--- /dev/null
+/**************************************************************************
+ *
+ * Copyright 2009 VMware, Inc.
+ * 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 VMWARE 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 bitmask implementation.
+ *
+ * @author Jose Fonseca <jfonseca@vmware.com>
+ */
+
+
+#include "pipe/p_compiler.h"
+#include "util/u_debug.h"
+
+#include "util/u_memory.h"
+#include "util/u_bitmask.h"
+
+
+typedef uint32_t util_bitmask_word;
+
+
+#define UTIL_BITMASK_INITIAL_WORDS 16
+#define UTIL_BITMASK_BITS_PER_BYTE 8
+#define UTIL_BITMASK_BITS_PER_WORD (sizeof(util_bitmask_word) * UTIL_BITMASK_BITS_PER_BYTE)
+
+
+struct util_bitmask
+{
+ util_bitmask_word *words;
+
+ /** Number of bits we can currently hold */
+ unsigned size;
+
+ /** Number of consecutive bits set at the start of the bitmask */
+ unsigned filled;
+};
+
+
+struct util_bitmask *
+util_bitmask_create(void)
+{
+ struct util_bitmask *bm;
+
+ bm = MALLOC_STRUCT(util_bitmask);
+ if(!bm)
+ return NULL;
+
+ bm->words = (util_bitmask_word *)CALLOC(UTIL_BITMASK_INITIAL_WORDS, sizeof(util_bitmask_word));
+ if(!bm->words) {
+ FREE(bm);
+ return NULL;
+ }
+
+ bm->size = UTIL_BITMASK_INITIAL_WORDS * UTIL_BITMASK_BITS_PER_WORD;
+ bm->filled = 0;
+
+ return bm;
+}
+
+
+/**
+ * Resize the bitmask if necessary
+ */
+static INLINE boolean
+util_bitmask_resize(struct util_bitmask *bm,
+ unsigned minimum_index)
+{
+ unsigned minimum_size = minimum_index + 1;
+ unsigned new_size;
+ util_bitmask_word *new_words;
+
+ /* Check integer overflow */
+ if(!minimum_size)
+ return FALSE;
+
+ if(bm->size > minimum_size)
+ return TRUE;
+
+ assert(bm->size % UTIL_BITMASK_BITS_PER_WORD == 0);
+ new_size = bm->size;
+ while(!(new_size > minimum_size)) {
+ new_size *= 2;
+ /* Check integer overflow */
+ if(new_size < bm->size)
+ return FALSE;
+ }
+ assert(new_size);
+ assert(new_size % UTIL_BITMASK_BITS_PER_WORD == 0);
+
+ new_words = (util_bitmask_word *)REALLOC((void *)bm->words,
+ bm->size / UTIL_BITMASK_BITS_PER_WORD,
+ new_size / UTIL_BITMASK_BITS_PER_WORD);
+ if(!new_words)
+ return FALSE;
+
+ memset(new_words + bm->size/UTIL_BITMASK_BITS_PER_WORD,
+ 0,
+ (new_size - bm->size)/UTIL_BITMASK_BITS_PER_BYTE);
+
+ bm->size = new_size;
+ bm->words = new_words;
+
+ return TRUE;
+}
+
+
+/**
+ * Lazily update the filled.
+ */
+static INLINE void
+util_bitmask_filled_set(struct util_bitmask *bm,
+ unsigned index)
+{
+ assert(bm->filled <= bm->size);
+ assert(index <= bm->size);
+
+ if(index == bm->filled) {
+ ++bm->filled;
+ assert(bm->filled <= bm->size);
+ }
+}
+
+static INLINE void
+util_bitmask_filled_unset(struct util_bitmask *bm,
+ unsigned index)
+{
+ assert(bm->filled <= bm->size);
+ assert(index <= bm->size);
+
+ if(index < bm->filled)
+ bm->filled = index;
+}
+
+
+unsigned
+util_bitmask_add(struct util_bitmask *bm)
+{
+ unsigned word;
+ unsigned bit;
+ util_bitmask_word mask;
+
+ assert(bm);
+
+ /* linear search for an empty index */
+ word = bm->filled / UTIL_BITMASK_BITS_PER_WORD;
+ bit = bm->filled % UTIL_BITMASK_BITS_PER_WORD;
+ mask = 1 << bit;
+ while(word < bm->size / UTIL_BITMASK_BITS_PER_WORD) {
+ while(bit < UTIL_BITMASK_BITS_PER_WORD) {
+ if(!(bm->words[word] & mask))
+ goto found;
+ ++bm->filled;
+ ++bit;
+ mask <<= 1;
+ }
+ ++word;
+ bit = 0;
+ mask = 1;
+ }
+found:
+
+ /* grow the bitmask if necessary */
+ if(!util_bitmask_resize(bm, bm->filled))
+ return UTIL_BITMASK_INVALID_INDEX;
+
+ assert(!(bm->words[word] & mask));
+ bm->words[word] |= mask;
+
+ return bm->filled++;
+}
+
+
+unsigned
+util_bitmask_set(struct util_bitmask *bm,
+ unsigned index)
+{
+ unsigned word = index / UTIL_BITMASK_BITS_PER_WORD;
+ unsigned bit = index % UTIL_BITMASK_BITS_PER_WORD;
+ util_bitmask_word mask = 1 << bit;
+
+ assert(bm);
+
+ /* grow the bitmask if necessary */
+ if(!util_bitmask_resize(bm, index))
+ return UTIL_BITMASK_INVALID_INDEX;
+
+ bm->words[word] |= mask;
+
+ util_bitmask_filled_set(bm, index);
+
+ return index;
+}
+
+
+void
+util_bitmask_clear(struct util_bitmask *bm,
+ unsigned index)
+{
+ unsigned word = index / UTIL_BITMASK_BITS_PER_WORD;
+ unsigned bit = index % UTIL_BITMASK_BITS_PER_WORD;
+ util_bitmask_word mask = 1 << bit;
+
+ assert(bm);
+
+ if(index >= bm->size)
+ return;
+
+ bm->words[word] &= ~mask;
+
+ util_bitmask_filled_unset(bm, index);
+}
+
+
+boolean
+util_bitmask_get(struct util_bitmask *bm,
+ unsigned index)
+{
+ unsigned word = index / UTIL_BITMASK_BITS_PER_WORD;
+ unsigned bit = index % UTIL_BITMASK_BITS_PER_WORD;
+ util_bitmask_word mask = 1 << bit;
+
+ assert(bm);
+
+ if(index < bm->filled) {
+ assert(bm->words[word] & mask);
+ return TRUE;
+ }
+
+ if(index > bm->size)
+ return FALSE;
+
+ if(bm->words[word] & mask) {
+ util_bitmask_filled_set(bm, index);
+ return TRUE;
+ }
+ else
+ return FALSE;
+}
+
+
+unsigned
+util_bitmask_get_next_index(struct util_bitmask *bm,
+ unsigned index)
+{
+ unsigned word = index / UTIL_BITMASK_BITS_PER_WORD;
+ unsigned bit = index % UTIL_BITMASK_BITS_PER_WORD;
+ util_bitmask_word mask = 1 << bit;
+
+ if(index < bm->filled) {
+ assert(bm->words[word] & mask);
+ return index;
+ }
+
+ if(index >= bm->size) {
+ return UTIL_BITMASK_INVALID_INDEX;
+ }
+
+ /* Do a linear search */
+ while(word < bm->size / UTIL_BITMASK_BITS_PER_WORD) {
+ while(bit < UTIL_BITMASK_BITS_PER_WORD) {
+ if(bm->words[word] & mask) {
+ if(index == bm->filled) {
+ ++bm->filled;
+ assert(bm->filled <= bm->size);
+ }
+ return index;
+ }
+ ++index;
+ ++bit;
+ mask <<= 1;
+ }
+ ++word;
+ bit = 0;
+ mask = 1;
+ }
+
+ return UTIL_BITMASK_INVALID_INDEX;
+}
+
+
+unsigned
+util_bitmask_get_first_index(struct util_bitmask *bm)
+{
+ return util_bitmask_get_next_index(bm, 0);
+}
+
+
+void
+util_bitmask_destroy(struct util_bitmask *bm)
+{
+ assert(bm);
+
+ FREE(bm->words);
+ FREE(bm);
+}
+
--- /dev/null
+/**************************************************************************
+ *
+ * Copyright 2009 VMware, Inc.
+ * 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 VMWARE 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 bitmask.
+ *
+ * @author Jose Fonseca <jfonseca@vmware.com>
+ */
+
+#ifndef U_HANDLE_BITMASK_H_
+#define U_HANDLE_BITMASK_H_
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+#define UTIL_BITMASK_INVALID_INDEX (~0U)
+
+
+/**
+ * Abstract data type to represent arbitrary set of bits.
+ */
+struct util_bitmask;
+
+
+struct util_bitmask *
+util_bitmask_create(void);
+
+
+/**
+ * Search a cleared bit and set it.
+ *
+ * It searches for the first cleared bit.
+ *
+ * Returns the bit index on success, or UTIL_BITMASK_INVALID_INDEX on out of
+ * memory growing the bitmask.
+ */
+unsigned
+util_bitmask_add(struct util_bitmask *bm);
+
+/**
+ * Set a bit.
+ *
+ * Returns the input index on success, or UTIL_BITMASK_INVALID_INDEX on out of
+ * memory growing the bitmask.
+ */
+unsigned
+util_bitmask_set(struct util_bitmask *bm,
+ unsigned index);
+
+void
+util_bitmask_clear(struct util_bitmask *bm,
+ unsigned index);
+
+boolean
+util_bitmask_get(struct util_bitmask *bm,
+ unsigned index);
+
+
+void
+util_bitmask_destroy(struct util_bitmask *bm);
+
+
+/**
+ * Search for the first set bit.
+ *
+ * Returns UTIL_BITMASK_INVALID_INDEX if a set bit cannot be found.
+ */
+unsigned
+util_bitmask_get_first_index(struct util_bitmask *bm);
+
+
+/**
+ * Search for the first set bit, starting from the giving index.
+ *
+ * Returns UTIL_BITMASK_INVALID_INDEX if a set bit cannot be found.
+ */
+unsigned
+util_bitmask_get_next_index(struct util_bitmask *bm,
+ unsigned index);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* U_HANDLE_BITMASK_H_ */
projects / mesa.git / commitdiff