2012-11-07 07:18:41 +00:00
|
|
|
/*
|
|
|
|
* 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>
|
|
|
|
*/
|
|
|
|
|
|
|
|
/**
|
|
|
|
* Implements an open-addressing, linear-reprobing hash table.
|
|
|
|
*
|
|
|
|
* For more information, see:
|
|
|
|
*
|
|
|
|
* http://cgit.freedesktop.org/~anholt/hash_table/tree/README
|
|
|
|
*/
|
|
|
|
|
|
|
|
#include <stdlib.h>
|
|
|
|
#include <string.h>
|
|
|
|
|
2014-02-25 09:08:45 +00:00
|
|
|
#include "hash_table.h"
|
|
|
|
#include "ralloc.h"
|
2014-07-23 22:58:52 +01:00
|
|
|
#include "macros.h"
|
2012-11-07 07:18:41 +00:00
|
|
|
|
|
|
|
static const uint32_t deleted_key_value;
|
|
|
|
|
|
|
|
/**
|
|
|
|
* 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 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(const struct hash_entry *entry)
|
|
|
|
{
|
|
|
|
return entry->key == NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int
|
|
|
|
entry_is_deleted(const struct hash_table *ht, struct hash_entry *entry)
|
|
|
|
{
|
|
|
|
return entry->key == ht->deleted_key;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int
|
|
|
|
entry_is_present(const struct hash_table *ht, struct hash_entry *entry)
|
|
|
|
{
|
|
|
|
return entry->key != NULL && entry->key != ht->deleted_key;
|
|
|
|
}
|
|
|
|
|
|
|
|
struct hash_table *
|
|
|
|
_mesa_hash_table_create(void *mem_ctx,
|
2013-07-08 16:58:12 +01:00
|
|
|
bool (*key_equals_function)(const void *a,
|
|
|
|
const void *b))
|
2012-11-07 07:18:41 +00:00
|
|
|
{
|
|
|
|
struct hash_table *ht;
|
|
|
|
|
|
|
|
ht = ralloc(mem_ctx, struct hash_table);
|
|
|
|
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->key_equals_function = key_equals_function;
|
|
|
|
ht->table = rzalloc_array(ht, struct hash_entry, ht->size);
|
|
|
|
ht->entries = 0;
|
|
|
|
ht->deleted_entries = 0;
|
|
|
|
ht->deleted_key = &deleted_key_value;
|
|
|
|
|
|
|
|
if (ht->table == NULL) {
|
|
|
|
ralloc_free(ht);
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
return ht;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* Frees the given hash table.
|
|
|
|
*
|
|
|
|
* If delete_function is passed, it gets called on each entry present before
|
|
|
|
* freeing.
|
|
|
|
*/
|
|
|
|
void
|
|
|
|
_mesa_hash_table_destroy(struct hash_table *ht,
|
|
|
|
void (*delete_function)(struct hash_entry *entry))
|
|
|
|
{
|
|
|
|
if (!ht)
|
|
|
|
return;
|
|
|
|
|
|
|
|
if (delete_function) {
|
|
|
|
struct hash_entry *entry;
|
|
|
|
|
|
|
|
hash_table_foreach(ht, entry) {
|
|
|
|
delete_function(entry);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
ralloc_free(ht);
|
|
|
|
}
|
|
|
|
|
|
|
|
/** Sets the value of the key pointer used for deleted entries in the table.
|
|
|
|
*
|
|
|
|
* The assumption is that usually keys are actual pointers, so we use a
|
|
|
|
* default value of a pointer to an arbitrary piece of storage in the library.
|
|
|
|
* But in some cases a consumer wants to store some other sort of value in the
|
|
|
|
* table, like a uint32_t, in which case that pointer may conflict with one of
|
|
|
|
* their valid keys. This lets that user select a safe value.
|
|
|
|
*
|
|
|
|
* This must be called before any keys are actually deleted from the table.
|
|
|
|
*/
|
|
|
|
void
|
|
|
|
_mesa_hash_table_set_deleted_key(struct hash_table *ht, const void *deleted_key)
|
|
|
|
{
|
|
|
|
ht->deleted_key = deleted_key;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* 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.
|
|
|
|
*/
|
|
|
|
struct hash_entry *
|
|
|
|
_mesa_hash_table_search(struct hash_table *ht, uint32_t hash,
|
|
|
|
const void *key)
|
|
|
|
{
|
|
|
|
uint32_t start_hash_address = hash % ht->size;
|
|
|
|
uint32_t hash_address = start_hash_address;
|
|
|
|
|
|
|
|
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(ht, 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 != start_hash_address);
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
static void
|
|
|
|
_mesa_hash_table_rehash(struct hash_table *ht, int new_size_index)
|
|
|
|
{
|
|
|
|
struct hash_table old_ht;
|
|
|
|
struct hash_entry *table, *entry;
|
|
|
|
|
|
|
|
if (new_size_index >= ARRAY_SIZE(hash_sizes))
|
|
|
|
return;
|
|
|
|
|
|
|
|
table = rzalloc_array(ht, struct hash_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;
|
|
|
|
|
|
|
|
hash_table_foreach(&old_ht, entry) {
|
|
|
|
_mesa_hash_table_insert(ht, entry->hash,
|
|
|
|
entry->key, entry->data);
|
|
|
|
}
|
|
|
|
|
|
|
|
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 hash_entry *
|
|
|
|
_mesa_hash_table_insert(struct hash_table *ht, uint32_t hash,
|
|
|
|
const void *key, void *data)
|
|
|
|
{
|
|
|
|
uint32_t start_hash_address, hash_address;
|
|
|
|
|
|
|
|
if (ht->entries >= ht->max_entries) {
|
|
|
|
_mesa_hash_table_rehash(ht, ht->size_index + 1);
|
|
|
|
} else if (ht->deleted_entries + ht->entries >= ht->max_entries) {
|
|
|
|
_mesa_hash_table_rehash(ht, ht->size_index);
|
|
|
|
}
|
|
|
|
|
|
|
|
start_hash_address = hash % ht->size;
|
|
|
|
hash_address = start_hash_address;
|
|
|
|
do {
|
|
|
|
struct hash_entry *entry = ht->table + hash_address;
|
|
|
|
uint32_t double_hash;
|
|
|
|
|
|
|
|
if (!entry_is_present(ht, entry)) {
|
|
|
|
if (entry_is_deleted(ht, entry))
|
|
|
|
ht->deleted_entries--;
|
|
|
|
entry->hash = hash;
|
|
|
|
entry->key = key;
|
|
|
|
entry->data = data;
|
|
|
|
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 data pointers 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;
|
|
|
|
entry->data = data;
|
|
|
|
return entry;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
double_hash = 1 + hash % ht->rehash;
|
|
|
|
|
|
|
|
hash_address = (hash_address + double_hash) % ht->size;
|
|
|
|
} while (hash_address != start_hash_address);
|
|
|
|
|
|
|
|
/* 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_hash_table_remove(struct hash_table *ht,
|
|
|
|
struct hash_entry *entry)
|
|
|
|
{
|
|
|
|
if (!entry)
|
|
|
|
return;
|
|
|
|
|
|
|
|
entry->key = ht->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 hash_entry *
|
|
|
|
_mesa_hash_table_next_entry(struct hash_table *ht,
|
|
|
|
struct hash_entry *entry)
|
|
|
|
{
|
|
|
|
if (entry == NULL)
|
|
|
|
entry = ht->table;
|
|
|
|
else
|
|
|
|
entry = entry + 1;
|
|
|
|
|
|
|
|
for (; entry != ht->table + ht->size; entry++) {
|
|
|
|
if (entry_is_present(ht, entry)) {
|
|
|
|
return entry;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* Returns a random entry from the hash table.
|
|
|
|
*
|
|
|
|
* This may be useful in implementing random replacement (as opposed
|
|
|
|
* to just removing everything) in caches based on this hash table
|
|
|
|
* implementation. @predicate may be used to filter entries, or may
|
|
|
|
* be set to NULL for no filtering.
|
|
|
|
*/
|
|
|
|
struct hash_entry *
|
|
|
|
_mesa_hash_table_random_entry(struct hash_table *ht,
|
|
|
|
bool (*predicate)(struct hash_entry *entry))
|
|
|
|
{
|
|
|
|
struct hash_entry *entry;
|
2012-11-13 06:15:42 +00:00
|
|
|
uint32_t i = rand() % ht->size;
|
2012-11-07 07:18:41 +00:00
|
|
|
|
|
|
|
if (ht->entries == 0)
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
for (entry = ht->table + i; entry != ht->table + ht->size; entry++) {
|
|
|
|
if (entry_is_present(ht, entry) &&
|
|
|
|
(!predicate || predicate(entry))) {
|
|
|
|
return entry;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
for (entry = ht->table; entry != ht->table + i; entry++) {
|
|
|
|
if (entry_is_present(ht, entry) &&
|
|
|
|
(!predicate || predicate(entry))) {
|
|
|
|
return entry;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/**
|
2014-11-18 10:58:11 +00:00
|
|
|
* Quick FNV-1a hash implementation based on:
|
2012-11-07 07:18:41 +00:00
|
|
|
* http://www.isthe.com/chongo/tech/comp/fnv/
|
|
|
|
*
|
2014-11-18 10:58:11 +00:00
|
|
|
* FNV-1a is not be the best hash out there -- Jenkins's lookup3 is supposed
|
|
|
|
* to be quite good, and it probably beats FNV. But FNV has the advantage
|
|
|
|
* that it involves almost no code. For an improvement on both, see Paul
|
2012-11-07 07:18:41 +00:00
|
|
|
* Hsieh's http://www.azillionmonkeys.com/qed/hash.html
|
|
|
|
*/
|
|
|
|
uint32_t
|
|
|
|
_mesa_hash_data(const void *data, size_t size)
|
|
|
|
{
|
|
|
|
uint32_t hash = 2166136261ul;
|
|
|
|
const uint8_t *bytes = data;
|
|
|
|
|
|
|
|
while (size-- != 0) {
|
|
|
|
hash ^= *bytes;
|
|
|
|
hash = hash * 0x01000193;
|
|
|
|
bytes++;
|
|
|
|
}
|
|
|
|
|
|
|
|
return hash;
|
|
|
|
}
|
|
|
|
|
2014-11-18 10:58:11 +00:00
|
|
|
/** FNV-1a string hash implementation */
|
2012-11-07 07:18:41 +00:00
|
|
|
uint32_t
|
|
|
|
_mesa_hash_string(const char *key)
|
|
|
|
{
|
|
|
|
uint32_t hash = 2166136261ul;
|
|
|
|
|
|
|
|
while (*key != 0) {
|
|
|
|
hash ^= *key;
|
|
|
|
hash = hash * 0x01000193;
|
|
|
|
key++;
|
|
|
|
}
|
|
|
|
|
|
|
|
return hash;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* String compare function for use as the comparison callback in
|
|
|
|
* _mesa_hash_table_create().
|
|
|
|
*/
|
|
|
|
bool
|
|
|
|
_mesa_key_string_equal(const void *a, const void *b)
|
|
|
|
{
|
|
|
|
return strcmp(a, b) == 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
bool
|
|
|
|
_mesa_key_pointer_equal(const void *a, const void *b)
|
|
|
|
{
|
|
|
|
return a == b;
|
|
|
|
}
|