/*
- * Copyright (c) 2008 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2011 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include <config.h>
#include "bitmap.h"
#include <string.h>
+#include "util.h"
+
+/* Allocates and returns a bitmap initialized to all-1-bits. */
+unsigned long *
+bitmap_allocate1(size_t n_bits)
+{
+ size_t n_bytes = bitmap_n_bytes(n_bits);
+ size_t n_longs = bitmap_n_longs(n_bits);
+ size_t r_bits = n_bits % BITMAP_ULONG_BITS;
+ unsigned long *bitmap;
+
+ /* Allocate and initialize most of the bitmap. */
+ bitmap = xmalloc(n_bytes);
+ memset(bitmap, 0xff, n_bytes);
+
+ /* Ensure that the last "unsigned long" in the bitmap only has as many
+ * 1-bits as there actually should be. */
+ if (r_bits) {
+ bitmap[n_longs - 1] = (1UL << r_bits) - 1;
+ }
+
+ return bitmap;
+}
/* Sets 'count' consecutive bits in 'bitmap', starting at bit offset 'start',
* to 'value'. */
}
return true;
}
+
+/* Scans 'bitmap' from bit offset 'start' to 'end', excluding 'end' itself.
+ * Returns the bit offset of the lowest-numbered bit set to 1, or 'end' if
+ * all of the bits are set to 0. */
+size_t
+bitmap_scan(const unsigned long int *bitmap, size_t start, size_t end)
+{
+ /* XXX slow */
+ size_t i;
+
+ for (i = start; i < end; i++) {
+ if (bitmap_is_set(bitmap, i)) {
+ break;
+ }
+ }
+ return i;
+}
+
+/* Returns the number of 1-bits in the 'n'-bit bitmap at 'bitmap'. */
+size_t
+bitmap_count1(const unsigned long int *bitmap, size_t n)
+{
+ size_t i;
+ size_t count = 0;
+
+ BUILD_ASSERT(ULONG_MAX <= UINT64_MAX);
+ for (i = 0; i < BITMAP_N_LONGS(n); i++) {
+ count += count_1bits(bitmap[i]);
+ }
+
+ return count;
+}