         j,
                k;

    for (j = 0; j < te1->nLockDeps; j++)
    {
        for (k = 0; k < te2->nDeps; k++)
        {
            if (te1->lockDeps[j] == te2->dependencies[k])
                return true;
        }
    }
    return false;
}


/*
 * Initialize the header of a parallel-processing list.
 *
 * These are circular lists with a dummy TocEntry as header, just like the
 * main TOC list; but we use separate list links so that an entry can be in
 * the main TOC list as well as in a parallel-processing list.
 */
static void
par_list_header_init(TocEntry *l)
{
    l->par_prev = l->par_next = l;
}

/* Append te to the end of the parallel-processing list headed by l */
static void
par_list_append(TocEntry *l, TocEntry *te)
{
    te->par_prev = l->par_prev;
    l->par_prev->par_next = te;
    l->par_prev = te;
    te->par_next = l;
}

/* Remove te from whatever parallel-processing list it's in */
static void
par_list_remove(TocEntry *te)
{
    te->par_prev->par_next = te->par_next;
    te->par_next->par_prev = te->par_prev;
    te->par_prev = NULL;
    te->par_next = NULL;
}


/*
 * Move all immediately-ready items from pending_list to ready_list.
 *
 * Items are considered ready if they have no remaining dependencies and
 * they belong in the current restore pass.  (See also reduce_dependencies,
 * which applies the same logic one-at-a-time.)
 */
static void
move_to_ready_list(TocEntry *pending_list, TocEntry *ready_list,
                   RestorePass pass)
{
    TocEntry   *te;
    TocEntry   *next_te;

    for (te = pending_list->par_next; te != pending_list; te = next_te)
    {
        /* must save list link before possibly moving te to other list */
        next_te = te->par_next;

        if (te->depCount == 0 &&
            _tocEntryRestorePass(te) == pass)
        {
            /* Remove it from pending_list ... */
            par_list_remove(te);
            /* ... and add to ready_list */
            par_list_append(ready_list, te);
        }
    }
}

/*
 * Find the next work item (if any) that is capable of being run now.
 *
 * To qualify, the item must have no remaining dependencies
 * and no requirements for locks that are incompatible with
 * items currently running.  Items in the ready_list are known to have
 * no remaining dependencies, but we have to check for lock conflicts.
 *
 * Note that the returned item has *not* been removed from ready_list.
 * The caller must do that after successfully dispatching the item.
 *
 * pref_non_data is for an alternative selection algorithm that gives
 * preference to non-data items if there is already a data load running.
 * It is currently disabled.
 */
static TocEntry *
get_next_work_item(ArchiveHandle *AH, TocEntry *ready_list,
                   ParallelState *pstate)
{
    bool        pref_non_data = false;  /* or get from AH->ropt */
    TocEntry   *data_te = NULL;
    TocEntry   *te;
    int         i,
                k;

    /*
     * Bogus heuristics for pref_non_data
     */
    if (pref_non_data)
    {
        int         count = 0;

        for (k = 0; k < pstate->numWorkers; k++)
        {
            TocEntry   *running_te = pstate->te[k];

            if (running_te != NULL &&
                running_te->section == SECTION_DATA)
                count++;
        }
        if (pstate->numWorkers == 0 || count * 4 < pstate->numWorkers)
            pref_non_data = false;
    }

    /*
     * Search the ready_list until we find a suitable item.
     */
    for (te = ready_list->par_next; te != ready_list; te = te->par_next)
    {
        bool        conflicts = false;

        /*
         * Check to see if the item would need exclusive lock on something
         * that a currently running item also needs lock on, or vice versa. If
         * so, we don't want to schedule them together.
         */
        for (i = 0; i < pstate->numWorkers; i++)
        {
            TocEntry   *running_te = pstate->te[i];

            if (running_te == NULL)
                continue;
            if (has_lock_conflicts(te, running_te) ||
                has_lock_conflicts(running_te, te))
            {
                conflicts = true;
                break;
            }
        }

        if (conflicts)
            continue;

        if (pref_non_data && te->section == SECTION_DATA)
        {
            if (data_te == NULL)
                data_te = te;
            continue;
        }

        /* passed all tests, so this item can run */
        return te;
    }

    if (data_te != NULL)
        return data_te;

    ahlog(AH, 2, "no item ready\n");
    return NULL;
}


/*
 * Restore a single TOC item in parallel with others
 *
 * this is run in the worker, i.e. in a thread (Windows) or a separate process
 * (everything else). A worker process executes several such work items during
 * a parallel backup or restore. Once we terminate here and report back that
 * our work is finished, the master process will assign us a new work item.
 */
int
parallel_restore(ArchiveHandle *AH, TocEntry *te)
{
    int         status;

    Assert(AH->connection != NULL);

    /* Count only errors associated with this TOC entry */
    AH->public.n_errors = 0;

    /* Restore the TOC item */
    status = restore_toc_entry(AH, te, true);

    return status;
}


/*
 * Callback function that's invoked in the master process after a step has
 * been parallel restored.
 *
 * Update status and reduce the dependency count of any dependent items.
 */
static void
mark_restore_job_done(ArchiveHandle *AH,
                      TocEntry *te,
                      int status,
                      void *callback_data)
{
    TocEntry   *ready_list = (TocEntry *) callback_data;

    ahlog(AH, 1, "finished item %d %s %s\n",
          te->dumpId, te->desc, te->tag);

    if (status == WORKER_CREATE_DONE)
        mark_create_done(AH, te);
    else if (status == WORKER_INHIBIT_DATA)
    {
        inhibit_data_for_failed_table(AH, te);
        AH->public.n_errors++;
    }
    else if (status == WORKER_IGNORED_ERRORS)
        AH->public.n_errors++;
    else if (status != 0)
        exit_horribly(modulename, "worker process failed: exit code %d\n",
                      status);

    reduce_dependencies(AH, te, ready_list);
}


/*
 * Process the dependency information into a form useful for parallel restore.
 *
 * This function takes care of fixing up some missing or badly designed
 * dependencies, and then prepares subsidiary data structures that will be
 * used in the main parallel-restore logic, including:
 * 1. We build the revDeps[] arrays of incoming dependency dumpIds.
 * 2. We set up depCount fields that are the number of as-yet-unprocessed
 * dependencies for each TOC entry.
 *
 * We also identify locking dependencies so that we can avoid trying to
 * schedule conflicting items at the same time.
 */
static void
fix_dependencies(ArchiveHandle *AH)
{
    TocEntry   *te;
    int         i;

    /*
     * Initialize the depCount/revDeps/nRevDeps fields, and make sure the TOC
     * items are marked as not being in any parallel-processing list.
     */
    for (te = AH->toc->next; te != AH->toc; te = te->next)
    {
        te->depCount = te->nDeps;
        te->revDeps = NULL;
        te->nRevDeps = 0;
        te->par_prev = NULL;
        te->par_next = NULL;
    }

    /*
     * POST_DATA items that are shown as depending on a table need to be
     * re-pointed to depend on that table's data, instead.  This ensures they
     * won't get scheduled until the data has been loaded.
     */
    repoint_table_dependencies(AH);

    /*
     * Pre-8.4 versions of pg_dump neglected to set up a dependency from BLOB
     * COMMENTS to BLOBS.  Cope.  (We assume there's only one BLOBS and only
     * one BLOB COMMENTS in such files.)
     */
    if (AH->version < K_VERS_1_11)
    {
        for (te = AH->toc->next; te != AH->toc; te = te->next)
        {
            if (strcmp(te->desc, "BLOB COMMENTS") == 0 && te->nDeps == 0)
            {
                TocEntry   *te2;

                for (te2 = AH->toc->next; te2 != AH->toc; te2 = te2->next)
                {
                    if (strcmp(te2->desc, "BLOBS") == 0)
                    {
                        te->dependencies = (DumpId *) pg_malloc(sizeof(DumpId));
                        te->dependencies[0] = te2->dumpId;
                        te->nDeps++;
                        te->depCount++;
                        break;
                    }
                }
                break;
            }
        }
    }

    /*
     * At this point we start to build the revDeps reverse-dependency arrays,
     * so all changes of dependencies must be complete.
     */

    /*
     * Count the incoming dependencies for each item.  Also, it is possible
     * that the dependencies list items that are not in the archive at all
     * (that should not happen in 9.2 and later, but is highly likely in older
     * archives).  Subtract such items from the depCounts.
     */
    for (te = AH->toc->next; te != AH->toc; te = te->next)
    {
        for (i = 0; i < te->nDeps; i++)
        {
            DumpId      depid = te->dependencies[i];

            if (depid <= AH->maxDumpId && AH->tocsByDumpId[depid] != NULL)
                AH->tocsByDumpId[depid]->nRevDeps++;
            else
                te->depCount--;
        }
    }

    /*
     * Allocate space for revDeps[] arrays, and reset nRevDeps so we can use
     * it as a counter below.
     */
    for (te = AH->toc->next; te != AH->toc; te = te->next)
    {
        if (te->nRevDeps > 0)
            te->revDeps = (DumpId *) pg_malloc(te->nRevDeps * sizeof(DumpId));
        te->nRevDeps = 0;
    }

    /*
     * Build the revDeps[] arrays of incoming-dependency dumpIds.  This had
     * better agree with the loops above.
     */
    for (te = AH->toc->next; te != AH->toc; te = te->next)
    {
        for (i = 0; i < te->nDeps; i++)
        {
            DumpId      depid = te->dependencies[i];

            if (depid <= AH->maxDumpId && AH->tocsByDumpId[depid] != NULL)
            {
                TocEntry   *otherte = AH->tocsByDumpId[depid];

                otherte->revDeps[otherte->nRevDeps++] = te->dumpId;
            }
        }
    }

    /*
     * Lastly, work out the locking dependencies.
     */
    for (te = AH->toc->next; te != AH->toc; te = te->next)
    {
        te->lockDeps = NULL;
        te->nLockDeps = 0;
        identify_locking_dependencies(AH, te);
    }
}

/*
 * Change dependencies on table items to depend on table data items instead,
 * but only in POST_DATA items.
 */
static void
repoint_table_dependencies(ArchiveHandle *AH)
{
    TocEntry   *te;
    int         i;
    DumpId      olddep;

    for (te = AH->toc->next; te != AH->toc; te = te->next)
    {
        if (te->section != SECTION_POST_DATA)
            continue;
        for (i = 0; i < te->nDeps; i++)
        {
            olddep = te->dependencies[i];
            if (olddep <= AH->maxDumpId &&
                AH->tableDataId[olddep] != 0)
            {
                te->dependencies[i] = AH->tableDataId[olddep];
                ahlog(AH, 2, "transferring dependency %d -> %d to %d\n",
                      te->dumpId, olddep, AH->tableDataId[olddep]);
            }
        }
    }
}

/*
 * Identify which objects we'll need exclusive lock on in order to restore
 * the given TOC entry (*other* than the one identified by the TOC entry
 * itself).  Record their dump IDs in the entry's lockDeps[] array.
 */
static void
identify_locking_dependencies(ArchiveHandle *AH, TocEntry *te)
{
    DumpId     *lockids;
    int         nlockids;
    int         i;

    /* Quick exit if no dependencies at all */
    if (te->nDeps == 0)
        return;

    /* Exit if this entry doesn't need exclusive lock on other objects */
    if (!(strcmp(te->desc, "CONSTRAINT") == 0 ||
          strcmp(te->desc, "CHECK CONSTRAINT") == 0 ||
          strcmp(te->desc, "FK CONSTRAINT") == 0 ||
          strcmp(te->desc, "RULE") == 0 ||
          strcmp(te->desc, "TRIGGER") == 0))
        return;

    /*
     * We assume the entry requires exclusive lock on each TABLE or TABLE DATA
     * item listed among its dependencies.  Originally all of these would have
     * been TABLE items, but repoint_table_dependencies would have repointed
     * them to the TABLE DATA items if those are present (which they might not
     * be, eg in a schema-only dump).  Note that all of the entries we are
     * processing here are POST_DATA; otherwise there might be a significant
     * difference between a dependency on a table and a dependency on its
     * data, so that closer analysis would be needed here.
     */
    lockids = (DumpId *) pg_malloc(te->nDeps * sizeof(DumpId));
    nlockids = 0;
    for (i = 0; i < te->nDeps; i++)
    {
        DumpId      depid = te->dependencies[i];

        if (depid <= AH->maxDumpId && AH->tocsByDumpId[depid] != NULL &&
            ((strcmp(AH->tocsByDumpId[depid]->desc, "TABLE DATA") == 0) ||
             strcmp(AH->tocsByDumpId[depid]->desc, "TABLE") == 0))
            lockids[nlockids++] = depid;
    }

    if (nlockids == 0)
    {
        free(lockids);
        return;
    }

    te->lockDeps = pg_realloc(lockids, nlockids * sizeof(DumpId));
    te->nLockDeps = nlockids;
}

/*
 * Remove the specified TOC entry from the depCounts of items that depend on
 * it, thereby possibly making them ready-to-run.  Any pending item that
 * becomes ready should be moved to the ready_list, if that's provided.
 */
static void
reduce_dependencies(ArchiveHandle *AH, TocEntry *te, TocEntry *ready_list)
{
    int         i;

    ahlog(AH, 2, "reducing dependencies for %d\n", te->dumpId);

    for (i = 0; i < te->nRevDeps; i++)
    {
        TocEntry   *otherte = AH->tocsByDumpId[te->revDeps[i]];

        Assert(otherte->depCount > 0);
        otherte->depCount--;

        /*
         * It's ready if it has no remaining dependencies, and it belongs in
         * the current restore pass, and it is currently a member of the
         * pending list (that check is needed to prevent double restore in
         * some cases where a list-file forces out-of-order restoring).
         * However, if ready_list == NULL then caller doesn't want any list
         * memberships changed.
         */
        if (otherte->depCount == 0 &&
            _tocEntryRestorePass(otherte) == AH->restorePass &&
            otherte->par_prev != NULL &&
            ready_list != NULL)
        {
            /* Remove it from pending list ... */
            par_list_remove(otherte);
            /* ... and add to ready_list */
            par_list_append(ready_list, otherte);
        }
    }
}

/*
 * Set the created flag on the DATA member corresponding to the given
 * TABLE member
 */
static void
mark_create_done(ArchiveHandle *AH, TocEntry *te)
{
    if (AH->tableDataId[te->dumpId] != 0)
    {
        TocEntry   *ted = AH->tocsByDumpId[AH->tableDataId[te->dumpId]];

        ted->created = true;
    }
}

/*
 * Mark the DATA member corresponding to the given TABLE member
 * as not wanted
 */
static void
inhibit_data_for_failed_table(ArchiveHandle *AH, TocEntry *te)
{
    ahlog(AH, 1, "table \"%s\" could not be created, will not restore its data\n",
          te->tag);

    if (AH->tableDataId[te->dumpId] != 0)
    {
        TocEntry   *ted = AH->tocsByDumpId[AH->tableDataId[te->dumpId]];

        ted->reqs = 0;
    }
}

/*
 * Clone and de-clone routines used in parallel restoration.
 *
 * Enough of the structure is cloned to ensure that there is no
 * conflict between different threads each with their own clone.
 */
ArchiveHandle *
CloneArchive(ArchiveHandle *AH)
{
    ArchiveHandle *clone;

    /* Make a "flat" copy */
    clone = (ArchiveHandle *) pg_malloc(sizeof(ArchiveHandle));
    memcpy(clone, AH, sizeof(ArchiveHandle));

    /* Handle format-independent fields */
    memset(&(clone->sqlparse), 0, sizeof(clone->sqlparse));

    /* The clone will have its own connection, so disregard connection state */
    clone->connection = NULL;
    clone->connCancel = NULL;
    clone->currUser = NULL;
    clone->currSchema = NULL;
    clone->currTablespace = NULL;
    clone->currWithOids = -1;

    /* savedPassword must be local in case we change it while connecting */
    if (clone->savedPassword)
        clone->savedPassword = pg_strdup(clone->savedPassword);

    /* clone has its own error count, too */
    clone->public.n_errors = 0;

    /*
     * Connect our new clone object to the database: In parallel restore the
     * parent is already disconnected, because we can connect the worker
     * processes independently to the database (no snapshot sync required). In
     * parallel backup we clone the parent's existing connection.
     */
    if (AH->mode == archModeRead)
    {
        RestoreOptions *ropt = AH->public.ropt;

        Assert(AH->connection == NULL);

        /* this also sets clone->connection */
        ConnectDatabase((Archive *) clone, ropt->dbname,
                        ropt->pghost, ropt->pgport, ropt->username,
                        ropt->promptPassword);

        /* re-establish fixed state */
        _doSetFixedOutputState(clone);
    }
    else
    {
        PQExpBufferData connstr;
        char       *pghost;
        char       *pgport;
        char       *username;

        Assert(AH->connection != NULL);

        /*
         * Even though we are technically accessing the parent's database
         * object here, these functions are fine to be called like that
         * because all just return a pointer and do not actually send/receive
         * any data to/from the database.
         */
        initPQExpBuffer(&connstr);
        appendPQExpBuffer(&connstr, "dbname=");
        appendConnStrVal(&connstr, PQdb(AH->connection));
        pghost = PQhost(AH->connection);
        pgport = PQport(AH->connection);
        username = PQuser(AH->connection);

        /* this also sets clone->connection */
        ConnectDatabase((Archive *) clone, connstr.data,
                        pghost, pgport, username, TRI_NO);

        termPQExpBuffer(&connstr);
        /* setupDumpWorker will fix up connection state */
    }

    /* Let the format-specific code have a chance too */
    clone->ClonePtr(clone);

    Assert(clone->connection != NULL);
    return clone;
}

/*
 * Release clone-local storage.
 *
 * Note: we assume any clone-local connection was already closed.
 */
void
DeCloneArchive(ArchiveHandle *AH)
{
    /* Should not have an open database connection */
    Assert(AH->connection == NULL);

    /* Clear format-specific state */
    AH->DeClonePtr(AH);

    /* Clear state allocated by CloneArchive */
    if (AH->sqlparse.curCmd)
        destroyPQExpBuffer(AH->sqlparse.curCmd);

    /* Clear any connection-local state */
    if (AH->currUser)
        free(AH->currUser);
    if (AH->currSchema)
        free(AH->currSchema);
    if (AH->currTablespace)
        free(AH->currTablespace);
    if (AH->savedPassword)
        free(AH->savedPassword);

    free(AH);
}