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Data Structures | Defines | Typedefs | Functions | Variables

dblink.c File Reference

#include "postgres.h"
#include <limits.h>
#include "libpq-fe.h"
#include "access/htup_details.h"
#include "access/reloptions.h"
#include "catalog/indexing.h"
#include "catalog/namespace.h"
#include "catalog/pg_foreign_server.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
#include "executor/spi.h"
#include "foreign/foreign.h"
#include "funcapi.h"
#include "lib/stringinfo.h"
#include "mb/pg_wchar.h"
#include "miscadmin.h"
#include "parser/scansup.h"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#include "utils/guc.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/rel.h"
#include "utils/tqual.h"
#include "dblink.h"
Include dependency graph for dblink.c:

Go to the source code of this file.

Data Structures

struct  remoteConn
struct  storeInfo
struct  remoteConnHashEnt

Defines

#define NUMCONN   16
#define xpfree(var_)
#define xpstrdup(var_c, var_)
#define DBLINK_RES_INTERNALERROR(p2)
#define DBLINK_CONN_NOT_AVAIL
#define DBLINK_GET_CONN
#define DBLINK_GET_NAMED_CONN
#define DBLINK_INIT
#define DBLINK_NOTIFY_COLS   3

Typedefs

typedef struct remoteConn remoteConn
typedef struct storeInfo storeInfo
typedef struct remoteConnHashEnt remoteConnHashEnt

Functions

static Datum dblink_record_internal (FunctionCallInfo fcinfo, bool is_async)
static void prepTuplestoreResult (FunctionCallInfo fcinfo)
static void materializeResult (FunctionCallInfo fcinfo, PGconn *conn, PGresult *res)
static void materializeQueryResult (FunctionCallInfo fcinfo, PGconn *conn, const char *conname, const char *sql, bool fail)
static PGresultstoreQueryResult (storeInfo *sinfo, PGconn *conn, const char *sql)
static void storeRow (storeInfo *sinfo, PGresult *res, bool first)
static remoteConngetConnectionByName (const char *name)
static HTABcreateConnHash (void)
static void createNewConnection (const char *name, remoteConn *rconn)
static void deleteConnection (const char *name)
static char ** get_pkey_attnames (Relation rel, int16 *numatts)
static char ** get_text_array_contents (ArrayType *array, int *numitems)
static char * get_sql_insert (Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals, char **tgt_pkattvals)
static char * get_sql_delete (Relation rel, int *pkattnums, int pknumatts, char **tgt_pkattvals)
static char * get_sql_update (Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals, char **tgt_pkattvals)
static char * quote_ident_cstr (char *rawstr)
static int get_attnum_pk_pos (int *pkattnums, int pknumatts, int key)
static HeapTuple get_tuple_of_interest (Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals)
static Relation get_rel_from_relname (text *relname_text, LOCKMODE lockmode, AclMode aclmode)
static char * generate_relation_name (Relation rel)
static void dblink_connstr_check (const char *connstr)
static void dblink_security_check (PGconn *conn, remoteConn *rconn)
static void dblink_res_error (const char *conname, PGresult *res, const char *dblink_context_msg, bool fail)
static char * get_connect_string (const char *servername)
static char * escape_param_str (const char *from)
static void validate_pkattnums (Relation rel, int2vector *pkattnums_arg, int32 pknumatts_arg, int **pkattnums, int *pknumatts)
static bool is_valid_dblink_option (const PQconninfoOption *options, const char *option, Oid context)
static int applyRemoteGucs (PGconn *conn)
static void restoreLocalGucs (int nestlevel)
 PG_FUNCTION_INFO_V1 (dblink_connect)
Datum dblink_connect (PG_FUNCTION_ARGS)
 PG_FUNCTION_INFO_V1 (dblink_disconnect)
Datum dblink_disconnect (PG_FUNCTION_ARGS)
 PG_FUNCTION_INFO_V1 (dblink_open)
Datum dblink_open (PG_FUNCTION_ARGS)
 PG_FUNCTION_INFO_V1 (dblink_close)
Datum dblink_close (PG_FUNCTION_ARGS)
 PG_FUNCTION_INFO_V1 (dblink_fetch)
Datum dblink_fetch (PG_FUNCTION_ARGS)
 PG_FUNCTION_INFO_V1 (dblink_record)
Datum dblink_record (PG_FUNCTION_ARGS)
 PG_FUNCTION_INFO_V1 (dblink_send_query)
Datum dblink_send_query (PG_FUNCTION_ARGS)
 PG_FUNCTION_INFO_V1 (dblink_get_result)
Datum dblink_get_result (PG_FUNCTION_ARGS)
 PG_FUNCTION_INFO_V1 (dblink_get_connections)
Datum dblink_get_connections (PG_FUNCTION_ARGS)
 PG_FUNCTION_INFO_V1 (dblink_is_busy)
Datum dblink_is_busy (PG_FUNCTION_ARGS)
 PG_FUNCTION_INFO_V1 (dblink_cancel_query)
Datum dblink_cancel_query (PG_FUNCTION_ARGS)
 PG_FUNCTION_INFO_V1 (dblink_error_message)
Datum dblink_error_message (PG_FUNCTION_ARGS)
 PG_FUNCTION_INFO_V1 (dblink_exec)
Datum dblink_exec (PG_FUNCTION_ARGS)
 PG_FUNCTION_INFO_V1 (dblink_get_pkey)
Datum dblink_get_pkey (PG_FUNCTION_ARGS)
 PG_FUNCTION_INFO_V1 (dblink_build_sql_insert)
Datum dblink_build_sql_insert (PG_FUNCTION_ARGS)
 PG_FUNCTION_INFO_V1 (dblink_build_sql_delete)
Datum dblink_build_sql_delete (PG_FUNCTION_ARGS)
 PG_FUNCTION_INFO_V1 (dblink_build_sql_update)
Datum dblink_build_sql_update (PG_FUNCTION_ARGS)
 PG_FUNCTION_INFO_V1 (dblink_current_query)
Datum dblink_current_query (PG_FUNCTION_ARGS)
 PG_FUNCTION_INFO_V1 (dblink_get_notify)
Datum dblink_get_notify (PG_FUNCTION_ARGS)
 PG_FUNCTION_INFO_V1 (dblink_fdw_validator)
Datum dblink_fdw_validator (PG_FUNCTION_ARGS)

Variables

 PG_MODULE_MAGIC
static remoteConnpconn = NULL
static HTABremoteConnHash = NULL

Define Documentation

#define DBLINK_CONN_NOT_AVAIL
Value:
do { \
        if(conname) \
            ereport(ERROR, \
                    (errcode(ERRCODE_CONNECTION_DOES_NOT_EXIST), \
                     errmsg("connection \"%s\" not available", conname))); \
        else \
            ereport(ERROR, \
                    (errcode(ERRCODE_CONNECTION_DOES_NOT_EXIST), \
                     errmsg("connection not available"))); \
    } while (0)

Definition at line 172 of file dblink.c.

#define DBLINK_GET_CONN

Definition at line 184 of file dblink.c.

#define DBLINK_GET_NAMED_CONN
Value:
do { \
            conname = text_to_cstring(PG_GETARG_TEXT_PP(0)); \
            rconn = getConnectionByName(conname); \
            if (rconn) \
                conn = rconn->conn; \
            else \
                DBLINK_CONN_NOT_AVAIL; \
    } while (0)

Definition at line 217 of file dblink.c.

Referenced by dblink_get_notify().

#define DBLINK_INIT
Value:
do { \
            if (!pconn) \
            { \
                pconn = (remoteConn *) MemoryContextAlloc(TopMemoryContext, sizeof(remoteConn)); \
                pconn->conn = NULL; \
                pconn->openCursorCount = 0; \
                pconn->newXactForCursor = FALSE; \
            } \
    } while (0)

Definition at line 227 of file dblink.c.

#define DBLINK_NOTIFY_COLS   3

Definition at line 1870 of file dblink.c.

Referenced by dblink_get_notify().

#define DBLINK_RES_INTERNALERROR (   p2  ) 
Value:
do { \
            msg = pstrdup(PQerrorMessage(conn)); \
            if (res) \
                PQclear(res); \
            elog(ERROR, "%s: %s", p2, msg); \
    } while (0)

Definition at line 164 of file dblink.c.

Referenced by dblink_close(), and dblink_open().

#define NUMCONN   16

Definition at line 144 of file dblink.c.

Referenced by createConnHash().

#define xpfree (   var_  ) 
Value:
do { \
        if (var_ != NULL) \
        { \
            pfree(var_); \
            var_ = NULL; \
        } \
    } while (0)

Definition at line 147 of file dblink.c.

#define xpstrdup (   var_c,
  var_ 
)
Value:
do { \
        if (var_ != NULL) \
            var_c = pstrdup(var_); \
        else \
            var_c = NULL; \
    } while (0)

Definition at line 156 of file dblink.c.

Referenced by dblink_res_error().


Typedef Documentation

typedef struct remoteConn remoteConn
typedef struct storeInfo storeInfo

Function Documentation

static int applyRemoteGucs ( PGconn conn  )  [static]

Definition at line 2938 of file dblink.c.

References Assert, GetConfigOption(), GUC_ACTION_SAVE, i, lengthof, NewGUCNestLevel(), NULL, PGC_S_SESSION, PGC_USERSET, PQparameterStatus(), and set_config_option().

Referenced by materializeResult(), and storeQueryResult().

{
    static const char *const GUCsAffectingIO[] = {
        "DateStyle",
        "IntervalStyle"
    };

    int         nestlevel = -1;
    int         i;

    for (i = 0; i < lengthof(GUCsAffectingIO); i++)
    {
        const char *gucName = GUCsAffectingIO[i];
        const char *remoteVal = PQparameterStatus(conn, gucName);
        const char *localVal;

        /*
         * If the remote server is pre-8.4, it won't have IntervalStyle, but
         * that's okay because its output format won't be ambiguous.  So just
         * skip the GUC if we don't get a value for it.  (We might eventually
         * need more complicated logic with remote-version checks here.)
         */
        if (remoteVal == NULL)
            continue;

        /*
         * Avoid GUC-setting overhead if the remote and local GUCs already
         * have the same value.
         */
        localVal = GetConfigOption(gucName, false, false);
        Assert(localVal != NULL);

        if (strcmp(remoteVal, localVal) == 0)
            continue;

        /* Create new GUC nest level if we didn't already */
        if (nestlevel < 0)
            nestlevel = NewGUCNestLevel();

        /* Apply the option (this will throw error on failure) */
        (void) set_config_option(gucName, remoteVal,
                                 PGC_USERSET, PGC_S_SESSION,
                                 GUC_ACTION_SAVE, true, 0);
    }

    return nestlevel;
}

static HTAB * createConnHash ( void   )  [static]

Definition at line 2542 of file dblink.c.

References HASHCTL::entrysize, hash_create(), HASH_ELEM, HASHCTL::keysize, and NUMCONN.

Referenced by createNewConnection(), deleteConnection(), and getConnectionByName().

{
    HASHCTL     ctl;

    ctl.keysize = NAMEDATALEN;
    ctl.entrysize = sizeof(remoteConnHashEnt);

    return hash_create("Remote Con hash", NUMCONN, &ctl, HASH_ELEM);
}

static void createNewConnection ( const char *  name,
remoteConn rconn 
) [static]

Definition at line 2553 of file dblink.c.

References remoteConn::conn, createConnHash(), ereport, errcode(), errmsg(), ERROR, HASH_ENTER, hash_search(), remoteConnHashEnt::name, pfree(), PQfinish(), pstrdup(), remoteConnHashEnt::rconn, strlcpy(), and truncate_identifier().

Referenced by dblink_connect().

{
    remoteConnHashEnt *hentry;
    bool        found;
    char       *key;

    if (!remoteConnHash)
        remoteConnHash = createConnHash();

    key = pstrdup(name);
    truncate_identifier(key, strlen(key), true);
    hentry = (remoteConnHashEnt *) hash_search(remoteConnHash, key,
                                               HASH_ENTER, &found);

    if (found)
    {
        PQfinish(rconn->conn);
        pfree(rconn);

        ereport(ERROR,
                (errcode(ERRCODE_DUPLICATE_OBJECT),
                 errmsg("duplicate connection name")));
    }

    hentry->rconn = rconn;
    strlcpy(hentry->name, name, sizeof(hentry->name));
}

Datum dblink_build_sql_delete ( PG_FUNCTION_ARGS   ) 

Definition at line 1698 of file dblink.c.

References AccessShareLock, ACL_SELECT, cstring_to_text(), ereport, errcode(), errmsg(), ERROR, get_rel_from_relname(), get_sql_delete(), get_text_array_contents(), PG_GETARG_ARRAYTYPE_P, PG_GETARG_INT32, PG_GETARG_POINTER, PG_GETARG_TEXT_P, PG_RETURN_TEXT_P, relation_close(), and validate_pkattnums().

{
    text       *relname_text = PG_GETARG_TEXT_P(0);
    int2vector *pkattnums_arg = (int2vector *) PG_GETARG_POINTER(1);
    int32       pknumatts_arg = PG_GETARG_INT32(2);
    ArrayType  *tgt_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(3);
    Relation    rel;
    int        *pkattnums;
    int         pknumatts;
    char      **tgt_pkattvals;
    int         tgt_nitems;
    char       *sql;

    /*
     * Open target relation.
     */
    rel = get_rel_from_relname(relname_text, AccessShareLock, ACL_SELECT);

    /*
     * Process pkattnums argument.
     */
    validate_pkattnums(rel, pkattnums_arg, pknumatts_arg,
                       &pkattnums, &pknumatts);

    /*
     * Target array is made up of key values that will be used to build the
     * SQL string for use on the remote system.
     */
    tgt_pkattvals = get_text_array_contents(tgt_pkattvals_arry, &tgt_nitems);

    /*
     * There should be one target array key value for each key attnum
     */
    if (tgt_nitems != pknumatts)
        ereport(ERROR,
                (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
                 errmsg("target key array length must match number of key " \
                        "attributes")));

    /*
     * Prep work is finally done. Go get the SQL string.
     */
    sql = get_sql_delete(rel, pkattnums, pknumatts, tgt_pkattvals);

    /*
     * Now we can close the relation.
     */
    relation_close(rel, AccessShareLock);

    /*
     * And send it
     */
    PG_RETURN_TEXT_P(cstring_to_text(sql));
}

Datum dblink_build_sql_insert ( PG_FUNCTION_ARGS   ) 

Definition at line 1607 of file dblink.c.

References AccessShareLock, ACL_SELECT, cstring_to_text(), ereport, errcode(), errmsg(), ERROR, get_rel_from_relname(), get_sql_insert(), get_text_array_contents(), PG_GETARG_ARRAYTYPE_P, PG_GETARG_INT32, PG_GETARG_POINTER, PG_GETARG_TEXT_P, PG_RETURN_TEXT_P, relation_close(), and validate_pkattnums().

{
    text       *relname_text = PG_GETARG_TEXT_P(0);
    int2vector *pkattnums_arg = (int2vector *) PG_GETARG_POINTER(1);
    int32       pknumatts_arg = PG_GETARG_INT32(2);
    ArrayType  *src_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(3);
    ArrayType  *tgt_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(4);
    Relation    rel;
    int        *pkattnums;
    int         pknumatts;
    char      **src_pkattvals;
    char      **tgt_pkattvals;
    int         src_nitems;
    int         tgt_nitems;
    char       *sql;

    /*
     * Open target relation.
     */
    rel = get_rel_from_relname(relname_text, AccessShareLock, ACL_SELECT);

    /*
     * Process pkattnums argument.
     */
    validate_pkattnums(rel, pkattnums_arg, pknumatts_arg,
                       &pkattnums, &pknumatts);

    /*
     * Source array is made up of key values that will be used to locate the
     * tuple of interest from the local system.
     */
    src_pkattvals = get_text_array_contents(src_pkattvals_arry, &src_nitems);

    /*
     * There should be one source array key value for each key attnum
     */
    if (src_nitems != pknumatts)
        ereport(ERROR,
                (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
                 errmsg("source key array length must match number of key " \
                        "attributes")));

    /*
     * Target array is made up of key values that will be used to build the
     * SQL string for use on the remote system.
     */
    tgt_pkattvals = get_text_array_contents(tgt_pkattvals_arry, &tgt_nitems);

    /*
     * There should be one target array key value for each key attnum
     */
    if (tgt_nitems != pknumatts)
        ereport(ERROR,
                (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
                 errmsg("target key array length must match number of key " \
                        "attributes")));

    /*
     * Prep work is finally done. Go get the SQL string.
     */
    sql = get_sql_insert(rel, pkattnums, pknumatts, src_pkattvals, tgt_pkattvals);

    /*
     * Now we can close the relation.
     */
    relation_close(rel, AccessShareLock);

    /*
     * And send it
     */
    PG_RETURN_TEXT_P(cstring_to_text(sql));
}

Datum dblink_build_sql_update ( PG_FUNCTION_ARGS   ) 

Definition at line 1775 of file dblink.c.

References AccessShareLock, ACL_SELECT, cstring_to_text(), ereport, errcode(), errmsg(), ERROR, get_rel_from_relname(), get_sql_update(), get_text_array_contents(), PG_GETARG_ARRAYTYPE_P, PG_GETARG_INT32, PG_GETARG_POINTER, PG_GETARG_TEXT_P, PG_RETURN_TEXT_P, relation_close(), and validate_pkattnums().

{
    text       *relname_text = PG_GETARG_TEXT_P(0);
    int2vector *pkattnums_arg = (int2vector *) PG_GETARG_POINTER(1);
    int32       pknumatts_arg = PG_GETARG_INT32(2);
    ArrayType  *src_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(3);
    ArrayType  *tgt_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(4);
    Relation    rel;
    int        *pkattnums;
    int         pknumatts;
    char      **src_pkattvals;
    char      **tgt_pkattvals;
    int         src_nitems;
    int         tgt_nitems;
    char       *sql;

    /*
     * Open target relation.
     */
    rel = get_rel_from_relname(relname_text, AccessShareLock, ACL_SELECT);

    /*
     * Process pkattnums argument.
     */
    validate_pkattnums(rel, pkattnums_arg, pknumatts_arg,
                       &pkattnums, &pknumatts);

    /*
     * Source array is made up of key values that will be used to locate the
     * tuple of interest from the local system.
     */
    src_pkattvals = get_text_array_contents(src_pkattvals_arry, &src_nitems);

    /*
     * There should be one source array key value for each key attnum
     */
    if (src_nitems != pknumatts)
        ereport(ERROR,
                (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
                 errmsg("source key array length must match number of key " \
                        "attributes")));

    /*
     * Target array is made up of key values that will be used to build the
     * SQL string for use on the remote system.
     */
    tgt_pkattvals = get_text_array_contents(tgt_pkattvals_arry, &tgt_nitems);

    /*
     * There should be one target array key value for each key attnum
     */
    if (tgt_nitems != pknumatts)
        ereport(ERROR,
                (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
                 errmsg("target key array length must match number of key " \
                        "attributes")));

    /*
     * Prep work is finally done. Go get the SQL string.
     */
    sql = get_sql_update(rel, pkattnums, pknumatts, src_pkattvals, tgt_pkattvals);

    /*
     * Now we can close the relation.
     */
    relation_close(rel, AccessShareLock);

    /*
     * And send it
     */
    PG_RETURN_TEXT_P(cstring_to_text(sql));
}

Datum dblink_cancel_query ( PG_FUNCTION_ARGS   ) 

Definition at line 1315 of file dblink.c.

References conn, cstring_to_text(), PG_RETURN_TEXT_P, PQcancel(), PQfreeCancel(), and PQgetCancel().

{
    int         res = 0;
    char       *conname = NULL;
    PGconn     *conn = NULL;
    remoteConn *rconn = NULL;
    PGcancel   *cancel;
    char        errbuf[256];

    DBLINK_INIT;
    DBLINK_GET_NAMED_CONN;
    cancel = PQgetCancel(conn);

    res = PQcancel(cancel, errbuf, 256);
    PQfreeCancel(cancel);

    if (res == 1)
        PG_RETURN_TEXT_P(cstring_to_text("OK"));
    else
        PG_RETURN_TEXT_P(cstring_to_text(errbuf));
}

Datum dblink_close ( PG_FUNCTION_ARGS   ) 

Definition at line 441 of file dblink.c.

References appendStringInfo(), BOOLOID, buf, remoteConn::conn, conn, cstring_to_text(), StringInfoData::data, dblink_res_error(), DBLINK_RES_INTERNALERROR, get_fn_expr_argtype(), getConnectionByName(), initStringInfo(), remoteConn::newXactForCursor, remoteConn::openCursorCount, PG_GETARG_BOOL, PG_GETARG_TEXT_PP, PG_NARGS, PG_RETURN_TEXT_P, PGRES_COMMAND_OK, PQclear(), PQexec(), PQresultStatus(), and text_to_cstring().

{
    PGconn     *conn = NULL;
    PGresult   *res = NULL;
    char       *curname = NULL;
    char       *conname = NULL;
    StringInfoData buf;
    char       *msg;
    remoteConn *rconn = NULL;
    bool        fail = true;    /* default to backward compatible behavior */

    DBLINK_INIT;
    initStringInfo(&buf);

    if (PG_NARGS() == 1)
    {
        /* text */
        curname = text_to_cstring(PG_GETARG_TEXT_PP(0));
        rconn = pconn;
    }
    else if (PG_NARGS() == 2)
    {
        /* might be text,text or text,bool */
        if (get_fn_expr_argtype(fcinfo->flinfo, 1) == BOOLOID)
        {
            curname = text_to_cstring(PG_GETARG_TEXT_PP(0));
            fail = PG_GETARG_BOOL(1);
            rconn = pconn;
        }
        else
        {
            conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
            curname = text_to_cstring(PG_GETARG_TEXT_PP(1));
            rconn = getConnectionByName(conname);
        }
    }
    if (PG_NARGS() == 3)
    {
        /* text,text,bool */
        conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
        curname = text_to_cstring(PG_GETARG_TEXT_PP(1));
        fail = PG_GETARG_BOOL(2);
        rconn = getConnectionByName(conname);
    }

    if (!rconn || !rconn->conn)
        DBLINK_CONN_NOT_AVAIL;
    else
        conn = rconn->conn;

    appendStringInfo(&buf, "CLOSE %s", curname);

    /* close the cursor */
    res = PQexec(conn, buf.data);
    if (!res || PQresultStatus(res) != PGRES_COMMAND_OK)
    {
        dblink_res_error(conname, res, "could not close cursor", fail);
        PG_RETURN_TEXT_P(cstring_to_text("ERROR"));
    }

    PQclear(res);

    /* if we started a transaction, decrement cursor count */
    if (rconn->newXactForCursor)
    {
        (rconn->openCursorCount)--;

        /* if count is zero, commit the transaction */
        if (rconn->openCursorCount == 0)
        {
            rconn->newXactForCursor = FALSE;

            res = PQexec(conn, "COMMIT");
            if (PQresultStatus(res) != PGRES_COMMAND_OK)
                DBLINK_RES_INTERNALERROR("commit error");
            PQclear(res);
        }
    }

    PG_RETURN_TEXT_P(cstring_to_text("OK"));
}

Datum dblink_connect ( PG_FUNCTION_ARGS   ) 

Definition at line 243 of file dblink.c.

References remoteConn::conn, conn, CONNECTION_BAD, connstr, createNewConnection(), cstring_to_text(), dblink_connstr_check(), dblink_security_check(), ereport, errcode(), errdetail_internal(), errmsg(), ERROR, get_connect_string(), GetDatabaseEncodingName(), MemoryContextAlloc(), NULL, pfree(), PG_GETARG_TEXT_PP, PG_NARGS, PG_RETURN_TEXT_P, PQconnectdb(), PQerrorMessage(), PQfinish(), PQsetClientEncoding(), PQstatus(), pstrdup(), text_to_cstring(), and TopMemoryContext.

{
    char       *conname_or_str = NULL;
    char       *connstr = NULL;
    char       *connname = NULL;
    char       *msg;
    PGconn     *conn = NULL;
    remoteConn *rconn = NULL;

    DBLINK_INIT;

    if (PG_NARGS() == 2)
    {
        conname_or_str = text_to_cstring(PG_GETARG_TEXT_PP(1));
        connname = text_to_cstring(PG_GETARG_TEXT_PP(0));
    }
    else if (PG_NARGS() == 1)
        conname_or_str = text_to_cstring(PG_GETARG_TEXT_PP(0));

    if (connname)
        rconn = (remoteConn *) MemoryContextAlloc(TopMemoryContext,
                                                  sizeof(remoteConn));

    /* first check for valid foreign data server */
    connstr = get_connect_string(conname_or_str);
    if (connstr == NULL)
        connstr = conname_or_str;

    /* check password in connection string if not superuser */
    dblink_connstr_check(connstr);
    conn = PQconnectdb(connstr);

    if (PQstatus(conn) == CONNECTION_BAD)
    {
        msg = pstrdup(PQerrorMessage(conn));
        PQfinish(conn);
        if (rconn)
            pfree(rconn);

        ereport(ERROR,
                (errcode(ERRCODE_SQLCLIENT_UNABLE_TO_ESTABLISH_SQLCONNECTION),
                 errmsg("could not establish connection"),
                 errdetail_internal("%s", msg)));
    }

    /* check password actually used if not superuser */
    dblink_security_check(conn, rconn);

    /* attempt to set client encoding to match server encoding */
    PQsetClientEncoding(conn, GetDatabaseEncodingName());

    if (connname)
    {
        rconn->conn = conn;
        createNewConnection(connname, rconn);
    }
    else
        pconn->conn = conn;

    PG_RETURN_TEXT_P(cstring_to_text("OK"));
}

static void dblink_connstr_check ( const char *  connstr  )  [static]

Definition at line 2630 of file dblink.c.

References ereport, errcode(), errdetail(), errmsg(), ERROR, _PQconninfoOption::keyword, NULL, PQconninfoFree(), PQconninfoParse(), superuser(), and _PQconninfoOption::val.

Referenced by dblink_connect().

{
    if (!superuser())
    {
        PQconninfoOption *options;
        PQconninfoOption *option;
        bool        connstr_gives_password = false;

        options = PQconninfoParse(connstr, NULL);
        if (options)
        {
            for (option = options; option->keyword != NULL; option++)
            {
                if (strcmp(option->keyword, "password") == 0)
                {
                    if (option->val != NULL && option->val[0] != '\0')
                    {
                        connstr_gives_password = true;
                        break;
                    }
                }
            }
            PQconninfoFree(options);
        }

        if (!connstr_gives_password)
            ereport(ERROR,
                  (errcode(ERRCODE_S_R_E_PROHIBITED_SQL_STATEMENT_ATTEMPTED),
                   errmsg("password is required"),
                   errdetail("Non-superusers must provide a password in the connection string.")));
    }
}

Datum dblink_current_query ( PG_FUNCTION_ARGS   ) 

Definition at line 1856 of file dblink.c.

References current_query(), and PG_RETURN_DATUM.

{
    /* This is now just an alias for the built-in function current_query() */
    PG_RETURN_DATUM(current_query(fcinfo));
}

Datum dblink_disconnect ( PG_FUNCTION_ARGS   ) 

Definition at line 310 of file dblink.c.

References remoteConn::conn, conn, cstring_to_text(), deleteConnection(), getConnectionByName(), pfree(), PG_GETARG_TEXT_PP, PG_NARGS, PG_RETURN_TEXT_P, PQfinish(), and text_to_cstring().

{
    char       *conname = NULL;
    remoteConn *rconn = NULL;
    PGconn     *conn = NULL;

    DBLINK_INIT;

    if (PG_NARGS() == 1)
    {
        conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
        rconn = getConnectionByName(conname);
        if (rconn)
            conn = rconn->conn;
    }
    else
        conn = pconn->conn;

    if (!conn)
        DBLINK_CONN_NOT_AVAIL;

    PQfinish(conn);
    if (rconn)
    {
        deleteConnection(conname);
        pfree(rconn);
    }
    else
        pconn->conn = NULL;

    PG_RETURN_TEXT_P(cstring_to_text("OK"));
}

Datum dblink_error_message ( PG_FUNCTION_ARGS   ) 

Definition at line 1350 of file dblink.c.

References conn, cstring_to_text(), NULL, PG_RETURN_TEXT_P, and PQerrorMessage().

{
    char       *msg;
    char       *conname = NULL;
    PGconn     *conn = NULL;
    remoteConn *rconn = NULL;

    DBLINK_INIT;
    DBLINK_GET_NAMED_CONN;

    msg = PQerrorMessage(conn);
    if (msg == NULL || msg[0] == '\0')
        PG_RETURN_TEXT_P(cstring_to_text("OK"));
    else
        PG_RETURN_TEXT_P(cstring_to_text(msg));
}

Datum dblink_exec ( PG_FUNCTION_ARGS   ) 

Definition at line 1372 of file dblink.c.

References BOOLOID, remoteConn::conn, conn, connstr, cstring_to_text(), dblink_res_error(), elog, ereport, errcode(), errmsg(), ERROR, get_fn_expr_argtype(), PG_CATCH, PG_END_TRY, PG_GETARG_BOOL, PG_GETARG_TEXT_PP, PG_NARGS, PG_RE_THROW, PG_RETURN_TEXT_P, PG_TRY, PGRES_COMMAND_OK, PGRES_TUPLES_OK, PQclear(), PQcmdStatus(), PQexec(), PQfinish(), PQresultStatus(), and text_to_cstring().

{
    text       *volatile sql_cmd_status = NULL;
    PGconn     *volatile conn = NULL;
    volatile bool freeconn = false;

    DBLINK_INIT;

    PG_TRY();
    {
        char       *msg;
        PGresult   *res = NULL;
        char       *connstr = NULL;
        char       *sql = NULL;
        char       *conname = NULL;
        remoteConn *rconn = NULL;
        bool        fail = true;    /* default to backward compatible behavior */

        if (PG_NARGS() == 3)
        {
            /* must be text,text,bool */
            DBLINK_GET_CONN;
            sql = text_to_cstring(PG_GETARG_TEXT_PP(1));
            fail = PG_GETARG_BOOL(2);
        }
        else if (PG_NARGS() == 2)
        {
            /* might be text,text or text,bool */
            if (get_fn_expr_argtype(fcinfo->flinfo, 1) == BOOLOID)
            {
                conn = pconn->conn;
                sql = text_to_cstring(PG_GETARG_TEXT_PP(0));
                fail = PG_GETARG_BOOL(1);
            }
            else
            {
                DBLINK_GET_CONN;
                sql = text_to_cstring(PG_GETARG_TEXT_PP(1));
            }
        }
        else if (PG_NARGS() == 1)
        {
            /* must be single text argument */
            conn = pconn->conn;
            sql = text_to_cstring(PG_GETARG_TEXT_PP(0));
        }
        else
            /* shouldn't happen */
            elog(ERROR, "wrong number of arguments");

        if (!conn)
            DBLINK_CONN_NOT_AVAIL;

        res = PQexec(conn, sql);
        if (!res ||
            (PQresultStatus(res) != PGRES_COMMAND_OK &&
             PQresultStatus(res) != PGRES_TUPLES_OK))
        {
            dblink_res_error(conname, res, "could not execute command", fail);

            /*
             * and save a copy of the command status string to return as our
             * result tuple
             */
            sql_cmd_status = cstring_to_text("ERROR");
        }
        else if (PQresultStatus(res) == PGRES_COMMAND_OK)
        {
            /*
             * and save a copy of the command status string to return as our
             * result tuple
             */
            sql_cmd_status = cstring_to_text(PQcmdStatus(res));
            PQclear(res);
        }
        else
        {
            PQclear(res);
            ereport(ERROR,
                  (errcode(ERRCODE_S_R_E_PROHIBITED_SQL_STATEMENT_ATTEMPTED),
                   errmsg("statement returning results not allowed")));
        }
    }
    PG_CATCH();
    {
        /* if needed, close the connection to the database */
        if (freeconn)
            PQfinish(conn);
        PG_RE_THROW();
    }
    PG_END_TRY();

    /* if needed, close the connection to the database */
    if (freeconn)
        PQfinish(conn);

    PG_RETURN_TEXT_P(sql_cmd_status);
}

Datum dblink_fdw_validator ( PG_FUNCTION_ARGS   ) 

Definition at line 1954 of file dblink.c.

References appendStringInfo(), buf, StringInfoData::data, DefElem::defname, ereport, errcode(), errdetail(), errhint(), errmsg(), ERROR, initStringInfo(), is_valid_dblink_option(), _PQconninfoOption::keyword, StringInfoData::len, lfirst, PG_GETARG_DATUM, PG_GETARG_OID, PG_RETURN_VOID, PQconndefaults(), and untransformRelOptions().

{
    List       *options_list = untransformRelOptions(PG_GETARG_DATUM(0));
    Oid         context = PG_GETARG_OID(1);
    ListCell   *cell;

    static const PQconninfoOption *options = NULL;

    /*
     * Get list of valid libpq options.
     *
     * To avoid unnecessary work, we get the list once and use it throughout
     * the lifetime of this backend process.  We don't need to care about
     * memory context issues, because PQconndefaults allocates with malloc.
     */
    if (!options)
    {
        options = PQconndefaults();
        if (!options)           /* assume reason for failure is OOM */
            ereport(ERROR,
                    (errcode(ERRCODE_FDW_OUT_OF_MEMORY),
                     errmsg("out of memory"),
                     errdetail("could not get libpq's default connection options")));
    }

    /* Validate each supplied option. */
    foreach(cell, options_list)
    {
        DefElem    *def = (DefElem *) lfirst(cell);

        if (!is_valid_dblink_option(options, def->defname, context))
        {
            /*
             * Unknown option, or invalid option for the context specified,
             * so complain about it.  Provide a hint with list of valid
             * options for the context.
             */
            StringInfoData buf;
            const PQconninfoOption *opt;

            initStringInfo(&buf);
            for (opt = options; opt->keyword; opt++)
            {
                if (is_valid_dblink_option(options, opt->keyword, context))
                    appendStringInfo(&buf, "%s%s",
                                     (buf.len > 0) ? ", " : "",
                                     opt->keyword);
            }
            ereport(ERROR,
                    (errcode(ERRCODE_FDW_OPTION_NAME_NOT_FOUND),
                     errmsg("invalid option \"%s\"", def->defname),
                     errhint("Valid options in this context are: %s",
                             buf.data)));
        }
    }

    PG_RETURN_VOID();
}

Datum dblink_fetch ( PG_FUNCTION_ARGS   ) 

Definition at line 528 of file dblink.c.

References appendStringInfo(), BOOLOID, buf, remoteConn::conn, conn, StringInfoData::data, dblink_res_error(), ereport, errcode(), errmsg(), ERROR, get_fn_expr_argtype(), getConnectionByName(), initStringInfo(), materializeResult(), PG_GETARG_BOOL, PG_GETARG_INT32, PG_GETARG_TEXT_PP, PG_NARGS, PGRES_COMMAND_OK, PGRES_TUPLES_OK, PQclear(), PQexec(), PQresultStatus(), prepTuplestoreResult(), and text_to_cstring().

{
    PGresult   *res = NULL;
    char       *conname = NULL;
    remoteConn *rconn = NULL;
    PGconn     *conn = NULL;
    StringInfoData buf;
    char       *curname = NULL;
    int         howmany = 0;
    bool        fail = true;    /* default to backward compatible */

    prepTuplestoreResult(fcinfo);

    DBLINK_INIT;

    if (PG_NARGS() == 4)
    {
        /* text,text,int,bool */
        conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
        curname = text_to_cstring(PG_GETARG_TEXT_PP(1));
        howmany = PG_GETARG_INT32(2);
        fail = PG_GETARG_BOOL(3);

        rconn = getConnectionByName(conname);
        if (rconn)
            conn = rconn->conn;
    }
    else if (PG_NARGS() == 3)
    {
        /* text,text,int or text,int,bool */
        if (get_fn_expr_argtype(fcinfo->flinfo, 2) == BOOLOID)
        {
            curname = text_to_cstring(PG_GETARG_TEXT_PP(0));
            howmany = PG_GETARG_INT32(1);
            fail = PG_GETARG_BOOL(2);
            conn = pconn->conn;
        }
        else
        {
            conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
            curname = text_to_cstring(PG_GETARG_TEXT_PP(1));
            howmany = PG_GETARG_INT32(2);

            rconn = getConnectionByName(conname);
            if (rconn)
                conn = rconn->conn;
        }
    }
    else if (PG_NARGS() == 2)
    {
        /* text,int */
        curname = text_to_cstring(PG_GETARG_TEXT_PP(0));
        howmany = PG_GETARG_INT32(1);
        conn = pconn->conn;
    }

    if (!conn)
        DBLINK_CONN_NOT_AVAIL;

    initStringInfo(&buf);
    appendStringInfo(&buf, "FETCH %d FROM %s", howmany, curname);

    /*
     * Try to execute the query.  Note that since libpq uses malloc, the
     * PGresult will be long-lived even though we are still in a short-lived
     * memory context.
     */
    res = PQexec(conn, buf.data);
    if (!res ||
        (PQresultStatus(res) != PGRES_COMMAND_OK &&
         PQresultStatus(res) != PGRES_TUPLES_OK))
    {
        dblink_res_error(conname, res, "could not fetch from cursor", fail);
        return (Datum) 0;
    }
    else if (PQresultStatus(res) == PGRES_COMMAND_OK)
    {
        /* cursor does not exist - closed already or bad name */
        PQclear(res);
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_CURSOR_NAME),
                 errmsg("cursor \"%s\" does not exist", curname)));
    }

    materializeResult(fcinfo, conn, res);
    return (Datum) 0;
}

Datum dblink_get_connections ( PG_FUNCTION_ARGS   ) 
Datum dblink_get_notify ( PG_FUNCTION_ARGS   ) 

Definition at line 1874 of file dblink.c.

References pgNotify::be_pid, remoteConn::conn, conn, CreateTemplateTupleDesc(), CStringGetTextDatum, DBLINK_GET_NAMED_CONN, DBLINK_NOTIFY_COLS, ReturnSetInfo::econtext, ExprContext::ecxt_per_query_memory, pgNotify::extra, Int32GetDatum, INT4OID, MemoryContextSwitchTo(), NULL, PG_NARGS, PQconsumeInput(), PQfreemem(), PQnotifies(), prepTuplestoreResult(), pgNotify::relname, ReturnSetInfo::setDesc, ReturnSetInfo::setResult, TEXTOID, TupleDescInitEntry(), tuplestore_begin_heap(), tuplestore_donestoring, tuplestore_putvalues(), values, and work_mem.

{
    char       *conname = NULL;
    PGconn     *conn = NULL;
    remoteConn *rconn = NULL;
    PGnotify   *notify;
    ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
    TupleDesc   tupdesc;
    Tuplestorestate *tupstore;
    MemoryContext per_query_ctx;
    MemoryContext oldcontext;

    prepTuplestoreResult(fcinfo);

    DBLINK_INIT;
    if (PG_NARGS() == 1)
        DBLINK_GET_NAMED_CONN;
    else
        conn = pconn->conn;

    /* create the tuplestore in per-query memory */
    per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
    oldcontext = MemoryContextSwitchTo(per_query_ctx);

    tupdesc = CreateTemplateTupleDesc(DBLINK_NOTIFY_COLS, false);
    TupleDescInitEntry(tupdesc, (AttrNumber) 1, "notify_name",
                       TEXTOID, -1, 0);
    TupleDescInitEntry(tupdesc, (AttrNumber) 2, "be_pid",
                       INT4OID, -1, 0);
    TupleDescInitEntry(tupdesc, (AttrNumber) 3, "extra",
                       TEXTOID, -1, 0);

    tupstore = tuplestore_begin_heap(true, false, work_mem);
    rsinfo->setResult = tupstore;
    rsinfo->setDesc = tupdesc;

    MemoryContextSwitchTo(oldcontext);

    PQconsumeInput(conn);
    while ((notify = PQnotifies(conn)) != NULL)
    {
        Datum       values[DBLINK_NOTIFY_COLS];
        bool        nulls[DBLINK_NOTIFY_COLS];

        memset(values, 0, sizeof(values));
        memset(nulls, 0, sizeof(nulls));

        if (notify->relname != NULL)
            values[0] = CStringGetTextDatum(notify->relname);
        else
            nulls[0] = true;

        values[1] = Int32GetDatum(notify->be_pid);

        if (notify->extra != NULL)
            values[2] = CStringGetTextDatum(notify->extra);
        else
            nulls[2] = true;

        tuplestore_putvalues(tupstore, tupdesc, values, nulls);

        PQfreemem(notify);
        PQconsumeInput(conn);
    }

    /* clean up and return the tuplestore */
    tuplestore_donestoring(tupstore);

    return (Datum) 0;
}

Datum dblink_get_pkey ( PG_FUNCTION_ARGS   ) 

Definition at line 1480 of file dblink.c.

References AccessShareLock, ACL_SELECT, FuncCallContext::attinmeta, BuildTupleFromCStrings(), FuncCallContext::call_cntr, CreateTemplateTupleDesc(), get_pkey_attnames(), get_rel_from_relname(), HeapTupleGetDatum, INT4OID, FuncCallContext::max_calls, MemoryContextSwitchTo(), FuncCallContext::multi_call_memory_ctx, NULL, palloc(), PG_GETARG_TEXT_P, relation_close(), SRF_FIRSTCALL_INIT, SRF_IS_FIRSTCALL, SRF_PERCALL_SETUP, SRF_RETURN_DONE, SRF_RETURN_NEXT, TEXTOID, TupleDescGetAttInMetadata(), TupleDescInitEntry(), FuncCallContext::user_fctx, and values.

{
    int16       numatts;
    char      **results;
    FuncCallContext *funcctx;
    int32       call_cntr;
    int32       max_calls;
    AttInMetadata *attinmeta;
    MemoryContext oldcontext;

    /* stuff done only on the first call of the function */
    if (SRF_IS_FIRSTCALL())
    {
        Relation    rel;
        TupleDesc   tupdesc;

        /* create a function context for cross-call persistence */
        funcctx = SRF_FIRSTCALL_INIT();

        /*
         * switch to memory context appropriate for multiple function calls
         */
        oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);

        /* open target relation */
        rel = get_rel_from_relname(PG_GETARG_TEXT_P(0), AccessShareLock, ACL_SELECT);

        /* get the array of attnums */
        results = get_pkey_attnames(rel, &numatts);

        relation_close(rel, AccessShareLock);

        /*
         * need a tuple descriptor representing one INT and one TEXT column
         */
        tupdesc = CreateTemplateTupleDesc(2, false);
        TupleDescInitEntry(tupdesc, (AttrNumber) 1, "position",
                           INT4OID, -1, 0);
        TupleDescInitEntry(tupdesc, (AttrNumber) 2, "colname",
                           TEXTOID, -1, 0);

        /*
         * Generate attribute metadata needed later to produce tuples from raw
         * C strings
         */
        attinmeta = TupleDescGetAttInMetadata(tupdesc);
        funcctx->attinmeta = attinmeta;

        if ((results != NULL) && (numatts > 0))
        {
            funcctx->max_calls = numatts;

            /* got results, keep track of them */
            funcctx->user_fctx = results;
        }
        else
        {
            /* fast track when no results */
            MemoryContextSwitchTo(oldcontext);
            SRF_RETURN_DONE(funcctx);
        }

        MemoryContextSwitchTo(oldcontext);
    }

    /* stuff done on every call of the function */
    funcctx = SRF_PERCALL_SETUP();

    /*
     * initialize per-call variables
     */
    call_cntr = funcctx->call_cntr;
    max_calls = funcctx->max_calls;

    results = (char **) funcctx->user_fctx;
    attinmeta = funcctx->attinmeta;

    if (call_cntr < max_calls)  /* do when there is more left to send */
    {
        char      **values;
        HeapTuple   tuple;
        Datum       result;

        values = (char **) palloc(2 * sizeof(char *));
        values[0] = (char *) palloc(12);        /* sign, 10 digits, '\0' */

        sprintf(values[0], "%d", call_cntr + 1);

        values[1] = results[call_cntr];

        /* build the tuple */
        tuple = BuildTupleFromCStrings(attinmeta, values);

        /* make the tuple into a datum */
        result = HeapTupleGetDatum(tuple);

        SRF_RETURN_NEXT(funcctx, result);
    }
    else
    {
        /* do when there is no more left */
        SRF_RETURN_DONE(funcctx);
    }
}

Datum dblink_get_result ( PG_FUNCTION_ARGS   ) 

Definition at line 655 of file dblink.c.

References dblink_record_internal().

{
    return dblink_record_internal(fcinfo, true);
}

Datum dblink_is_busy ( PG_FUNCTION_ARGS   ) 

Definition at line 1289 of file dblink.c.

References conn, PG_RETURN_INT32, PQconsumeInput(), and PQisBusy().

{
    char       *conname = NULL;
    PGconn     *conn = NULL;
    remoteConn *rconn = NULL;

    DBLINK_INIT;
    DBLINK_GET_NAMED_CONN;

    PQconsumeInput(conn);
    PG_RETURN_INT32(PQisBusy(conn));
}

Datum dblink_open ( PG_FUNCTION_ARGS   ) 

Definition at line 348 of file dblink.c.

References appendStringInfo(), BOOLOID, buf, remoteConn::conn, conn, cstring_to_text(), StringInfoData::data, dblink_res_error(), DBLINK_RES_INTERNALERROR, get_fn_expr_argtype(), getConnectionByName(), initStringInfo(), remoteConn::newXactForCursor, remoteConn::openCursorCount, PG_GETARG_BOOL, PG_GETARG_TEXT_PP, PG_NARGS, PG_RETURN_TEXT_P, PGRES_COMMAND_OK, PQclear(), PQexec(), PQresultStatus(), PQTRANS_IDLE, PQtransactionStatus(), and text_to_cstring().

{
    char       *msg;
    PGresult   *res = NULL;
    PGconn     *conn = NULL;
    char       *curname = NULL;
    char       *sql = NULL;
    char       *conname = NULL;
    StringInfoData buf;
    remoteConn *rconn = NULL;
    bool        fail = true;    /* default to backward compatible behavior */

    DBLINK_INIT;
    initStringInfo(&buf);

    if (PG_NARGS() == 2)
    {
        /* text,text */
        curname = text_to_cstring(PG_GETARG_TEXT_PP(0));
        sql = text_to_cstring(PG_GETARG_TEXT_PP(1));
        rconn = pconn;
    }
    else if (PG_NARGS() == 3)
    {
        /* might be text,text,text or text,text,bool */
        if (get_fn_expr_argtype(fcinfo->flinfo, 2) == BOOLOID)
        {
            curname = text_to_cstring(PG_GETARG_TEXT_PP(0));
            sql = text_to_cstring(PG_GETARG_TEXT_PP(1));
            fail = PG_GETARG_BOOL(2);
            rconn = pconn;
        }
        else
        {
            conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
            curname = text_to_cstring(PG_GETARG_TEXT_PP(1));
            sql = text_to_cstring(PG_GETARG_TEXT_PP(2));
            rconn = getConnectionByName(conname);
        }
    }
    else if (PG_NARGS() == 4)
    {
        /* text,text,text,bool */
        conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
        curname = text_to_cstring(PG_GETARG_TEXT_PP(1));
        sql = text_to_cstring(PG_GETARG_TEXT_PP(2));
        fail = PG_GETARG_BOOL(3);
        rconn = getConnectionByName(conname);
    }

    if (!rconn || !rconn->conn)
        DBLINK_CONN_NOT_AVAIL;
    else
        conn = rconn->conn;

    /* If we are not in a transaction, start one */
    if (PQtransactionStatus(conn) == PQTRANS_IDLE)
    {
        res = PQexec(conn, "BEGIN");
        if (PQresultStatus(res) != PGRES_COMMAND_OK)
            DBLINK_RES_INTERNALERROR("begin error");
        PQclear(res);
        rconn->newXactForCursor = TRUE;

        /*
         * Since transaction state was IDLE, we force cursor count to
         * initially be 0. This is needed as a previous ABORT might have wiped
         * out our transaction without maintaining the cursor count for us.
         */
        rconn->openCursorCount = 0;
    }

    /* if we started a transaction, increment cursor count */
    if (rconn->newXactForCursor)
        (rconn->openCursorCount)++;

    appendStringInfo(&buf, "DECLARE %s CURSOR FOR %s", curname, sql);
    res = PQexec(conn, buf.data);
    if (!res || PQresultStatus(res) != PGRES_COMMAND_OK)
    {
        dblink_res_error(conname, res, "could not open cursor", fail);
        PG_RETURN_TEXT_P(cstring_to_text("ERROR"));
    }

    PQclear(res);
    PG_RETURN_TEXT_P(cstring_to_text("OK"));
}

Datum dblink_record ( PG_FUNCTION_ARGS   ) 

Definition at line 621 of file dblink.c.

References dblink_record_internal().

{
    return dblink_record_internal(fcinfo, false);
}

static Datum dblink_record_internal ( FunctionCallInfo  fcinfo,
bool  is_async 
) [static]

Definition at line 661 of file dblink.c.

References BOOLOID, remoteConn::conn, conn, connstr, dblink_res_error(), elog, ERROR, FunctionCallInfoData::flinfo, get_fn_expr_argtype(), materializeQueryResult(), materializeResult(), PG_CATCH, PG_END_TRY, PG_GETARG_BOOL, PG_GETARG_TEXT_PP, PG_NARGS, PG_RE_THROW, PG_TRY, PGRES_COMMAND_OK, PGRES_TUPLES_OK, PQfinish(), PQgetResult(), PQresultStatus(), prepTuplestoreResult(), and text_to_cstring().

Referenced by dblink_get_result(), and dblink_record().

{
    PGconn     *volatile conn = NULL;
    volatile bool freeconn = false;

    prepTuplestoreResult(fcinfo);

    DBLINK_INIT;

    PG_TRY();
    {
        char       *msg;
        char       *connstr = NULL;
        char       *sql = NULL;
        char       *conname = NULL;
        remoteConn *rconn = NULL;
        bool        fail = true;    /* default to backward compatible */

        if (!is_async)
        {
            if (PG_NARGS() == 3)
            {
                /* text,text,bool */
                DBLINK_GET_CONN;
                sql = text_to_cstring(PG_GETARG_TEXT_PP(1));
                fail = PG_GETARG_BOOL(2);
            }
            else if (PG_NARGS() == 2)
            {
                /* text,text or text,bool */
                if (get_fn_expr_argtype(fcinfo->flinfo, 1) == BOOLOID)
                {
                    conn = pconn->conn;
                    sql = text_to_cstring(PG_GETARG_TEXT_PP(0));
                    fail = PG_GETARG_BOOL(1);
                }
                else
                {
                    DBLINK_GET_CONN;
                    sql = text_to_cstring(PG_GETARG_TEXT_PP(1));
                }
            }
            else if (PG_NARGS() == 1)
            {
                /* text */
                conn = pconn->conn;
                sql = text_to_cstring(PG_GETARG_TEXT_PP(0));
            }
            else
                /* shouldn't happen */
                elog(ERROR, "wrong number of arguments");
        }
        else    /* is_async */
        {
            /* get async result */
            if (PG_NARGS() == 2)
            {
                /* text,bool */
                DBLINK_GET_NAMED_CONN;
                fail = PG_GETARG_BOOL(1);
            }
            else if (PG_NARGS() == 1)
            {
                /* text */
                DBLINK_GET_NAMED_CONN;
            }
            else
                /* shouldn't happen */
                elog(ERROR, "wrong number of arguments");
        }

        if (!conn)
            DBLINK_CONN_NOT_AVAIL;

        if (!is_async)
        {
            /* synchronous query, use efficient tuple collection method */
            materializeQueryResult(fcinfo, conn, conname, sql, fail);
        }
        else
        {
            /* async result retrieval, do it the old way */
            PGresult   *res = PQgetResult(conn);

            /* NULL means we're all done with the async results */
            if (res)
            {
                if (PQresultStatus(res) != PGRES_COMMAND_OK &&
                    PQresultStatus(res) != PGRES_TUPLES_OK)
                {
                    dblink_res_error(conname, res, "could not execute query",
                                     fail);
                    /* if fail isn't set, we'll return an empty query result */
                }
                else
                {
                    materializeResult(fcinfo, conn, res);
                }
            }
        }
    }
    PG_CATCH();
    {
        /* if needed, close the connection to the database */
        if (freeconn)
            PQfinish(conn);
        PG_RE_THROW();
    }
    PG_END_TRY();

    /* if needed, close the connection to the database */
    if (freeconn)
        PQfinish(conn);

    return (Datum) 0;
}

static void dblink_res_error ( const char *  conname,
PGresult res,
const char *  dblink_context_msg,
bool  fail 
) [static]

Definition at line 2664 of file dblink.c.

References ereport, errcode(), errcontext, errdetail_internal(), errhint(), errmsg(), errmsg_internal(), MAKE_SQLSTATE, PG_DIAG_CONTEXT, PG_DIAG_MESSAGE_DETAIL, PG_DIAG_MESSAGE_HINT, PG_DIAG_MESSAGE_PRIMARY, PG_DIAG_SQLSTATE, PQclear(), PQresultErrorField(), and xpstrdup.

Referenced by dblink_close(), dblink_exec(), dblink_fetch(), dblink_open(), dblink_record_internal(), and materializeQueryResult().

{
    int         level;
    char       *pg_diag_sqlstate = PQresultErrorField(res, PG_DIAG_SQLSTATE);
    char       *pg_diag_message_primary = PQresultErrorField(res, PG_DIAG_MESSAGE_PRIMARY);
    char       *pg_diag_message_detail = PQresultErrorField(res, PG_DIAG_MESSAGE_DETAIL);
    char       *pg_diag_message_hint = PQresultErrorField(res, PG_DIAG_MESSAGE_HINT);
    char       *pg_diag_context = PQresultErrorField(res, PG_DIAG_CONTEXT);
    int         sqlstate;
    char       *message_primary;
    char       *message_detail;
    char       *message_hint;
    char       *message_context;
    const char *dblink_context_conname = "unnamed";

    if (fail)
        level = ERROR;
    else
        level = NOTICE;

    if (pg_diag_sqlstate)
        sqlstate = MAKE_SQLSTATE(pg_diag_sqlstate[0],
                                 pg_diag_sqlstate[1],
                                 pg_diag_sqlstate[2],
                                 pg_diag_sqlstate[3],
                                 pg_diag_sqlstate[4]);
    else
        sqlstate = ERRCODE_CONNECTION_FAILURE;

    xpstrdup(message_primary, pg_diag_message_primary);
    xpstrdup(message_detail, pg_diag_message_detail);
    xpstrdup(message_hint, pg_diag_message_hint);
    xpstrdup(message_context, pg_diag_context);

    if (res)
        PQclear(res);

    if (conname)
        dblink_context_conname = conname;

    ereport(level,
            (errcode(sqlstate),
             message_primary ? errmsg_internal("%s", message_primary) :
             errmsg("unknown error"),
             message_detail ? errdetail_internal("%s", message_detail) : 0,
             message_hint ? errhint("%s", message_hint) : 0,
             message_context ? errcontext("%s", message_context) : 0,
          errcontext("Error occurred on dblink connection named \"%s\": %s.",
                     dblink_context_conname, dblink_context_msg)));
}

static void dblink_security_check ( PGconn conn,
remoteConn rconn 
) [static]

Definition at line 2604 of file dblink.c.

References ereport, errcode(), errdetail(), errhint(), errmsg(), ERROR, pfree(), PQconnectionUsedPassword(), PQfinish(), and superuser().

Referenced by dblink_connect().

{
    if (!superuser())
    {
        if (!PQconnectionUsedPassword(conn))
        {
            PQfinish(conn);
            if (rconn)
                pfree(rconn);

            ereport(ERROR,
                  (errcode(ERRCODE_S_R_E_PROHIBITED_SQL_STATEMENT_ATTEMPTED),
                   errmsg("password is required"),
                   errdetail("Non-superuser cannot connect if the server does not request a password."),
                   errhint("Target server's authentication method must be changed.")));
        }
    }
}

Datum dblink_send_query ( PG_FUNCTION_ARGS   ) 

Definition at line 628 of file dblink.c.

References conn, elog, ERROR, NOTICE, PG_GETARG_TEXT_PP, PG_NARGS, PG_RETURN_INT32, PQerrorMessage(), PQsendQuery(), and text_to_cstring().

{
    char       *conname = NULL;
    PGconn     *conn = NULL;
    char       *sql = NULL;
    remoteConn *rconn = NULL;
    int         retval;

    if (PG_NARGS() == 2)
    {
        DBLINK_GET_NAMED_CONN;
        sql = text_to_cstring(PG_GETARG_TEXT_PP(1));
    }
    else
        /* shouldn't happen */
        elog(ERROR, "wrong number of arguments");

    /* async query send */
    retval = PQsendQuery(conn, sql);
    if (retval != 1)
        elog(NOTICE, "could not send query: %s", PQerrorMessage(conn));

    PG_RETURN_INT32(retval);
}

static void deleteConnection ( const char *  name  )  [static]

Definition at line 2582 of file dblink.c.

References createConnHash(), ereport, errcode(), errmsg(), ERROR, HASH_REMOVE, hash_search(), pstrdup(), and truncate_identifier().

Referenced by dblink_disconnect().

{
    remoteConnHashEnt *hentry;
    bool        found;
    char       *key;

    if (!remoteConnHash)
        remoteConnHash = createConnHash();

    key = pstrdup(name);
    truncate_identifier(key, strlen(key), false);
    hentry = (remoteConnHashEnt *) hash_search(remoteConnHash,
                                               key, HASH_REMOVE, &found);

    if (!hentry)
        ereport(ERROR,
                (errcode(ERRCODE_UNDEFINED_OBJECT),
                 errmsg("undefined connection name")));

}

static char * escape_param_str ( const char *  from  )  [static]

Definition at line 2785 of file dblink.c.

References appendStringInfoChar(), buf, StringInfoData::data, and makeStringInfo().

Referenced by get_connect_string().

{
    const char *cp;
    StringInfo  buf = makeStringInfo();

    for (cp = str; *cp; cp++)
    {
        if (*cp == '\\' || *cp == '\'')
            appendStringInfoChar(buf, '\\');
        appendStringInfoChar(buf, *cp);
    }

    return buf->data;
}

static char * generate_relation_name ( Relation  rel  )  [static]

Definition at line 2504 of file dblink.c.

References get_namespace_name(), quote_qualified_identifier(), RelationData::rd_rel, RelationGetRelationName, RelationGetRelid, and RelationIsVisible().

Referenced by get_sql_delete(), get_sql_insert(), get_sql_update(), and get_tuple_of_interest().

{
    char       *nspname;
    char       *result;

    /* Qualify the name if not visible in search path */
    if (RelationIsVisible(RelationGetRelid(rel)))
        nspname = NULL;
    else
        nspname = get_namespace_name(rel->rd_rel->relnamespace);

    result = quote_qualified_identifier(nspname, RelationGetRelationName(rel));

    return result;
}

static int get_attnum_pk_pos ( int *  pkattnums,
int  pknumatts,
int  key 
) [static]

Definition at line 2354 of file dblink.c.

References i.

Referenced by get_sql_insert(), and get_sql_update().

{
    int         i;

    /*
     * Not likely a long list anyway, so just scan for the value
     */
    for (i = 0; i < pknumatts; i++)
        if (key == pkattnums[i])
            return i;

    return -1;
}

static char * get_connect_string ( const char *  servername  )  [static]

Definition at line 2719 of file dblink.c.

References ACL_KIND_FOREIGN_SERVER, ACL_USAGE, aclcheck_error(), ACLCHECK_OK, appendStringInfo(), DefElem::arg, buf, StringInfoData::data, DefElem::defname, escape_param_str(), ForeignServer::fdwid, GetForeignDataWrapper(), GetForeignServerByName(), GetUserId(), GetUserMapping(), lfirst, makeStringInfo(), UserMapping::options, ForeignServer::options, ForeignDataWrapper::options, pg_foreign_server_aclcheck(), pstrdup(), ForeignServer::serverid, ForeignServer::servername, strVal, and truncate_identifier().

Referenced by dblink_connect().

{
    ForeignServer *foreign_server = NULL;
    UserMapping *user_mapping;
    ListCell   *cell;
    StringInfo  buf = makeStringInfo();
    ForeignDataWrapper *fdw;
    AclResult   aclresult;
    char       *srvname;

    /* first gather the server connstr options */
    srvname = pstrdup(servername);
    truncate_identifier(srvname, strlen(srvname), false);
    foreign_server = GetForeignServerByName(srvname, true);

    if (foreign_server)
    {
        Oid         serverid = foreign_server->serverid;
        Oid         fdwid = foreign_server->fdwid;
        Oid         userid = GetUserId();

        user_mapping = GetUserMapping(userid, serverid);
        fdw = GetForeignDataWrapper(fdwid);

        /* Check permissions, user must have usage on the server. */
        aclresult = pg_foreign_server_aclcheck(serverid, userid, ACL_USAGE);
        if (aclresult != ACLCHECK_OK)
            aclcheck_error(aclresult, ACL_KIND_FOREIGN_SERVER, foreign_server->servername);

        foreach(cell, fdw->options)
        {
            DefElem    *def = lfirst(cell);

            appendStringInfo(buf, "%s='%s' ", def->defname,
                             escape_param_str(strVal(def->arg)));
        }

        foreach(cell, foreign_server->options)
        {
            DefElem    *def = lfirst(cell);

            appendStringInfo(buf, "%s='%s' ", def->defname,
                             escape_param_str(strVal(def->arg)));
        }

        foreach(cell, user_mapping->options)
        {

            DefElem    *def = lfirst(cell);

            appendStringInfo(buf, "%s='%s' ", def->defname,
                             escape_param_str(strVal(def->arg)));
        }

        return buf->data;
    }
    else
        return NULL;
}

static char ** get_pkey_attnames ( Relation  rel,
int16 numatts 
) [static]

Definition at line 2026 of file dblink.c.

References AccessShareLock, Anum_pg_index_indrelid, BTEqualStrategyNumber, GETSTRUCT, heap_close, heap_open(), HeapTupleIsValid, i, IndexIndrelidIndexId, IndexRelationId, ObjectIdGetDatum, palloc(), RelationData::rd_att, RelationGetRelid, ScanKeyInit(), SnapshotNow, SPI_fname(), systable_beginscan(), systable_endscan(), and systable_getnext().

Referenced by dblink_get_pkey().

{
    Relation    indexRelation;
    ScanKeyData skey;
    SysScanDesc scan;
    HeapTuple   indexTuple;
    int         i;
    char      **result = NULL;
    TupleDesc   tupdesc;

    /* initialize numatts to 0 in case no primary key exists */
    *numatts = 0;

    tupdesc = rel->rd_att;

    /* Prepare to scan pg_index for entries having indrelid = this rel. */
    indexRelation = heap_open(IndexRelationId, AccessShareLock);
    ScanKeyInit(&skey,
                Anum_pg_index_indrelid,
                BTEqualStrategyNumber, F_OIDEQ,
                ObjectIdGetDatum(RelationGetRelid(rel)));

    scan = systable_beginscan(indexRelation, IndexIndrelidIndexId, true,
                              SnapshotNow, 1, &skey);

    while (HeapTupleIsValid(indexTuple = systable_getnext(scan)))
    {
        Form_pg_index index = (Form_pg_index) GETSTRUCT(indexTuple);

        /* we're only interested if it is the primary key */
        if (index->indisprimary)
        {
            *numatts = index->indnatts;
            if (*numatts > 0)
            {
                result = (char **) palloc(*numatts * sizeof(char *));

                for (i = 0; i < *numatts; i++)
                    result[i] = SPI_fname(tupdesc, index->indkey.values[i]);
            }
            break;
        }
    }

    systable_endscan(scan);
    heap_close(indexRelation, AccessShareLock);

    return result;
}

static Relation get_rel_from_relname ( text relname_text,
LOCKMODE  lockmode,
AclMode  aclmode 
) [static]
static char * get_sql_delete ( Relation  rel,
int *  pkattnums,
int  pknumatts,
char **  tgt_pkattvals 
) [static]

Definition at line 2215 of file dblink.c.

References appendStringInfo(), appendStringInfoString(), tupleDesc::attrs, buf, StringInfoData::data, generate_relation_name(), i, initStringInfo(), NameStr, NULL, quote_ident_cstr(), quote_literal_cstr(), and RelationData::rd_att.

Referenced by dblink_build_sql_delete().

{
    char       *relname;
    TupleDesc   tupdesc;
    StringInfoData buf;
    int         i;

    initStringInfo(&buf);

    /* get relation name including any needed schema prefix and quoting */
    relname = generate_relation_name(rel);

    tupdesc = rel->rd_att;

    appendStringInfo(&buf, "DELETE FROM %s WHERE ", relname);
    for (i = 0; i < pknumatts; i++)
    {
        int         pkattnum = pkattnums[i];

        if (i > 0)
            appendStringInfo(&buf, " AND ");

        appendStringInfoString(&buf,
               quote_ident_cstr(NameStr(tupdesc->attrs[pkattnum]->attname)));

        if (tgt_pkattvals[i] != NULL)
            appendStringInfo(&buf, " = %s",
                             quote_literal_cstr(tgt_pkattvals[i]));
        else
            appendStringInfo(&buf, " IS NULL");
    }

    return (buf.data);
}

static char * get_sql_insert ( Relation  rel,
int *  pkattnums,
int  pknumatts,
char **  src_pkattvals,
char **  tgt_pkattvals 
) [static]

Definition at line 2137 of file dblink.c.

References appendStringInfo(), appendStringInfoString(), tupleDesc::attrs, buf, StringInfoData::data, ereport, errcode(), errmsg(), ERROR, generate_relation_name(), get_attnum_pk_pos(), get_tuple_of_interest(), i, initStringInfo(), NameStr, tupleDesc::natts, NULL, pfree(), pstrdup(), quote_ident_cstr(), quote_literal_cstr(), RelationData::rd_att, SPI_getvalue(), and val.

Referenced by dblink_build_sql_insert().

{
    char       *relname;
    HeapTuple   tuple;
    TupleDesc   tupdesc;
    int         natts;
    StringInfoData buf;
    char       *val;
    int         key;
    int         i;
    bool        needComma;

    initStringInfo(&buf);

    /* get relation name including any needed schema prefix and quoting */
    relname = generate_relation_name(rel);

    tupdesc = rel->rd_att;
    natts = tupdesc->natts;

    tuple = get_tuple_of_interest(rel, pkattnums, pknumatts, src_pkattvals);
    if (!tuple)
        ereport(ERROR,
                (errcode(ERRCODE_CARDINALITY_VIOLATION),
                 errmsg("source row not found")));

    appendStringInfo(&buf, "INSERT INTO %s(", relname);

    needComma = false;
    for (i = 0; i < natts; i++)
    {
        if (tupdesc->attrs[i]->attisdropped)
            continue;

        if (needComma)
            appendStringInfo(&buf, ",");

        appendStringInfoString(&buf,
                      quote_ident_cstr(NameStr(tupdesc->attrs[i]->attname)));
        needComma = true;
    }

    appendStringInfo(&buf, ") VALUES(");

    /*
     * Note: i is physical column number (counting from 0).
     */
    needComma = false;
    for (i = 0; i < natts; i++)
    {
        if (tupdesc->attrs[i]->attisdropped)
            continue;

        if (needComma)
            appendStringInfo(&buf, ",");

        key = get_attnum_pk_pos(pkattnums, pknumatts, i);

        if (key >= 0)
            val = tgt_pkattvals[key] ? pstrdup(tgt_pkattvals[key]) : NULL;
        else
            val = SPI_getvalue(tuple, tupdesc, i + 1);

        if (val != NULL)
        {
            appendStringInfoString(&buf, quote_literal_cstr(val));
            pfree(val);
        }
        else
            appendStringInfo(&buf, "NULL");
        needComma = true;
    }
    appendStringInfo(&buf, ")");

    return (buf.data);
}

static char * get_sql_update ( Relation  rel,
int *  pkattnums,
int  pknumatts,
char **  src_pkattvals,
char **  tgt_pkattvals 
) [static]

Definition at line 2251 of file dblink.c.

References appendStringInfo(), appendStringInfoString(), tupleDesc::attrs, buf, StringInfoData::data, ereport, errcode(), errmsg(), ERROR, generate_relation_name(), get_attnum_pk_pos(), get_tuple_of_interest(), i, initStringInfo(), NameStr, tupleDesc::natts, NULL, pfree(), pstrdup(), quote_ident_cstr(), quote_literal_cstr(), RelationData::rd_att, SPI_getvalue(), and val.

Referenced by dblink_build_sql_update().

{
    char       *relname;
    HeapTuple   tuple;
    TupleDesc   tupdesc;
    int         natts;
    StringInfoData buf;
    char       *val;
    int         key;
    int         i;
    bool        needComma;

    initStringInfo(&buf);

    /* get relation name including any needed schema prefix and quoting */
    relname = generate_relation_name(rel);

    tupdesc = rel->rd_att;
    natts = tupdesc->natts;

    tuple = get_tuple_of_interest(rel, pkattnums, pknumatts, src_pkattvals);
    if (!tuple)
        ereport(ERROR,
                (errcode(ERRCODE_CARDINALITY_VIOLATION),
                 errmsg("source row not found")));

    appendStringInfo(&buf, "UPDATE %s SET ", relname);

    /*
     * Note: i is physical column number (counting from 0).
     */
    needComma = false;
    for (i = 0; i < natts; i++)
    {
        if (tupdesc->attrs[i]->attisdropped)
            continue;

        if (needComma)
            appendStringInfo(&buf, ", ");

        appendStringInfo(&buf, "%s = ",
                      quote_ident_cstr(NameStr(tupdesc->attrs[i]->attname)));

        key = get_attnum_pk_pos(pkattnums, pknumatts, i);

        if (key >= 0)
            val = tgt_pkattvals[key] ? pstrdup(tgt_pkattvals[key]) : NULL;
        else
            val = SPI_getvalue(tuple, tupdesc, i + 1);

        if (val != NULL)
        {
            appendStringInfoString(&buf, quote_literal_cstr(val));
            pfree(val);
        }
        else
            appendStringInfoString(&buf, "NULL");
        needComma = true;
    }

    appendStringInfo(&buf, " WHERE ");

    for (i = 0; i < pknumatts; i++)
    {
        int         pkattnum = pkattnums[i];

        if (i > 0)
            appendStringInfo(&buf, " AND ");

        appendStringInfo(&buf, "%s",
               quote_ident_cstr(NameStr(tupdesc->attrs[pkattnum]->attname)));

        val = tgt_pkattvals[i];

        if (val != NULL)
            appendStringInfo(&buf, " = %s", quote_literal_cstr(val));
        else
            appendStringInfo(&buf, " IS NULL");
    }

    return (buf.data);
}

static char ** get_text_array_contents ( ArrayType array,
int *  numitems 
) [static]

Definition at line 2081 of file dblink.c.

References ARR_DATA_PTR, ARR_DIMS, ARR_ELEMTYPE, ARR_NDIM, ARR_NULLBITMAP, ArrayGetNItems(), Assert, att_addlength_pointer, att_align_nominal, get_typlenbyvalalign(), i, palloc(), PointerGetDatum, TextDatumGetCString, TEXTOID, and values.

Referenced by dblink_build_sql_delete(), dblink_build_sql_insert(), and dblink_build_sql_update().

{
    int         ndim = ARR_NDIM(array);
    int        *dims = ARR_DIMS(array);
    int         nitems;
    int16       typlen;
    bool        typbyval;
    char        typalign;
    char      **values;
    char       *ptr;
    bits8      *bitmap;
    int         bitmask;
    int         i;

    Assert(ARR_ELEMTYPE(array) == TEXTOID);

    *numitems = nitems = ArrayGetNItems(ndim, dims);

    get_typlenbyvalalign(ARR_ELEMTYPE(array),
                         &typlen, &typbyval, &typalign);

    values = (char **) palloc(nitems * sizeof(char *));

    ptr = ARR_DATA_PTR(array);
    bitmap = ARR_NULLBITMAP(array);
    bitmask = 1;

    for (i = 0; i < nitems; i++)
    {
        if (bitmap && (*bitmap & bitmask) == 0)
        {
            values[i] = NULL;
        }
        else
        {
            values[i] = TextDatumGetCString(PointerGetDatum(ptr));
            ptr = att_addlength_pointer(ptr, typlen, ptr);
            ptr = (char *) att_align_nominal(ptr, typalign);
        }

        /* advance bitmap pointer if any */
        if (bitmap)
        {
            bitmask <<= 1;
            if (bitmask == 0x100)
            {
                bitmap++;
                bitmask = 1;
            }
        }
    }

    return values;
}

static HeapTuple get_tuple_of_interest ( Relation  rel,
int *  pkattnums,
int  pknumatts,
char **  src_pkattvals 
) [static]

Definition at line 2369 of file dblink.c.

References appendStringInfo(), appendStringInfoString(), tupleDesc::attrs, buf, StringInfoData::data, elog, ereport, errcode(), errmsg(), ERROR, generate_relation_name(), i, initStringInfo(), NameStr, tupleDesc::natts, NULL, pfree(), quote_ident_cstr(), quote_literal_cstr(), RelationData::rd_att, SPI_connect(), SPI_copytuple(), SPI_exec(), SPI_finish(), SPI_OK_SELECT, SPI_processed, SPI_tuptable, and SPITupleTable::vals.

Referenced by get_sql_insert(), and get_sql_update().

{
    char       *relname;
    TupleDesc   tupdesc;
    int         natts;
    StringInfoData buf;
    int         ret;
    HeapTuple   tuple;
    int         i;

    /*
     * Connect to SPI manager
     */
    if ((ret = SPI_connect()) < 0)
        /* internal error */
        elog(ERROR, "SPI connect failure - returned %d", ret);

    initStringInfo(&buf);

    /* get relation name including any needed schema prefix and quoting */
    relname = generate_relation_name(rel);

    tupdesc = rel->rd_att;
    natts = tupdesc->natts;

    /*
     * Build sql statement to look up tuple of interest, ie, the one matching
     * src_pkattvals.  We used to use "SELECT *" here, but it's simpler to
     * generate a result tuple that matches the table's physical structure,
     * with NULLs for any dropped columns.  Otherwise we have to deal with two
     * different tupdescs and everything's very confusing.
     */
    appendStringInfoString(&buf, "SELECT ");

    for (i = 0; i < natts; i++)
    {
        if (i > 0)
            appendStringInfoString(&buf, ", ");

        if (tupdesc->attrs[i]->attisdropped)
            appendStringInfoString(&buf, "NULL");
        else
            appendStringInfoString(&buf,
                      quote_ident_cstr(NameStr(tupdesc->attrs[i]->attname)));
    }

    appendStringInfo(&buf, " FROM %s WHERE ", relname);

    for (i = 0; i < pknumatts; i++)
    {
        int         pkattnum = pkattnums[i];

        if (i > 0)
            appendStringInfo(&buf, " AND ");

        appendStringInfoString(&buf,
               quote_ident_cstr(NameStr(tupdesc->attrs[pkattnum]->attname)));

        if (src_pkattvals[i] != NULL)
            appendStringInfo(&buf, " = %s",
                             quote_literal_cstr(src_pkattvals[i]));
        else
            appendStringInfo(&buf, " IS NULL");
    }

    /*
     * Retrieve the desired tuple
     */
    ret = SPI_exec(buf.data, 0);
    pfree(buf.data);

    /*
     * Only allow one qualifying tuple
     */
    if ((ret == SPI_OK_SELECT) && (SPI_processed > 1))
        ereport(ERROR,
                (errcode(ERRCODE_CARDINALITY_VIOLATION),
                 errmsg("source criteria matched more than one record")));

    else if (ret == SPI_OK_SELECT && SPI_processed == 1)
    {
        SPITupleTable *tuptable = SPI_tuptable;

        tuple = SPI_copytuple(tuptable->vals[0]);
        SPI_finish();

        return tuple;
    }
    else
    {
        /*
         * no qualifying tuples
         */
        SPI_finish();

        return NULL;
    }

    /*
     * never reached, but keep compiler quiet
     */
    return NULL;
}

static remoteConn * getConnectionByName ( const char *  name  )  [static]

Definition at line 2522 of file dblink.c.

References createConnHash(), HASH_FIND, hash_search(), NULL, pstrdup(), remoteConnHashEnt::rconn, and truncate_identifier().

Referenced by dblink_close(), dblink_disconnect(), dblink_fetch(), and dblink_open().

{
    remoteConnHashEnt *hentry;
    char       *key;

    if (!remoteConnHash)
        remoteConnHash = createConnHash();

    key = pstrdup(name);
    truncate_identifier(key, strlen(key), false);
    hentry = (remoteConnHashEnt *) hash_search(remoteConnHash,
                                               key, HASH_FIND, NULL);

    if (hentry)
        return (hentry->rconn);

    return (NULL);
}

static bool is_valid_dblink_option ( const PQconninfoOption options,
const char *  option,
Oid  context 
) [static]

Definition at line 2887 of file dblink.c.

References _PQconninfoOption::dispchar, ForeignServerRelationId, _PQconninfoOption::keyword, NULL, and UserMappingRelationId.

Referenced by dblink_fdw_validator().

{
    const PQconninfoOption *opt;

    /* Look up the option in libpq result */
    for (opt = options; opt->keyword; opt++)
    {
        if (strcmp(opt->keyword, option) == 0)
            break;
    }
    if (opt->keyword == NULL)
        return false;

    /* Disallow debug options (particularly "replication") */
    if (strchr(opt->dispchar, 'D'))
        return false;

    /* Disallow "client_encoding" */
    if (strcmp(opt->keyword, "client_encoding") == 0)
        return false;

    /*
     * If the option is "user" or marked secure, it should be specified only
     * in USER MAPPING.  Others should be specified only in SERVER.
     */
    if (strcmp(opt->keyword, "user") == 0 || strchr(opt->dispchar, '*'))
    {
        if (context != UserMappingRelationId)
            return false;
    }
    else
    {
        if (context != ForeignServerRelationId)
            return false;
    }

    return true;
}

static void materializeQueryResult ( FunctionCallInfo  fcinfo,
PGconn conn,
const char *  conname,
const char *  sql,
bool  fail 
) [static]

Definition at line 959 of file dblink.c.

References Assert, BuildTupleFromCStrings(), CreateTemplateTupleDesc(), dblink_res_error(), ReturnSetInfo::econtext, ExprContext::ecxt_per_query_memory, MemoryContextSwitchTo(), NULL, PG_CATCH, PG_END_TRY, PG_RE_THROW, PG_TRY, PGRES_COMMAND_OK, PGRES_TUPLES_OK, PQclear(), PQcmdStatus(), PQgetResult(), PQresultStatus(), FunctionCallInfoData::resultinfo, ReturnSetInfo::returnMode, ReturnSetInfo::setDesc, ReturnSetInfo::setResult, SFRM_Materialize, storeQueryResult(), TEXTOID, TupleDescGetAttInMetadata(), TupleDescInitEntry(), tuplestore_begin_heap(), tuplestore_puttuple(), values, and work_mem.

Referenced by dblink_record_internal().

{
    ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
    PGresult   *volatile res = NULL;
    storeInfo   sinfo;

    /* prepTuplestoreResult must have been called previously */
    Assert(rsinfo->returnMode == SFRM_Materialize);

    /* initialize storeInfo to empty */
    memset(&sinfo, 0, sizeof(sinfo));
    sinfo.fcinfo = fcinfo;

    PG_TRY();
    {
        /* execute query, collecting any tuples into the tuplestore */
        res = storeQueryResult(&sinfo, conn, sql);

        if (!res ||
            (PQresultStatus(res) != PGRES_COMMAND_OK &&
             PQresultStatus(res) != PGRES_TUPLES_OK))
        {
            /*
             * dblink_res_error will clear the passed PGresult, so we need
             * this ugly dance to avoid doing so twice during error exit
             */
            PGresult   *res1 = res;

            res = NULL;
            dblink_res_error(conname, res1, "could not execute query", fail);
            /* if fail isn't set, we'll return an empty query result */
        }
        else if (PQresultStatus(res) == PGRES_COMMAND_OK)
        {
            /*
             * storeRow didn't get called, so we need to convert the command
             * status string to a tuple manually
             */
            TupleDesc   tupdesc;
            AttInMetadata *attinmeta;
            Tuplestorestate *tupstore;
            HeapTuple   tuple;
            char       *values[1];
            MemoryContext oldcontext;

            /*
             * need a tuple descriptor representing one TEXT column to return
             * the command status string as our result tuple
             */
            tupdesc = CreateTemplateTupleDesc(1, false);
            TupleDescInitEntry(tupdesc, (AttrNumber) 1, "status",
                               TEXTOID, -1, 0);
            attinmeta = TupleDescGetAttInMetadata(tupdesc);

            oldcontext = MemoryContextSwitchTo(
                                    rsinfo->econtext->ecxt_per_query_memory);
            tupstore = tuplestore_begin_heap(true, false, work_mem);
            rsinfo->setResult = tupstore;
            rsinfo->setDesc = tupdesc;
            MemoryContextSwitchTo(oldcontext);

            values[0] = PQcmdStatus(res);

            /* build the tuple and put it into the tuplestore. */
            tuple = BuildTupleFromCStrings(attinmeta, values);
            tuplestore_puttuple(tupstore, tuple);

            PQclear(res);
            res = NULL;
        }
        else
        {
            Assert(PQresultStatus(res) == PGRES_TUPLES_OK);
            /* storeRow should have created a tuplestore */
            Assert(rsinfo->setResult != NULL);

            PQclear(res);
            res = NULL;
        }
        PQclear(sinfo.last_res);
        sinfo.last_res = NULL;
        PQclear(sinfo.cur_res);
        sinfo.cur_res = NULL;
    }
    PG_CATCH();
    {
        /* be sure to release any libpq result we collected */
        PQclear(res);
        PQclear(sinfo.last_res);
        PQclear(sinfo.cur_res);
        /* and clear out any pending data in libpq */
        while ((res = PQgetResult(conn)) != NULL)
            PQclear(res);
        PG_RE_THROW();
    }
    PG_END_TRY();
}

static void materializeResult ( FunctionCallInfo  fcinfo,
PGconn conn,
PGresult res 
) [static]

Definition at line 813 of file dblink.c.

References applyRemoteGucs(), Assert, BuildTupleFromCStrings(), CreateTemplateTupleDesc(), CreateTupleDescCopy(), ReturnSetInfo::econtext, ExprContext::ecxt_per_query_memory, elog, ereport, errcode(), errmsg(), ERROR, get_call_result_type(), i, MemoryContextSwitchTo(), tupleDesc::natts, NULL, palloc(), PG_CATCH, PG_END_TRY, PG_RE_THROW, PG_TRY, PGRES_COMMAND_OK, PGRES_TUPLES_OK, PQclear(), PQcmdStatus(), PQgetisnull(), PQgetvalue(), PQnfields(), PQntuples(), PQresultStatus(), restoreLocalGucs(), FunctionCallInfoData::resultinfo, ReturnSetInfo::returnMode, ReturnSetInfo::setDesc, ReturnSetInfo::setResult, SFRM_Materialize, TEXTOID, TupleDescGetAttInMetadata(), TupleDescInitEntry(), tuplestore_begin_heap(), tuplestore_donestoring, tuplestore_puttuple(), TYPEFUNC_COMPOSITE, TYPEFUNC_RECORD, values, and work_mem.

Referenced by dblink_fetch(), and dblink_record_internal().

{
    ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;

    /* prepTuplestoreResult must have been called previously */
    Assert(rsinfo->returnMode == SFRM_Materialize);

    PG_TRY();
    {
        TupleDesc   tupdesc;
        bool        is_sql_cmd;
        int         ntuples;
        int         nfields;

        if (PQresultStatus(res) == PGRES_COMMAND_OK)
        {
            is_sql_cmd = true;

            /*
             * need a tuple descriptor representing one TEXT column to return
             * the command status string as our result tuple
             */
            tupdesc = CreateTemplateTupleDesc(1, false);
            TupleDescInitEntry(tupdesc, (AttrNumber) 1, "status",
                               TEXTOID, -1, 0);
            ntuples = 1;
            nfields = 1;
        }
        else
        {
            Assert(PQresultStatus(res) == PGRES_TUPLES_OK);

            is_sql_cmd = false;

            /* get a tuple descriptor for our result type */
            switch (get_call_result_type(fcinfo, NULL, &tupdesc))
            {
                case TYPEFUNC_COMPOSITE:
                    /* success */
                    break;
                case TYPEFUNC_RECORD:
                    /* failed to determine actual type of RECORD */
                    ereport(ERROR,
                            (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                        errmsg("function returning record called in context "
                               "that cannot accept type record")));
                    break;
                default:
                    /* result type isn't composite */
                    elog(ERROR, "return type must be a row type");
                    break;
            }

            /* make sure we have a persistent copy of the tupdesc */
            tupdesc = CreateTupleDescCopy(tupdesc);
            ntuples = PQntuples(res);
            nfields = PQnfields(res);
        }

        /*
         * check result and tuple descriptor have the same number of columns
         */
        if (nfields != tupdesc->natts)
            ereport(ERROR,
                    (errcode(ERRCODE_DATATYPE_MISMATCH),
                     errmsg("remote query result rowtype does not match "
                            "the specified FROM clause rowtype")));

        if (ntuples > 0)
        {
            AttInMetadata *attinmeta;
            int         nestlevel = -1;
            Tuplestorestate *tupstore;
            MemoryContext oldcontext;
            int         row;
            char      **values;

            attinmeta = TupleDescGetAttInMetadata(tupdesc);

            /* Set GUCs to ensure we read GUC-sensitive data types correctly */
            if (!is_sql_cmd)
                nestlevel = applyRemoteGucs(conn);

            oldcontext = MemoryContextSwitchTo(
                                    rsinfo->econtext->ecxt_per_query_memory);
            tupstore = tuplestore_begin_heap(true, false, work_mem);
            rsinfo->setResult = tupstore;
            rsinfo->setDesc = tupdesc;
            MemoryContextSwitchTo(oldcontext);

            values = (char **) palloc(nfields * sizeof(char *));

            /* put all tuples into the tuplestore */
            for (row = 0; row < ntuples; row++)
            {
                HeapTuple   tuple;

                if (!is_sql_cmd)
                {
                    int         i;

                    for (i = 0; i < nfields; i++)
                    {
                        if (PQgetisnull(res, row, i))
                            values[i] = NULL;
                        else
                            values[i] = PQgetvalue(res, row, i);
                    }
                }
                else
                {
                    values[0] = PQcmdStatus(res);
                }

                /* build the tuple and put it into the tuplestore. */
                tuple = BuildTupleFromCStrings(attinmeta, values);
                tuplestore_puttuple(tupstore, tuple);
            }

            /* clean up GUC settings, if we changed any */
            restoreLocalGucs(nestlevel);

            /* clean up and return the tuplestore */
            tuplestore_donestoring(tupstore);
        }

        PQclear(res);
    }
    PG_CATCH();
    {
        /* be sure to release the libpq result */
        PQclear(res);
        PG_RE_THROW();
    }
    PG_END_TRY();
}

PG_FUNCTION_INFO_V1 ( dblink_get_notify   ) 
PG_FUNCTION_INFO_V1 ( dblink_get_pkey   ) 
PG_FUNCTION_INFO_V1 ( dblink_build_sql_delete   ) 
PG_FUNCTION_INFO_V1 ( dblink_exec   ) 
PG_FUNCTION_INFO_V1 ( dblink_get_connections   ) 
PG_FUNCTION_INFO_V1 ( dblink_fdw_validator   ) 
PG_FUNCTION_INFO_V1 ( dblink_current_query   ) 
PG_FUNCTION_INFO_V1 ( dblink_build_sql_insert   ) 
PG_FUNCTION_INFO_V1 ( dblink_close   ) 
PG_FUNCTION_INFO_V1 ( dblink_fetch   ) 
PG_FUNCTION_INFO_V1 ( dblink_get_result   ) 
PG_FUNCTION_INFO_V1 ( dblink_record   ) 
PG_FUNCTION_INFO_V1 ( dblink_disconnect   ) 
PG_FUNCTION_INFO_V1 ( dblink_cancel_query   ) 
PG_FUNCTION_INFO_V1 ( dblink_build_sql_update   ) 
PG_FUNCTION_INFO_V1 ( dblink_send_query   ) 
PG_FUNCTION_INFO_V1 ( dblink_error_message   ) 
PG_FUNCTION_INFO_V1 ( dblink_connect   ) 
PG_FUNCTION_INFO_V1 ( dblink_is_busy   ) 
PG_FUNCTION_INFO_V1 ( dblink_open   ) 
static void prepTuplestoreResult ( FunctionCallInfo  fcinfo  )  [static]

Definition at line 785 of file dblink.c.

References ReturnSetInfo::allowedModes, ereport, errcode(), errmsg(), ERROR, IsA, NULL, FunctionCallInfoData::resultinfo, ReturnSetInfo::returnMode, ReturnSetInfo::setDesc, ReturnSetInfo::setResult, and SFRM_Materialize.

Referenced by dblink_fetch(), dblink_get_notify(), and dblink_record_internal().

{
    ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;

    /* check to see if query supports us returning a tuplestore */
    if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
        ereport(ERROR,
                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                 errmsg("set-valued function called in context that cannot accept a set")));
    if (!(rsinfo->allowedModes & SFRM_Materialize))
        ereport(ERROR,
                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                 errmsg("materialize mode required, but it is not allowed in this context")));

    /* let the executor know we're sending back a tuplestore */
    rsinfo->returnMode = SFRM_Materialize;

    /* caller must fill these to return a non-empty result */
    rsinfo->setResult = NULL;
    rsinfo->setDesc = NULL;
}

static char * quote_ident_cstr ( char *  rawstr  )  [static]

Definition at line 2339 of file dblink.c.

References cstring_to_text(), DatumGetTextP, DirectFunctionCall1, PointerGetDatum, quote_ident(), and text_to_cstring().

Referenced by get_sql_delete(), get_sql_insert(), get_sql_update(), and get_tuple_of_interest().

{
    text       *rawstr_text;
    text       *result_text;
    char       *result;

    rawstr_text = cstring_to_text(rawstr);
    result_text = DatumGetTextP(DirectFunctionCall1(quote_ident,
                                              PointerGetDatum(rawstr_text)));
    result = text_to_cstring(result_text);

    return result;
}

static void restoreLocalGucs ( int  nestlevel  )  [static]

Definition at line 2990 of file dblink.c.

References AtEOXact_GUC().

Referenced by materializeResult(), and storeQueryResult().

{
    /* Do nothing if no new nestlevel was created */
    if (nestlevel > 0)
        AtEOXact_GUC(true, nestlevel);
}

static PGresult * storeQueryResult ( storeInfo sinfo,
PGconn conn,
const char *  sql 
) [static]

Definition at line 1065 of file dblink.c.

References applyRemoteGucs(), CHECK_FOR_INTERRUPTS, storeInfo::cur_res, elog, ERROR, storeInfo::last_res, PGRES_SINGLE_TUPLE, PGRES_TUPLES_OK, PQclear(), PQerrorMessage(), PQgetResult(), PQresultStatus(), PQsendQuery(), PQsetSingleRowMode(), restoreLocalGucs(), and storeRow().

Referenced by materializeQueryResult().

{
    bool        first = true;
    int         nestlevel = -1;
    PGresult   *res;

    if (!PQsendQuery(conn, sql))
        elog(ERROR, "could not send query: %s", PQerrorMessage(conn));

    if (!PQsetSingleRowMode(conn))      /* shouldn't fail */
        elog(ERROR, "failed to set single-row mode for dblink query");

    for (;;)
    {
        CHECK_FOR_INTERRUPTS();

        sinfo->cur_res = PQgetResult(conn);
        if (!sinfo->cur_res)
            break;

        if (PQresultStatus(sinfo->cur_res) == PGRES_SINGLE_TUPLE)
        {
            /* got one row from possibly-bigger resultset */

            /*
             * Set GUCs to ensure we read GUC-sensitive data types correctly.
             * We shouldn't do this until we have a row in hand, to ensure
             * libpq has seen any earlier ParameterStatus protocol messages.
             */
            if (first && nestlevel < 0)
                nestlevel = applyRemoteGucs(conn);

            storeRow(sinfo, sinfo->cur_res, first);

            PQclear(sinfo->cur_res);
            sinfo->cur_res = NULL;
            first = false;
        }
        else
        {
            /* if empty resultset, fill tuplestore header */
            if (first && PQresultStatus(sinfo->cur_res) == PGRES_TUPLES_OK)
                storeRow(sinfo, sinfo->cur_res, first);

            /* store completed result at last_res */
            PQclear(sinfo->last_res);
            sinfo->last_res = sinfo->cur_res;
            sinfo->cur_res = NULL;
            first = true;
        }
    }

    /* clean up GUC settings, if we changed any */
    restoreLocalGucs(nestlevel);

    /* return last_res */
    res = sinfo->last_res;
    sinfo->last_res = NULL;
    return res;
}

static void storeRow ( storeInfo sinfo,
PGresult res,
bool  first 
) [static]

Definition at line 1133 of file dblink.c.

References ALLOCSET_DEFAULT_INITSIZE, ALLOCSET_DEFAULT_MAXSIZE, ALLOCSET_DEFAULT_MINSIZE, AllocSetContextCreate(), Assert, storeInfo::attinmeta, BuildTupleFromCStrings(), CreateTupleDescCopy(), storeInfo::cstrs, CurrentMemoryContext, ReturnSetInfo::econtext, ExprContext::ecxt_per_query_memory, elog, ereport, errcode(), errmsg(), ERROR, storeInfo::fcinfo, get_call_result_type(), i, MemoryContextReset(), MemoryContextSwitchTo(), NULL, palloc(), pfree(), PQgetisnull(), PQgetvalue(), PQnfields(), PQntuples(), FunctionCallInfoData::resultinfo, ReturnSetInfo::setDesc, ReturnSetInfo::setResult, storeInfo::tmpcontext, TupleDescGetAttInMetadata(), storeInfo::tuplestore, tuplestore_begin_heap(), tuplestore_end(), tuplestore_puttuple(), TYPEFUNC_COMPOSITE, TYPEFUNC_RECORD, and work_mem.

Referenced by storeQueryResult().

{
    int         nfields = PQnfields(res);
    HeapTuple   tuple;
    int         i;
    MemoryContext oldcontext;

    if (first)
    {
        /* Prepare for new result set */
        ReturnSetInfo *rsinfo = (ReturnSetInfo *) sinfo->fcinfo->resultinfo;
        TupleDesc   tupdesc;

        /*
         * It's possible to get more than one result set if the query string
         * contained multiple SQL commands.  In that case, we follow PQexec's
         * traditional behavior of throwing away all but the last result.
         */
        if (sinfo->tuplestore)
            tuplestore_end(sinfo->tuplestore);
        sinfo->tuplestore = NULL;

        /* get a tuple descriptor for our result type */
        switch (get_call_result_type(sinfo->fcinfo, NULL, &tupdesc))
        {
            case TYPEFUNC_COMPOSITE:
                /* success */
                break;
            case TYPEFUNC_RECORD:
                /* failed to determine actual type of RECORD */
                ereport(ERROR,
                        (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                         errmsg("function returning record called in context "
                                "that cannot accept type record")));
                break;
            default:
                /* result type isn't composite */
                elog(ERROR, "return type must be a row type");
                break;
        }

        /* make sure we have a persistent copy of the tupdesc */
        tupdesc = CreateTupleDescCopy(tupdesc);

        /* check result and tuple descriptor have the same number of columns */
        if (nfields != tupdesc->natts)
            ereport(ERROR,
                    (errcode(ERRCODE_DATATYPE_MISMATCH),
                     errmsg("remote query result rowtype does not match "
                            "the specified FROM clause rowtype")));

        /* Prepare attinmeta for later data conversions */
        sinfo->attinmeta = TupleDescGetAttInMetadata(tupdesc);

        /* Create a new, empty tuplestore */
        oldcontext = MemoryContextSwitchTo(rsinfo->econtext->ecxt_per_query_memory);
        sinfo->tuplestore = tuplestore_begin_heap(true, false, work_mem);
        rsinfo->setResult = sinfo->tuplestore;
        rsinfo->setDesc = tupdesc;
        MemoryContextSwitchTo(oldcontext);

        /* Done if empty resultset */
        if (PQntuples(res) == 0)
            return;

        /*
         * Set up sufficiently-wide string pointers array; this won't change
         * in size so it's easy to preallocate.
         */
        if (sinfo->cstrs)
            pfree(sinfo->cstrs);
        sinfo->cstrs = (char **) palloc(nfields * sizeof(char *));

        /* Create short-lived memory context for data conversions */
        if (!sinfo->tmpcontext)
            sinfo->tmpcontext =
                AllocSetContextCreate(CurrentMemoryContext,
                                      "dblink temporary context",
                                      ALLOCSET_DEFAULT_MINSIZE,
                                      ALLOCSET_DEFAULT_INITSIZE,
                                      ALLOCSET_DEFAULT_MAXSIZE);
    }

    /* Should have a single-row result if we get here */
    Assert(PQntuples(res) == 1);

    /*
     * Do the following work in a temp context that we reset after each tuple.
     * This cleans up not only the data we have direct access to, but any
     * cruft the I/O functions might leak.
     */
    oldcontext = MemoryContextSwitchTo(sinfo->tmpcontext);

    /*
     * Fill cstrs with null-terminated strings of column values.
     */
    for (i = 0; i < nfields; i++)
    {
        if (PQgetisnull(res, 0, i))
            sinfo->cstrs[i] = NULL;
        else
            sinfo->cstrs[i] = PQgetvalue(res, 0, i);
    }

    /* Convert row to a tuple, and add it to the tuplestore */
    tuple = BuildTupleFromCStrings(sinfo->attinmeta, sinfo->cstrs);

    tuplestore_puttuple(sinfo->tuplestore, tuple);

    /* Clean up */
    MemoryContextSwitchTo(oldcontext);
    MemoryContextReset(sinfo->tmpcontext);
}

static void validate_pkattnums ( Relation  rel,
int2vector pkattnums_arg,
int32  pknumatts_arg,
int **  pkattnums,
int *  pknumatts 
) [static]

Definition at line 2816 of file dblink.c.

References tupleDesc::attrs, int2vector::dim1, ereport, errcode(), errmsg(), ERROR, i, Min, tupleDesc::natts, palloc(), RelationData::rd_att, and int2vector::values.

Referenced by dblink_build_sql_delete(), dblink_build_sql_insert(), and dblink_build_sql_update().

{
    TupleDesc   tupdesc = rel->rd_att;
    int         natts = tupdesc->natts;
    int         i;

    /* Don't take more array elements than there are */
    pknumatts_arg = Min(pknumatts_arg, pkattnums_arg->dim1);

    /* Must have at least one pk attnum selected */
    if (pknumatts_arg <= 0)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("number of key attributes must be > 0")));

    /* Allocate output array */
    *pkattnums = (int *) palloc(pknumatts_arg * sizeof(int));
    *pknumatts = pknumatts_arg;

    /* Validate attnums and convert to internal form */
    for (i = 0; i < pknumatts_arg; i++)
    {
        int         pkattnum = pkattnums_arg->values[i];
        int         lnum;
        int         j;

        /* Can throw error immediately if out of range */
        if (pkattnum <= 0 || pkattnum > natts)
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                     errmsg("invalid attribute number %d", pkattnum)));

        /* Identify which physical column has this logical number */
        lnum = 0;
        for (j = 0; j < natts; j++)
        {
            /* dropped columns don't count */
            if (tupdesc->attrs[j]->attisdropped)
                continue;

            if (++lnum == pkattnum)
                break;
        }

        if (j < natts)
            (*pkattnums)[i] = j;
        else
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                     errmsg("invalid attribute number %d", pkattnum)));
    }
}


Variable Documentation

remoteConn* pconn = NULL [static]

Definition at line 127 of file dblink.c.

Definition at line 64 of file dblink.c.

HTAB* remoteConnHash = NULL [static]

Definition at line 128 of file dblink.c.