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Diffstat (limited to 'src/gallium/auxiliary/util/u_handle_table.c')
| -rw-r--r-- | src/gallium/auxiliary/util/u_handle_table.c | 293 |
1 files changed, 293 insertions, 0 deletions
diff --git a/src/gallium/auxiliary/util/u_handle_table.c b/src/gallium/auxiliary/util/u_handle_table.c new file mode 100644 index 00000000000..2d15932ce3b --- /dev/null +++ b/src/gallium/auxiliary/util/u_handle_table.c @@ -0,0 +1,293 @@ +/************************************************************************** + * + * 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 <[email protected]> + */ + + +#include "pipe/p_compiler.h" +#include "pipe/p_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); + 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) + 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) + 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 || 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 || 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->destroy) + for(index = 0; index < ht->size; ++index) + handle_table_clear(ht, index); + + FREE(ht->objects); + FREE(ht); +} + |