| /************************************************************************** |
| * |
| * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas. |
| * 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, sub license, 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 NON-INFRINGEMENT. |
| * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS 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. |
| * |
| **************************************************************************/ |
| |
| /** |
| * @file |
| * Generic handle table implementation. |
| * |
| * @author José Fonseca <jrfonseca@tungstengraphics.com> |
| */ |
| |
| |
| #include "pipe/p_compiler.h" |
| #include "util/u_debug.h" |
| |
| #include "util/u_memory.h" |
| #include "util/u_handle_table.h" |
| |
| |
| #define HANDLE_TABLE_INITIAL_SIZE 16 |
| |
| |
| struct handle_table |
| { |
| /** Object array. Empty handles have a null object */ |
| void **objects; |
| |
| /** Number of objects the handle can currently hold */ |
| unsigned size; |
| /** Number of consecutive objects allocated at the start of the table */ |
| unsigned filled; |
| |
| /** Optional object destructor */ |
| void (*destroy)(void *object); |
| }; |
| |
| |
| struct handle_table * |
| handle_table_create(void) |
| { |
| struct handle_table *ht; |
| |
| ht = MALLOC_STRUCT(handle_table); |
| if(!ht) |
| return NULL; |
| |
| ht->objects = (void **)CALLOC(HANDLE_TABLE_INITIAL_SIZE, sizeof(void *)); |
| if(!ht->objects) { |
| FREE(ht); |
| return NULL; |
| } |
| |
| ht->size = HANDLE_TABLE_INITIAL_SIZE; |
| ht->filled = 0; |
| |
| ht->destroy = NULL; |
| |
| return ht; |
| } |
| |
| |
| void |
| handle_table_set_destroy(struct handle_table *ht, |
| void (*destroy)(void *object)) |
| { |
| assert(ht); |
| if (!ht) |
| return; |
| ht->destroy = destroy; |
| } |
| |
| |
| /** |
| * Resize the table if necessary |
| */ |
| static INLINE int |
| handle_table_resize(struct handle_table *ht, |
| unsigned minimum_size) |
| { |
| unsigned new_size; |
| void **new_objects; |
| |
| if(ht->size > minimum_size) |
| return ht->size; |
| |
| new_size = ht->size; |
| while(!(new_size > minimum_size)) |
| new_size *= 2; |
| assert(new_size); |
| |
| new_objects = (void **)REALLOC((void *)ht->objects, |
| ht->size*sizeof(void *), |
| new_size*sizeof(void *)); |
| if(!new_objects) |
| return 0; |
| |
| memset(new_objects + ht->size, 0, (new_size - ht->size)*sizeof(void *)); |
| |
| ht->size = new_size; |
| ht->objects = new_objects; |
| |
| return ht->size; |
| } |
| |
| |
| static INLINE void |
| handle_table_clear(struct handle_table *ht, |
| unsigned index) |
| { |
| void *object; |
| |
| /* The order here is important so that the object being destroyed is not |
| * present in the table when seen by the destroy callback, because the |
| * destroy callback may directly or indirectly call the other functions in |
| * this module. |
| */ |
| |
| object = ht->objects[index]; |
| if(object) { |
| ht->objects[index] = NULL; |
| |
| if(ht->destroy) |
| ht->destroy(object); |
| } |
| } |
| |
| |
| unsigned |
| handle_table_add(struct handle_table *ht, |
| void *object) |
| { |
| unsigned index; |
| unsigned handle; |
| |
| assert(ht); |
| assert(object); |
| if(!object || !ht) |
| return 0; |
| |
| /* linear search for an empty handle */ |
| while(ht->filled < ht->size) { |
| if(!ht->objects[ht->filled]) |
| break; |
| ++ht->filled; |
| } |
| |
| index = ht->filled; |
| handle = index + 1; |
| |
| /* check integer overflow */ |
| if(!handle) |
| return 0; |
| |
| /* grow the table if necessary */ |
| if(!handle_table_resize(ht, index)) |
| return 0; |
| |
| assert(!ht->objects[index]); |
| ht->objects[index] = object; |
| ++ht->filled; |
| |
| return handle; |
| } |
| |
| |
| unsigned |
| handle_table_set(struct handle_table *ht, |
| unsigned handle, |
| void *object) |
| { |
| unsigned index; |
| |
| assert(ht); |
| assert(handle); |
| if(!handle || !ht) |
| return 0; |
| |
| assert(object); |
| if(!object) |
| return 0; |
| |
| index = handle - 1; |
| |
| /* grow the table if necessary */ |
| if(!handle_table_resize(ht, index)) |
| return 0; |
| |
| handle_table_clear(ht, index); |
| |
| ht->objects[index] = object; |
| |
| return handle; |
| } |
| |
| |
| void * |
| handle_table_get(struct handle_table *ht, |
| unsigned handle) |
| { |
| void *object; |
| |
| assert(ht); |
| assert(handle); |
| if(!handle || !ht || handle > ht->size) |
| return NULL; |
| |
| object = ht->objects[handle - 1]; |
| |
| return object; |
| } |
| |
| |
| void |
| handle_table_remove(struct handle_table *ht, |
| unsigned handle) |
| { |
| void *object; |
| unsigned index; |
| |
| assert(ht); |
| assert(handle); |
| if(!handle || !ht || handle > ht->size) |
| return; |
| |
| index = handle - 1; |
| object = ht->objects[index]; |
| if(!object) |
| return; |
| |
| handle_table_clear(ht, index); |
| |
| if(index < ht->filled) |
| ht->filled = index; |
| } |
| |
| |
| unsigned |
| handle_table_get_next_handle(struct handle_table *ht, |
| unsigned handle) |
| { |
| unsigned index; |
| |
| for(index = handle; index < ht->size; ++index) { |
| if(ht->objects[index]) |
| return index + 1; |
| } |
| |
| return 0; |
| } |
| |
| |
| unsigned |
| handle_table_get_first_handle(struct handle_table *ht) |
| { |
| return handle_table_get_next_handle(ht, 0); |
| } |
| |
| |
| void |
| handle_table_destroy(struct handle_table *ht) |
| { |
| unsigned index; |
| assert(ht); |
| |
| if (!ht) |
| return; |
| |
| if(ht->destroy) |
| for(index = 0; index < ht->size; ++index) |
| handle_table_clear(ht, index); |
| |
| FREE(ht->objects); |
| FREE(ht); |
| } |
| |