mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-08-26 07:07:19 +02:00
Per discussion, the existing routine name able to initialize a SRF
function with materialize mode is unpopular, so rename it. Equally, the
flags of this function are renamed, as of:
- SRF_SINGLE_USE_EXPECTED -> MAT_SRF_USE_EXPECTED_DESC
- SRF_SINGLE_BLESS -> MAT_SRF_BLESS
The previous function and flags introduced in 9e98583
are kept around
for compatibility purposes, so as any extension code already compiled
with v15 continues to work as-is. The declarations introduced here for
compatibility will be removed from HEAD in a follow-up commit.
The new names have been suggested by Andres Freund and Melanie
Plageman.
Discussion: https://postgr.es/m/20221013194820.ciktb2sbbpw7cljm@awork3.anarazel.de
Backpatch-through: 15
3095 lines
77 KiB
C
3095 lines
77 KiB
C
/*
|
|
* dblink.c
|
|
*
|
|
* Functions returning results from a remote database
|
|
*
|
|
* Joe Conway <mail@joeconway.com>
|
|
* And contributors:
|
|
* Darko Prenosil <Darko.Prenosil@finteh.hr>
|
|
* Shridhar Daithankar <shridhar_daithankar@persistent.co.in>
|
|
*
|
|
* contrib/dblink/dblink.c
|
|
* Copyright (c) 2001-2022, PostgreSQL Global Development Group
|
|
* ALL RIGHTS RESERVED;
|
|
*
|
|
* Permission to use, copy, modify, and distribute this software and its
|
|
* documentation for any purpose, without fee, and without a written agreement
|
|
* is hereby granted, provided that the above copyright notice and this
|
|
* paragraph and the following two paragraphs appear in all copies.
|
|
*
|
|
* IN NO EVENT SHALL THE AUTHOR OR DISTRIBUTORS BE LIABLE TO ANY PARTY FOR
|
|
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
|
|
* LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
|
|
* DOCUMENTATION, EVEN IF THE AUTHOR OR DISTRIBUTORS HAVE BEEN ADVISED OF THE
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
|
*
|
|
* THE AUTHOR AND DISTRIBUTORS SPECIFICALLY DISCLAIMS ANY WARRANTIES,
|
|
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
|
|
* AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
|
|
* ON AN "AS IS" BASIS, AND THE AUTHOR AND DISTRIBUTORS HAS NO OBLIGATIONS TO
|
|
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
|
|
*
|
|
*/
|
|
#include "postgres.h"
|
|
|
|
#include <limits.h>
|
|
|
|
#include "access/htup_details.h"
|
|
#include "access/relation.h"
|
|
#include "access/reloptions.h"
|
|
#include "access/table.h"
|
|
#include "catalog/namespace.h"
|
|
#include "catalog/pg_foreign_data_wrapper.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 "libpq-fe.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/varlena.h"
|
|
|
|
PG_MODULE_MAGIC;
|
|
|
|
typedef struct remoteConn
|
|
{
|
|
PGconn *conn; /* Hold the remote connection */
|
|
int openCursorCount; /* The number of open cursors */
|
|
bool newXactForCursor; /* Opened a transaction for a cursor */
|
|
} remoteConn;
|
|
|
|
typedef struct storeInfo
|
|
{
|
|
FunctionCallInfo fcinfo;
|
|
Tuplestorestate *tuplestore;
|
|
AttInMetadata *attinmeta;
|
|
MemoryContext tmpcontext;
|
|
char **cstrs;
|
|
/* temp storage for results to avoid leaks on exception */
|
|
PGresult *last_res;
|
|
PGresult *cur_res;
|
|
} storeInfo;
|
|
|
|
/*
|
|
* Internal declarations
|
|
*/
|
|
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 PGresult *storeQueryResult(volatile storeInfo *sinfo, PGconn *conn, const char *sql);
|
|
static void storeRow(volatile storeInfo *sinfo, PGresult *res, bool first);
|
|
static remoteConn *getConnectionByName(const char *name);
|
|
static HTAB *createConnHash(void);
|
|
static void createNewConnection(const char *name, remoteConn *rconn);
|
|
static void deleteConnection(const char *name);
|
|
static char **get_pkey_attnames(Relation rel, int16 *indnkeyatts);
|
|
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(PGconn *conn, const char *conname, PGresult *res,
|
|
bool fail, const char *fmt,...) pg_attribute_printf(5, 6);
|
|
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);
|
|
|
|
/* Global */
|
|
static remoteConn *pconn = NULL;
|
|
static HTAB *remoteConnHash = NULL;
|
|
|
|
/*
|
|
* Following is list that holds multiple remote connections.
|
|
* Calling convention of each dblink function changes to accept
|
|
* connection name as the first parameter. The connection list is
|
|
* much like ecpg e.g. a mapping between a name and a PGconn object.
|
|
*/
|
|
|
|
typedef struct remoteConnHashEnt
|
|
{
|
|
char name[NAMEDATALEN];
|
|
remoteConn *rconn;
|
|
} remoteConnHashEnt;
|
|
|
|
/* initial number of connection hashes */
|
|
#define NUMCONN 16
|
|
|
|
static char *
|
|
xpstrdup(const char *in)
|
|
{
|
|
if (in == NULL)
|
|
return NULL;
|
|
return pstrdup(in);
|
|
}
|
|
|
|
static void
|
|
pg_attribute_noreturn()
|
|
dblink_res_internalerror(PGconn *conn, PGresult *res, const char *p2)
|
|
{
|
|
char *msg = pchomp(PQerrorMessage(conn));
|
|
|
|
if (res)
|
|
PQclear(res);
|
|
elog(ERROR, "%s: %s", p2, msg);
|
|
}
|
|
|
|
static void
|
|
pg_attribute_noreturn()
|
|
dblink_conn_not_avail(const char *conname)
|
|
{
|
|
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")));
|
|
}
|
|
|
|
static void
|
|
dblink_get_conn(char *conname_or_str,
|
|
PGconn *volatile *conn_p, char **conname_p, volatile bool *freeconn_p)
|
|
{
|
|
remoteConn *rconn = getConnectionByName(conname_or_str);
|
|
PGconn *conn;
|
|
char *conname;
|
|
bool freeconn;
|
|
|
|
if (rconn)
|
|
{
|
|
conn = rconn->conn;
|
|
conname = conname_or_str;
|
|
freeconn = false;
|
|
}
|
|
else
|
|
{
|
|
const char *connstr;
|
|
|
|
connstr = get_connect_string(conname_or_str);
|
|
if (connstr == NULL)
|
|
connstr = conname_or_str;
|
|
dblink_connstr_check(connstr);
|
|
|
|
/*
|
|
* We must obey fd.c's limit on non-virtual file descriptors. Assume
|
|
* that a PGconn represents one long-lived FD. (Doing this here also
|
|
* ensures that VFDs are closed if needed to make room.)
|
|
*/
|
|
if (!AcquireExternalFD())
|
|
{
|
|
#ifndef WIN32 /* can't write #if within ereport() macro */
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_SQLCLIENT_UNABLE_TO_ESTABLISH_SQLCONNECTION),
|
|
errmsg("could not establish connection"),
|
|
errdetail("There are too many open files on the local server."),
|
|
errhint("Raise the server's max_files_per_process and/or \"ulimit -n\" limits.")));
|
|
#else
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_SQLCLIENT_UNABLE_TO_ESTABLISH_SQLCONNECTION),
|
|
errmsg("could not establish connection"),
|
|
errdetail("There are too many open files on the local server."),
|
|
errhint("Raise the server's max_files_per_process setting.")));
|
|
#endif
|
|
}
|
|
|
|
/* OK to make connection */
|
|
conn = PQconnectdb(connstr);
|
|
|
|
if (PQstatus(conn) == CONNECTION_BAD)
|
|
{
|
|
char *msg = pchomp(PQerrorMessage(conn));
|
|
|
|
PQfinish(conn);
|
|
ReleaseExternalFD();
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_SQLCLIENT_UNABLE_TO_ESTABLISH_SQLCONNECTION),
|
|
errmsg("could not establish connection"),
|
|
errdetail_internal("%s", msg)));
|
|
}
|
|
dblink_security_check(conn, rconn);
|
|
if (PQclientEncoding(conn) != GetDatabaseEncoding())
|
|
PQsetClientEncoding(conn, GetDatabaseEncodingName());
|
|
freeconn = true;
|
|
conname = NULL;
|
|
}
|
|
|
|
*conn_p = conn;
|
|
*conname_p = conname;
|
|
*freeconn_p = freeconn;
|
|
}
|
|
|
|
static PGconn *
|
|
dblink_get_named_conn(const char *conname)
|
|
{
|
|
remoteConn *rconn = getConnectionByName(conname);
|
|
|
|
if (rconn)
|
|
return rconn->conn;
|
|
|
|
dblink_conn_not_avail(conname);
|
|
return NULL; /* keep compiler quiet */
|
|
}
|
|
|
|
static void
|
|
dblink_init(void)
|
|
{
|
|
if (!pconn)
|
|
{
|
|
pconn = (remoteConn *) MemoryContextAlloc(TopMemoryContext, sizeof(remoteConn));
|
|
pconn->conn = NULL;
|
|
pconn->openCursorCount = 0;
|
|
pconn->newXactForCursor = false;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Create a persistent connection to another database
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_connect);
|
|
Datum
|
|
dblink_connect(PG_FUNCTION_ARGS)
|
|
{
|
|
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));
|
|
rconn->conn = NULL;
|
|
rconn->openCursorCount = 0;
|
|
rconn->newXactForCursor = false;
|
|
}
|
|
|
|
/* 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);
|
|
|
|
/*
|
|
* We must obey fd.c's limit on non-virtual file descriptors. Assume that
|
|
* a PGconn represents one long-lived FD. (Doing this here also ensures
|
|
* that VFDs are closed if needed to make room.)
|
|
*/
|
|
if (!AcquireExternalFD())
|
|
{
|
|
#ifndef WIN32 /* can't write #if within ereport() macro */
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_SQLCLIENT_UNABLE_TO_ESTABLISH_SQLCONNECTION),
|
|
errmsg("could not establish connection"),
|
|
errdetail("There are too many open files on the local server."),
|
|
errhint("Raise the server's max_files_per_process and/or \"ulimit -n\" limits.")));
|
|
#else
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_SQLCLIENT_UNABLE_TO_ESTABLISH_SQLCONNECTION),
|
|
errmsg("could not establish connection"),
|
|
errdetail("There are too many open files on the local server."),
|
|
errhint("Raise the server's max_files_per_process setting.")));
|
|
#endif
|
|
}
|
|
|
|
/* OK to make connection */
|
|
conn = PQconnectdb(connstr);
|
|
|
|
if (PQstatus(conn) == CONNECTION_BAD)
|
|
{
|
|
msg = pchomp(PQerrorMessage(conn));
|
|
PQfinish(conn);
|
|
ReleaseExternalFD();
|
|
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, if needed */
|
|
if (PQclientEncoding(conn) != GetDatabaseEncoding())
|
|
PQsetClientEncoding(conn, GetDatabaseEncodingName());
|
|
|
|
if (connname)
|
|
{
|
|
rconn->conn = conn;
|
|
createNewConnection(connname, rconn);
|
|
}
|
|
else
|
|
{
|
|
if (pconn->conn)
|
|
{
|
|
PQfinish(pconn->conn);
|
|
ReleaseExternalFD();
|
|
}
|
|
pconn->conn = conn;
|
|
}
|
|
|
|
PG_RETURN_TEXT_P(cstring_to_text("OK"));
|
|
}
|
|
|
|
/*
|
|
* Clear a persistent connection to another database
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_disconnect);
|
|
Datum
|
|
dblink_disconnect(PG_FUNCTION_ARGS)
|
|
{
|
|
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(conname);
|
|
|
|
PQfinish(conn);
|
|
ReleaseExternalFD();
|
|
if (rconn)
|
|
{
|
|
deleteConnection(conname);
|
|
pfree(rconn);
|
|
}
|
|
else
|
|
pconn->conn = NULL;
|
|
|
|
PG_RETURN_TEXT_P(cstring_to_text("OK"));
|
|
}
|
|
|
|
/*
|
|
* opens a cursor using a persistent connection
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_open);
|
|
Datum
|
|
dblink_open(PG_FUNCTION_ARGS)
|
|
{
|
|
PGresult *res = NULL;
|
|
PGconn *conn;
|
|
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(conname);
|
|
|
|
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(conn, res, "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(conn, conname, res, fail,
|
|
"while opening cursor \"%s\"", curname);
|
|
PG_RETURN_TEXT_P(cstring_to_text("ERROR"));
|
|
}
|
|
|
|
PQclear(res);
|
|
PG_RETURN_TEXT_P(cstring_to_text("OK"));
|
|
}
|
|
|
|
/*
|
|
* closes a cursor
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_close);
|
|
Datum
|
|
dblink_close(PG_FUNCTION_ARGS)
|
|
{
|
|
PGconn *conn;
|
|
PGresult *res = NULL;
|
|
char *curname = NULL;
|
|
char *conname = NULL;
|
|
StringInfoData buf;
|
|
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(conname);
|
|
|
|
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(conn, conname, res, fail,
|
|
"while closing cursor \"%s\"", curname);
|
|
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(conn, res, "commit error");
|
|
PQclear(res);
|
|
}
|
|
}
|
|
|
|
PG_RETURN_TEXT_P(cstring_to_text("OK"));
|
|
}
|
|
|
|
/*
|
|
* Fetch results from an open cursor
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_fetch);
|
|
Datum
|
|
dblink_fetch(PG_FUNCTION_ARGS)
|
|
{
|
|
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(conname);
|
|
|
|
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(conn, conname, res, fail,
|
|
"while fetching from cursor \"%s\"", curname);
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* Note: this is the new preferred version of dblink
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_record);
|
|
Datum
|
|
dblink_record(PG_FUNCTION_ARGS)
|
|
{
|
|
return dblink_record_internal(fcinfo, false);
|
|
}
|
|
|
|
PG_FUNCTION_INFO_V1(dblink_send_query);
|
|
Datum
|
|
dblink_send_query(PG_FUNCTION_ARGS)
|
|
{
|
|
PGconn *conn;
|
|
char *sql;
|
|
int retval;
|
|
|
|
if (PG_NARGS() == 2)
|
|
{
|
|
conn = dblink_get_named_conn(text_to_cstring(PG_GETARG_TEXT_PP(0)));
|
|
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", pchomp(PQerrorMessage(conn)));
|
|
|
|
PG_RETURN_INT32(retval);
|
|
}
|
|
|
|
PG_FUNCTION_INFO_V1(dblink_get_result);
|
|
Datum
|
|
dblink_get_result(PG_FUNCTION_ARGS)
|
|
{
|
|
return dblink_record_internal(fcinfo, true);
|
|
}
|
|
|
|
static Datum
|
|
dblink_record_internal(FunctionCallInfo fcinfo, bool is_async)
|
|
{
|
|
PGconn *volatile conn = NULL;
|
|
volatile bool freeconn = false;
|
|
|
|
prepTuplestoreResult(fcinfo);
|
|
|
|
dblink_init();
|
|
|
|
PG_TRY();
|
|
{
|
|
char *sql = NULL;
|
|
char *conname = NULL;
|
|
bool fail = true; /* default to backward compatible */
|
|
|
|
if (!is_async)
|
|
{
|
|
if (PG_NARGS() == 3)
|
|
{
|
|
/* text,text,bool */
|
|
conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
|
|
sql = text_to_cstring(PG_GETARG_TEXT_PP(1));
|
|
fail = PG_GETARG_BOOL(2);
|
|
dblink_get_conn(conname, &conn, &conname, &freeconn);
|
|
}
|
|
else if (PG_NARGS() == 2)
|
|
{
|
|
/* text,text or text,bool */
|
|
if (get_fn_expr_argtype(fcinfo->flinfo, 1) == BOOLOID)
|
|
{
|
|
sql = text_to_cstring(PG_GETARG_TEXT_PP(0));
|
|
fail = PG_GETARG_BOOL(1);
|
|
conn = pconn->conn;
|
|
}
|
|
else
|
|
{
|
|
conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
|
|
sql = text_to_cstring(PG_GETARG_TEXT_PP(1));
|
|
dblink_get_conn(conname, &conn, &conname, &freeconn);
|
|
}
|
|
}
|
|
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 */
|
|
conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
|
|
|
|
if (PG_NARGS() == 2)
|
|
{
|
|
/* text,bool */
|
|
fail = PG_GETARG_BOOL(1);
|
|
conn = dblink_get_named_conn(conname);
|
|
}
|
|
else if (PG_NARGS() == 1)
|
|
{
|
|
/* text */
|
|
conn = dblink_get_named_conn(conname);
|
|
}
|
|
else
|
|
/* shouldn't happen */
|
|
elog(ERROR, "wrong number of arguments");
|
|
}
|
|
|
|
if (!conn)
|
|
dblink_conn_not_avail(conname);
|
|
|
|
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(conn, conname, res, fail,
|
|
"while executing query");
|
|
/* if fail isn't set, we'll return an empty query result */
|
|
}
|
|
else
|
|
{
|
|
materializeResult(fcinfo, conn, res);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
PG_FINALLY();
|
|
{
|
|
/* if needed, close the connection to the database */
|
|
if (freeconn)
|
|
{
|
|
PQfinish(conn);
|
|
ReleaseExternalFD();
|
|
}
|
|
}
|
|
PG_END_TRY();
|
|
|
|
return (Datum) 0;
|
|
}
|
|
|
|
/*
|
|
* Verify function caller can handle a tuplestore result, and set up for that.
|
|
*
|
|
* Note: if the caller returns without actually creating a tuplestore, the
|
|
* executor will treat the function result as an empty set.
|
|
*/
|
|
static void
|
|
prepTuplestoreResult(FunctionCallInfo fcinfo)
|
|
{
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* Copy the contents of the PGresult into a tuplestore to be returned
|
|
* as the result of the current function.
|
|
* The PGresult will be released in this function.
|
|
*/
|
|
static void
|
|
materializeResult(FunctionCallInfo fcinfo, PGconn *conn, PGresult *res)
|
|
{
|
|
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);
|
|
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);
|
|
}
|
|
}
|
|
PG_FINALLY();
|
|
{
|
|
/* be sure to release the libpq result */
|
|
PQclear(res);
|
|
}
|
|
PG_END_TRY();
|
|
}
|
|
|
|
/*
|
|
* Execute the given SQL command and store its results into a tuplestore
|
|
* to be returned as the result of the current function.
|
|
*
|
|
* This is equivalent to PQexec followed by materializeResult, but we make
|
|
* use of libpq's single-row mode to avoid accumulating the whole result
|
|
* inside libpq before it gets transferred to the tuplestore.
|
|
*/
|
|
static void
|
|
materializeQueryResult(FunctionCallInfo fcinfo,
|
|
PGconn *conn,
|
|
const char *conname,
|
|
const char *sql,
|
|
bool fail)
|
|
{
|
|
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
|
|
PGresult *volatile res = NULL;
|
|
volatile storeInfo sinfo = {0};
|
|
|
|
/* prepTuplestoreResult must have been called previously */
|
|
Assert(rsinfo->returnMode == SFRM_Materialize);
|
|
|
|
sinfo.fcinfo = fcinfo;
|
|
|
|
PG_TRY();
|
|
{
|
|
/* Create short-lived memory context for data conversions */
|
|
sinfo.tmpcontext = AllocSetContextCreate(CurrentMemoryContext,
|
|
"dblink temporary context",
|
|
ALLOCSET_DEFAULT_SIZES);
|
|
|
|
/* 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(conn, conname, res1, fail,
|
|
"while executing query");
|
|
/* 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);
|
|
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;
|
|
}
|
|
|
|
/* clean up data conversion short-lived memory context */
|
|
if (sinfo.tmpcontext != NULL)
|
|
MemoryContextDelete(sinfo.tmpcontext);
|
|
sinfo.tmpcontext = 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();
|
|
}
|
|
|
|
/*
|
|
* Execute query, and send any result rows to sinfo->tuplestore.
|
|
*/
|
|
static PGresult *
|
|
storeQueryResult(volatile storeInfo *sinfo, PGconn *conn, const char *sql)
|
|
{
|
|
bool first = true;
|
|
int nestlevel = -1;
|
|
PGresult *res;
|
|
|
|
if (!PQsendQuery(conn, sql))
|
|
elog(ERROR, "could not send query: %s", pchomp(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;
|
|
}
|
|
|
|
/*
|
|
* Send single row to sinfo->tuplestore.
|
|
*
|
|
* If "first" is true, create the tuplestore using PGresult's metadata
|
|
* (in this case the PGresult might contain either zero or one row).
|
|
*/
|
|
static void
|
|
storeRow(volatile storeInfo *sinfo, PGresult *res, bool first)
|
|
{
|
|
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 *));
|
|
}
|
|
|
|
/* 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);
|
|
}
|
|
|
|
/*
|
|
* List all open dblink connections by name.
|
|
* Returns an array of all connection names.
|
|
* Takes no params
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_get_connections);
|
|
Datum
|
|
dblink_get_connections(PG_FUNCTION_ARGS)
|
|
{
|
|
HASH_SEQ_STATUS status;
|
|
remoteConnHashEnt *hentry;
|
|
ArrayBuildState *astate = NULL;
|
|
|
|
if (remoteConnHash)
|
|
{
|
|
hash_seq_init(&status, remoteConnHash);
|
|
while ((hentry = (remoteConnHashEnt *) hash_seq_search(&status)) != NULL)
|
|
{
|
|
/* stash away current value */
|
|
astate = accumArrayResult(astate,
|
|
CStringGetTextDatum(hentry->name),
|
|
false, TEXTOID, CurrentMemoryContext);
|
|
}
|
|
}
|
|
|
|
if (astate)
|
|
PG_RETURN_ARRAYTYPE_P(makeArrayResult(astate,
|
|
CurrentMemoryContext));
|
|
else
|
|
PG_RETURN_NULL();
|
|
}
|
|
|
|
/*
|
|
* Checks if a given remote connection is busy
|
|
*
|
|
* Returns 1 if the connection is busy, 0 otherwise
|
|
* Params:
|
|
* text connection_name - name of the connection to check
|
|
*
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_is_busy);
|
|
Datum
|
|
dblink_is_busy(PG_FUNCTION_ARGS)
|
|
{
|
|
PGconn *conn;
|
|
|
|
dblink_init();
|
|
conn = dblink_get_named_conn(text_to_cstring(PG_GETARG_TEXT_PP(0)));
|
|
|
|
PQconsumeInput(conn);
|
|
PG_RETURN_INT32(PQisBusy(conn));
|
|
}
|
|
|
|
/*
|
|
* Cancels a running request on a connection
|
|
*
|
|
* Returns text:
|
|
* "OK" if the cancel request has been sent correctly,
|
|
* an error message otherwise
|
|
*
|
|
* Params:
|
|
* text connection_name - name of the connection to check
|
|
*
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_cancel_query);
|
|
Datum
|
|
dblink_cancel_query(PG_FUNCTION_ARGS)
|
|
{
|
|
int res;
|
|
PGconn *conn;
|
|
PGcancel *cancel;
|
|
char errbuf[256];
|
|
|
|
dblink_init();
|
|
conn = dblink_get_named_conn(text_to_cstring(PG_GETARG_TEXT_PP(0)));
|
|
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));
|
|
}
|
|
|
|
|
|
/*
|
|
* Get error message from a connection
|
|
*
|
|
* Returns text:
|
|
* "OK" if no error, an error message otherwise
|
|
*
|
|
* Params:
|
|
* text connection_name - name of the connection to check
|
|
*
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_error_message);
|
|
Datum
|
|
dblink_error_message(PG_FUNCTION_ARGS)
|
|
{
|
|
char *msg;
|
|
PGconn *conn;
|
|
|
|
dblink_init();
|
|
conn = dblink_get_named_conn(text_to_cstring(PG_GETARG_TEXT_PP(0)));
|
|
|
|
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(pchomp(msg)));
|
|
}
|
|
|
|
/*
|
|
* Execute an SQL non-SELECT command
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_exec);
|
|
Datum
|
|
dblink_exec(PG_FUNCTION_ARGS)
|
|
{
|
|
text *volatile sql_cmd_status = NULL;
|
|
PGconn *volatile conn = NULL;
|
|
volatile bool freeconn = false;
|
|
|
|
dblink_init();
|
|
|
|
PG_TRY();
|
|
{
|
|
PGresult *res = NULL;
|
|
char *sql = NULL;
|
|
char *conname = NULL;
|
|
bool fail = true; /* default to backward compatible behavior */
|
|
|
|
if (PG_NARGS() == 3)
|
|
{
|
|
/* must be text,text,bool */
|
|
conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
|
|
sql = text_to_cstring(PG_GETARG_TEXT_PP(1));
|
|
fail = PG_GETARG_BOOL(2);
|
|
dblink_get_conn(conname, &conn, &conname, &freeconn);
|
|
}
|
|
else if (PG_NARGS() == 2)
|
|
{
|
|
/* might be text,text or text,bool */
|
|
if (get_fn_expr_argtype(fcinfo->flinfo, 1) == BOOLOID)
|
|
{
|
|
sql = text_to_cstring(PG_GETARG_TEXT_PP(0));
|
|
fail = PG_GETARG_BOOL(1);
|
|
conn = pconn->conn;
|
|
}
|
|
else
|
|
{
|
|
conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
|
|
sql = text_to_cstring(PG_GETARG_TEXT_PP(1));
|
|
dblink_get_conn(conname, &conn, &conname, &freeconn);
|
|
}
|
|
}
|
|
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(conname);
|
|
|
|
res = PQexec(conn, sql);
|
|
if (!res ||
|
|
(PQresultStatus(res) != PGRES_COMMAND_OK &&
|
|
PQresultStatus(res) != PGRES_TUPLES_OK))
|
|
{
|
|
dblink_res_error(conn, conname, res, fail,
|
|
"while executing command");
|
|
|
|
/*
|
|
* 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_FINALLY();
|
|
{
|
|
/* if needed, close the connection to the database */
|
|
if (freeconn)
|
|
{
|
|
PQfinish(conn);
|
|
ReleaseExternalFD();
|
|
}
|
|
}
|
|
PG_END_TRY();
|
|
|
|
PG_RETURN_TEXT_P(sql_cmd_status);
|
|
}
|
|
|
|
|
|
/*
|
|
* dblink_get_pkey
|
|
*
|
|
* Return list of primary key fields for the supplied relation,
|
|
* or NULL if none exists.
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_get_pkey);
|
|
Datum
|
|
dblink_get_pkey(PG_FUNCTION_ARGS)
|
|
{
|
|
int16 indnkeyatts;
|
|
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_PP(0), AccessShareLock, ACL_SELECT);
|
|
|
|
/* get the array of attnums */
|
|
results = get_pkey_attnames(rel, &indnkeyatts);
|
|
|
|
relation_close(rel, AccessShareLock);
|
|
|
|
/*
|
|
* need a tuple descriptor representing one INT and one TEXT column
|
|
*/
|
|
tupdesc = CreateTemplateTupleDesc(2);
|
|
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) && (indnkeyatts > 0))
|
|
{
|
|
funcctx->max_calls = indnkeyatts;
|
|
|
|
/* 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] = psprintf("%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);
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* dblink_build_sql_insert
|
|
*
|
|
* Used to generate an SQL insert statement
|
|
* based on an existing tuple in a local relation.
|
|
* This is useful for selectively replicating data
|
|
* to another server via dblink.
|
|
*
|
|
* API:
|
|
* <relname> - name of local table of interest
|
|
* <pkattnums> - an int2vector of attnums which will be used
|
|
* to identify the local tuple of interest
|
|
* <pknumatts> - number of attnums in pkattnums
|
|
* <src_pkattvals_arry> - text array of key values which will be used
|
|
* to identify the local tuple of interest
|
|
* <tgt_pkattvals_arry> - text array of key values which will be used
|
|
* to build the string for execution remotely. These are substituted
|
|
* for their counterparts in src_pkattvals_arry
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_build_sql_insert);
|
|
Datum
|
|
dblink_build_sql_insert(PG_FUNCTION_ARGS)
|
|
{
|
|
text *relname_text = PG_GETARG_TEXT_PP(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));
|
|
}
|
|
|
|
|
|
/*
|
|
* dblink_build_sql_delete
|
|
*
|
|
* Used to generate an SQL delete statement.
|
|
* This is useful for selectively replicating a
|
|
* delete to another server via dblink.
|
|
*
|
|
* API:
|
|
* <relname> - name of remote table of interest
|
|
* <pkattnums> - an int2vector of attnums which will be used
|
|
* to identify the remote tuple of interest
|
|
* <pknumatts> - number of attnums in pkattnums
|
|
* <tgt_pkattvals_arry> - text array of key values which will be used
|
|
* to build the string for execution remotely.
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_build_sql_delete);
|
|
Datum
|
|
dblink_build_sql_delete(PG_FUNCTION_ARGS)
|
|
{
|
|
text *relname_text = PG_GETARG_TEXT_PP(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));
|
|
}
|
|
|
|
|
|
/*
|
|
* dblink_build_sql_update
|
|
*
|
|
* Used to generate an SQL update statement
|
|
* based on an existing tuple in a local relation.
|
|
* This is useful for selectively replicating data
|
|
* to another server via dblink.
|
|
*
|
|
* API:
|
|
* <relname> - name of local table of interest
|
|
* <pkattnums> - an int2vector of attnums which will be used
|
|
* to identify the local tuple of interest
|
|
* <pknumatts> - number of attnums in pkattnums
|
|
* <src_pkattvals_arry> - text array of key values which will be used
|
|
* to identify the local tuple of interest
|
|
* <tgt_pkattvals_arry> - text array of key values which will be used
|
|
* to build the string for execution remotely. These are substituted
|
|
* for their counterparts in src_pkattvals_arry
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_build_sql_update);
|
|
Datum
|
|
dblink_build_sql_update(PG_FUNCTION_ARGS)
|
|
{
|
|
text *relname_text = PG_GETARG_TEXT_PP(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));
|
|
}
|
|
|
|
/*
|
|
* dblink_current_query
|
|
* return the current query string
|
|
* to allow its use in (among other things)
|
|
* rewrite rules
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_current_query);
|
|
Datum
|
|
dblink_current_query(PG_FUNCTION_ARGS)
|
|
{
|
|
/* This is now just an alias for the built-in function current_query() */
|
|
PG_RETURN_DATUM(current_query(fcinfo));
|
|
}
|
|
|
|
/*
|
|
* Retrieve async notifications for a connection.
|
|
*
|
|
* Returns a setof record of notifications, or an empty set if none received.
|
|
* Can optionally take a named connection as parameter, but uses the unnamed
|
|
* connection per default.
|
|
*
|
|
*/
|
|
#define DBLINK_NOTIFY_COLS 3
|
|
|
|
PG_FUNCTION_INFO_V1(dblink_get_notify);
|
|
Datum
|
|
dblink_get_notify(PG_FUNCTION_ARGS)
|
|
{
|
|
PGconn *conn;
|
|
PGnotify *notify;
|
|
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
|
|
|
|
dblink_init();
|
|
if (PG_NARGS() == 1)
|
|
conn = dblink_get_named_conn(text_to_cstring(PG_GETARG_TEXT_PP(0)));
|
|
else
|
|
conn = pconn->conn;
|
|
|
|
InitMaterializedSRF(fcinfo, 0);
|
|
|
|
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(rsinfo->setResult, rsinfo->setDesc, values, nulls);
|
|
|
|
PQfreemem(notify);
|
|
PQconsumeInput(conn);
|
|
}
|
|
|
|
return (Datum) 0;
|
|
}
|
|
|
|
/*
|
|
* Validate the options given to a dblink foreign server or user mapping.
|
|
* Raise an error if any option is invalid.
|
|
*
|
|
* We just check the names of options here, so semantic errors in options,
|
|
* such as invalid numeric format, will be detected at the attempt to connect.
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_fdw_validator);
|
|
Datum
|
|
dblink_fdw_validator(PG_FUNCTION_ARGS)
|
|
{
|
|
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),
|
|
buf.len > 0
|
|
? errhint("Valid options in this context are: %s",
|
|
buf.data)
|
|
: errhint("There are no valid options in this context.")));
|
|
}
|
|
}
|
|
|
|
PG_RETURN_VOID();
|
|
}
|
|
|
|
|
|
/*************************************************************
|
|
* internal functions
|
|
*/
|
|
|
|
|
|
/*
|
|
* get_pkey_attnames
|
|
*
|
|
* Get the primary key attnames for the given relation.
|
|
* Return NULL, and set indnkeyatts = 0, if no primary key exists.
|
|
*/
|
|
static char **
|
|
get_pkey_attnames(Relation rel, int16 *indnkeyatts)
|
|
{
|
|
Relation indexRelation;
|
|
ScanKeyData skey;
|
|
SysScanDesc scan;
|
|
HeapTuple indexTuple;
|
|
int i;
|
|
char **result = NULL;
|
|
TupleDesc tupdesc;
|
|
|
|
/* initialize indnkeyatts to 0 in case no primary key exists */
|
|
*indnkeyatts = 0;
|
|
|
|
tupdesc = rel->rd_att;
|
|
|
|
/* Prepare to scan pg_index for entries having indrelid = this rel. */
|
|
indexRelation = table_open(IndexRelationId, AccessShareLock);
|
|
ScanKeyInit(&skey,
|
|
Anum_pg_index_indrelid,
|
|
BTEqualStrategyNumber, F_OIDEQ,
|
|
ObjectIdGetDatum(RelationGetRelid(rel)));
|
|
|
|
scan = systable_beginscan(indexRelation, IndexIndrelidIndexId, true,
|
|
NULL, 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)
|
|
{
|
|
*indnkeyatts = index->indnkeyatts;
|
|
if (*indnkeyatts > 0)
|
|
{
|
|
result = (char **) palloc(*indnkeyatts * sizeof(char *));
|
|
|
|
for (i = 0; i < *indnkeyatts; i++)
|
|
result[i] = SPI_fname(tupdesc, index->indkey.values[i]);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
systable_endscan(scan);
|
|
table_close(indexRelation, AccessShareLock);
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* Deconstruct a text[] into C-strings (note any NULL elements will be
|
|
* returned as NULL pointers)
|
|
*/
|
|
static char **
|
|
get_text_array_contents(ArrayType *array, int *numitems)
|
|
{
|
|
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 char *
|
|
get_sql_insert(Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals, char **tgt_pkattvals)
|
|
{
|
|
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++)
|
|
{
|
|
Form_pg_attribute att = TupleDescAttr(tupdesc, i);
|
|
|
|
if (att->attisdropped)
|
|
continue;
|
|
|
|
if (needComma)
|
|
appendStringInfoChar(&buf, ',');
|
|
|
|
appendStringInfoString(&buf,
|
|
quote_ident_cstr(NameStr(att->attname)));
|
|
needComma = true;
|
|
}
|
|
|
|
appendStringInfoString(&buf, ") VALUES(");
|
|
|
|
/*
|
|
* Note: i is physical column number (counting from 0).
|
|
*/
|
|
needComma = false;
|
|
for (i = 0; i < natts; i++)
|
|
{
|
|
if (TupleDescAttr(tupdesc, i)->attisdropped)
|
|
continue;
|
|
|
|
if (needComma)
|
|
appendStringInfoChar(&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
|
|
appendStringInfoString(&buf, "NULL");
|
|
needComma = true;
|
|
}
|
|
appendStringInfoChar(&buf, ')');
|
|
|
|
return buf.data;
|
|
}
|
|
|
|
static char *
|
|
get_sql_delete(Relation rel, int *pkattnums, int pknumatts, char **tgt_pkattvals)
|
|
{
|
|
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];
|
|
Form_pg_attribute attr = TupleDescAttr(tupdesc, pkattnum);
|
|
|
|
if (i > 0)
|
|
appendStringInfoString(&buf, " AND ");
|
|
|
|
appendStringInfoString(&buf,
|
|
quote_ident_cstr(NameStr(attr->attname)));
|
|
|
|
if (tgt_pkattvals[i] != NULL)
|
|
appendStringInfo(&buf, " = %s",
|
|
quote_literal_cstr(tgt_pkattvals[i]));
|
|
else
|
|
appendStringInfoString(&buf, " IS NULL");
|
|
}
|
|
|
|
return buf.data;
|
|
}
|
|
|
|
static char *
|
|
get_sql_update(Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals, char **tgt_pkattvals)
|
|
{
|
|
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++)
|
|
{
|
|
Form_pg_attribute attr = TupleDescAttr(tupdesc, i);
|
|
|
|
if (attr->attisdropped)
|
|
continue;
|
|
|
|
if (needComma)
|
|
appendStringInfoString(&buf, ", ");
|
|
|
|
appendStringInfo(&buf, "%s = ",
|
|
quote_ident_cstr(NameStr(attr->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;
|
|
}
|
|
|
|
appendStringInfoString(&buf, " WHERE ");
|
|
|
|
for (i = 0; i < pknumatts; i++)
|
|
{
|
|
int pkattnum = pkattnums[i];
|
|
Form_pg_attribute attr = TupleDescAttr(tupdesc, pkattnum);
|
|
|
|
if (i > 0)
|
|
appendStringInfoString(&buf, " AND ");
|
|
|
|
appendStringInfoString(&buf,
|
|
quote_ident_cstr(NameStr(attr->attname)));
|
|
|
|
val = tgt_pkattvals[i];
|
|
|
|
if (val != NULL)
|
|
appendStringInfo(&buf, " = %s", quote_literal_cstr(val));
|
|
else
|
|
appendStringInfoString(&buf, " IS NULL");
|
|
}
|
|
|
|
return buf.data;
|
|
}
|
|
|
|
/*
|
|
* Return a properly quoted identifier.
|
|
* Uses quote_ident in quote.c
|
|
*/
|
|
static char *
|
|
quote_ident_cstr(char *rawstr)
|
|
{
|
|
text *rawstr_text;
|
|
text *result_text;
|
|
char *result;
|
|
|
|
rawstr_text = cstring_to_text(rawstr);
|
|
result_text = DatumGetTextPP(DirectFunctionCall1(quote_ident,
|
|
PointerGetDatum(rawstr_text)));
|
|
result = text_to_cstring(result_text);
|
|
|
|
return result;
|
|
}
|
|
|
|
static int
|
|
get_attnum_pk_pos(int *pkattnums, int pknumatts, int key)
|
|
{
|
|
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 HeapTuple
|
|
get_tuple_of_interest(Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals)
|
|
{
|
|
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++)
|
|
{
|
|
Form_pg_attribute attr = TupleDescAttr(tupdesc, i);
|
|
|
|
if (i > 0)
|
|
appendStringInfoString(&buf, ", ");
|
|
|
|
if (attr->attisdropped)
|
|
appendStringInfoString(&buf, "NULL");
|
|
else
|
|
appendStringInfoString(&buf,
|
|
quote_ident_cstr(NameStr(attr->attname)));
|
|
}
|
|
|
|
appendStringInfo(&buf, " FROM %s WHERE ", relname);
|
|
|
|
for (i = 0; i < pknumatts; i++)
|
|
{
|
|
int pkattnum = pkattnums[i];
|
|
Form_pg_attribute attr = TupleDescAttr(tupdesc, pkattnum);
|
|
|
|
if (i > 0)
|
|
appendStringInfoString(&buf, " AND ");
|
|
|
|
appendStringInfoString(&buf,
|
|
quote_ident_cstr(NameStr(attr->attname)));
|
|
|
|
if (src_pkattvals[i] != NULL)
|
|
appendStringInfo(&buf, " = %s",
|
|
quote_literal_cstr(src_pkattvals[i]));
|
|
else
|
|
appendStringInfoString(&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;
|
|
}
|
|
|
|
/*
|
|
* Open the relation named by relname_text, acquire specified type of lock,
|
|
* verify we have specified permissions.
|
|
* Caller must close rel when done with it.
|
|
*/
|
|
static Relation
|
|
get_rel_from_relname(text *relname_text, LOCKMODE lockmode, AclMode aclmode)
|
|
{
|
|
RangeVar *relvar;
|
|
Relation rel;
|
|
AclResult aclresult;
|
|
|
|
relvar = makeRangeVarFromNameList(textToQualifiedNameList(relname_text));
|
|
rel = table_openrv(relvar, lockmode);
|
|
|
|
aclresult = pg_class_aclcheck(RelationGetRelid(rel), GetUserId(),
|
|
aclmode);
|
|
if (aclresult != ACLCHECK_OK)
|
|
aclcheck_error(aclresult, get_relkind_objtype(rel->rd_rel->relkind),
|
|
RelationGetRelationName(rel));
|
|
|
|
return rel;
|
|
}
|
|
|
|
/*
|
|
* generate_relation_name - copied from ruleutils.c
|
|
* Compute the name to display for a relation
|
|
*
|
|
* The result includes all necessary quoting and schema-prefixing.
|
|
*/
|
|
static char *
|
|
generate_relation_name(Relation rel)
|
|
{
|
|
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 remoteConn *
|
|
getConnectionByName(const char *name)
|
|
{
|
|
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 HTAB *
|
|
createConnHash(void)
|
|
{
|
|
HASHCTL ctl;
|
|
|
|
ctl.keysize = NAMEDATALEN;
|
|
ctl.entrysize = sizeof(remoteConnHashEnt);
|
|
|
|
return hash_create("Remote Con hash", NUMCONN, &ctl,
|
|
HASH_ELEM | HASH_STRINGS);
|
|
}
|
|
|
|
static void
|
|
createNewConnection(const char *name, remoteConn *rconn)
|
|
{
|
|
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);
|
|
ReleaseExternalFD();
|
|
pfree(rconn);
|
|
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_DUPLICATE_OBJECT),
|
|
errmsg("duplicate connection name")));
|
|
}
|
|
|
|
hentry->rconn = rconn;
|
|
strlcpy(hentry->name, name, sizeof(hentry->name));
|
|
}
|
|
|
|
static void
|
|
deleteConnection(const char *name)
|
|
{
|
|
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 void
|
|
dblink_security_check(PGconn *conn, remoteConn *rconn)
|
|
{
|
|
if (!superuser())
|
|
{
|
|
if (!PQconnectionUsedPassword(conn))
|
|
{
|
|
PQfinish(conn);
|
|
ReleaseExternalFD();
|
|
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.")));
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* For non-superusers, insist that the connstr specify a password. This
|
|
* prevents a password from being picked up from .pgpass, a service file,
|
|
* the environment, etc. We don't want the postgres user's passwords
|
|
* to be accessible to non-superusers.
|
|
*/
|
|
static void
|
|
dblink_connstr_check(const char *connstr)
|
|
{
|
|
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.")));
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Report an error received from the remote server
|
|
*
|
|
* res: the received error result (will be freed)
|
|
* fail: true for ERROR ereport, false for NOTICE
|
|
* fmt and following args: sprintf-style format and values for errcontext;
|
|
* the resulting string should be worded like "while <some action>"
|
|
*/
|
|
static void
|
|
dblink_res_error(PGconn *conn, const char *conname, PGresult *res,
|
|
bool fail, const char *fmt,...)
|
|
{
|
|
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;
|
|
va_list ap;
|
|
char dblink_context_msg[512];
|
|
|
|
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;
|
|
|
|
message_primary = xpstrdup(pg_diag_message_primary);
|
|
message_detail = xpstrdup(pg_diag_message_detail);
|
|
message_hint = xpstrdup(pg_diag_message_hint);
|
|
message_context = xpstrdup(pg_diag_context);
|
|
|
|
/*
|
|
* If we don't get a message from the PGresult, try the PGconn. This is
|
|
* needed because for connection-level failures, PQexec may just return
|
|
* NULL, not a PGresult at all.
|
|
*/
|
|
if (message_primary == NULL)
|
|
message_primary = pchomp(PQerrorMessage(conn));
|
|
|
|
/*
|
|
* Now that we've copied all the data we need out of the PGresult, it's
|
|
* safe to free it. We must do this to avoid PGresult leakage. We're
|
|
* leaking all the strings too, but those are in palloc'd memory that will
|
|
* get cleaned up eventually.
|
|
*/
|
|
if (res)
|
|
PQclear(res);
|
|
|
|
/*
|
|
* Format the basic errcontext string. Below, we'll add on something
|
|
* about the connection name. That's a violation of the translatability
|
|
* guidelines about constructing error messages out of parts, but since
|
|
* there's no translation support for dblink, there's no need to worry
|
|
* about that (yet).
|
|
*/
|
|
va_start(ap, fmt);
|
|
vsnprintf(dblink_context_msg, sizeof(dblink_context_msg), fmt, ap);
|
|
va_end(ap);
|
|
|
|
ereport(level,
|
|
(errcode(sqlstate),
|
|
(message_primary != NULL && message_primary[0] != '\0') ?
|
|
errmsg_internal("%s", message_primary) :
|
|
errmsg("could not obtain message string for remote error"),
|
|
message_detail ? errdetail_internal("%s", message_detail) : 0,
|
|
message_hint ? errhint("%s", message_hint) : 0,
|
|
message_context ? (errcontext("%s", message_context)) : 0,
|
|
conname ?
|
|
(errcontext("%s on dblink connection named \"%s\"",
|
|
dblink_context_msg, conname)) :
|
|
(errcontext("%s on unnamed dblink connection",
|
|
dblink_context_msg))));
|
|
}
|
|
|
|
/*
|
|
* Obtain connection string for a foreign server
|
|
*/
|
|
static char *
|
|
get_connect_string(const char *servername)
|
|
{
|
|
ForeignServer *foreign_server = NULL;
|
|
UserMapping *user_mapping;
|
|
ListCell *cell;
|
|
StringInfoData buf;
|
|
ForeignDataWrapper *fdw;
|
|
AclResult aclresult;
|
|
char *srvname;
|
|
|
|
static const PQconninfoOption *options = NULL;
|
|
|
|
initStringInfo(&buf);
|
|
|
|
/*
|
|
* 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.")));
|
|
}
|
|
|
|
/* 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, OBJECT_FOREIGN_SERVER, foreign_server->servername);
|
|
|
|
foreach(cell, fdw->options)
|
|
{
|
|
DefElem *def = lfirst(cell);
|
|
|
|
if (is_valid_dblink_option(options, def->defname, ForeignDataWrapperRelationId))
|
|
appendStringInfo(&buf, "%s='%s' ", def->defname,
|
|
escape_param_str(strVal(def->arg)));
|
|
}
|
|
|
|
foreach(cell, foreign_server->options)
|
|
{
|
|
DefElem *def = lfirst(cell);
|
|
|
|
if (is_valid_dblink_option(options, def->defname, ForeignServerRelationId))
|
|
appendStringInfo(&buf, "%s='%s' ", def->defname,
|
|
escape_param_str(strVal(def->arg)));
|
|
}
|
|
|
|
foreach(cell, user_mapping->options)
|
|
{
|
|
|
|
DefElem *def = lfirst(cell);
|
|
|
|
if (is_valid_dblink_option(options, def->defname, UserMappingRelationId))
|
|
appendStringInfo(&buf, "%s='%s' ", def->defname,
|
|
escape_param_str(strVal(def->arg)));
|
|
}
|
|
|
|
return buf.data;
|
|
}
|
|
else
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Escaping libpq connect parameter strings.
|
|
*
|
|
* Replaces "'" with "\'" and "\" with "\\".
|
|
*/
|
|
static char *
|
|
escape_param_str(const char *str)
|
|
{
|
|
const char *cp;
|
|
StringInfoData buf;
|
|
|
|
initStringInfo(&buf);
|
|
|
|
for (cp = str; *cp; cp++)
|
|
{
|
|
if (*cp == '\\' || *cp == '\'')
|
|
appendStringInfoChar(&buf, '\\');
|
|
appendStringInfoChar(&buf, *cp);
|
|
}
|
|
|
|
return buf.data;
|
|
}
|
|
|
|
/*
|
|
* Validate the PK-attnums argument for dblink_build_sql_insert() and related
|
|
* functions, and translate to the internal representation.
|
|
*
|
|
* The user supplies an int2vector of 1-based logical attnums, plus a count
|
|
* argument (the need for the separate count argument is historical, but we
|
|
* still check it). We check that each attnum corresponds to a valid,
|
|
* non-dropped attribute of the rel. We do *not* prevent attnums from being
|
|
* listed twice, though the actual use-case for such things is dubious.
|
|
* Note that before Postgres 9.0, the user's attnums were interpreted as
|
|
* physical not logical column numbers; this was changed for future-proofing.
|
|
*
|
|
* The internal representation is a palloc'd int array of 0-based physical
|
|
* attnums.
|
|
*/
|
|
static void
|
|
validate_pkattnums(Relation rel,
|
|
int2vector *pkattnums_arg, int32 pknumatts_arg,
|
|
int **pkattnums, int *pknumatts)
|
|
{
|
|
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 (TupleDescAttr(tupdesc, 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)));
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Check if the specified connection option is valid.
|
|
*
|
|
* We basically allow whatever libpq thinks is an option, with these
|
|
* restrictions:
|
|
* debug options: disallowed
|
|
* "client_encoding": disallowed
|
|
* "user": valid only in USER MAPPING options
|
|
* secure options (eg password): valid only in USER MAPPING options
|
|
* others: valid only in FOREIGN SERVER options
|
|
*
|
|
* We disallow client_encoding because it would be overridden anyway via
|
|
* PQclientEncoding; allowing it to be specified would merely promote
|
|
* confusion.
|
|
*/
|
|
static bool
|
|
is_valid_dblink_option(const PQconninfoOption *options, const char *option,
|
|
Oid context)
|
|
{
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* Copy the remote session's values of GUCs that affect datatype I/O
|
|
* and apply them locally in a new GUC nesting level. Returns the new
|
|
* nestlevel (which is needed by restoreLocalGucs to undo the settings),
|
|
* or -1 if no new nestlevel was needed.
|
|
*
|
|
* We use the equivalent of a function SET option to allow the settings to
|
|
* persist only until the caller calls restoreLocalGucs. If an error is
|
|
* thrown in between, guc.c will take care of undoing the settings.
|
|
*/
|
|
static int
|
|
applyRemoteGucs(PGconn *conn)
|
|
{
|
|
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, false);
|
|
}
|
|
|
|
return nestlevel;
|
|
}
|
|
|
|
/*
|
|
* Restore local GUCs after they have been overlaid with remote settings.
|
|
*/
|
|
static void
|
|
restoreLocalGucs(int nestlevel)
|
|
{
|
|
/* Do nothing if no new nestlevel was created */
|
|
if (nestlevel > 0)
|
|
AtEOXact_GUC(true, nestlevel);
|
|
}
|