Changeset 7de18418 in mainline for kernel/generic/include/adt/bitmap.h

Timestamp:

2013-09-08T10:34:41Z (11 years ago)

Author:

Martin Decky <martin@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

29a3886

Parents:

063a74b9

Message:

partial implementation of a two-level bitmap data structure

File:

• kernel/generic/include/adt/bitmap.h (modified) (1 diff)

kernel/generic/include/adt/bitmap.h

@@ -38 +38 @@
 #include <typedefs.h>
 
-#define BITS2BYTES(bits)        (bits ? ((((bits)-1)>>3)+1) : 0)
+#define BITMAP_ELEMENT   8
+#define BITMAP_REMAINER  7
 
 typedef struct {
-        uint8_t *map;
-        size_t bits;
+        size_t elements;
+        uint8_t *bits;
+        
+        size_t block_size;
+        uint8_t *blocks;
 } bitmap_t;
 
-extern void bitmap_initialize(bitmap_t *bitmap, uint8_t *map, size_t bits);
-extern void bitmap_set_range(bitmap_t *bitmap, size_t start, size_t bits);
-extern void bitmap_clear_range(bitmap_t *bitmap, size_t start, size_t bits);
-extern void bitmap_copy(bitmap_t *dst, bitmap_t *src, size_t bits);
+static inline void bitmap_set(bitmap_t *bitmap, size_t element,
+    unsigned int value)
+{
+        if (element < bitmap->elements) {
+                /*
+                 * The 2nd level bitmap is conservative.
+                 * Make sure we update it properly.
+                 */
+                
+                if (value) {
+                        bitmap->bits[element / BITMAP_ELEMENT] |=
+                            (1 << (element & BITMAP_REMAINER));
+                } else {
+                        bitmap->bits[element / BITMAP_ELEMENT] &=
+                            ~(1 << (element & BITMAP_REMAINER));
+                        
+                        if (bitmap->block_size > 0) {
+                                size_t block = element / bitmap->block_size;
+                                
+                                bitmap->blocks[block / BITMAP_ELEMENT] &=
+                                    ~(1 << (block & BITMAP_REMAINER));
+                        }
+                }
+        }
+}
 
-static inline int bitmap_get(bitmap_t *bitmap, size_t bit)
+static inline unsigned int bitmap_get(bitmap_t *bitmap, size_t element)
 {
-        if(bit >= bitmap->bits)
+        if (element >= bitmap->elements)
                 return 0;
         
-        return !! ((bitmap->map)[bit/8] & (1 << (bit & 7)));
+        return !!((bitmap->bits)[element / BITMAP_ELEMENT] &
+            (1 << (element & BITMAP_REMAINER)));
 }
 
+extern size_t bitmap_size(size_t, size_t);
+extern void bitmap_initialize(bitmap_t *, size_t, size_t, void *);
+
+extern void bitmap_set_range(bitmap_t *, size_t, size_t);
+extern void bitmap_clear_range(bitmap_t *, size_t, size_t);
+
+extern int bitmap_find_range(bitmap_t *, size_t, size_t, size_t);
+extern int bitmap_allocate_range(bitmap_t *, size_t, size_t, size_t, size_t *);
+extern void bitmap_free_range(bitmap_t *, size_t, size_t);
+extern void bitmap_copy(bitmap_t *, bitmap_t *, size_t);
 
 #endif