util: bitmask data type.

3 files changed, 435 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/util/SConscript b/src/gallium/auxiliary/util/SConscript
index 5d336ea082..9d5dd006f0 100644
--- a/src/gallium/auxiliary/util/SConscript
+++ b/src/gallium/auxiliary/util/SConscript
@@ -3,6 +3,7 @@ Import('*')
 util = env.ConvenienceLibrary(
 	target = 'util',
 	source = [
+		'u_bitmask.c',
 		'u_blit.c',
 		'u_cache.c',
 		'u_debug.c',
diff --git a/src/gallium/auxiliary/util/u_bitmask.c b/src/gallium/auxiliary/util/u_bitmask.c
new file mode 100644
index 0000000000..4b6a230960
--- /dev/null
+++ b/src/gallium/auxiliary/util/u_bitmask.c
@@ -0,0 +1,320 @@
+/**************************************************************************
+ * 
+ * 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);
+}
+
diff --git a/src/gallium/auxiliary/util/u_bitmask.h b/src/gallium/auxiliary/util/u_bitmask.h
new file mode 100644
index 0000000000..87f1110296
--- /dev/null
+++ b/src/gallium/auxiliary/util/u_bitmask.h
@@ -0,0 +1,114 @@
+/**************************************************************************
+ * 
+ * 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_ */