Retire miniglx and move the actual glx code up to src/glx

1 files changed, 473 insertions, 0 deletions

diff --git a/src/glx/glxhash.c b/src/glx/glxhash.c
new file mode 100644
index 0000000000..b76ec32345
--- /dev/null
+++ b/src/glx/glxhash.c
@@ -0,0 +1,473 @@
+/* glxhash.c -- Small hash table support for integer -> integer mapping
+ * Taken from libdrm.
+ *
+ * Created: Sun Apr 18 09:35:45 1999 by faith@precisioninsight.com
+ *
+ * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
+ * All Rights Reserved.
+ *
+ * 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
+ * PRECISION INSIGHT AND/OR ITS SUPPLIERS 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: Rickard E. (Rik) Faith <faith@valinux.com>
+ *
+ * DESCRIPTION
+ *
+ * This file contains a straightforward implementation of a fixed-sized
+ * hash table using self-organizing linked lists [Knuth73, pp. 398-399] for
+ * collision resolution.  There are two potentially interesting things
+ * about this implementation:
+ *
+ * 1) The table is power-of-two sized.  Prime sized tables are more
+ * traditional, but do not have a significant advantage over power-of-two
+ * sized table, especially when double hashing is not used for collision
+ * resolution.
+ *
+ * 2) The hash computation uses a table of random integers [Hanson97,
+ * pp. 39-41].
+ *
+ * FUTURE ENHANCEMENTS
+ *
+ * With a table size of 512, the current implementation is sufficient for a
+ * few hundred keys.  Since this is well above the expected size of the
+ * tables for which this implementation was designed, the implementation of
+ * dynamic hash tables was postponed until the need arises.  A common (and
+ * naive) approach to dynamic hash table implementation simply creates a
+ * new hash table when necessary, rehashes all the data into the new table,
+ * and destroys the old table.  The approach in [Larson88] is superior in
+ * two ways: 1) only a portion of the table is expanded when needed,
+ * distributing the expansion cost over several insertions, and 2) portions
+ * of the table can be locked, enabling a scalable thread-safe
+ * implementation.
+ *
+ * REFERENCES
+ *
+ * [Hanson97] David R. Hanson.  C Interfaces and Implementations:
+ * Techniques for Creating Reusable Software.  Reading, Massachusetts:
+ * Addison-Wesley, 1997.
+ *
+ * [Knuth73] Donald E. Knuth. The Art of Computer Programming.  Volume 3:
+ * Sorting and Searching.  Reading, Massachusetts: Addison-Wesley, 1973.
+ *
+ * [Larson88] Per-Ake Larson. "Dynamic Hash Tables".  CACM 31(4), April
+ * 1988, pp. 446-457.
+ *
+ */
+
+#include "glxhash.h"
+#include <X11/Xfuncproto.h>
+
+#define HASH_MAIN 0
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define HASH_MAGIC 0xdeadbeef
+#define HASH_DEBUG 0
+#define HASH_SIZE  512          /* Good for about 100 entries */
+                                /* If you change this value, you probably
+                                   have to change the HashHash hashing
+                                   function! */
+
+#define HASH_ALLOC malloc
+#define HASH_FREE  free
+#ifndef __GLIBC__
+#define HASH_RANDOM_DECL	char *ps, rs[256]
+#define HASH_RANDOM_INIT(seed)	ps = initstate(seed, rs, sizeof(rs))
+#define HASH_RANDOM		random()
+#define HASH_RANDOM_DESTROY	setstate(ps)
+#else
+#define HASH_RANDOM_DECL	struct random_data rd; int32_t rv; char rs[256]
+#define HASH_RANDOM_INIT(seed)					\
+   do {								\
+      (void) memset(&rd, 0, sizeof(rd));			\
+      (void) initstate_r(seed, rs, sizeof(rs), &rd);		\
+   } while(0)
+#define HASH_RANDOM             ((void) random_r(&rd, &rv), rv)
+#define HASH_RANDOM_DESTROY
+#endif
+
+typedef struct __glxHashBucket
+{
+   unsigned long key;
+   void *value;
+   struct __glxHashBucket *next;
+} __glxHashBucket, *__glxHashBucketPtr;
+
+typedef struct __glxHashTable *__glxHashTablePtr;
+struct __glxHashTable
+{
+   unsigned long magic;
+   unsigned long hits;          /* At top of linked list */
+   unsigned long partials;      /* Not at top of linked list */
+   unsigned long misses;        /* Not in table */
+   __glxHashBucketPtr buckets[HASH_SIZE];
+   int p0;
+   __glxHashBucketPtr p1;
+};
+
+static unsigned long
+HashHash(unsigned long key)
+{
+   unsigned long hash = 0;
+   unsigned long tmp = key;
+   static int init = 0;
+   static unsigned long scatter[256];
+   int i;
+
+   if (!init) {
+      HASH_RANDOM_DECL;
+      HASH_RANDOM_INIT(37);
+      for (i = 0; i < 256; i++)
+         scatter[i] = HASH_RANDOM;
+      HASH_RANDOM_DESTROY;
+      ++init;
+   }
+
+   while (tmp) {
+      hash = (hash << 1) + scatter[tmp & 0xff];
+      tmp >>= 8;
+   }
+
+   hash %= HASH_SIZE;
+#if HASH_DEBUG
+   printf("Hash(%d) = %d\n", key, hash);
+#endif
+   return hash;
+}
+
+_X_HIDDEN __glxHashTable *
+__glxHashCreate(void)
+{
+   __glxHashTablePtr table;
+   int i;
+
+   table = HASH_ALLOC(sizeof(*table));
+   if (!table)
+      return NULL;
+   table->magic = HASH_MAGIC;
+   table->hits = 0;
+   table->partials = 0;
+   table->misses = 0;
+
+   for (i = 0; i < HASH_SIZE; i++)
+      table->buckets[i] = NULL;
+   return table;
+}
+
+_X_HIDDEN int
+__glxHashDestroy(__glxHashTable * t)
+{
+   __glxHashTablePtr table = (__glxHashTablePtr) t;
+   __glxHashBucketPtr bucket;
+   __glxHashBucketPtr next;
+   int i;
+
+   if (table->magic != HASH_MAGIC)
+      return -1;                /* Bad magic */
+
+   for (i = 0; i < HASH_SIZE; i++) {
+      for (bucket = table->buckets[i]; bucket;) {
+         next = bucket->next;
+         HASH_FREE(bucket);
+         bucket = next;
+      }
+   }
+   HASH_FREE(table);
+   return 0;
+}
+
+/* Find the bucket and organize the list so that this bucket is at the
+   top. */
+
+static __glxHashBucketPtr
+HashFind(__glxHashTablePtr table, unsigned long key, unsigned long *h)
+{
+   unsigned long hash = HashHash(key);
+   __glxHashBucketPtr prev = NULL;
+   __glxHashBucketPtr bucket;
+
+   if (h)
+      *h = hash;
+
+   for (bucket = table->buckets[hash]; bucket; bucket = bucket->next) {
+      if (bucket->key == key) {
+         if (prev) {
+            /* Organize */
+            prev->next = bucket->next;
+            bucket->next = table->buckets[hash];
+            table->buckets[hash] = bucket;
+            ++table->partials;
+         }
+         else {
+            ++table->hits;
+         }
+         return bucket;
+      }
+      prev = bucket;
+   }
+   ++table->misses;
+   return NULL;
+}
+
+_X_HIDDEN int
+__glxHashLookup(__glxHashTable * t, unsigned long key, void **value)
+{
+   __glxHashTablePtr table = (__glxHashTablePtr) t;
+   __glxHashBucketPtr bucket;
+
+   if (!table || table->magic != HASH_MAGIC)
+      return -1;                /* Bad magic */
+
+   bucket = HashFind(table, key, NULL);
+   if (!bucket)
+      return 1;                 /* Not found */
+   *value = bucket->value;
+   return 0;                    /* Found */
+}
+
+_X_HIDDEN int
+__glxHashInsert(__glxHashTable * t, unsigned long key, void *value)
+{
+   __glxHashTablePtr table = (__glxHashTablePtr) t;
+   __glxHashBucketPtr bucket;
+   unsigned long hash;
+
+   if (table->magic != HASH_MAGIC)
+      return -1;                /* Bad magic */
+
+   if (HashFind(table, key, &hash))
+      return 1;                 /* Already in table */
+
+   bucket = HASH_ALLOC(sizeof(*bucket));
+   if (!bucket)
+      return -1;                /* Error */
+   bucket->key = key;
+   bucket->value = value;
+   bucket->next = table->buckets[hash];
+   table->buckets[hash] = bucket;
+#if HASH_DEBUG
+   printf("Inserted %d at %d/%p\n", key, hash, bucket);
+#endif
+   return 0;                    /* Added to table */
+}
+
+_X_HIDDEN int
+__glxHashDelete(__glxHashTable * t, unsigned long key)
+{
+   __glxHashTablePtr table = (__glxHashTablePtr) t;
+   unsigned long hash;
+   __glxHashBucketPtr bucket;
+
+   if (table->magic != HASH_MAGIC)
+      return -1;                /* Bad magic */
+
+   bucket = HashFind(table, key, &hash);
+
+   if (!bucket)
+      return 1;                 /* Not found */
+
+   table->buckets[hash] = bucket->next;
+   HASH_FREE(bucket);
+   return 0;
+}
+
+_X_HIDDEN int
+__glxHashNext(__glxHashTable * t, unsigned long *key, void **value)
+{
+   __glxHashTablePtr table = (__glxHashTablePtr) t;
+
+   while (table->p0 < HASH_SIZE) {
+      if (table->p1) {
+         *key = table->p1->key;
+         *value = table->p1->value;
+         table->p1 = table->p1->next;
+         return 1;
+      }
+      table->p1 = table->buckets[table->p0];
+      ++table->p0;
+   }
+   return 0;
+}
+
+_X_HIDDEN int
+__glxHashFirst(__glxHashTable * t, unsigned long *key, void **value)
+{
+   __glxHashTablePtr table = (__glxHashTablePtr) t;
+
+   if (table->magic != HASH_MAGIC)
+      return -1;                /* Bad magic */
+
+   table->p0 = 0;
+   table->p1 = table->buckets[0];
+   return __glxHashNext(table, key, value);
+}
+
+#if HASH_MAIN
+#define DIST_LIMIT 10
+static int dist[DIST_LIMIT];
+
+static void
+clear_dist(void)
+{
+   int i;
+
+   for (i = 0; i < DIST_LIMIT; i++)
+      dist[i] = 0;
+}
+
+static int
+count_entries(__glxHashBucketPtr bucket)
+{
+   int count = 0;
+
+   for (; bucket; bucket = bucket->next)
+      ++count;
+   return count;
+}
+
+static void
+update_dist(int count)
+{
+   if (count >= DIST_LIMIT)
+      ++dist[DIST_LIMIT - 1];
+   else
+      ++dist[count];
+}
+
+static void
+compute_dist(__glxHashTablePtr table)
+{
+   int i;
+   __glxHashBucketPtr bucket;
+
+   printf("Hits = %ld, partials = %ld, misses = %ld\n",
+          table->hits, table->partials, table->misses);
+   clear_dist();
+   for (i = 0; i < HASH_SIZE; i++) {
+      bucket = table->buckets[i];
+      update_dist(count_entries(bucket));
+   }
+   for (i = 0; i < DIST_LIMIT; i++) {
+      if (i != DIST_LIMIT - 1)
+         printf("%5d %10d\n", i, dist[i]);
+      else
+         printf("other %10d\n", dist[i]);
+   }
+}
+
+static void
+check_table(__glxHashTablePtr table, unsigned long key, unsigned long value)
+{
+   unsigned long retval = 0;
+   int retcode = __glxHashLookup(table, key, &retval);
+
+   switch (retcode) {
+   case -1:
+      printf("Bad magic = 0x%08lx:"
+             " key = %lu, expected = %lu, returned = %lu\n",
+             table->magic, key, value, retval);
+      break;
+   case 1:
+      printf("Not found: key = %lu, expected = %lu returned = %lu\n",
+             key, value, retval);
+      break;
+   case 0:
+      if (value != retval)
+         printf("Bad value: key = %lu, expected = %lu, returned = %lu\n",
+                key, value, retval);
+      break;
+   default:
+      printf("Bad retcode = %d: key = %lu, expected = %lu, returned = %lu\n",
+             retcode, key, value, retval);
+      break;
+   }
+}
+
+int
+main(void)
+{
+   __glxHashTablePtr table;
+   int i;
+
+   printf("\n***** 256 consecutive integers ****\n");
+   table = __glxHashCreate();
+   for (i = 0; i < 256; i++)
+      __glxHashInsert(table, i, i);
+   for (i = 0; i < 256; i++)
+      check_table(table, i, i);
+   for (i = 256; i >= 0; i--)
+      check_table(table, i, i);
+   compute_dist(table);
+   __glxHashDestroy(table);
+
+   printf("\n***** 1024 consecutive integers ****\n");
+   table = __glxHashCreate();
+   for (i = 0; i < 1024; i++)
+      __glxHashInsert(table, i, i);
+   for (i = 0; i < 1024; i++)
+      check_table(table, i, i);
+   for (i = 1024; i >= 0; i--)
+      check_table(table, i, i);
+   compute_dist(table);
+   __glxHashDestroy(table);
+
+   printf("\n***** 1024 consecutive page addresses (4k pages) ****\n");
+   table = __glxHashCreate();
+   for (i = 0; i < 1024; i++)
+      __glxHashInsert(table, i * 4096, i);
+   for (i = 0; i < 1024; i++)
+      check_table(table, i * 4096, i);
+   for (i = 1024; i >= 0; i--)
+      check_table(table, i * 4096, i);
+   compute_dist(table);
+   __glxHashDestroy(table);
+
+   printf("\n***** 1024 random integers ****\n");
+   table = __glxHashCreate();
+   srandom(0xbeefbeef);
+   for (i = 0; i < 1024; i++)
+      __glxHashInsert(table, random(), i);
+   srandom(0xbeefbeef);
+   for (i = 0; i < 1024; i++)
+      check_table(table, random(), i);
+   srandom(0xbeefbeef);
+   for (i = 0; i < 1024; i++)
+      check_table(table, random(), i);
+   compute_dist(table);
+   __glxHashDestroy(table);
+
+   printf("\n***** 5000 random integers ****\n");
+   table = __glxHashCreate();
+   srandom(0xbeefbeef);
+   for (i = 0; i < 5000; i++)
+      __glxHashInsert(table, random(), i);
+   srandom(0xbeefbeef);
+   for (i = 0; i < 5000; i++)
+      check_table(table, random(), i);
+   srandom(0xbeefbeef);
+   for (i = 0; i < 5000; i++)
+      check_table(table, random(), i);
+   compute_dist(table);
+   __glxHashDestroy(table);
+
+   return 0;
+}
+#endif