+++ /dev/null
-/*
- * 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 = 1 + hash % ht->rehash;
-
- hash_address = (hash_address + double_hash) % ht->size;
- } while (hash_address != hash % ht->size);
-
- return NULL;
-}
-
-WL_EXPORT void
-wl_hash_table_for_each(struct wl_hash_table *ht,
- wl_iterator_func_t func, void *data)
-{
- struct hash_entry *entry;
- uint32_t i;
-
- for (i = 0; i < ht->size; i++) {
- entry = ht->table + i;
- if (entry_is_present(entry))
- func(entry->data, data);
- }
-}
-
-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 = 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 -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++;
- }
-}
projects / profile / ivi / wayland.git / commitdiff