*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/utils/fmgr/fmgr.c,v 1.79 2004/01/07 18:56:29 neilc Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/fmgr/fmgr.c,v 1.80 2004/01/19 02:06:41 tgl Exp $
*
*-------------------------------------------------------------------------
*/
* toastable datatype? */
} Oldstyle_fnextra;
+/*
+ * Hashtable for fast lookup of external C functions
+ */
+typedef struct
+{
+ /* fn_oid is the hash key and so must be first! */
+ Oid fn_oid; /* OID of an external C function */
+ TransactionId fn_xmin; /* for checking up-to-dateness */
+ CommandId fn_cmin;
+ PGFunction user_fn; /* the function's address */
+ Pg_finfo_record *inforec; /* address of its info record */
+} CFuncHashTabEntry;
+
+static HTAB *CFuncHash = NULL;
+
static void fmgr_info_cxt_security(Oid functionId, FmgrInfo *finfo, MemoryContext mcxt,
bool ignore_security);
static void fmgr_info_C_lang(Oid functionId, FmgrInfo *finfo, HeapTuple procedureTuple);
static void fmgr_info_other_lang(Oid functionId, FmgrInfo *finfo, HeapTuple procedureTuple);
+static CFuncHashTabEntry *lookup_C_func(HeapTuple procedureTuple);
+static void record_C_func(HeapTuple procedureTuple,
+ PGFunction user_fn, Pg_finfo_record *inforec);
static Datum fmgr_oldstyle(PG_FUNCTION_ARGS);
static Datum fmgr_security_definer(PG_FUNCTION_ARGS);
fmgr_info_C_lang(Oid functionId, FmgrInfo *finfo, HeapTuple procedureTuple)
{
Form_pg_proc procedureStruct = (Form_pg_proc) GETSTRUCT(procedureTuple);
- Datum prosrcattr,
- probinattr;
- char *prosrcstring,
- *probinstring;
- void *libraryhandle;
+ CFuncHashTabEntry *hashentry;
PGFunction user_fn;
Pg_finfo_record *inforec;
Oldstyle_fnextra *fnextra;
bool isnull;
int i;
- /* Get prosrc and probin strings (link symbol and library filename) */
- prosrcattr = SysCacheGetAttr(PROCOID, procedureTuple,
- Anum_pg_proc_prosrc, &isnull);
- if (isnull)
- elog(ERROR, "null prosrc for function %u", functionId);
- prosrcstring = DatumGetCString(DirectFunctionCall1(textout, prosrcattr));
-
- probinattr = SysCacheGetAttr(PROCOID, procedureTuple,
- Anum_pg_proc_probin, &isnull);
- if (isnull)
- elog(ERROR, "null probin for function %u", functionId);
- probinstring = DatumGetCString(DirectFunctionCall1(textout, probinattr));
-
- /* Look up the function itself */
- user_fn = load_external_function(probinstring, prosrcstring, true,
- &libraryhandle);
-
- /* Get the function information record (real or default) */
- inforec = fetch_finfo_record(libraryhandle, prosrcstring);
+ /*
+ * See if we have the function address cached already
+ */
+ hashentry = lookup_C_func(procedureTuple);
+ if (hashentry)
+ {
+ user_fn = hashentry->user_fn;
+ inforec = hashentry->inforec;
+ }
+ else
+ {
+ Datum prosrcattr,
+ probinattr;
+ char *prosrcstring,
+ *probinstring;
+ void *libraryhandle;
+
+ /* Get prosrc and probin strings (link symbol and library filename) */
+ prosrcattr = SysCacheGetAttr(PROCOID, procedureTuple,
+ Anum_pg_proc_prosrc, &isnull);
+ if (isnull)
+ elog(ERROR, "null prosrc for function %u", functionId);
+ prosrcstring = DatumGetCString(DirectFunctionCall1(textout,
+ prosrcattr));
+
+ probinattr = SysCacheGetAttr(PROCOID, procedureTuple,
+ Anum_pg_proc_probin, &isnull);
+ if (isnull)
+ elog(ERROR, "null probin for function %u", functionId);
+ probinstring = DatumGetCString(DirectFunctionCall1(textout,
+ probinattr));
+
+ /* Look up the function itself */
+ user_fn = load_external_function(probinstring, prosrcstring, true,
+ &libraryhandle);
+
+ /* Get the function information record (real or default) */
+ inforec = fetch_finfo_record(libraryhandle, prosrcstring);
+
+ /* Cache the addresses for later calls */
+ record_C_func(procedureTuple, user_fn, inforec);
+
+ pfree(prosrcstring);
+ pfree(probinstring);
+ }
switch (inforec->api_version)
{
inforec->api_version);
break;
}
-
- pfree(prosrcstring);
- pfree(probinstring);
}
/*
}
+/*-------------------------------------------------------------------------
+ * Routines for caching lookup information for external C functions.
+ *
+ * The routines in dfmgr.c are relatively slow, so we try to avoid running
+ * them more than once per external function per session. We use a hash table
+ * with the function OID as the lookup key.
+ *-------------------------------------------------------------------------
+ */
+
+/*
+ * lookup_C_func: try to find a C function in the hash table
+ *
+ * If an entry exists and is up to date, return it; else return NULL
+ */
+static CFuncHashTabEntry *
+lookup_C_func(HeapTuple procedureTuple)
+{
+ Oid fn_oid = HeapTupleGetOid(procedureTuple);
+ CFuncHashTabEntry *entry;
+
+ if (CFuncHash == NULL)
+ return NULL; /* no table yet */
+ entry = (CFuncHashTabEntry *)
+ hash_search(CFuncHash,
+ &fn_oid,
+ HASH_FIND,
+ NULL);
+ if (entry == NULL)
+ return NULL; /* no such entry */
+ if (entry->fn_xmin == HeapTupleHeaderGetXmin(procedureTuple->t_data) &&
+ entry->fn_cmin == HeapTupleHeaderGetCmin(procedureTuple->t_data))
+ return entry; /* OK */
+ return NULL; /* entry is out of date */
+}
+
+/*
+ * record_C_func: enter (or update) info about a C function in the hash table
+ */
+static void
+record_C_func(HeapTuple procedureTuple,
+ PGFunction user_fn, Pg_finfo_record *inforec)
+{
+ Oid fn_oid = HeapTupleGetOid(procedureTuple);
+ CFuncHashTabEntry *entry;
+ bool found;
+
+ /* Create the hash table if it doesn't exist yet */
+ if (CFuncHash == NULL)
+ {
+ HASHCTL hash_ctl;
+
+ MemSet(&hash_ctl, 0, sizeof(hash_ctl));
+ hash_ctl.keysize = sizeof(Oid);
+ hash_ctl.entrysize = sizeof(CFuncHashTabEntry);
+ hash_ctl.hash = tag_hash;
+ CFuncHash = hash_create("CFuncHash",
+ 100,
+ &hash_ctl,
+ HASH_ELEM | HASH_FUNCTION);
+ if (CFuncHash == NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_OUT_OF_MEMORY),
+ errmsg("out of memory")));
+ }
+
+ entry = (CFuncHashTabEntry *)
+ hash_search(CFuncHash,
+ &fn_oid,
+ HASH_ENTER,
+ &found);
+ if (entry == NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_OUT_OF_MEMORY),
+ errmsg("out of memory")));
+ /* OID is already filled in */
+ entry->fn_xmin = HeapTupleHeaderGetXmin(procedureTuple->t_data);
+ entry->fn_cmin = HeapTupleHeaderGetCmin(procedureTuple->t_data);
+ entry->user_fn = user_fn;
+ entry->inforec = inforec;
+}
+
+/*
+ * clear_external_function_hash: remove entries for a library being closed
+ *
+ * Presently we just zap the entire hash table, but later it might be worth
+ * the effort to remove only the entries associated with the given handle.
+ */
+void
+clear_external_function_hash(void *filehandle)
+{
+ if (CFuncHash)
+ hash_destroy(CFuncHash);
+ CFuncHash = NULL;
+}
+
+
/*
* Copy an FmgrInfo struct
*
projects / postgresql.git / commitdiff