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author | marha <marha@users.sourceforge.net> | 2012-12-10 08:33:13 +0100 |
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committer | marha <marha@users.sourceforge.net> | 2012-12-10 08:33:13 +0100 |
commit | 0328076efb5ff6e62152c09e38d0d11f7931d07b (patch) | |
tree | ce71cf0fe95186671dc75862c2ced47f4735214f /mesalib/src/mesa/main/set.c | |
parent | e82692e521240c5f8592f9ce56c9d5b3d68870ec (diff) | |
download | vcxsrv-0328076efb5ff6e62152c09e38d0d11f7931d07b.tar.gz vcxsrv-0328076efb5ff6e62152c09e38d0d11f7931d07b.tar.bz2 vcxsrv-0328076efb5ff6e62152c09e38d0d11f7931d07b.zip |
fontconfig libX11 mesa pixman git update 10 dec 2012
libX11 9833489e6c3829a1e835bc0a11f028fc180809e4
mesa 17f5dc57306b8f5079304701e455bf4b927d3cae
pixman 8ca4e144724ba2041bc5ef077ccf6d24e7cf4d1f
fontconfig 608c5b590bd3428dfcd30f3d68ee8b7131e2f019
Diffstat (limited to 'mesalib/src/mesa/main/set.c')
-rw-r--r-- | mesalib/src/mesa/main/set.c | 348 |
1 files changed, 348 insertions, 0 deletions
diff --git a/mesalib/src/mesa/main/set.c b/mesalib/src/mesa/main/set.c new file mode 100644 index 000000000..736841fc9 --- /dev/null +++ b/mesalib/src/mesa/main/set.c @@ -0,0 +1,348 @@ +/* + * Copyright © 2009-2012 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 "set.h" +#include "ralloc.h" + +#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 + */ + +uint32_t deleted_key_value; +const void *deleted_key = &deleted_key_value; + +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 set_entry *entry) +{ + return entry->key == NULL; +} + +static int +entry_is_deleted(struct set_entry *entry) +{ + return entry->key == deleted_key; +} + +static int +entry_is_present(struct set_entry *entry) +{ + return entry->key != NULL && entry->key != deleted_key; +} + +struct set * +_mesa_set_create(void *mem_ctx, + bool key_equals_function(const void *a, + const void *b)) +{ + struct set *ht; + + ht = ralloc(mem_ctx, struct set); + if (ht == NULL) + return NULL; + + ht->mem_ctx = mem_ctx; + 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->key_equals_function = key_equals_function; + ht->table = rzalloc_array(ht, struct set_entry, ht->size); + ht->entries = 0; + ht->deleted_entries = 0; + + if (ht->table == NULL) { + ralloc_free(ht); + return NULL; + } + + return ht; +} + +/** + * Frees the given set. + * + * If delete_function is passed, it gets called on each entry present before + * freeing. + */ +void +_mesa_set_destroy(struct set *ht, void (*delete_function)(struct set_entry *entry)) +{ + if (!ht) + return; + + if (delete_function) { + struct set_entry *entry; + + set_foreach (ht, entry) { + delete_function(entry); + } + } + ralloc_free(ht->table); + ralloc_free(ht); +} + +/** + * Finds a set entry with the given key and hash of that key. + * + * Returns NULL if no entry is found. + */ +struct set_entry * +_mesa_set_search(const struct set *ht, uint32_t hash, const void *key) +{ + uint32_t hash_address; + + hash_address = hash % ht->size; + do { + uint32_t double_hash; + + struct set_entry *entry = ht->table + hash_address; + + if (entry_is_free(entry)) { + return NULL; + } else if (entry_is_present(entry) && entry->hash == hash) { + if (ht->key_equals_function(key, entry->key)) { + return entry; + } + } + + double_hash = 1 + hash % ht->rehash; + + hash_address = (hash_address + double_hash) % ht->size; + } while (hash_address != hash % ht->size); + + return NULL; +} + +static void +set_rehash(struct set *ht, int new_size_index) +{ + struct set old_ht; + struct set_entry *table, *entry; + + if (new_size_index >= ARRAY_SIZE(hash_sizes)) + return; + + table = rzalloc_array(ht, struct set_entry, + hash_sizes[new_size_index].size); + 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)) { + _mesa_set_add(ht, entry->hash, entry->key); + } + } + + ralloc_free(old_ht.table); +} + +/** + * Inserts the key 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. + */ +struct set_entry * +_mesa_set_add(struct set *ht, uint32_t hash, const void *key) +{ + uint32_t hash_address; + + if (ht->entries >= ht->max_entries) { + set_rehash(ht, ht->size_index + 1); + } else if (ht->deleted_entries + ht->entries >= ht->max_entries) { + set_rehash(ht, ht->size_index); + } + + hash_address = hash % ht->size; + do { + struct set_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->key = key; + ht->entries++; + return entry; + } + + /* Implement replacement when another insert happens + * with a matching key. This is a relatively common + * feature of hash tables, with the alternative + * generally being "insert the new value as well, and + * return it first when the key is searched for". + * + * Note that the hash table doesn't have a delete callback. + * If freeing of old keys is required to avoid memory leaks, + * perform a search before inserting. + */ + if (entry->hash == hash && + ht->key_equals_function(key, entry->key)) { + entry->key = key; + return entry; + } + + double_hash = 1 + hash % ht->rehash; + + 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 NULL; +} + +/** + * 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. + */ +void +_mesa_set_remove(struct set *ht, struct set_entry *entry) +{ + if (!entry) + return; + + entry->key = deleted_key; + ht->entries--; + ht->deleted_entries++; +} + +/** + * This function is an iterator over the hash table. + * + * Pass in NULL for the first entry, as in the start of a for loop. Note that + * an iteration over the table is O(table_size) not O(entries). + */ +struct set_entry * +_mesa_set_next_entry(const struct set *ht, struct set_entry *entry) +{ + if (entry == NULL) + entry = ht->table; + else + entry = entry + 1; + + for (; entry != ht->table + ht->size; entry++) { + if (entry_is_present(entry)) { + return entry; + } + } + + return NULL; +} + +struct set_entry * +_mesa_set_random_entry(struct set *ht, + int (*predicate)(struct set_entry *entry)) +{ + struct set_entry *entry; + uint32_t i = rand() % ht->size; + + if (ht->entries == 0) + return NULL; + + for (entry = ht->table + i; entry != ht->table + ht->size; entry++) { + if (entry_is_present(entry) && + (!predicate || predicate(entry))) { + return entry; + } + } + + for (entry = ht->table; entry != ht->table + i; entry++) { + if (entry_is_present(entry) && + (!predicate || predicate(entry))) { + return entry; + } + } + + return NULL; +} + |