util: Move the open-addressing linear-probing hash_table to src/util.

This hash table is used in core Mesa, the GLSL compiler, and the i965
driver, which makes it a good candidate for the new src/util module.

It's much faster than program/hash_table.[ch] (see commit 6991c2922f5
for data), and José's u_hash_table.c has a comment saying Gallium should
probably consider switching to a linear probing hash table at some point.
So this seems like the best candidate for a shared data structure.

Signed-off-by: Kenneth Graunke <[email protected]>

v2 (Jason Ekstrand): Pick up another hash_table use and patch up scons

Signed-off-by: Jason Ekstrand <[email protected]>
Reviewed-by: Marek Olšák <[email protected]>

1 files changed, 80 insertions, 0 deletions

diff --git a/src/util/tests/hash_table/collision.c b/src/util/tests/hash_table/collision.c
new file mode 100644
index 00000000000..9174c396151
--- /dev/null
+++ b/src/util/tests/hash_table/collision.c
@@ -0,0 +1,80 @@
+/*
+ * Copyright © 2012 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Authors:
+ *    Eric Anholt <[email protected]>
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include "hash_table.h"
+
+int
+main(int argc, char **argv)
+{
+   struct hash_table *ht;
+   const char *str1 = "test1";
+   const char *str2 = "test2";
+   struct hash_entry *entry1, *entry2;
+   uint32_t bad_hash = 5;
+   int i;
+
+   ht = _mesa_hash_table_create(NULL, _mesa_key_string_equal);
+
+   _mesa_hash_table_insert(ht, bad_hash, str1, NULL);
+   _mesa_hash_table_insert(ht, bad_hash, str2, NULL);
+
+   entry1 = _mesa_hash_table_search(ht, bad_hash, str1);
+   assert(entry1->key == str1);
+
+   entry2 = _mesa_hash_table_search(ht, bad_hash, str2);
+   assert(entry2->key == str2);
+
+   /* Check that we can still find #1 after inserting #2 */
+   entry1 = _mesa_hash_table_search(ht, bad_hash, str1);
+   assert(entry1->key == str1);
+
+   /* Remove the collided entry and look again. */
+   _mesa_hash_table_remove(ht, entry1);
+   entry2 = _mesa_hash_table_search(ht, bad_hash, str2);
+   assert(entry2->key == str2);
+
+   /* Put str1 back, then spam junk into the table to force a
+    * resize and make sure we can still find them both.
+    */
+   _mesa_hash_table_insert(ht, bad_hash, str1, NULL);
+   for (i = 0; i < 100; i++) {
+      char *key = malloc(10);
+      sprintf(key, "spam%d", i);
+      _mesa_hash_table_insert(ht, _mesa_hash_string(key), key, NULL);
+   }
+   entry1 = _mesa_hash_table_search(ht, bad_hash, str1);
+   assert(entry1->key == str1);
+   entry2 = _mesa_hash_table_search(ht, bad_hash, str2);
+   assert(entry2->key == str2);
+
+   _mesa_hash_table_destroy(ht, NULL);
+
+   return 0;
+}