diff --git a/contrib/dblink/dblink.c b/contrib/dblink/dblink.c
index df1ff05a8fe339f88771d8d5ae803049ed0706a1..46c7cc5923f18d3f0d614dbd327c37bef46c4af8 100644
--- a/contrib/dblink/dblink.c
+++ b/contrib/dblink/dblink.c
@@ -67,6 +67,7 @@ typedef struct remoteConn
* Internal declarations
*/
static Datum dblink_record_internal(FunctionCallInfo fcinfo, bool is_async);
+static void prepTuplestoreResult(FunctionCallInfo fcinfo);
static void materializeResult(FunctionCallInfo fcinfo, PGresult *res);
static remoteConn *getConnectionByName(const char *name);
static HTAB *createConnHash(void);
@@ -495,7 +496,6 @@ PG_FUNCTION_INFO_V1(dblink_fetch);
Datum
dblink_fetch(PG_FUNCTION_ARGS)
{
- ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
PGresult *res = NULL;
char *conname = NULL;
remoteConn *rconn = NULL;
@@ -505,6 +505,8 @@ dblink_fetch(PG_FUNCTION_ARGS)
int howmany = 0;
bool fail = true; /* default to backward compatible */
+ prepTuplestoreResult(fcinfo);
+
DBLINK_INIT;
if (PG_NARGS() == 4)
@@ -551,11 +553,6 @@ dblink_fetch(PG_FUNCTION_ARGS)
if (!conn)
DBLINK_CONN_NOT_AVAIL;
- /* let the caller know we're sending back a tuplestore */
- rsinfo->returnMode = SFRM_Materialize;
- rsinfo->setResult = NULL;
- rsinfo->setDesc = NULL;
-
initStringInfo(&buf);
appendStringInfo(&buf, "FETCH %d FROM %s", howmany, curname);
@@ -632,7 +629,6 @@ dblink_get_result(PG_FUNCTION_ARGS)
static Datum
dblink_record_internal(FunctionCallInfo fcinfo, bool is_async)
{
- ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
char *msg;
PGresult *res = NULL;
PGconn *conn = NULL;
@@ -643,16 +639,7 @@ dblink_record_internal(FunctionCallInfo fcinfo, bool is_async)
bool fail = true; /* default to backward compatible */
bool freeconn = false;
- /* check to see if caller 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")));
+ prepTuplestoreResult(fcinfo);
DBLINK_INIT;
@@ -712,11 +699,6 @@ dblink_record_internal(FunctionCallInfo fcinfo, bool is_async)
if (!conn)
DBLINK_CONN_NOT_AVAIL;
- /* let the caller know we're sending back a tuplestore */
- rsinfo->returnMode = SFRM_Materialize;
- rsinfo->setResult = NULL;
- rsinfo->setDesc = NULL;
-
/* synchronous query, or async result retrieval */
if (!is_async)
res = PQexec(conn, sql);
@@ -745,14 +727,45 @@ dblink_record_internal(FunctionCallInfo fcinfo, bool is_async)
}
/*
- * Materialize the PGresult to return them as the function result.
- * The res will be released in this function.
+ * 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, PGresult *res)
{
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+ /* prepTuplestoreResult must have been called previously */
Assert(rsinfo->returnMode == SFRM_Materialize);
PG_TRY();
@@ -1004,85 +1017,97 @@ PG_FUNCTION_INFO_V1(dblink_exec);
Datum
dblink_exec(PG_FUNCTION_ARGS)
{
- char *msg;
- PGresult *res = NULL;
- text *sql_cmd_status = NULL;
- PGconn *conn = NULL;
- char *connstr = NULL;
- char *sql = NULL;
- char *conname = NULL;
- remoteConn *rconn = NULL;
- bool freeconn = false;
- bool fail = true; /* default to backward compatible behavior */
+ text *volatile sql_cmd_status = NULL;
+ PGconn *volatile conn = NULL;
+ volatile bool freeconn = false;
DBLINK_INIT;
- 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)
+ PG_TRY();
{
- /* might be text,text or text,bool */
- if (get_fn_expr_argtype(fcinfo->flinfo, 1) == BOOLOID)
+ 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));
- 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");
+ /* shouldn't happen */
+ elog(ERROR, "wrong number of arguments");
- if (!conn)
- DBLINK_CONN_NOT_AVAIL;
+ 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);
+ 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);
+ /*
+ * 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")));
+ }
}
- else
+ PG_CATCH();
{
- PQclear(res);
- ereport(ERROR,
- (errcode(ERRCODE_S_R_E_PROHIBITED_SQL_STATEMENT_ATTEMPTED),
- errmsg("statement returning results not allowed")));
+ /* 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 and cleanup */
+ /* if needed, close the connection to the database */
if (freeconn)
PQfinish(conn);
@@ -1503,13 +1528,15 @@ dblink_get_notify(PG_FUNCTION_ARGS)
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 */
+ /* create the tuplestore in per-query memory */
per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
oldcontext = MemoryContextSwitchTo(per_query_ctx);
@@ -1522,7 +1549,6 @@ dblink_get_notify(PG_FUNCTION_ARGS)
TEXTOID, -1, 0);
tupstore = tuplestore_begin_heap(true, false, work_mem);
- rsinfo->returnMode = SFRM_Materialize;
rsinfo->setResult = tupstore;
rsinfo->setDesc = tupdesc;