introduce safe wrapper function pathman_cache_search_relid()

Author: funbringer

.gitignore

@@ -9,4 +9,4 @@ regression.out
 *.gcda
 *.gcno
 *.gcov
-pg_pathman--1.3.sql
+pg_pathman--*.sql

src/init.c

@@ -105,6 +105,44 @@ static uint32 build_sql_facade_version(char *version_cstr);
 static uint32 get_sql_facade_version(void);
 static void validate_sql_facade_version(uint32 ver);
 
+
+/*
+ * Safe hash search (takes care of disabled pg_pathman).
+ */
+void *
+pathman_cache_search_relid(HTAB *cache_table,
+						   Oid relid,
+						   HASHACTION action,
+						   bool *found)
+{
+	switch (action)
+	{
+		/* May return NULL */
+		case HASH_FIND:
+		case HASH_REMOVE:
+			if (!cache_table)
+				return NULL;
+			break;
+
+		/* Must return valid pointer */
+		case HASH_ENTER:
+			if (!cache_table)
+				elog(ERROR, "pg_pathman is not initialized yet");
+			break;
+
+		/* Something strange has just happened */
+		default:
+			elog(ERROR, "unexpected action in function "
+				 CppAsString(pathman_cache_search_relid));
+			break;
+	}
+
+	Assert(cache_table);
+
+	/* Everything is fine */
+	return hash_search(cache_table, (const void *) &relid, action, found);
+}
+
 /*
  * Save and restore main init state.
  */
@@ -279,6 +317,10 @@ init_local_cache(void)
 {
 	HASHCTL ctl;
 
+	/* Destroy caches, just in case */
+	hash_destroy(partitioned_rels);
+	hash_destroy(parent_cache);
+
 	memset(&ctl, 0, sizeof(ctl));
 	ctl.keysize = sizeof(Oid);
 	ctl.entrysize = sizeof(PartRelationInfo);

src/init.h

@@ -102,6 +102,11 @@ extern PathmanInitState 	pg_pathman_init_state;
 #define CURRENT_LIB_VERSION			0x010300
 
 
+void *pathman_cache_search_relid(HTAB *cache_table,
+								 Oid relid,
+								 HASHACTION action,
+								 bool *found);
+
 /*
  * Save and restore PathmanInitState.
  */

src/relation_info.c

@@ -81,9 +81,9 @@ refresh_pathman_relation_info(Oid relid,
 	Datum					param_values[Natts_pathman_config_params];
 	bool					param_isnull[Natts_pathman_config_params];
 
-	prel = (PartRelationInfo *) hash_search(partitioned_rels,
-											(const void *) &relid,
-											HASH_ENTER, &found_entry);
+	prel = (PartRelationInfo *) pathman_cache_search_relid(partitioned_rels,
+														   relid, HASH_ENTER,
+														   &found_entry);
 	elog(DEBUG2,
 		 found_entry ?
 			 "Refreshing record for relation %u in pg_pathman's cache [%u]" :
@@ -239,9 +239,9 @@ invalidate_pathman_relation_info(Oid relid, bool *found)
 	HASHACTION			action = found ? HASH_FIND : HASH_ENTER;
 	PartRelationInfo   *prel;
 
-	prel = hash_search(partitioned_rels,
-					   (const void *) &relid,
-					   action, &prel_found);
+	prel = pathman_cache_search_relid(partitioned_rels,
+									  relid, action,
+									  &prel_found);
 
 	if ((action == HASH_FIND ||
 		(action == HASH_ENTER && prel_found)) && PrelIsValid(prel))
@@ -272,10 +272,9 @@ invalidate_pathman_relation_info(Oid relid, bool *found)
 const PartRelationInfo *
 get_pathman_relation_info(Oid relid)
 {
-	const PartRelationInfo *prel = hash_search(partitioned_rels,
-											   (const void *) &relid,
-											   HASH_FIND, NULL);
-
+	const PartRelationInfo *prel = pathman_cache_search_relid(partitioned_rels,
+															  relid, HASH_FIND,
+															  NULL);
 	/* Refresh PartRelationInfo if needed */
 	if (prel && !PrelIsValid(prel))
 	{
@@ -345,20 +344,19 @@ get_pathman_relation_info_after_lock(Oid relid,
 void
 remove_pathman_relation_info(Oid relid)
 {
-	PartRelationInfo *prel = hash_search(partitioned_rels,
-										 (const void *) &relid,
-										 HASH_FIND, NULL);
-	if (prel && PrelIsValid(prel))
+	PartRelationInfo *prel = pathman_cache_search_relid(partitioned_rels,
+														relid, HASH_FIND,
+														NULL);
+	if (PrelIsValid(prel))
 	{
 		/* Free these arrays iff they're not NULL */
 		FreeChildrenArray(prel);
 		FreeRangesArray(prel);
 	}
 
 	/* Now let's remove the entry completely */
-	hash_search(partitioned_rels,
-				(const void *) &relid,
-				HASH_REMOVE, NULL);
+	pathman_cache_search_relid(partitioned_rels, relid,
+							   HASH_REMOVE, NULL);
 
 	elog(DEBUG2,
 		 "Removing record for relation %u in pg_pathman's cache [%u]",
@@ -509,10 +507,10 @@ cache_parent_of_partition(Oid partition, Oid parent)
 	bool			found;
 	PartParentInfo *ppar;
 
-	ppar = hash_search(parent_cache,
-					   (const void *) &partition,
-					   HASH_ENTER, &found);
-
+	ppar = pathman_cache_search_relid(parent_cache,
+									  partition,
+									  HASH_ENTER,
+									  &found);
 	elog(DEBUG2,
 		 found ?
 			 "Refreshing record for child %u in pg_pathman's cache [%u]" :
@@ -551,10 +549,10 @@ get_parent_of_partition_internal(Oid partition,
 {
 	const char	   *action_str; /* "Fetching"\"Resetting" */
 	Oid				parent;
-	PartParentInfo *ppar = hash_search(parent_cache,
-									   (const void *) &partition,
-									   HASH_FIND, NULL);
-
+	PartParentInfo *ppar = pathman_cache_search_relid(parent_cache,
+													  partition,
+													  HASH_FIND,
+													  NULL);
 	/* Set 'action_str' */
 	switch (action)
 	{
@@ -581,9 +579,8 @@ get_parent_of_partition_internal(Oid partition,
 
 		/* Remove entry if necessary */
 		if (action == HASH_REMOVE)
-			hash_search(parent_cache,
-						(const void *) &partition,
-						HASH_REMOVE, NULL);
+			pathman_cache_search_relid(parent_cache, partition,
+									   HASH_REMOVE, NULL);
 	}
 	/* Try fetching parent from syscache if 'status' is provided */
 	else if (status)