[CF 6301] v3 - Safer hash table initialization macro

This branch was automatically generated by a robot using patches from an
email thread registered at:

https://commitfest.postgresql.org/patch/6301

The branch will be overwritten each time a new patch version is posted to
the thread, and also periodically to check for bitrot caused by changes
on the master branch.

Patch(es): https://www.postgresql.org/message-id/DESS1U66SWHO.2JT1YL2Q20K0F@jeltef.nl
Author(s): Bertrand Drouvot, Jelte Fennema-Nio

Author: Commitfest Bot

contrib/dblink/dblink.c

@@ -1275,14 +1275,11 @@ 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)
+		foreach_hash(remoteConnHashEnt, hentry, remoteConnHash)
 		{
 			/* ignore it if it's not an open connection */
 			if (hentry->rconn.conn == NULL)
@@ -2540,13 +2537,9 @@ getConnectionByName(const char *name)
 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);
+	return hash_make_cxt(remoteConnHashEnt, name,
+						 "Remote Con hash", NUMCONN,
+						 TopMemoryContext);
 }
 
 static remoteConn *

contrib/pg_stat_statements/pg_stat_statements.c

@@ -517,7 +517,6 @@ static void
 pgss_shmem_startup(void)
 {
 	bool		found;
-	HASHCTL		info;
 	FILE	   *file = NULL;
 	FILE	   *qfile = NULL;
 	uint32		header;
@@ -557,12 +556,9 @@ pgss_shmem_startup(void)
 		pgss->stats.stats_reset = GetCurrentTimestamp();
 	}
 
-	info.keysize = sizeof(pgssHashKey);
-	info.entrysize = sizeof(pgssEntry);
-	pgss_hash = ShmemInitHash("pg_stat_statements hash",
-							  pgss_max, pgss_max,
-							  &info,
-							  HASH_ELEM | HASH_BLOBS);
+	pgss_hash = shmem_hash_make(pgssEntry, key,
+								"pg_stat_statements hash",
+								pgss_max, pgss_max);
 
 	LWLockRelease(AddinShmemInitLock);
 
@@ -745,9 +741,7 @@ pgss_shmem_shutdown(int code, Datum arg)
 	FILE	   *file;
 	char	   *qbuffer = NULL;
 	Size		qbuffer_size = 0;
-	HASH_SEQ_STATUS hash_seq;
 	int32		num_entries;
-	pgssEntry  *entry;
 
 	/* Don't try to dump during a crash. */
 	if (code)
@@ -781,8 +775,7 @@ pgss_shmem_shutdown(int code, Datum arg)
 	 * When serializing to disk, we store query texts immediately after their
 	 * entry data.  Any orphaned query texts are thereby excluded.
 	 */
-	hash_seq_init(&hash_seq, pgss_hash);
-	while ((entry = hash_seq_search(&hash_seq)) != NULL)
+	foreach_hash(pgssEntry, entry, pgss_hash)
 	{
 		int			len = entry->query_len;
 		char	   *qstr = qtext_fetch(entry->query_offset, len,
@@ -794,8 +787,8 @@ pgss_shmem_shutdown(int code, Datum arg)
 		if (fwrite(entry, sizeof(pgssEntry), 1, file) != 1 ||
 			fwrite(qstr, 1, len + 1, file) != len + 1)
 		{
-			/* note: we assume hash_seq_term won't change errno */
-			hash_seq_term(&hash_seq);
+			/* note: we assume foreach_hash_term won't change errno */
+			foreach_hash_term(entry);
 			goto error;
 		}
 	}
@@ -1699,8 +1692,6 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo,
 	Size		qbuffer_size = 0;
 	Size		extent = 0;
 	int			gc_count = 0;
-	HASH_SEQ_STATUS hash_seq;
-	pgssEntry  *entry;
 
 	/*
 	 * Superusers or roles with the privileges of pg_read_all_stats members
@@ -1829,8 +1820,7 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo,
 		}
 	}
 
-	hash_seq_init(&hash_seq, pgss_hash);
-	while ((entry = hash_seq_search(&hash_seq)) != NULL)
+	foreach_hash(pgssEntry, entry, pgss_hash)
 	{
 		Datum		values[PG_STAT_STATEMENTS_COLS];
 		bool		nulls[PG_STAT_STATEMENTS_COLS];
@@ -2174,9 +2164,7 @@ entry_cmp(const void *lhs, const void *rhs)
 static void
 entry_dealloc(void)
 {
-	HASH_SEQ_STATUS hash_seq;
 	pgssEntry **entries;
-	pgssEntry  *entry;
 	int			nvictims;
 	int			i;
 	Size		tottextlen;
@@ -2200,8 +2188,7 @@ entry_dealloc(void)
 	tottextlen = 0;
 	nvalidtexts = 0;
 
-	hash_seq_init(&hash_seq, pgss_hash);
-	while ((entry = hash_seq_search(&hash_seq)) != NULL)
+	foreach_hash(pgssEntry, entry, pgss_hash)
 	{
 		entries[i++] = entry;
 		/* "Sticky" entries get a different usage decay rate. */
@@ -2513,8 +2500,6 @@ gc_qtexts(void)
 	char	   *qbuffer;
 	Size		qbuffer_size;
 	FILE	   *qfile = NULL;
-	HASH_SEQ_STATUS hash_seq;
-	pgssEntry  *entry;
 	Size		extent;
 	int			nentries;
 
@@ -2556,8 +2541,7 @@ gc_qtexts(void)
 	extent = 0;
 	nentries = 0;
 
-	hash_seq_init(&hash_seq, pgss_hash);
-	while ((entry = hash_seq_search(&hash_seq)) != NULL)
+	foreach_hash(pgssEntry, entry, pgss_hash)
 	{
 		int			query_len = entry->query_len;
 		char	   *qry = qtext_fetch(entry->query_offset,
@@ -2580,7 +2564,7 @@ gc_qtexts(void)
 					(errcode_for_file_access(),
 					 errmsg("could not write file \"%s\": %m",
 							PGSS_TEXT_FILE)));
-			hash_seq_term(&hash_seq);
+			foreach_hash_term(entry);
 			goto gc_fail;
 		}
 
@@ -2647,8 +2631,7 @@ gc_qtexts(void)
 	 * Since the contents of the external file are now uncertain, mark all
 	 * hashtable entries as having invalid texts.
 	 */
-	hash_seq_init(&hash_seq, pgss_hash);
-	while ((entry = hash_seq_search(&hash_seq)) != NULL)
+	foreach_hash(pgssEntry, entry, pgss_hash)
 	{
 		entry->query_offset = 0;
 		entry->query_len = -1;
@@ -2712,8 +2695,6 @@ if (e) { \
 static TimestampTz
 entry_reset(Oid userid, Oid dbid, int64 queryid, bool minmax_only)
 {
-	HASH_SEQ_STATUS hash_seq;
-	pgssEntry  *entry;
 	FILE	   *qfile;
 	int64		num_entries;
 	int64		num_remove = 0;
@@ -2733,6 +2714,8 @@ entry_reset(Oid userid, Oid dbid, int64 queryid, bool minmax_only)
 	if (userid != 0 && dbid != 0 && queryid != INT64CONST(0))
 	{
 		/* If all the parameters are available, use the fast path. */
+		pgssEntry  *entry;
+
 		memset(&key, 0, sizeof(pgssHashKey));
 		key.userid = userid;
 		key.dbid = dbid;
@@ -2756,8 +2739,7 @@ entry_reset(Oid userid, Oid dbid, int64 queryid, bool minmax_only)
 	else if (userid != 0 || dbid != 0 || queryid != INT64CONST(0))
 	{
 		/* Reset entries corresponding to valid parameters. */
-		hash_seq_init(&hash_seq, pgss_hash);
-		while ((entry = hash_seq_search(&hash_seq)) != NULL)
+		foreach_hash(pgssEntry, entry, pgss_hash)
 		{
 			if ((!userid || entry->key.userid == userid) &&
 				(!dbid || entry->key.dbid == dbid) &&
@@ -2770,8 +2752,7 @@ entry_reset(Oid userid, Oid dbid, int64 queryid, bool minmax_only)
 	else
 	{
 		/* Reset all entries. */
-		hash_seq_init(&hash_seq, pgss_hash);
-		while ((entry = hash_seq_search(&hash_seq)) != NULL)
+		foreach_hash(pgssEntry, entry, pgss_hash)
 		{
 			SINGLE_ENTRY_RESET(entry);
 		}

contrib/pg_trgm/trgm_regexp.c

@@ -893,7 +893,6 @@ convertPgWchar(pg_wchar c, trgm_mb_char *result)
 static void
 transformGraph(TrgmNFA *trgmNFA)
 {
-	HASHCTL		hashCtl;
 	TrgmStateKey initkey;
 	TrgmState  *initstate;
 	ListCell   *lc;
@@ -905,13 +904,7 @@ transformGraph(TrgmNFA *trgmNFA)
 	trgmNFA->overflowed = false;
 
 	/* Create hashtable for states */
-	hashCtl.keysize = sizeof(TrgmStateKey);
-	hashCtl.entrysize = sizeof(TrgmState);
-	hashCtl.hcxt = CurrentMemoryContext;
-	trgmNFA->states = hash_create("Trigram NFA",
-								  1024,
-								  &hashCtl,
-								  HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
+	trgmNFA->states = hash_make(TrgmState, stateKey, "Trigram NFA", 1024);
 	trgmNFA->nstates = 0;
 
 	/* Create initial state: ambiguous prefix, NFA's initial state */
@@ -1456,10 +1449,8 @@ prefixContains(TrgmPrefix *prefix1, TrgmPrefix *prefix2)
 static bool
 selectColorTrigrams(TrgmNFA *trgmNFA)
 {
-	HASH_SEQ_STATUS scan_status;
 	int			arcsCount = trgmNFA->arcsCount,
 				i;
-	TrgmState  *state;
 	ColorTrgmInfo *colorTrgms;
 	int64		totalTrgmCount;
 	float4		totalTrgmPenalty;
@@ -1470,8 +1461,7 @@ selectColorTrigrams(TrgmNFA *trgmNFA)
 	trgmNFA->colorTrgms = colorTrgms;
 
 	i = 0;
-	hash_seq_init(&scan_status, trgmNFA->states);
-	while ((state = (TrgmState *) hash_seq_search(&scan_status)) != NULL)
+	foreach_hash(TrgmState, state, trgmNFA->states)
 	{
 		ListCell   *cell;
 
@@ -1933,17 +1923,14 @@ packGraph(TrgmNFA *trgmNFA, MemoryContext rcontext)
 	int			snumber = 2,
 				arcIndex,
 				arcsCount;
-	HASH_SEQ_STATUS scan_status;
-	TrgmState  *state;
 	TrgmPackArcInfo *arcs;
 	TrgmPackedArc *packedArcs;
 	TrgmPackedGraph *result;
 	int			i,
 				j;
 
 	/* Enumerate surviving states, giving init and fin reserved numbers */
-	hash_seq_init(&scan_status, trgmNFA->states);
-	while ((state = (TrgmState *) hash_seq_search(&scan_status)) != NULL)
+	foreach_hash(TrgmState, state, trgmNFA->states)
 	{
 		while (state->parent)
 			state = state->parent;
@@ -1965,8 +1952,7 @@ packGraph(TrgmNFA *trgmNFA, MemoryContext rcontext)
 	/* Collect array of all arcs */
 	arcs = palloc_array(TrgmPackArcInfo, trgmNFA->arcsCount);
 	arcIndex = 0;
-	hash_seq_init(&scan_status, trgmNFA->states);
-	while ((state = (TrgmState *) hash_seq_search(&scan_status)) != NULL)
+	foreach_hash(TrgmState, state, trgmNFA->states)
 	{
 		TrgmState  *source = state;
 		ListCell   *cell;
@@ -2209,16 +2195,13 @@ static void
 printTrgmNFA(TrgmNFA *trgmNFA)
 {
 	StringInfoData buf;
-	HASH_SEQ_STATUS scan_status;
-	TrgmState  *state;
 	TrgmState  *initstate = NULL;
 
 	initStringInfo(&buf);
 
 	appendStringInfoString(&buf, "\ndigraph transformedNFA {\n");
 
-	hash_seq_init(&scan_status, trgmNFA->states);
-	while ((state = (TrgmState *) hash_seq_search(&scan_status)) != NULL)
+	foreach_hash(TrgmState, state, trgmNFA->states)
 	{
 		ListCell   *cell;