genfile.c File Reference

#include "postgres.h"
#include <sys/file.h>
#include <sys/stat.h>
#include <unistd.h>
#include <dirent.h>
#include "access/htup_details.h"
#include "access/xlog_internal.h"
#include "catalog/pg_authid.h"
#include "catalog/pg_tablespace_d.h"
#include "catalog/pg_type.h"
#include "funcapi.h"
#include "mb/pg_wchar.h"
#include "miscadmin.h"
#include "postmaster/syslogger.h"
#include "replication/slot.h"
#include "storage/fd.h"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/memutils.h"
#include "utils/syscache.h"
#include "utils/timestamp.h"

Include dependency graph for genfile.c:

Go to the source code of this file.

Macros
#define	MIN_READ_SIZE   4096

Functions
static char *	convert_and_check_filename (text *arg)
static bytea *	read_binary_file (const char *filename, int64 seek_offset, int64 bytes_to_read, bool missing_ok)
static text *	read_text_file (const char *filename, int64 seek_offset, int64 bytes_to_read, bool missing_ok)
Datum	pg_read_file (PG_FUNCTION_ARGS)
Datum	pg_read_file_v2 (PG_FUNCTION_ARGS)
Datum	pg_read_binary_file (PG_FUNCTION_ARGS)
Datum	pg_read_file_off_len (PG_FUNCTION_ARGS)
Datum	pg_read_file_all (PG_FUNCTION_ARGS)
Datum	pg_read_binary_file_off_len (PG_FUNCTION_ARGS)
Datum	pg_read_binary_file_all (PG_FUNCTION_ARGS)
Datum	pg_stat_file (PG_FUNCTION_ARGS)
Datum	pg_stat_file_1arg (PG_FUNCTION_ARGS)
Datum	pg_ls_dir (PG_FUNCTION_ARGS)
Datum	pg_ls_dir_1arg (PG_FUNCTION_ARGS)
static Datum	pg_ls_dir_files (FunctionCallInfo fcinfo, const char *dir, bool missing_ok)
Datum	pg_ls_logdir (PG_FUNCTION_ARGS)
Datum	pg_ls_waldir (PG_FUNCTION_ARGS)
static Datum	pg_ls_tmpdir (FunctionCallInfo fcinfo, Oid tblspc)
Datum	pg_ls_tmpdir_noargs (PG_FUNCTION_ARGS)
Datum	pg_ls_tmpdir_1arg (PG_FUNCTION_ARGS)
Datum	pg_ls_archive_statusdir (PG_FUNCTION_ARGS)
Datum	pg_ls_logicalsnapdir (PG_FUNCTION_ARGS)
Datum	pg_ls_logicalmapdir (PG_FUNCTION_ARGS)
Datum	pg_ls_replslotdir (PG_FUNCTION_ARGS)

Macro Definition Documentation

MIN_READ_SIZE

#define MIN_READ_SIZE   4096

Function Documentation

convert_and_check_filename()

static char* convert_and_check_filename ( text *  arg )

static

Definition at line 54 of file genfile.c.

{
    char       *filename;
 
    filename = text_to_cstring(arg);
    canonicalize_path(filename);    /* filename can change length here */
 
    /*
     * Roles with privileges of the 'pg_read_server_files' role are allowed to
     * access any files on the server as the PG user, so no need to do any
     * further checks here.
     */
    if (has_privs_of_role(GetUserId(), ROLE_PG_READ_SERVER_FILES))
        return filename;
 
    /*
     * User isn't a member of the pg_read_server_files role, so check if it's
     * allowable
     */
    if (is_absolute_path(filename))
    {
        /*
         * Allow absolute paths if within DataDir or Log_directory, even
         * though Log_directory might be outside DataDir.
         */
        if (!path_is_prefix_of_path(DataDir, filename) &&
            (!is_absolute_path(Log_directory) ||
             !path_is_prefix_of_path(Log_directory, filename)))
            ereport(ERROR,
                    (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
                     errmsg("absolute path not allowed")));
    }
    else if (!path_is_relative_and_below_cwd(filename))
        ereport(ERROR,
                (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
                 errmsg("path must be in or below the current directory")));
 
    return filename;
}

References arg, canonicalize_path(), DataDir, ereport, errcode(), errmsg(), ERROR, filename, GetUserId(), has_privs_of_role(), is_absolute_path, Log_directory, path_is_prefix_of_path(), path_is_relative_and_below_cwd(), and text_to_cstring().

Referenced by pg_ls_dir(), pg_read_binary_file(), pg_read_file(), pg_read_file_v2(), and pg_stat_file().

pg_ls_archive_statusdir()

Datum pg_ls_archive_statusdir

(

PG_FUNCTION_ARGS

)

Definition at line 663 of file genfile.c.

{
    return pg_ls_dir_files(fcinfo, XLOGDIR "/archive_status", true);
}

References pg_ls_dir_files(), and XLOGDIR.

pg_ls_dir()

Datum pg_ls_dir

(

PG_FUNCTION_ARGS

)

Definition at line 474 of file genfile.c.

{
    ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
    char       *location;
    bool        missing_ok = false;
    bool        include_dot_dirs = false;
    DIR        *dirdesc;
    struct dirent *de;
 
    location = convert_and_check_filename(PG_GETARG_TEXT_PP(0));
 
    /* check the optional arguments */
    if (PG_NARGS() == 3)
    {
        if (!PG_ARGISNULL(1))
            missing_ok = PG_GETARG_BOOL(1);
        if (!PG_ARGISNULL(2))
            include_dot_dirs = PG_GETARG_BOOL(2);
    }
 
    SetSingleFuncCall(fcinfo, SRF_SINGLE_USE_EXPECTED);
 
    dirdesc = AllocateDir(location);
    if (!dirdesc)
    {
        /* Return empty tuplestore if appropriate */
        if (missing_ok && errno == ENOENT)
            return (Datum) 0;
        /* Otherwise, we can let ReadDir() throw the error */
    }
 
    while ((de = ReadDir(dirdesc, location)) != NULL)
    {
        Datum       values[1];
        bool        nulls[1];
 
        if (!include_dot_dirs &&
            (strcmp(de->d_name, ".") == 0 ||
             strcmp(de->d_name, "..") == 0))
            continue;
 
        values[0] = CStringGetTextDatum(de->d_name);
        nulls[0] = false;
 
        tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc,
                             values, nulls);
    }
 
    FreeDir(dirdesc);
    return (Datum) 0;
}

References AllocateDir(), convert_and_check_filename(), CStringGetTextDatum, FreeDir(), PG_ARGISNULL, PG_GETARG_BOOL, PG_GETARG_TEXT_PP, PG_NARGS, ReadDir(), ReturnSetInfo::setDesc, ReturnSetInfo::setResult, SetSingleFuncCall(), SRF_SINGLE_USE_EXPECTED, tuplestore_putvalues(), and values.

Referenced by pg_ls_dir_1arg().

pg_ls_dir_1arg()

Datum pg_ls_dir_1arg

(

PG_FUNCTION_ARGS

)

Definition at line 534 of file genfile.c.

{
    return pg_ls_dir(fcinfo);
}

References pg_ls_dir().

pg_ls_dir_files()

static Datum pg_ls_dir_files ( FunctionCallInfo  fcinfo, const char *  dir, bool  missing_ok  )

static

Definition at line 546 of file genfile.c.

{
    ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
    DIR        *dirdesc;
    struct dirent *de;
 
    SetSingleFuncCall(fcinfo, 0);
 
    /*
     * Now walk the directory.  Note that we must do this within a single SRF
     * call, not leave the directory open across multiple calls, since we
     * can't count on the SRF being run to completion.
     */
    dirdesc = AllocateDir(dir);
    if (!dirdesc)
    {
        /* Return empty tuplestore if appropriate */
        if (missing_ok && errno == ENOENT)
            return (Datum) 0;
        /* Otherwise, we can let ReadDir() throw the error */
    }
 
    while ((de = ReadDir(dirdesc, dir)) != NULL)
    {
        Datum       values[3];
        bool        nulls[3];
        char        path[MAXPGPATH * 2];
        struct stat attrib;
 
        /* Skip hidden files */
        if (de->d_name[0] == '.')
            continue;
 
        /* Get the file info */
        snprintf(path, sizeof(path), "%s/%s", dir, de->d_name);
        if (stat(path, &attrib) < 0)
        {
            /* Ignore concurrently-deleted files, else complain */
            if (errno == ENOENT)
                continue;
            ereport(ERROR,
                    (errcode_for_file_access(),
                     errmsg("could not stat file \"%s\": %m", path)));
        }
 
        /* Ignore anything but regular files */
        if (!S_ISREG(attrib.st_mode))
            continue;
 
        values[0] = CStringGetTextDatum(de->d_name);
        values[1] = Int64GetDatum((int64) attrib.st_size);
        values[2] = TimestampTzGetDatum(time_t_to_timestamptz(attrib.st_mtime));
        memset(nulls, 0, sizeof(nulls));
 
        tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
    }
 
    FreeDir(dirdesc);
    return (Datum) 0;
}

References AllocateDir(), CStringGetTextDatum, ereport, errcode_for_file_access(), errmsg(), ERROR, FreeDir(), Int64GetDatum(), MAXPGPATH, ReadDir(), FunctionCallInfoBaseData::resultinfo, S_ISREG, ReturnSetInfo::setDesc, ReturnSetInfo::setResult, SetSingleFuncCall(), snprintf, stat::st_mode, stat::st_mtime, stat::st_size, stat, time_t_to_timestamptz(), TimestampTzGetDatum, tuplestore_putvalues(), and values.

Referenced by pg_ls_archive_statusdir(), pg_ls_logdir(), pg_ls_logicalmapdir(), pg_ls_logicalsnapdir(), pg_ls_replslotdir(), pg_ls_tmpdir(), and pg_ls_waldir().

pg_ls_logdir()

Datum pg_ls_logdir

(

PG_FUNCTION_ARGS

)

Definition at line 609 of file genfile.c.

{
    return pg_ls_dir_files(fcinfo, Log_directory, false);
}

References Log_directory, and pg_ls_dir_files().

pg_ls_logicalmapdir()

Datum pg_ls_logicalmapdir

(

PG_FUNCTION_ARGS

)

Definition at line 681 of file genfile.c.

{
    return pg_ls_dir_files(fcinfo, "pg_logical/mappings", false);
}

References pg_ls_dir_files().

pg_ls_logicalsnapdir()

Datum pg_ls_logicalsnapdir

(

PG_FUNCTION_ARGS

)

Definition at line 672 of file genfile.c.

{
    return pg_ls_dir_files(fcinfo, "pg_logical/snapshots", false);
}

References pg_ls_dir_files().

pg_ls_replslotdir()

Datum pg_ls_replslotdir

(

PG_FUNCTION_ARGS

)

Definition at line 691 of file genfile.c.

{
    text       *slotname_t;
    char        path[MAXPGPATH];
    char       *slotname;
 
    slotname_t = PG_GETARG_TEXT_PP(0);
 
    slotname = text_to_cstring(slotname_t);
 
    if (!SearchNamedReplicationSlot(slotname, true))
        ereport(ERROR,
                (errcode(ERRCODE_UNDEFINED_OBJECT),
                 errmsg("replication slot \"%s\" does not exist",
                        slotname)));
 
    snprintf(path, sizeof(path), "pg_replslot/%s", slotname);
    return pg_ls_dir_files(fcinfo, path, false);
}

References ereport, errcode(), errmsg(), ERROR, MAXPGPATH, PG_GETARG_TEXT_PP, pg_ls_dir_files(), SearchNamedReplicationSlot(), snprintf, and text_to_cstring().

pg_ls_tmpdir()

static Datum pg_ls_tmpdir ( FunctionCallInfo  fcinfo, Oid  tblspc  )

static

Definition at line 625 of file genfile.c.

{
    char        path[MAXPGPATH];
 
    if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspc)))
        ereport(ERROR,
                (errcode(ERRCODE_UNDEFINED_OBJECT),
                 errmsg("tablespace with OID %u does not exist",
                        tblspc)));
 
    TempTablespacePath(path, tblspc);
    return pg_ls_dir_files(fcinfo, path, true);
}

References ereport, errcode(), errmsg(), ERROR, MAXPGPATH, ObjectIdGetDatum, pg_ls_dir_files(), SearchSysCacheExists1, TABLESPACEOID, and TempTablespacePath().

Referenced by pg_ls_tmpdir_1arg(), and pg_ls_tmpdir_noargs().

pg_ls_tmpdir_1arg()

Datum pg_ls_tmpdir_1arg

(

PG_FUNCTION_ARGS

)

Definition at line 654 of file genfile.c.

{
    return pg_ls_tmpdir(fcinfo, PG_GETARG_OID(0));
}

References PG_GETARG_OID, and pg_ls_tmpdir().

pg_ls_tmpdir_noargs()

Datum pg_ls_tmpdir_noargs

(

PG_FUNCTION_ARGS

)

Definition at line 644 of file genfile.c.

{
    return pg_ls_tmpdir(fcinfo, DEFAULTTABLESPACE_OID);
}

References pg_ls_tmpdir().

pg_ls_waldir()

Datum pg_ls_waldir

(

PG_FUNCTION_ARGS

)

Definition at line 616 of file genfile.c.

{
    return pg_ls_dir_files(fcinfo, XLOGDIR, false);
}

References pg_ls_dir_files(), and XLOGDIR.

pg_read_binary_file()

Datum pg_read_binary_file

(

PG_FUNCTION_ARGS

)

Definition at line 319 of file genfile.c.

{
    text       *filename_t = PG_GETARG_TEXT_PP(0);
    int64       seek_offset = 0;
    int64       bytes_to_read = -1;
    bool        missing_ok = false;
    char       *filename;
    bytea      *result;
 
    /* handle optional arguments */
    if (PG_NARGS() >= 3)
    {
        seek_offset = PG_GETARG_INT64(1);
        bytes_to_read = PG_GETARG_INT64(2);
 
        if (bytes_to_read < 0)
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                     errmsg("requested length cannot be negative")));
    }
    if (PG_NARGS() >= 4)
        missing_ok = PG_GETARG_BOOL(3);
 
    filename = convert_and_check_filename(filename_t);
 
    result = read_binary_file(filename, seek_offset,
                              bytes_to_read, missing_ok);
    if (result)
        PG_RETURN_BYTEA_P(result);
    else
        PG_RETURN_NULL();
}

References convert_and_check_filename(), ereport, errcode(), errmsg(), ERROR, filename, PG_GETARG_BOOL, PG_GETARG_INT64, PG_GETARG_TEXT_PP, PG_NARGS, PG_RETURN_BYTEA_P, PG_RETURN_NULL, and read_binary_file().

Referenced by pg_read_binary_file_all(), and pg_read_binary_file_off_len().

pg_read_binary_file_all()

Datum pg_read_binary_file_all

(

PG_FUNCTION_ARGS

)

Definition at line 380 of file genfile.c.

{
    return pg_read_binary_file(fcinfo);
}

References pg_read_binary_file().

pg_read_binary_file_off_len()

Datum pg_read_binary_file_off_len

(

PG_FUNCTION_ARGS

)

Definition at line 374 of file genfile.c.

{
    return pg_read_binary_file(fcinfo);
}

References pg_read_binary_file().

pg_read_file()

Datum pg_read_file

(

PG_FUNCTION_ARGS

)

Definition at line 236 of file genfile.c.

{
    text       *filename_t = PG_GETARG_TEXT_PP(0);
    int64       seek_offset = 0;
    int64       bytes_to_read = -1;
    bool        missing_ok = false;
    char       *filename;
    text       *result;
 
    if (!superuser())
        ereport(ERROR,
                (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
                 errmsg("must be superuser to read files with adminpack 1.0"),
        /* translator: %s is a SQL function name */
                 errhint("Consider using %s, which is part of core, instead.",
                         "pg_read_file()")));
 
    /* handle optional arguments */
    if (PG_NARGS() >= 3)
    {
        seek_offset = PG_GETARG_INT64(1);
        bytes_to_read = PG_GETARG_INT64(2);
 
        if (bytes_to_read < 0)
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                     errmsg("requested length cannot be negative")));
    }
    if (PG_NARGS() >= 4)
        missing_ok = PG_GETARG_BOOL(3);
 
    filename = convert_and_check_filename(filename_t);
 
    result = read_text_file(filename, seek_offset, bytes_to_read, missing_ok);
    if (result)
        PG_RETURN_TEXT_P(result);
    else
        PG_RETURN_NULL();
}

References convert_and_check_filename(), ereport, errcode(), errhint(), errmsg(), ERROR, filename, PG_GETARG_BOOL, PG_GETARG_INT64, PG_GETARG_TEXT_PP, PG_NARGS, PG_RETURN_NULL, PG_RETURN_TEXT_P, read_text_file(), and superuser().

pg_read_file_all()

Datum pg_read_file_all

(

PG_FUNCTION_ARGS

)

Definition at line 368 of file genfile.c.

{
    return pg_read_file_v2(fcinfo);
}

References pg_read_file_v2().

pg_read_file_off_len()

Datum pg_read_file_off_len

(

PG_FUNCTION_ARGS

)

Definition at line 362 of file genfile.c.

{
    return pg_read_file_v2(fcinfo);
}

References pg_read_file_v2().

pg_read_file_v2()

Datum pg_read_file_v2

(

PG_FUNCTION_ARGS

)

Definition at line 283 of file genfile.c.

{
    text       *filename_t = PG_GETARG_TEXT_PP(0);
    int64       seek_offset = 0;
    int64       bytes_to_read = -1;
    bool        missing_ok = false;
    char       *filename;
    text       *result;
 
    /* handle optional arguments */
    if (PG_NARGS() >= 3)
    {
        seek_offset = PG_GETARG_INT64(1);
        bytes_to_read = PG_GETARG_INT64(2);
 
        if (bytes_to_read < 0)
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                     errmsg("requested length cannot be negative")));
    }
    if (PG_NARGS() >= 4)
        missing_ok = PG_GETARG_BOOL(3);
 
    filename = convert_and_check_filename(filename_t);
 
    result = read_text_file(filename, seek_offset, bytes_to_read, missing_ok);
    if (result)
        PG_RETURN_TEXT_P(result);
    else
        PG_RETURN_NULL();
}

References convert_and_check_filename(), ereport, errcode(), errmsg(), ERROR, filename, PG_GETARG_BOOL, PG_GETARG_INT64, PG_GETARG_TEXT_PP, PG_NARGS, PG_RETURN_NULL, PG_RETURN_TEXT_P, and read_text_file().

Referenced by pg_read_file_all(), and pg_read_file_off_len().

pg_stat_file()

Datum pg_stat_file

(

PG_FUNCTION_ARGS

)

Definition at line 389 of file genfile.c.

{
    text       *filename_t = PG_GETARG_TEXT_PP(0);
    char       *filename;
    struct stat fst;
    Datum       values[6];
    bool        isnull[6];
    HeapTuple   tuple;
    TupleDesc   tupdesc;
    bool        missing_ok = false;
 
    /* check the optional argument */
    if (PG_NARGS() == 2)
        missing_ok = PG_GETARG_BOOL(1);
 
    filename = convert_and_check_filename(filename_t);
 
    if (stat(filename, &fst) < 0)
    {
        if (missing_ok && errno == ENOENT)
            PG_RETURN_NULL();
        else
            ereport(ERROR,
                    (errcode_for_file_access(),
                     errmsg("could not stat file \"%s\": %m", filename)));
    }
 
    /*
     * This record type had better match the output parameters declared for me
     * in pg_proc.h.
     */
    tupdesc = CreateTemplateTupleDesc(6);
    TupleDescInitEntry(tupdesc, (AttrNumber) 1,
                       "size", INT8OID, -1, 0);
    TupleDescInitEntry(tupdesc, (AttrNumber) 2,
                       "access", TIMESTAMPTZOID, -1, 0);
    TupleDescInitEntry(tupdesc, (AttrNumber) 3,
                       "modification", TIMESTAMPTZOID, -1, 0);
    TupleDescInitEntry(tupdesc, (AttrNumber) 4,
                       "change", TIMESTAMPTZOID, -1, 0);
    TupleDescInitEntry(tupdesc, (AttrNumber) 5,
                       "creation", TIMESTAMPTZOID, -1, 0);
    TupleDescInitEntry(tupdesc, (AttrNumber) 6,
                       "isdir", BOOLOID, -1, 0);
    BlessTupleDesc(tupdesc);
 
    memset(isnull, false, sizeof(isnull));
 
    values[0] = Int64GetDatum((int64) fst.st_size);
    values[1] = TimestampTzGetDatum(time_t_to_timestamptz(fst.st_atime));
    values[2] = TimestampTzGetDatum(time_t_to_timestamptz(fst.st_mtime));
    /* Unix has file status change time, while Win32 has creation time */
#if !defined(WIN32) && !defined(__CYGWIN__)
    values[3] = TimestampTzGetDatum(time_t_to_timestamptz(fst.st_ctime));
    isnull[4] = true;
#else
    isnull[3] = true;
    values[4] = TimestampTzGetDatum(time_t_to_timestamptz(fst.st_ctime));
#endif
    values[5] = BoolGetDatum(S_ISDIR(fst.st_mode));
 
    tuple = heap_form_tuple(tupdesc, values, isnull);
 
    pfree(filename);
 
    PG_RETURN_DATUM(HeapTupleGetDatum(tuple));
}

References BlessTupleDesc(), BoolGetDatum, convert_and_check_filename(), CreateTemplateTupleDesc(), ereport, errcode_for_file_access(), errmsg(), ERROR, filename, heap_form_tuple(), HeapTupleGetDatum, Int64GetDatum(), pfree(), PG_GETARG_BOOL, PG_GETARG_TEXT_PP, PG_NARGS, PG_RETURN_DATUM, PG_RETURN_NULL, S_ISDIR, stat::st_atime, stat::st_ctime, stat::st_mode, stat::st_mtime, stat::st_size, stat, time_t_to_timestamptz(), TimestampTzGetDatum, TupleDescInitEntry(), and values.

Referenced by pg_stat_file_1arg().

pg_stat_file_1arg()

Datum pg_stat_file_1arg

(

PG_FUNCTION_ARGS

)

Definition at line 465 of file genfile.c.

{
    return pg_stat_file(fcinfo);
}

References pg_stat_file().

read_binary_file()

static bytea* read_binary_file ( const char *  filename, int64  seek_offset, int64  bytes_to_read, bool  missing_ok  )

static

Definition at line 103 of file genfile.c.

{
    bytea      *buf;
    size_t      nbytes = 0;
    FILE       *file;
 
    /* clamp request size to what we can actually deliver */
    if (bytes_to_read > (int64) (MaxAllocSize - VARHDRSZ))
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("requested length too large")));
 
    if ((file = AllocateFile(filename, PG_BINARY_R)) == NULL)
    {
        if (missing_ok && errno == ENOENT)
            return NULL;
        else
            ereport(ERROR,
                    (errcode_for_file_access(),
                     errmsg("could not open file \"%s\" for reading: %m",
                            filename)));
    }
 
    if (fseeko(file, (off_t) seek_offset,
               (seek_offset >= 0) ? SEEK_SET : SEEK_END) != 0)
        ereport(ERROR,
                (errcode_for_file_access(),
                 errmsg("could not seek in file \"%s\": %m", filename)));
 
    if (bytes_to_read >= 0)
    {
        /* If passed explicit read size just do it */
        buf = (bytea *) palloc((Size) bytes_to_read + VARHDRSZ);
 
        nbytes = fread(VARDATA(buf), 1, (size_t) bytes_to_read, file);
    }
    else
    {
        /* Negative read size, read rest of file */
        StringInfoData sbuf;
 
        initStringInfo(&sbuf);
        /* Leave room in the buffer for the varlena length word */
        sbuf.len += VARHDRSZ;
        Assert(sbuf.len < sbuf.maxlen);
 
        while (!(feof(file) || ferror(file)))
        {
            size_t      rbytes;
 
            /* Minimum amount to read at a time */
#define MIN_READ_SIZE 4096
 
            /*
             * If not at end of file, and sbuf.len is equal to MaxAllocSize -
             * 1, then either the file is too large, or there is nothing left
             * to read. Attempt to read one more byte to see if the end of
             * file has been reached. If not, the file is too large; we'd
             * rather give the error message for that ourselves.
             */
            if (sbuf.len == MaxAllocSize - 1)
            {
                char        rbuf[1];
 
                if (fread(rbuf, 1, 1, file) != 0 || !feof(file))
                    ereport(ERROR,
                            (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
                             errmsg("file length too large")));
                else
                    break;
            }
 
            /* OK, ensure that we can read at least MIN_READ_SIZE */
            enlargeStringInfo(&sbuf, MIN_READ_SIZE);
 
            /*
             * stringinfo.c likes to allocate in powers of 2, so it's likely
             * that much more space is available than we asked for.  Use all
             * of it, rather than making more fread calls than necessary.
             */
            rbytes = fread(sbuf.data + sbuf.len, 1,
                           (size_t) (sbuf.maxlen - sbuf.len - 1), file);
            sbuf.len += rbytes;
            nbytes += rbytes;
        }
 
        /* Now we can commandeer the stringinfo's buffer as the result */
        buf = (bytea *) sbuf.data;
    }
 
    if (ferror(file))
        ereport(ERROR,
                (errcode_for_file_access(),
                 errmsg("could not read file \"%s\": %m", filename)));
 
    SET_VARSIZE(buf, nbytes + VARHDRSZ);
 
    FreeFile(file);
 
    return buf;
}

References AllocateFile(), Assert(), buf, StringInfoData::data, enlargeStringInfo(), ereport, errcode(), errcode_for_file_access(), errmsg(), ERROR, filename, FreeFile(), fseeko, initStringInfo(), StringInfoData::len, MaxAllocSize, StringInfoData::maxlen, MIN_READ_SIZE, palloc(), PG_BINARY_R, SET_VARSIZE, VARDATA, and VARHDRSZ.

Referenced by pg_read_binary_file(), and read_text_file().

read_text_file()

static text* read_text_file ( const char *  filename, int64  seek_offset, int64  bytes_to_read, bool  missing_ok  )

static

Definition at line 211 of file genfile.c.

{
    bytea      *buf;
 
    buf = read_binary_file(filename, seek_offset, bytes_to_read, missing_ok);
 
    if (buf != NULL)
    {
        /* Make sure the input is valid */
        pg_verifymbstr(VARDATA(buf), VARSIZE(buf) - VARHDRSZ, false);
 
        /* OK, we can cast it to text safely */
        return (text *) buf;
    }
    else
        return NULL;
}

References buf, filename, pg_verifymbstr(), read_binary_file(), VARDATA, VARHDRSZ, and VARSIZE.

Referenced by pg_read_file(), and pg_read_file_v2().