#include <assert.h>
#include <string.h>
+#include "hash_table.h"
#include "macros.h"
#include "ralloc.h"
#include "set.h"
+#include "fast_urem_by_const.h"
/*
* From Knuth -- a good choice for hash/rehash values is p, p-2 where
static const struct {
uint32_t max_entries, size, rehash;
+ uint64_t size_magic, rehash_magic;
} 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 }
+#define ENTRY(max_entries, size, rehash) \
+ { max_entries, size, rehash, \
+ REMAINDER_MAGIC(size), REMAINDER_MAGIC(rehash) }
+
+ ENTRY(2, 5, 3 ),
+ ENTRY(4, 7, 5 ),
+ ENTRY(8, 13, 11 ),
+ ENTRY(16, 19, 17 ),
+ ENTRY(32, 43, 41 ),
+ ENTRY(64, 73, 71 ),
+ ENTRY(128, 151, 149 ),
+ ENTRY(256, 283, 281 ),
+ ENTRY(512, 571, 569 ),
+ ENTRY(1024, 1153, 1151 ),
+ ENTRY(2048, 2269, 2267 ),
+ ENTRY(4096, 4519, 4517 ),
+ ENTRY(8192, 9013, 9011 ),
+ ENTRY(16384, 18043, 18041 ),
+ ENTRY(32768, 36109, 36107 ),
+ ENTRY(65536, 72091, 72089 ),
+ ENTRY(131072, 144409, 144407 ),
+ ENTRY(262144, 288361, 288359 ),
+ ENTRY(524288, 576883, 576881 ),
+ ENTRY(1048576, 1153459, 1153457 ),
+ ENTRY(2097152, 2307163, 2307161 ),
+ ENTRY(4194304, 4613893, 4613891 ),
+ ENTRY(8388608, 9227641, 9227639 ),
+ ENTRY(16777216, 18455029, 18455027 ),
+ ENTRY(33554432, 36911011, 36911009 ),
+ ENTRY(67108864, 73819861, 73819859 ),
+ ENTRY(134217728, 147639589, 147639587 ),
+ ENTRY(268435456, 295279081, 295279079 ),
+ ENTRY(536870912, 590559793, 590559791 ),
+ ENTRY(1073741824, 1181116273, 1181116271 ),
+ ENTRY(2147483648ul, 2362232233ul, 2362232231ul )
};
+ASSERTED static inline bool
+key_pointer_is_reserved(const void *key)
+{
+ return key == NULL || key == deleted_key;
+}
+
static int
entry_is_free(struct set_entry *entry)
{
ht->size_index = 0;
ht->size = hash_sizes[ht->size_index].size;
ht->rehash = hash_sizes[ht->size_index].rehash;
+ ht->size_magic = hash_sizes[ht->size_index].size_magic;
+ ht->rehash_magic = hash_sizes[ht->size_index].rehash_magic;
ht->max_entries = hash_sizes[ht->size_index].max_entries;
ht->key_hash_function = key_hash_function;
ht->key_equals_function = key_equals_function;
return;
if (delete_function) {
- struct set_entry *entry;
-
set_foreach (ht, entry) {
delete_function(entry);
}
void
_mesa_set_clear(struct set *set, void (*delete_function)(struct set_entry *entry))
{
- struct set_entry *entry;
-
if (!set)
return;
static struct set_entry *
set_search(const struct set *ht, uint32_t hash, const void *key)
{
- uint32_t hash_address;
+ assert(!key_pointer_is_reserved(key));
- hash_address = hash % ht->size;
+ uint32_t size = ht->size;
+ uint32_t start_address = util_fast_urem32(hash, size, ht->size_magic);
+ uint32_t double_hash = util_fast_urem32(hash, ht->rehash,
+ ht->rehash_magic) + 1;
+ uint32_t hash_address = start_address;
do {
- uint32_t double_hash;
-
struct set_entry *entry = ht->table + hash_address;
if (entry_is_free(entry)) {
}
}
- double_hash = 1 + hash % ht->rehash;
-
- hash_address = (hash_address + double_hash) % ht->size;
- } while (hash_address != hash % ht->size);
+ hash_address += double_hash;
+ if (hash_address >= size)
+ hash_address -= size;
+ } while (hash_address != start_address);
return NULL;
}
return set_search(set, hash, key);
}
-static struct set_entry *
-set_add(struct set *ht, uint32_t hash, const void *key);
+static void
+set_add_rehash(struct set *ht, uint32_t hash, const void *key)
+{
+ uint32_t size = ht->size;
+ uint32_t start_address = util_fast_urem32(hash, size, ht->size_magic);
+ uint32_t double_hash = util_fast_urem32(hash, ht->rehash,
+ ht->rehash_magic) + 1;
+ uint32_t hash_address = start_address;
+ do {
+ struct set_entry *entry = ht->table + hash_address;
+ if (likely(entry->key == NULL)) {
+ entry->hash = hash;
+ entry->key = key;
+ return;
+ }
+
+ hash_address = hash_address + double_hash;
+ if (hash_address >= size)
+ hash_address -= size;
+ } while (true);
+}
static void
set_rehash(struct set *ht, unsigned new_size_index)
{
struct set old_ht;
- struct set_entry *table, *entry;
+ struct set_entry *table;
if (new_size_index >= ARRAY_SIZE(hash_sizes))
return;
ht->size_index = new_size_index;
ht->size = hash_sizes[ht->size_index].size;
ht->rehash = hash_sizes[ht->size_index].rehash;
+ ht->size_magic = hash_sizes[ht->size_index].size_magic;
+ ht->rehash_magic = hash_sizes[ht->size_index].rehash_magic;
ht->max_entries = hash_sizes[ht->size_index].max_entries;
ht->entries = 0;
ht->deleted_entries = 0;
set_foreach(&old_ht, entry) {
- set_add(ht, entry->hash, entry->key);
+ set_add_rehash(ht, entry->hash, entry->key);
}
+ ht->entries = old_ht.entries;
+
ralloc_free(old_ht.table);
}
+void
+_mesa_set_resize(struct set *set, uint32_t entries)
+{
+ /* You can't shrink a set below its number of entries */
+ if (set->entries > entries)
+ entries = set->entries;
+
+ unsigned size_index = 0;
+ while (hash_sizes[size_index].max_entries < entries)
+ size_index++;
+
+ set_rehash(set, size_index);
+}
+
/**
- * Inserts the key with the given hash into the table.
+ * Find a matching entry for the given key, or insert it if it doesn't already
+ * exist.
*
* Note that insertion may rearrange the table on a resize or rehash,
* so previously found hash_entries are no longer valid after this function.
*/
static struct set_entry *
-set_add(struct set *ht, uint32_t hash, const void *key)
+set_search_or_add(struct set *ht, uint32_t hash, const void *key, bool *found)
{
- uint32_t hash_address;
struct set_entry *available_entry = NULL;
+ assert(!key_pointer_is_reserved(key));
+
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;
+ uint32_t size = ht->size;
+ uint32_t start_address = util_fast_urem32(hash, size, ht->size_magic);
+ uint32_t double_hash = util_fast_urem32(hash, ht->rehash,
+ ht->rehash_magic) + 1;
+ uint32_t hash_address = start_address;
do {
struct set_entry *entry = ht->table + hash_address;
- uint32_t double_hash;
if (!entry_is_present(entry)) {
/* Stash the first available entry we find */
break;
}
- /* 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_is_deleted(entry) &&
entry->hash == hash &&
ht->key_equals_function(key, entry->key)) {
- entry->key = key;
+ if (found)
+ *found = true;
return entry;
}
- double_hash = 1 + hash % ht->rehash;
-
- hash_address = (hash_address + double_hash) % ht->size;
- } while (hash_address != hash % ht->size);
+ hash_address = hash_address + double_hash;
+ if (hash_address >= size)
+ hash_address -= size;
+ } while (hash_address != start_address);
if (available_entry) {
+ /* There is no matching entry, create it. */
if (entry_is_deleted(available_entry))
ht->deleted_entries--;
available_entry->hash = hash;
available_entry->key = key;
ht->entries++;
+ if (found)
+ *found = false;
return available_entry;
}
return NULL;
}
+/**
+ * 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.
+ */
+static struct set_entry *
+set_add(struct set *ht, uint32_t hash, const void *key)
+{
+ struct set_entry *entry = set_search_or_add(ht, hash, key, NULL);
+
+ if (unlikely(!entry))
+ return NULL;
+
+ /* Note: If a matching entry already exists, this will replace it. 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, use the alternative
+ * _mesa_set_search_or_add function and implement the replacement yourself.
+ */
+ entry->key = key;
+ return entry;
+}
+
struct set_entry *
_mesa_set_add(struct set *set, const void *key)
{
return set_add(set, hash, key);
}
+struct set_entry *
+_mesa_set_search_and_add(struct set *set, const void *key, bool *replaced)
+{
+ assert(set->key_hash_function);
+ return _mesa_set_search_and_add_pre_hashed(set,
+ set->key_hash_function(key),
+ key, replaced);
+}
+
+struct set_entry *
+_mesa_set_search_and_add_pre_hashed(struct set *set, uint32_t hash,
+ const void *key, bool *replaced)
+{
+ assert(set->key_hash_function == NULL ||
+ hash == set->key_hash_function(key));
+ struct set_entry *entry = set_search_or_add(set, hash, key, replaced);
+
+ if (unlikely(!entry))
+ return NULL;
+
+ /* This implements the replacement, same as _mesa_set_add(). The user will
+ * be notified if we're overwriting a found entry.
+ */
+ entry->key = key;
+ return entry;
+}
+
+struct set_entry *
+_mesa_set_search_or_add(struct set *set, const void *key)
+{
+ assert(set->key_hash_function);
+ return set_search_or_add(set, set->key_hash_function(key), key, NULL);
+}
+
+struct set_entry *
+_mesa_set_search_or_add_pre_hashed(struct set *set, uint32_t hash,
+ const void *key)
+{
+ assert(set->key_hash_function == NULL ||
+ hash == set->key_hash_function(key));
+ return set_search_or_add(set, hash, key, NULL);
+}
+
/**
* This function deletes the given hash table entry.
*
ht->deleted_entries++;
}
+/**
+ * Removes the entry with the corresponding key, if exists.
+ */
+void
+_mesa_set_remove_key(struct set *set, const void *key)
+{
+ _mesa_set_remove(set, _mesa_set_search(set, key));
+}
+
/**
* This function is an iterator over the hash table.
*
return NULL;
}
+
+/**
+ * Helper to create a set with pointer keys.
+ */
+struct set *
+_mesa_pointer_set_create(void *mem_ctx)
+{
+ return _mesa_set_create(mem_ctx, _mesa_hash_pointer,
+ _mesa_key_pointer_equal);
+}