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-rw-r--r--lib/bitmap.c51
1 files changed, 51 insertions, 0 deletions
diff --git a/lib/bitmap.c b/lib/bitmap.c
new file mode 100644
index 0000000..bfd6cbc
--- /dev/null
+++ b/lib/bitmap.c
@@ -0,0 +1,51 @@
+#include "bitmap.h"
+#include "api/error.h"
+
+inline bool
+bitmap_check(struct bitmap *bitmap, size_t idx)
+{
+ return bitmap->data[idx / BITMAP_BLOCK_BITS] & (1U << (idx % BITMAP_BLOCK_BITS));
+}
+
+inline void
+bitmap_set(struct bitmap *bitmap, size_t idx)
+{
+ bitmap->data[idx / BITMAP_BLOCK_BITS] |= (1U << (idx % BITMAP_BLOCK_BITS));
+ bitmap->free_bits--;
+}
+
+inline void
+bitmap_unset(struct bitmap *bitmap, size_t idx)
+{
+ bitmap->data[idx / BITMAP_BLOCK_BITS] &= ~(1U << (idx % BITMAP_BLOCK_BITS));
+ bitmap->free_bits++;
+}
+
+int
+bitmap_findfree(struct bitmap *bitmap)
+{
+ int cycles = 0;
+ while(cycles++ < bitmap->total_bits) {
+ if(bitmap_check(bitmap, bitmap->last_free_bit)) {
+ bitmap->last_free_bit = (bitmap->last_free_bit + 1) % bitmap->total_bits;
+ continue;
+ }
+ return bitmap->last_free_bit++;
+ }
+ return -EFULL;
+}
+
+int
+bitmap_findfree_contig(struct bitmap *bitmap, size_t size)
+{
+ size_t last_contig = 0;
+ for(size_t i = 0; i < bitmap->total_bits; i++) {
+ if(bitmap_check(bitmap, i)) {
+ last_contig = i++;
+ continue;
+ }
+ if(last_contig - i == size - 1)
+ return last_contig;
+ }
+ return -EFULL;
+}