tablespace.c

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/*
 *  tablespace.c
 *
 *  tablespace functions
 *
 *  Copyright (c) 2010-2013, PostgreSQL Global Development Group
 *  contrib/pg_upgrade/tablespace.c
 */

#include "postgres_fe.h"

#include "pg_upgrade.h"

static void get_tablespace_paths(void);
static void set_tablespace_directory_suffix(ClusterInfo *cluster);


void
init_tablespaces(void)
{
    get_tablespace_paths();

    set_tablespace_directory_suffix(&old_cluster);
    set_tablespace_directory_suffix(&new_cluster);

    if (os_info.num_old_tablespaces > 0 &&
    strcmp(old_cluster.tablespace_suffix, new_cluster.tablespace_suffix) == 0)
        pg_log(PG_FATAL,
               "Cannot upgrade to/from the same system catalog version when\n"
               "using tablespaces.\n");
}


/*
 * get_tablespace_paths()
 *
 * Scans pg_tablespace and returns a malloc'ed array of all tablespace
 * paths. Its the caller's responsibility to free the array.
 */
static void
get_tablespace_paths(void)
{
    PGconn     *conn = connectToServer(&old_cluster, "template1");
    PGresult   *res;
    int         tblnum;
    int         i_spclocation;
    char        query[QUERY_ALLOC];

    snprintf(query, sizeof(query),
             "SELECT    %s "
             "FROM  pg_catalog.pg_tablespace "
             "WHERE spcname != 'pg_default' AND "
             "      spcname != 'pg_global'",
    /* 9.2 removed the spclocation column */
             (GET_MAJOR_VERSION(old_cluster.major_version) <= 901) ?
    "spclocation" : "pg_catalog.pg_tablespace_location(oid) AS spclocation");

    res = executeQueryOrDie(conn, "%s", query);

    if ((os_info.num_old_tablespaces = PQntuples(res)) != 0)
        os_info.old_tablespaces = (char **) pg_malloc(
                                   os_info.num_old_tablespaces * sizeof(char *));
    else
        os_info.old_tablespaces = NULL;

    i_spclocation = PQfnumber(res, "spclocation");

    for (tblnum = 0; tblnum < os_info.num_old_tablespaces; tblnum++)
        os_info.old_tablespaces[tblnum] = pg_strdup(
                                     PQgetvalue(res, tblnum, i_spclocation));

    PQclear(res);

    PQfinish(conn);

    return;
}


static void
set_tablespace_directory_suffix(ClusterInfo *cluster)
{
    if (GET_MAJOR_VERSION(cluster->major_version) <= 804)
        cluster->tablespace_suffix = pg_strdup("");
    else
    {
        /* This cluster has a version-specific subdirectory */
        cluster->tablespace_suffix = pg_malloc(4 +
                                         strlen(cluster->major_version_str) +
                                               10 /* OIDCHARS */ + 1);

        /* The leading slash is needed to start a new directory. */
        sprintf(cluster->tablespace_suffix, "/PG_%s_%d", cluster->major_version_str,
                cluster->controldata.cat_ver);
    }
}