/**
* \file hash.c
* Generic hash table.
*
* Used for display lists, texture objects, vertex/fragment programs,
* buffer objects, etc. The hash functions are thread-safe.
*
* \note key=0 is illegal.
*
* \author Brian Paul
*/
/*
* Mesa 3-D graphics library
*
* Copyright (C) 1999-2006 Brian Paul All Rights Reserved.
*
* 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 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.
*/
#include "glheader.h"
#include "hash.h"
#include "util/hash_table.h"
/**
* Create a new hash table.
*
* \return pointer to a new, empty hash table.
*/
struct _mesa_HashTable *
_mesa_NewHashTable(void)
{
struct _mesa_HashTable *table = CALLOC_STRUCT(_mesa_HashTable);
if (table) {
table->ht = _mesa_hash_table_create(NULL, uint_key_hash,
uint_key_compare);
if (table->ht == NULL) {
free(table);
_mesa_error_no_memory(__func__);
return NULL;
}
_mesa_hash_table_set_deleted_key(table->ht, uint_key(DELETED_KEY_VALUE));
/*
* Needs to be recursive, since the callback in _mesa_HashWalk()
* is allowed to call _mesa_HashRemove().
*/
mtx_init(&table->Mutex, mtx_recursive);
}
else {
_mesa_error_no_memory(__func__);
}
return table;
}
/**
* Delete a hash table.
* Frees each entry on the hash table and then the hash table structure itself.
* Note that the caller should have already traversed the table and deleted
* the objects in the table (i.e. We don't free the entries' data pointer).
*
* \param table the hash table to delete.
*/
void
_mesa_DeleteHashTable(struct _mesa_HashTable *table)
{
assert(table);
if (_mesa_hash_table_next_entry(table->ht, NULL) != NULL) {
_mesa_problem(NULL, "In _mesa_DeleteHashTable, found non-freed data");
}
_mesa_hash_table_destroy(table->ht, NULL);
mtx_destroy(&table->Mutex);
free(table);
}
/**
* Lookup an entry in the hash table, without locking.
* \sa _mesa_HashLookup
*/
static inline void *
_mesa_HashLookup_unlocked(struct _mesa_HashTable *table, GLuint key)
{
const struct hash_entry *entry;
assert(table);
assert(key);
if (key == DELETED_KEY_VALUE)
return table->deleted_key_data;
entry = _mesa_hash_table_search_pre_hashed(table->ht,
uint_hash(key),
uint_key(key));
if (!entry)
return NULL;
return entry->data;
}
/**
* Lookup an entry in the hash table.
*
* \param table the hash table.
* \param key the key.
*
* \return pointer to user's data or NULL if key not in table
*/
void *
_mesa_HashLookup(struct _mesa_HashTable *table, GLuint key)
{
void *res;
_mesa_HashLockMutex(table);
res = _mesa_HashLookup_unlocked(table, key);
_mesa_HashUnlockMutex(table);
return res;
}
/**
* Lookup an entry in the hash table without locking the mutex.
*
* The hash table mutex must be locked manually by calling
* _mesa_HashLockMutex() before calling this function.
*
* \param table the hash table.
* \param key the key.
*
* \return pointer to user's data or NULL if key not in table
*/
void *
_mesa_HashLookupLocked(struct _mesa_HashTable *table, GLuint key)
{
return _mesa_HashLookup_unlocked(table, key);
}
static inline void
_mesa_HashInsert_unlocked(struct _mesa_HashTable *table, GLuint key, void *data)
{
uint32_t hash = uint_hash(key);
struct hash_entry *entry;
assert(table);
assert(key);
if (key > table->MaxKey)
table->MaxKey = key;
if (key == DELETED_KEY_VALUE) {
table->deleted_key_data = data;
} else {
entry = _mesa_hash_table_search_pre_hashed(table->ht, hash, uint_key(key));
if (entry) {
entry->data = data;
} else {
_mesa_hash_table_insert_pre_hashed(table->ht, hash, uint_key(key), data);
}
}
}
/**
* Insert a key/pointer pair into the hash table without locking the mutex.
* If an entry with this key already exists we'll replace the existing entry.
*
* The hash table mutex must be locked manually by calling
* _mesa_HashLockMutex() before calling this function.
*
* \param table the hash table.
* \param key the key (not zero).
* \param data pointer to user data.
*/
void
_mesa_HashInsertLocked(struct _mesa_HashTable *table, GLuint key, void *data)
{
_mesa_HashInsert_unlocked(table, key, data);
}
/**
* Insert a key/pointer pair into the hash table.
* If an entry with this key already exists we'll replace the existing entry.
*
* \param table the hash table.
* \param key the key (not zero).
* \param data pointer to user data.
*/
void
_mesa_HashInsert(struct _mesa_HashTable *table, GLuint key, void *data)
{
_mesa_HashLockMutex(table);
_mesa_HashInsert_unlocked(table, key, data);
_mesa_HashUnlockMutex(table);
}
/**
* Remove an entry from the hash table.
*
* \param table the hash table.
* \param key key of entry to remove.
*
* While holding the hash table's lock, searches the entry with the matching
* key and unlinks it.
*/
static inline void
_mesa_HashRemove_unlocked(struct _mesa_HashTable *table, GLuint key)
{
struct hash_entry *entry;
assert(table);
assert(key);
/* assert if _mesa_HashRemove illegally called from _mesa_HashDeleteAll
* callback function. Have to check this outside of mutex lock.
*/
assert(!table->InDeleteAll);
if (key == DELETED_KEY_VALUE) {
table->deleted_key_data = NULL;
} else {
entry = _mesa_hash_table_search_pre_hashed(table->ht,
uint_hash(key),
uint_key(key));
_mesa_hash_table_remove(table->ht, entry);
}
}
void
_mesa_HashRemoveLocked(struct _mesa_HashTable *table, GLuint key)
{
_mesa_HashRemove_unlocked(table, key);
}
void
_mesa_HashRemove(struct _mesa_HashTable *table, GLuint key)
{
_mesa_HashLockMutex(table);
_mesa_HashRemove_unlocked(table, key);
_mesa_HashUnlockMutex(table);
}
/**
* Delete all entries in a hash table, but don't delete the table itself.
* Invoke the given callback function for each table entry.
*
* \param table the hash table to delete
* \param callback the callback function
* \param userData arbitrary pointer to pass along to the callback
* (this is typically a struct gl_context pointer)
*/
void
_mesa_HashDeleteAll(struct _mesa_HashTable *table,
void (*callback)(GLuint key, void *data, void *userData),
void *userData)
{
struct hash_entry *entry;
assert(callback);
_mesa_HashLockMutex(table);
table->InDeleteAll = GL_TRUE;
hash_table_foreach(table->ht, entry) {
callback((uintptr_t)entry->key, entry->data, userData);
_mesa_hash_table_remove(table->ht, entry);
}
if (table->deleted_key_data) {
callback(DELETED_KEY_VALUE, table->deleted_key_data, userData);
table->deleted_key_data = NULL;
}
table->InDeleteAll = GL_FALSE;
_mesa_HashUnlockMutex(table);
}
/**
* Walk over all entries in a hash table, calling callback function for each.
* \param table the hash table to walk
* \param callback the callback function
* \param userData arbitrary pointer to pass along to the callback
* (this is typically a struct gl_context pointer)
*/
static void
hash_walk_unlocked(const struct _mesa_HashTable *table,
void (*callback)(GLuint key, void *data, void *userData),
void *userData)
{
assert(table);
assert(callback);
struct hash_entry *entry;
hash_table_foreach(table->ht, entry) {
callback((uintptr_t)entry->key, entry->data, userData);
}
if (table->deleted_key_data)
callback(DELETED_KEY_VALUE, table->deleted_key_data, userData);
}
void
_mesa_HashWalk(const struct _mesa_HashTable *table,
void (*callback)(GLuint key, void *data, void *userData),
void *userData)
{
/* cast-away const */
struct _mesa_HashTable *table2 = (struct _mesa_HashTable *) table;
_mesa_HashLockMutex(table2);
hash_walk_unlocked(table, callback, userData);
_mesa_HashUnlockMutex(table2);
}
void
_mesa_HashWalkLocked(const struct _mesa_HashTable *table,
void (*callback)(GLuint key, void *data, void *userData),
void *userData)
{
hash_walk_unlocked(table, callback, userData);
}
static void
debug_print_entry(GLuint key, void *data, void *userData)
{
_mesa_debug(NULL, "%u %p\n", key, data);
}
/**
* Dump contents of hash table for debugging.
*
* \param table the hash table.
*/
void
_mesa_HashPrint(const struct _mesa_HashTable *table)
{
if (table->deleted_key_data)
debug_print_entry(DELETED_KEY_VALUE, table->deleted_key_data, NULL);
_mesa_HashWalk(table, debug_print_entry, NULL);
}
/**
* Find a block of adjacent unused hash keys.
*
* \param table the hash table.
* \param numKeys number of keys needed.
*
* \return Starting key of free block or 0 if failure.
*
* If there are enough free keys between the maximum key existing in the table
* (_mesa_HashTable::MaxKey) and the maximum key possible, then simply return
* the adjacent key. Otherwise do a full search for a free key block in the
* allowable key range.
*/
GLuint
_mesa_HashFindFreeKeyBlock(struct _mesa_HashTable *table, GLuint numKeys)
{
const GLuint maxKey = ~((GLuint) 0) - 1;
if (maxKey - numKeys > table->MaxKey) {
/* the quick solution */
return table->MaxKey + 1;
}
else {
/* the slow solution */
GLuint freeCount = 0;
GLuint freeStart = 1;
GLuint key;
for (key = 1; key != maxKey; key++) {
if (_mesa_HashLookup_unlocked(table, key)) {
/* darn, this key is already in use */
freeCount = 0;
freeStart = key+1;
}
else {
/* this key not in use, check if we've found enough */
freeCount++;
if (freeCount == numKeys) {
return freeStart;
}
}
}
/* cannot allocate a block of numKeys consecutive keys */
return 0;
}
}
/**
* Return the number of entries in the hash table.
*/
GLuint
_mesa_HashNumEntries(const struct _mesa_HashTable *table)
{
GLuint count = 0;
if (table->deleted_key_data)
count++;
count += _mesa_hash_table_num_entries(table->ht);
return count;
}