Import Eric Anholts hash table implementation

Adapted from git://people.freedesktop.org/~anholt/hash_table.

Makefile.in

@@ -17,12 +17,14 @@ libwayland-server.so :				\
 	event-loop.o				\
 	connection.o				\
 	wayland-util.o				\
+	wayland-hash.o				\
 	wayland-protocol.o
 
 libwayland.so :					\
 	wayland-client.o			\
 	connection.o				\
 	wayland-util.o				\
+	wayland-hash.o				\
 	wayland-protocol.o
 
 $(libs) : CFLAGS += -fPIC @FFI_CFLAGS@

connection.c

@@ -280,7 +280,7 @@ wl_connection_vmarshal(struct wl_connection *connection,
 void
 wl_connection_demarshal(struct wl_connection *connection,
 			uint32_t size,
-			struct wl_hash *objects,
+			struct wl_hash_table *objects,
 			void (*func)(void),
 			void *data, struct wl_object *target,
 			const struct wl_message *message)
@@ -342,7 +342,7 @@ wl_connection_demarshal(struct wl_connection *connection,
 			break;
 		case 'o':
 			types[i] = &ffi_type_pointer;
-			object = wl_hash_lookup(objects, *p);
+			object = wl_hash_table_lookup(objects, *p);
 			if (object == NULL && *p != 0)
 				printf("unknown object (%d)\n", *p);
 			values[i].object = object;
@@ -351,7 +351,7 @@ wl_connection_demarshal(struct wl_connection *connection,
 		case 'n':
 			types[i] = &ffi_type_uint32;
 			values[i].new_id = *p;
-			object = wl_hash_lookup(objects, *p);
+			object = wl_hash_table_lookup(objects, *p);
 			if (object != NULL)
 				printf("object already exists (%d)\n", *p);
 			p++;

connection.h

@@ -50,7 +50,7 @@ void wl_connection_vmarshal(struct wl_connection *connection,
 
 void wl_connection_demarshal(struct wl_connection *connection,
 			     uint32_t size,
-			     struct wl_hash *objects,
+			     struct wl_hash_table *objects,
 			     void (*func)(void),
 			     void *data, struct wl_object *target,
 			     const struct wl_message *message);

wayland-client.c

@@ -95,7 +95,7 @@ struct wl_display {
 	int fd;
 	uint32_t id, id_count, next_range;
 	uint32_t mask;
-	struct wl_hash *objects;
+	struct wl_hash_table *objects;
 	struct wl_list global_list;
 	struct wl_listener listener;
 	struct wl_list global_listener_list;
@@ -184,7 +184,7 @@ wl_proxy_create_for_global(struct wl_display *display,
 	proxy->display = display;
 	global->proxy = proxy;
 	wl_list_init(&proxy->listener_list);
-	wl_hash_insert(display->objects, &proxy->base);
+	wl_hash_table_insert(display->objects, proxy->base.id, proxy);
 
 	wl_list_for_each(listener, &display->global_listener_list, link)
 		(*listener->handler)(display, &proxy->base, listener->data);
@@ -311,7 +311,8 @@ display_handle_global(void *data,
 	wl_list_insert(display->global_list.prev, &global->link);
 
 	if (strcmp(global->interface, "display") == 0)
-		wl_hash_insert(display->objects, &display->proxy.base);
+		wl_hash_table_insert(display->objects,
+				     id, &display->proxy.base);
 	else if (strcmp(global->interface, "compositor") == 0)
 		display->compositor = (struct wl_compositor *) 
 			wl_proxy_create_for_global(display, global,
@@ -383,7 +384,7 @@ wl_display_create(const char *name, size_t name_size)
 		return NULL;
 	}
 
-	display->objects = wl_hash_create();
+	display->objects = wl_hash_table_create();
 	wl_list_init(&display->global_list);
 	wl_list_init(&display->global_listener_list);
 
@@ -448,7 +449,8 @@ handle_event(struct wl_display *display,
 	if (id == 1)
 		proxy = &display->proxy;
 	else
-		proxy = (struct wl_proxy *) wl_hash_lookup(display->objects, id);
+		proxy = (struct wl_proxy *)
+			wl_hash_table_lookup(display->objects, id);
 
 	if (proxy != NULL) {
 		if (wl_list_empty(&proxy->listener_list)) {
@@ -544,7 +546,8 @@ wl_compositor_create_surface(struct wl_compositor *compositor)
 	surface->proxy.base.interface = &wl_surface_interface;
 	surface->proxy.base.id = wl_display_allocate_id(compositor->proxy.display);
 	surface->proxy.display = compositor->proxy.display;
-	wl_hash_insert(compositor->proxy.display->objects, &surface->proxy.base);
+	wl_hash_table_insert(compositor->proxy.display->objects,
+			     surface->proxy.base.id, surface);
 	wl_proxy_marshal(&compositor->proxy,
 			  WL_COMPOSITOR_CREATE_SURFACE, surface);
 

wayland-hash.c

@@ -0,0 +1,296 @@
+/*
+ * Copyright © 2009 Intel Corporation
+ * Copyright © 1988-2004 Keith Packard and Bart Massey.
+ *
+ * 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.
+ *
+ * Except as contained in this notice, the names of the authors
+ * or their institutions shall not be used in advertising or
+ * otherwise to promote the sale, use or other dealings in this
+ * Software without prior written authorization from the
+ * authors.
+ *
+ * Authors:
+ *    Eric Anholt <eric@anholt.net>
+ *    Keith Packard <keithp@keithp.com>
+ */
+
+#include <stdlib.h>
+
+#include "wayland-util.h"
+
+struct hash_entry {
+	uint32_t hash;
+	void *data;
+};
+
+struct wl_hash_table {
+	struct hash_entry *table;
+	uint32_t size;
+	uint32_t rehash;
+	uint32_t max_entries;
+	uint32_t size_index;
+	uint32_t entries;
+	uint32_t deleted_entries;
+};
+
+#define ARRAY_SIZE(array) (sizeof(array) / sizeof(array[0]))
+
+/*
+ * From Knuth -- a good choice for hash/rehash values is p, p-2 where
+ * p and p-2 are both prime.  These tables are sized to have an extra 10%
+ * free to avoid exponential performance degradation as the hash table fills
+ */
+
+static const uint32_t deleted_data;
+
+static const struct {
+   uint32_t max_entries, size, rehash;
+} hash_sizes[] = {
+    { 2,		5,		3	  },
+    { 4,		7,		5	  },
+    { 8,		13,		11	  },
+    { 16,		19,		17	  },
+    { 32,		43,		41        },
+    { 64,		73,		71        },
+    { 128,		151,		149       },
+    { 256,		283,		281       },
+    { 512,		571,		569       },
+    { 1024,		1153,		1151      },
+    { 2048,		2269,		2267      },
+    { 4096,		4519,		4517      },
+    { 8192,		9013,		9011      },
+    { 16384,		18043,		18041     },
+    { 32768,		36109,		36107     },
+    { 65536,		72091,		72089     },
+    { 131072,		144409,		144407    },
+    { 262144,		288361,		288359    },
+    { 524288,		576883,		576881    },
+    { 1048576,		1153459,	1153457   },
+    { 2097152,		2307163,	2307161   },
+    { 4194304,		4613893,	4613891   },
+    { 8388608,		9227641,	9227639   },
+    { 16777216,		18455029,	18455027  },
+    { 33554432,		36911011,	36911009  },
+    { 67108864,		73819861,	73819859  },
+    { 134217728,	147639589,	147639587 },
+    { 268435456,	295279081,	295279079 },
+    { 536870912,	590559793,	590559791 },
+    { 1073741824,	1181116273,	1181116271},
+    { 2147483648ul,	2362232233ul,	2362232231ul}
+};
+
+static int
+entry_is_free(struct hash_entry *entry)
+{
+	return entry->data == NULL;
+}
+
+static int
+entry_is_deleted(struct hash_entry *entry)
+{
+	return entry->data == &deleted_data;
+}
+
+static int
+entry_is_present(struct hash_entry *entry)
+{
+	return entry->data != NULL && entry->data != &deleted_data;
+}
+
+WL_EXPORT struct wl_hash_table *
+wl_hash_table_create(void)
+{
+	struct wl_hash_table *ht;
+
+	ht = malloc(sizeof(*ht));
+	if (ht == NULL)
+		return NULL;
+
+	ht->size_index = 0;
+	ht->size = hash_sizes[ht->size_index].size;
+	ht->rehash = hash_sizes[ht->size_index].rehash;
+	ht->max_entries = hash_sizes[ht->size_index].max_entries;
+	ht->table = calloc(ht->size, sizeof(*ht->table));
+	ht->entries = 0;
+	ht->deleted_entries = 0;
+
+	if (ht->table == NULL) {
+		free(ht);
+		return NULL;
+	}
+
+	return ht;
+}
+
+/**
+ * Frees the given hash table.
+ */
+WL_EXPORT void
+wl_hash_table_destroy(struct wl_hash_table *ht)
+{
+	if (!ht)
+		return;
+
+	free(ht->table);
+	free(ht);
+}
+
+/**
+ * Finds a hash table entry with the given key and hash of that key.
+ *
+ * Returns NULL if no entry is found.  Note that the data pointer may be
+ * modified by the user.
+ */
+static void *
+hash_table_search(struct wl_hash_table *ht, uint32_t hash)
+{
+	uint32_t hash_address;
+
+	hash_address = hash % ht->size;
+	do {
+		uint32_t double_hash;
+
+		struct hash_entry *entry = ht->table + hash_address;
+
+		if (entry_is_free(entry)) {
+			return NULL;
+		} else if (entry_is_present(entry) && entry->hash == hash) {
+			return entry;
+		}
+
+		double_hash = hash % ht->rehash;
+		if (double_hash == 0)
+			double_hash = 1;
+
+		hash_address = (hash_address + double_hash) % ht->size;
+	} while (hash_address != hash % ht->size);
+
+	return NULL;
+}
+
+WL_EXPORT void *
+wl_hash_table_lookup(struct wl_hash_table *ht, uint32_t hash)
+{
+	struct hash_entry *entry;
+
+	entry = hash_table_search(ht, hash);
+	if (entry != NULL)
+		return entry->data;
+
+	return NULL;
+}
+
+static void
+hash_table_rehash(struct wl_hash_table *ht, int new_size_index)
+{
+	struct wl_hash_table old_ht;
+	struct hash_entry *table, *entry;
+
+	if (new_size_index >= ARRAY_SIZE(hash_sizes))
+		return;
+
+	table = calloc(hash_sizes[new_size_index].size, sizeof(*ht->table));
+	if (table == NULL)
+		return;
+
+	old_ht = *ht;
+
+	ht->table = table;
+	ht->size_index = new_size_index;
+	ht->size = hash_sizes[ht->size_index].size;
+	ht->rehash = hash_sizes[ht->size_index].rehash;
+	ht->max_entries = hash_sizes[ht->size_index].max_entries;
+	ht->entries = 0;
+	ht->deleted_entries = 0;
+
+	for (entry = old_ht.table;
+	     entry != old_ht.table + old_ht.size;
+	     entry++) {
+		if (entry_is_present(entry)) {
+			wl_hash_table_insert(ht, entry->hash, entry->data);
+		}
+	}
+
+	free(old_ht.table);
+}
+
+/**
+ * Inserts the data with the given hash into the table.
+ *
+ * Note that insertion may rearrange the table on a resize or rehash,
+ * so previously found hash_entries are no longer valid after this function.
+ */
+WL_EXPORT int
+wl_hash_table_insert(struct wl_hash_table *ht, uint32_t hash, void *data)
+{
+	uint32_t hash_address;
+
+	if (ht->entries >= ht->max_entries) {
+		hash_table_rehash(ht, ht->size_index + 1);
+	} else if (ht->deleted_entries + ht->entries >= ht->max_entries) {
+		hash_table_rehash(ht, ht->size_index);
+	}
+
+	hash_address = hash % ht->size;
+	do {
+		struct hash_entry *entry = ht->table + hash_address;
+		uint32_t double_hash;
+
+		if (!entry_is_present(entry)) {
+			if (entry_is_deleted(entry))
+				ht->deleted_entries--;
+			entry->hash = hash;
+			entry->data = data;
+			ht->entries++;
+			return 0;
+		}
+
+		double_hash = hash % ht->rehash;
+		if (double_hash == 0)
+			double_hash = 1;
+
+		hash_address = (hash_address + double_hash) % ht->size;
+	} while (hash_address != hash % ht->size);
+
+	/* We could hit here if a required resize failed. An unchecked-malloc
+	 * application could ignore this result.
+	 */
+	return -1;
+}
+
+/**
+ * This function deletes the given hash table entry.
+ *
+ * Note that deletion doesn't otherwise modify the table, so an iteration over
+ * the table deleting entries is safe.
+ */
+WL_EXPORT void
+wl_hash_table_remove(struct wl_hash_table *ht, uint32_t hash)
+{
+	struct hash_entry *entry;
+
+	entry = hash_table_search(ht, hash);
+	if (entry != NULL) {
+		entry->data = (void *) &deleted_data;
+		ht->entries--;
+		ht->deleted_entries++;
+	}
+}

wayland-util.c

@@ -25,82 +25,6 @@
 #include <string.h>
 #include "wayland-util.h"
 
-struct wl_hash {
-	struct wl_object **objects;
-	uint32_t count, alloc;
-};
-
-struct wl_hash *
-wl_hash_create(void)
-{
-	struct wl_hash *hash;
-
-	hash = malloc(sizeof *hash);
-	if (hash == NULL)
-		return hash;
-
-	memset(hash, 0, sizeof *hash);
-
-	return hash;
-}
-
-void
-wl_hash_destroy(struct wl_hash *hash)
-{
-	free(hash);
-}
-
-int wl_hash_insert(struct wl_hash *hash, struct wl_object *object)
-{
-	struct wl_object **objects;
-	uint32_t alloc;
-
-	if (hash->count == hash->alloc) {
-		if (hash->alloc == 0)
-			alloc = 16;
-		else
-			alloc = hash->alloc * 2;
-		objects = realloc(hash->objects, alloc * sizeof *objects);
-		if (objects == NULL)
-			return -1;
-
-		hash->objects = objects;
-		hash->alloc = alloc;
-	}
-
-	hash->objects[hash->count] = object;
-	hash->count++;
-
-	return 0;
-}
-
-struct wl_object *
-wl_hash_lookup(struct wl_hash *hash, uint32_t id)
-{
-	int i;
-
-	for (i = 0; i < hash->count; i++) {
-		if (hash->objects[i]->id == id)
-			return hash->objects[i];
-	}
-
-	return NULL;
-}
-
-void
-wl_hash_remove(struct wl_hash *hash, struct wl_object *object)
-{
-	int i;
-
-	for (i = 0; i < hash->count; i++) {
-		if (hash->objects[i]->id == object->id) {
-			hash->objects[i] = hash->objects[hash->count - 1];
-			hash->count--;
-			break;
-		}
-	}
-}
-
 WL_EXPORT void
 wl_list_init(struct wl_list *list)
 {

wayland-util.h

@@ -23,6 +23,8 @@
 #ifndef WAYLAND_UTIL_H
 #define WAYLAND_UTIL_H
 
+#include <inttypes.h>
+
 /* GCC visibility */
 #if defined(__GNUC__) && __GNUC__ >= 4
 #define WL_EXPORT __attribute__ ((visibility("default")))
@@ -64,12 +66,13 @@ struct wl_object {
 	uint32_t id;
 };
 
-struct wl_hash;
+struct wl_hash_table;
-struct wl_hash *wl_hash_create(void);
+struct wl_hash_table *wl_hash_table_create(void);
-void wl_hash_destroy(struct wl_hash *hash);
+void wl_hash_table_destroy(struct wl_hash_table *ht);
-int wl_hash_insert(struct wl_hash *hash, struct wl_object *object);
+void *wl_hash_table_lookup(struct wl_hash_table *ht, uint32_t hash);
-struct wl_object *wl_hash_lookup(struct wl_hash *hash, uint32_t id);
+int wl_hash_table_insert(struct wl_hash_table *ht, uint32_t hash, void *data);
-void wl_hash_remove(struct wl_hash *hash, struct wl_object *object);
+void wl_hash_table_remove(struct wl_hash_table *ht, uint32_t hash);
+
 
 struct wl_list {
 	struct wl_list *prev;

wayland.c

@@ -50,7 +50,7 @@ struct wl_client {
 struct wl_display {
 	struct wl_object base;
 	struct wl_event_loop *loop;
-	struct wl_hash *objects;
+	struct wl_hash_table *objects;
 
 	struct wl_list pending_frame_list;
 	uint32_t client_id_range;
@@ -109,7 +109,7 @@ wl_client_connection_data(int fd, uint32_t mask, void *data)
 		if (len < size)
 			break;
 
-		object = wl_hash_lookup(client->display->objects, p[0]);
+		object = wl_hash_table_lookup(client->display->objects, p[0]);
 		if (object == NULL) {
 			wl_client_post_event(client, &client->display->base,
 					     WL_DISPLAY_INVALID_OBJECT, p[0]);
@@ -247,7 +247,7 @@ wl_client_add_surface(struct wl_client *client,
 	surface->base.implementation = (void (**)(void)) implementation;
 	surface->client = client;
 
-	wl_hash_insert(display->objects, &surface->base);
+	wl_hash_table_insert(display->objects, id, surface);
 	wl_list_insert(client->surface_list.prev, &surface->link);
 
 	return 0;
@@ -259,7 +259,7 @@ wl_client_remove_surface(struct wl_client *client,
 {
 	struct wl_display *display = client->display;
 
-	wl_hash_remove(display->objects, &surface->base);
+	wl_hash_table_remove(display->objects, surface->base.id);
 	wl_list_remove(&surface->link);
 }
 
@@ -305,7 +305,7 @@ wl_display_create(void)
 		return NULL;
 	}
 
-	display->objects = wl_hash_create();
+	display->objects = wl_hash_table_create();
 	if (display->objects == NULL) {
 		free(display);
 		return NULL;
@@ -333,7 +333,7 @@ WL_EXPORT void
 wl_display_add_object(struct wl_display *display, struct wl_object *object)
 {
 	object->id = display->id++;
-	wl_hash_insert(display->objects, object);
+	wl_hash_table_insert(display->objects, object->id, object);
 }
 
 WL_EXPORT int