From b9817c2a4879ca94bf8e7ab979a88d5436e16c66 Mon Sep 17 00:00:00 2001
From: Robert Haas <rhaas@postgresql.org>
Date: Wed, 25 Jul 2012 10:52:54 -0400
Subject: [PATCH] Beginnings of dynahash testing code.

---
 contrib/hashtest/hashtest.c | 57 +++++++++++++++++++++++++++++++++----
 1 file changed, 52 insertions(+), 5 deletions(-)

diff --git a/contrib/hashtest/hashtest.c b/contrib/hashtest/hashtest.c
index 7c68e982a4..0b18bfccb9 100644
--- a/contrib/hashtest/hashtest.c
+++ b/contrib/hashtest/hashtest.c
@@ -36,6 +36,7 @@ static CHashDescriptor cdesc = {
 
 static shmem_startup_hook_type prev_shmem_startup_hook = NULL;
 static CHashTable chash;
+static HTAB *dynahash;
 
 void
 _PG_init(void)
@@ -53,15 +54,24 @@ _PG_init(void)
 static void
 hashtest_shmem_startup(void)
 {
+	HASHCTL		info;
+
 	if (prev_shmem_startup_hook)
 		prev_shmem_startup_hook();
+
+	/* Initialize concurrent hash table. */
 	chash = CHashInitialize(chash, &cdesc);
-}
 
-Datum
-test_dynahash(PG_FUNCTION_ARGS)
-{
-	PG_RETURN_VOID();
+	/* Initialize shared dynahash table. */
+	info.keysize = sizeof(cdesc.key_size);
+	info.entrysize = sizeof(cdesc.element_size);
+	info.hash = tag_hash;
+	info.num_partitions = 16;
+
+	dynahash = ShmemInitHash("hashtest-dynahash",
+							 cdesc.capacity, cdesc.capacity,
+							 &info,
+							 HASH_ELEM | HASH_FUNCTION | HASH_PARTITION);
 }
 
 Datum
@@ -98,3 +108,40 @@ test_chash(PG_FUNCTION_ARGS)
 
 	PG_RETURN_VOID();
 }
+
+static bool
+dynahash_insert(uint32 key, uint32 val)
+{
+	bool	found;
+	uint32	hashcode;
+	hentry *e;
+
+	hashcode = get_hash_value(dynahash, (void *) &key);
+	/* lock */
+	e = hash_search_with_hash_value(dynahash, (void *) &key,
+									hashcode, HASH_ENTER, &found);
+	if (!found)
+		e->val = val;
+	/* unlock */
+
+	return !found;
+}
+
+Datum
+test_dynahash(PG_FUNCTION_ARGS)
+{
+	uint32	i;
+	bool	ok;
+
+	for (i = 0; i < 1000000; ++i)
+	{
+		ok = dynahash_insert(i, i * 31);
+		if (!ok)
+			elog(LOG, "insert %u: failed", i);
+		ok = dynahash_insert(i, i * 31);
+		if (ok)
+			elog(LOG, "insert %u: worked twice", i);
+	}
+
+	PG_RETURN_VOID();
+}
-- 
2.39.5