Import Eric Anholts hash table implementation
authorKristian Høgsberg <krh@bitplanet.net>
Fri, 26 Feb 2010 16:42:59 +0000 (11:42 -0500)
committerKristian Høgsberg <krh@bitplanet.net>
Fri, 26 Feb 2010 16:42:59 +0000 (11:42 -0500)
Adapted from git://people.freedesktop.org/~anholt/hash_table.

Makefile.in
connection.c
connection.h
wayland-client.c
wayland-hash.c [new file with mode: 0644]
wayland-util.c
wayland-util.h
wayland.c

index 3f666e2..04538ab 100644 (file)
@@ -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@
index b37e940..264c6ab 100644 (file)
@@ -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++;
index 3db07ee..30e82e1 100644 (file)
@@ -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);
index 80e2832..8cabbb2 100644 (file)
@@ -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);
 
diff --git a/wayland-hash.c b/wayland-hash.c
new file mode 100644 (file)
index 0000000..b299a33
--- /dev/null
@@ -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++;
+       }
+}
index cd73542..a287cce 100644 (file)
 #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)
 {
index 0233cb3..ed4acbc 100644 (file)
@@ -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 *wl_hash_create(void);
-void wl_hash_destroy(struct wl_hash *hash);
-int wl_hash_insert(struct wl_hash *hash, struct wl_object *object);
-struct wl_object *wl_hash_lookup(struct wl_hash *hash, uint32_t id);
-void wl_hash_remove(struct wl_hash *hash, struct wl_object *object);
+struct wl_hash_table;
+struct wl_hash_table *wl_hash_table_create(void);
+void wl_hash_table_destroy(struct wl_hash_table *ht);
+void *wl_hash_table_lookup(struct wl_hash_table *ht, uint32_t hash);
+int wl_hash_table_insert(struct wl_hash_table *ht, uint32_t hash, void *data);
+void wl_hash_table_remove(struct wl_hash_table *ht, uint32_t hash);
+
 
 struct wl_list {
        struct wl_list *prev;
index 700e01a..db42741 100644 (file)
--- a/wayland.c
+++ b/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