common.c File Reference

#include "postgres_fe.h"
#include <signal.h>
#include <unistd.h>
#include "common.h"
#include "common/connect.h"
#include "common/logging.h"
#include "common/string.h"
#include "fe_utils/cancel.h"
#include "fe_utils/string_utils.h"

Include dependency graph for common.c:

Go to the source code of this file.

Macros
#define	ERRCODE_UNDEFINED_TABLE   "42P01"
#define	PG_YESLETTER   gettext_noop("y")
#define	PG_NOLETTER   gettext_noop("n")

Functions
void	handle_help_version_opts (int argc, char *argv[], const char *fixed_progname, help_handler hlp)
PGconn *	connectDatabase (const ConnParams *cparams, const char *progname, bool echo, bool fail_ok, bool allow_password_reuse)
PGconn *	connectMaintenanceDatabase (ConnParams *cparams, const char *progname, bool echo)
void	disconnectDatabase (PGconn *conn)
PGresult *	executeQuery (PGconn *conn, const char *query, bool echo)
void	executeCommand (PGconn *conn, const char *query, bool echo)
bool	executeMaintenanceCommand (PGconn *conn, const char *query, bool echo)
bool	consumeQueryResult (PGconn *conn)
bool	processQueryResult (PGconn *conn, PGresult *result)
void	splitTableColumnsSpec (const char *spec, int encoding, char **table, const char **columns)
void	appendQualifiedRelation (PQExpBuffer buf, const char *spec, PGconn *conn, bool echo)
bool	yesno_prompt (const char *question)

Macro Definition Documentation

ERRCODE_UNDEFINED_TABLE

#define ERRCODE_UNDEFINED_TABLE   "42P01"

Definition at line 27 of file common.c.

Referenced by processQueryResult().

PG_NOLETTER

#define PG_NOLETTER   gettext_noop("n")

Definition at line 450 of file common.c.

Referenced by yesno_prompt().

PG_YESLETTER

#define PG_YESLETTER   gettext_noop("y")

Definition at line 448 of file common.c.

Referenced by yesno_prompt().

Function Documentation

appendQualifiedRelation()

void appendQualifiedRelation	(	PQExpBuffer	buf,
		const char *	spec,
		PGconn *	conn,
		bool	echo
	)

Definition at line 386 of file common.c.

References ALWAYS_SECURE_SEARCH_PATH_SQL, appendPQExpBufferStr(), appendStringLiteralConn(), PQExpBufferData::data, executeCommand(), executeQuery(), fmtQualifiedId(), initPQExpBuffer(), ngettext, pg_free(), pg_log_error, PQclear(), PQclientEncoding(), PQfinish(), PQgetvalue(), PQntuples(), splitTableColumnsSpec(), and termPQExpBuffer().

Referenced by cluster_one_database(), and run_reindex_command().

{
    char       *table;
    const char *columns;
    PQExpBufferData sql;
    PGresult   *res;
    int         ntups;

    splitTableColumnsSpec(spec, PQclientEncoding(conn), &table, &columns);

    /*
     * Query must remain ABSOLUTELY devoid of unqualified names.  This would
     * be unnecessary given a regclassin() variant taking a search_path
     * argument.
     */
    initPQExpBuffer(&sql);
    appendPQExpBufferStr(&sql,
                         "SELECT c.relname, ns.nspname\n"
                         " FROM pg_catalog.pg_class c,"
                         " pg_catalog.pg_namespace ns\n"
                         " WHERE c.relnamespace OPERATOR(pg_catalog.=) ns.oid\n"
                         "  AND c.oid OPERATOR(pg_catalog.=) ");
    appendStringLiteralConn(&sql, table, conn);
    appendPQExpBufferStr(&sql, "::pg_catalog.regclass;");

    executeCommand(conn, "RESET search_path;", echo);

    /*
     * One row is a typical result, as is a nonexistent relation ERROR.
     * regclassin() unconditionally accepts all-digits input as an OID; if no
     * relation has that OID; this query returns no rows.  Catalog corruption
     * might elicit other row counts.
     */
    res = executeQuery(conn, sql.data, echo);
    ntups = PQntuples(res);
    if (ntups != 1)
    {
        pg_log_error(ngettext("query returned %d row instead of one: %s",
                              "query returned %d rows instead of one: %s",
                              ntups),
                     ntups, sql.data);
        PQfinish(conn);
        exit(1);
    }
    appendPQExpBufferStr(buf,
                         fmtQualifiedId(PQgetvalue(res, 0, 1),
                                        PQgetvalue(res, 0, 0)));
    appendPQExpBufferStr(buf, columns);
    PQclear(res);
    termPQExpBuffer(&sql);
    pg_free(table);

    PQclear(executeQuery(conn, ALWAYS_SECURE_SEARCH_PATH_SQL, echo));
}

connectDatabase()

PGconn* connectDatabase	(	const ConnParams *	cparams,
		const char *	progname,
		bool	echo,
		bool	fail_ok,
		bool	allow_password_reuse
	)

Definition at line 65 of file common.c.

References ALWAYS_SECURE_SEARCH_PATH_SQL, Assert, conn, CONNECTION_BAD, _connParams::dbname, executeQuery(), free, i, lengthof, _connParams::override_dbname, password, pg_log_error, _connParams::pghost, _connParams::pgport, _connParams::pguser, PQclear(), PQconnectdbParams(), PQconnectionNeedsPassword(), PQerrorMessage(), PQfinish(), PQstatus(), progname, _connParams::prompt_password, simple_prompt(), TRI_NO, TRI_YES, and values.

Referenced by connectMaintenanceDatabase().

{
    PGconn     *conn;
    bool        new_pass;
    static char *password = NULL;

    /* Callers must supply at least dbname; other params can be NULL */
    Assert(cparams->dbname);

    if (!allow_password_reuse && password)
    {
        free(password);
        password = NULL;
    }

    if (cparams->prompt_password == TRI_YES && password == NULL)
        password = simple_prompt("Password: ", false);

    /*
     * Start the connection.  Loop until we have a password if requested by
     * backend.
     */
    do
    {
        const char *keywords[8];
        const char *values[8];
        int         i = 0;

        /*
         * If dbname is a connstring, its entries can override the other
         * values obtained from cparams; but in turn, override_dbname can
         * override the dbname component of it.
         */
        keywords[i] = "host";
        values[i++] = cparams->pghost;
        keywords[i] = "port";
        values[i++] = cparams->pgport;
        keywords[i] = "user";
        values[i++] = cparams->pguser;
        keywords[i] = "password";
        values[i++] = password;
        keywords[i] = "dbname";
        values[i++] = cparams->dbname;
        if (cparams->override_dbname)
        {
            keywords[i] = "dbname";
            values[i++] = cparams->override_dbname;
        }
        keywords[i] = "fallback_application_name";
        values[i++] = progname;
        keywords[i] = NULL;
        values[i++] = NULL;
        Assert(i <= lengthof(keywords));

        new_pass = false;
        conn = PQconnectdbParams(keywords, values, true);

        if (!conn)
        {
            pg_log_error("could not connect to database %s: out of memory",
                         cparams->dbname);
            exit(1);
        }

        /*
         * No luck?  Trying asking (again) for a password.
         */
        if (PQstatus(conn) == CONNECTION_BAD &&
            PQconnectionNeedsPassword(conn) &&
            cparams->prompt_password != TRI_NO)
        {
            PQfinish(conn);
            if (password)
                free(password);
            password = simple_prompt("Password: ", false);
            new_pass = true;
        }
    } while (new_pass);

    /* check to see that the backend connection was successfully made */
    if (PQstatus(conn) == CONNECTION_BAD)
    {
        if (fail_ok)
        {
            PQfinish(conn);
            return NULL;
        }
        pg_log_error("could not connect to database %s: %s",
                     cparams->dbname, PQerrorMessage(conn));
        exit(1);
    }

    /* Start strict; callers may override this. */
    PQclear(executeQuery(conn, ALWAYS_SECURE_SEARCH_PATH_SQL, echo));

    return conn;
}

connectMaintenanceDatabase()

PGconn* connectMaintenanceDatabase	(	ConnParams *	cparams,
		const char *	progname,
		bool	echo
	)

Definition at line 173 of file common.c.

References conn, connectDatabase(), and _connParams::dbname.

Referenced by cluster_all_databases(), main(), reindex_all_databases(), and vacuum_all_databases().

{
    PGconn     *conn;

    /* If a maintenance database name was specified, just connect to it. */
    if (cparams->dbname)
        return connectDatabase(cparams, progname, echo, false, false);

    /* Otherwise, try postgres first and then template1. */
    cparams->dbname = "postgres";
    conn = connectDatabase(cparams, progname, echo, true, false);
    if (!conn)
    {
        cparams->dbname = "template1";
        conn = connectDatabase(cparams, progname, echo, false, false);
    }
    return conn;
}

consumeQueryResult()

bool consumeQueryResult

(

PGconn *

conn

)

Definition at line 299 of file common.c.

References PQgetResult(), processQueryResult(), ResetCancelConn(), and SetCancelConn().

Referenced by ParallelSlotsWaitCompletion().

{
    bool        ok = true;
    PGresult   *result;

    SetCancelConn(conn);
    while ((result = PQgetResult(conn)) != NULL)
    {
        if (!processQueryResult(conn, result))
            ok = false;
    }
    ResetCancelConn();
    return ok;
}

disconnectDatabase()

void disconnectDatabase

(

PGconn *

conn

)

Definition at line 197 of file common.c.

References Assert, PQcancel(), PQfinish(), PQfreeCancel(), PQgetCancel(), PQTRANS_ACTIVE, and PQtransactionStatus().

Referenced by ParallelSlotsTerminate().

{
    char        errbuf[256];

    Assert(conn != NULL);

    if (PQtransactionStatus(conn) == PQTRANS_ACTIVE)
    {
        PGcancel   *cancel;

        if ((cancel = PQgetCancel(conn)))
        {
            (void) PQcancel(cancel, errbuf, sizeof(errbuf));
            PQfreeCancel(cancel);
        }
    }

    PQfinish(conn);
}

executeCommand()

void executeCommand	(	PGconn *	conn,
		const char *	query,
		bool	echo
	)

Definition at line 246 of file common.c.

References pg_log_error, pg_log_info, PGRES_COMMAND_OK, PQclear(), PQerrorMessage(), PQexec(), PQfinish(), PQresultStatus(), and printf.

Referenced by appendQualifiedRelation().

{
    PGresult   *res;

    if (echo)
        printf("%s\n", query);

    res = PQexec(conn, query);
    if (!res ||
        PQresultStatus(res) != PGRES_COMMAND_OK)
    {
        pg_log_error("query failed: %s", PQerrorMessage(conn));
        pg_log_info("query was: %s", query);
        PQfinish(conn);
        exit(1);
    }

    PQclear(res);
}

executeMaintenanceCommand()

bool executeMaintenanceCommand	(	PGconn *	conn,
		const char *	query,
		bool	echo
	)

Definition at line 273 of file common.c.

References PGRES_COMMAND_OK, PQclear(), PQexec(), PQresultStatus(), printf, ResetCancelConn(), and SetCancelConn().

Referenced by cluster_one_database(), and run_reindex_command().

{
    PGresult   *res;
    bool        r;

    if (echo)
        printf("%s\n", query);

    SetCancelConn(conn);
    res = PQexec(conn, query);
    ResetCancelConn();

    r = (res && PQresultStatus(res) == PGRES_COMMAND_OK);

    if (res)
        PQclear(res);

    return r;
}

executeQuery()

PGresult* executeQuery	(	PGconn *	conn,
		const char *	query,
		bool	echo
	)

Definition at line 221 of file common.c.

References pg_log_error, pg_log_info, PGRES_TUPLES_OK, PQerrorMessage(), PQexec(), PQfinish(), PQresultStatus(), and printf.

Referenced by appendQualifiedRelation(), and connectDatabase().

{
    PGresult   *res;

    if (echo)
        printf("%s\n", query);

    res = PQexec(conn, query);
    if (!res ||
        PQresultStatus(res) != PGRES_TUPLES_OK)
    {
        pg_log_error("query failed: %s", PQerrorMessage(conn));
        pg_log_info("query was: %s", query);
        PQfinish(conn);
        exit(1);
    }

    return res;
}

handle_help_version_opts()

void handle_help_version_opts	(	int	argc,
		char *	argv[],
		const char *	fixed_progname,
		help_handler	hlp
	)

Definition at line 34 of file common.c.

References get_progname(), and printf.

Referenced by main().

{
    if (argc > 1)
    {
        if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
        {
            hlp(get_progname(argv[0]));
            exit(0);
        }
        if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
        {
            printf("%s (PostgreSQL) " PG_VERSION "\n", fixed_progname);
            exit(0);
        }
    }
}

processQueryResult()

bool processQueryResult	(	PGconn *	conn,
		PGresult *	result
	)

Definition at line 320 of file common.c.

References ERRCODE_UNDEFINED_TABLE, PG_DIAG_SQLSTATE, pg_log_error, PGRES_COMMAND_OK, PQclear(), PQdb(), PQerrorMessage(), PQresultErrorField(), and PQresultStatus().

Referenced by consumeQueryResult(), and ParallelSlotsGetIdle().

{
    /*
     * If it's an error, report it.  Errors about a missing table are harmless
     * so we continue processing; but die for other errors.
     */
    if (PQresultStatus(result) != PGRES_COMMAND_OK)
    {
        char       *sqlState = PQresultErrorField(result, PG_DIAG_SQLSTATE);

        pg_log_error("processing of database \"%s\" failed: %s",
                     PQdb(conn), PQerrorMessage(conn));

        if (sqlState && strcmp(sqlState, ERRCODE_UNDEFINED_TABLE) != 0)
        {
            PQclear(result);
            return false;
        }
    }

    PQclear(result);
    return true;
}

splitTableColumnsSpec()

void splitTableColumnsSpec	(	const char *	spec,
		int	encoding,
		char **	table,
		const char **	columns
	)

Definition at line 351 of file common.c.

References pnstrdup(), and PQmblen().

Referenced by appendQualifiedRelation(), and vacuum_one_database().

{
    bool        inquotes = false;
    const char *cp = spec;

    /*
     * Find the first '(' not identifier-quoted.  Based on
     * dequote_downcase_identifier().
     */
    while (*cp && (*cp != '(' || inquotes))
    {
        if (*cp == '"')
        {
            if (inquotes && cp[1] == '"')
                cp++;           /* pair does not affect quoting */
            else
                inquotes = !inquotes;
            cp++;
        }
        else
            cp += PQmblen(cp, encoding);
    }
    *table = pnstrdup(spec, cp - spec);
    *columns = cp;
}

yesno_prompt()

bool yesno_prompt

(

const char *

question

)

Definition at line 453 of file common.c.

References _, free, PG_NOLETTER, PG_YESLETTER, printf, simple_prompt(), and snprintf.

Referenced by main().

{
    char        prompt[256];

    /*------
       translator: This is a question followed by the translated options for
       "yes" and "no". */
    snprintf(prompt, sizeof(prompt), _("%s (%s/%s) "),
             _(question), _(PG_YESLETTER), _(PG_NOLETTER));

    for (;;)
    {
        char       *resp;

        resp = simple_prompt(prompt, true);

        if (strcmp(resp, _(PG_YESLETTER)) == 0)
        {
            free(resp);
            return true;
        }
        if (strcmp(resp, _(PG_NOLETTER)) == 0)
        {
            free(resp);
            return false;
        }
        free(resp);

        printf(_("Please answer \"%s\" or \"%s\".\n"),
               _(PG_YESLETTER), _(PG_NOLETTER));
    }
}