add memory region object for better memory managment

2 files changed, 76 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;
+}
diff --git a/lib/bitmap.h b/lib/bitmap.h
new file mode 100644
index 0000000..db9653a
--- /dev/null
+++ b/lib/bitmap.h
@@ -0,0 +1,25 @@
+#ifndef _JOVE_LIB_BITMAP_H
+#define _JOVE_LIB_BITMAP_H 1
+
+#include <stddef.h>
+#include <stdbool.h>
+
+typedef unsigned char bitmap_block_t;
+#define BITMAP_BLOCK_BITS (sizeof(bitmap_block_t) * 8)
+
+struct bitmap
+{
+    unsigned int total_bits;
+    unsigned int free_bits;
+    unsigned int last_free_bit;
+    bitmap_block_t data[];
+};
+
+extern bool bitmap_check(struct bitmap *bitmap, size_t idx);
+extern void bitmap_set(struct bitmap *bitmap, size_t idx);
+extern void bitmap_unset(struct bitmap *bitmap, size_t idx);
+
+int bitmap_findfree(struct bitmap *bitmap);
+int bitmap_findfree_contig(struct bitmap *bitmap, size_t size);
+
+#endif