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| author | Kristian Høgsberg <krh@bitplanet.net> | 2010-09-14 11:13:18 -0400 |
|---|---|---|
| committer | Kristian Høgsberg <krh@bitplanet.net> | 2010-09-14 12:41:55 -0400 |
| commit | 6dd08ebbe108c2c78cc23d6af0b00a84199d8b2c (patch) | |
| tree | 7670e24beb6fab2629d0ccd4451df5f90a344d89 /wayland-hash.c | |
| parent | Move example compositor to subdirectory (diff) | |
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Move core protocol libraries into wayland/ subdirectory
Diffstat (limited to 'wayland-hash.c')
| -rw-r--r-- | wayland-hash.c | 296 |
1 files changed, 0 insertions, 296 deletions
diff --git a/wayland-hash.c b/wayland-hash.c deleted file mode 100644 index b299a33..0000000 --- a/wayland-hash.c +++ /dev/null @@ -1,296 +0,0 @@ -/* - * 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++; - } -} |
