diff options
Diffstat (limited to 'mesalib/src/gallium/auxiliary/util/u_handle_table.c')
| -rw-r--r-- | mesalib/src/gallium/auxiliary/util/u_handle_table.c | 298 |
1 files changed, 298 insertions, 0 deletions
diff --git a/mesalib/src/gallium/auxiliary/util/u_handle_table.c b/mesalib/src/gallium/auxiliary/util/u_handle_table.c new file mode 100644 index 000000000..532d1ea6c --- /dev/null +++ b/mesalib/src/gallium/auxiliary/util/u_handle_table.c @@ -0,0 +1,298 @@ +/**************************************************************************
+ *
+ * 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);
+}
+
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