bitmap: Add first cut at a bitmap module

[ccan] / ccan / bitmap / bitmap.h

diff --git a/ccan/bitmap/bitmap.h b/ccan/bitmap/bitmap.h
new file mode 100644 (file)
index 0000000..4c6c950
--- /dev/null
+++ b/ccan/bitmap/bitmap.h
@@ -0,0 +1,210 @@
+/* Licensed under LGPLv2+ - see LICENSE file for details */
+#ifndef CCAN_BITMAP_H_
+#define CCAN_BITMAP_H_
+
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define BITS_PER_LONG  (sizeof(unsigned long) * 8)
+
+#define BYTE(_bm, _n)  (((unsigned char *)(_bm))[(_n) / 8])
+#define LONG(_bm, _n)  (((unsigned long *)(_bm))[(_n) / BITS_PER_LONG])
+#define BIT(_n)                (0x80 >> ((_n) % 8))
+
+#define BYTES(_nbits)  ((_nbits) / 8)
+#define BITS(_nbits)   ((~(0xff >> ((_nbits) % 8))) & 0xff)
+
+static inline void bitmap_set_bit(void *bitmap, int n)
+{
+       BYTE(bitmap, n) |= BIT(n);
+}
+
+static inline void bitmap_clear_bit(void *bitmap, int n)
+{
+       BYTE(bitmap, n) &= ~BIT(n);
+}
+
+static inline void bitmap_change_bit(void *bitmap, int n)
+{
+       BYTE(bitmap, n) ^= BIT(n);
+}
+
+static inline bool bitmap_test_bit(void *bitmap, int n)
+{
+       return !!(BYTE(bitmap, n) & BIT(n));
+}
+
+
+static inline void bitmap_zero(void *bitmap, int nbits)
+{
+       memset(bitmap, 0, BYTES(nbits));
+       if (BITS(nbits))
+               BYTE(bitmap, nbits) &= ~BITS(nbits);
+}
+
+static inline void bitmap_fill(void *bitmap, int nbits)
+{
+       memset(bitmap, 0xff, BYTES(nbits));
+       if (BITS(nbits))
+               BYTE(bitmap, nbits) |= BITS(nbits);
+}
+
+static inline void bitmap_copy(void *dst, void *src, int nbits)
+{
+       memcpy(dst, src, BYTES(nbits));
+       if (BITS(nbits)) {
+               BYTE(dst, nbits) &= ~BITS(nbits);
+               BYTE(dst, nbits) |= BYTE(src, nbits) & BITS(nbits);
+       }
+}
+
+#define DEF_BINOP(_name, _op) \
+       static inline void bitmap_##_name(void *dst, void *src1, void *src2, \
+                                        int nbits) \
+       { \
+               int n = 0; \
+               while ((nbits - n) >= BITS_PER_LONG) { \
+                       LONG(dst, n) = LONG(src1, n) _op LONG(src2, n); \
+                       n += BITS_PER_LONG; \
+               } \
+               while ((nbits - n) >= 8) { \
+                       BYTE(dst, n) = BYTE(src1, n) _op BYTE(src2, n); \
+                       n += 8; \
+               } \
+               if (BITS(nbits)) { \
+                       BYTE(dst, nbits) &= ~BITS(nbits); \
+                       BYTE(dst, nbits) |= (BYTE(src1, nbits) _op BYTE(src2, nbits)) \
+                               & BITS(nbits); \
+               } \
+       }
+
+DEF_BINOP(and, &)
+DEF_BINOP(or, |)
+DEF_BINOP(xor, ^)
+DEF_BINOP(andnot, & ~)
+
+#undef DEF_BINOP
+
+static inline void bitmap_complement(void *dst, void *src, int nbits)
+{
+       int n = 0;
+
+       while ((nbits - n) >= BITS_PER_LONG) {
+               LONG(dst, n) = ~LONG(src, n);
+               n += BITS_PER_LONG;
+       }
+       while ((nbits - n) >= 8) {
+               BYTE(dst, n) = ~BYTE(src, n);
+               n += 8;
+       }
+       if (BITS(nbits)) {
+               BYTE(dst, nbits) &= ~BITS(nbits);
+               BYTE(dst, nbits) |= ~BYTE(src, nbits) & BITS(nbits);
+       }
+}
+
+static inline bool bitmap_equal(void *src1, void *src2, int nbits)
+{
+       if (memcmp(src1, src2, BYTES(nbits)) != 0)
+               return false;
+       if ((BYTE(src1, nbits) & BITS(nbits))
+           != (BYTE(src2, nbits) & BITS(nbits)))
+               return false;
+       return true;
+}
+
+static inline bool bitmap_intersects(void *src1, void *src2, int nbits)
+{
+       int n = 0;
+
+       while ((nbits - n) >= BITS_PER_LONG) {
+               if (LONG(src1, n) & LONG(src2, n))
+                       return true;
+               n += BITS_PER_LONG;
+       }
+       while ((nbits - n) >= 8) {
+               if (BYTE(src1, n) & BYTE(src2, n))
+                       return true;
+               n += 8;
+       }
+       if (BITS(nbits) & BYTE(src1, nbits) & BYTE(src2, nbits)) {
+               return true;
+       }
+       return false;
+}
+
+static inline bool bitmap_subset(void *src1, void *src2, int nbits)
+{
+       int n = 0;
+
+       while ((nbits - n) >= BITS_PER_LONG) {
+               if (LONG(src1, n) & ~LONG(src2, n))
+                       return false;
+               n += BITS_PER_LONG;
+       }
+       while ((nbits - n) >= 8) {
+               if (BYTE(src1, n) & ~BYTE(src2, n))
+                       return false;
+               n += 8;
+       }
+       if (BITS(nbits) & (BYTE(src1, nbits) & ~BYTE(src2, nbits))) {
+               return false;
+       }
+       return true;
+}
+
+static inline bool bitmap_full(void *bitmap, int nbits)
+{
+       int n = 0;
+
+       while ((nbits - n) >= BITS_PER_LONG) {
+               if (LONG(bitmap, n) != -1UL)
+                       return false;
+               n += BITS_PER_LONG;
+       }
+       while ((nbits - n) >= 8) {
+               if (BYTE(bitmap, n) != 0xff)
+                       return false;
+               n += 8;
+       }
+       if (BITS(nbits)
+           && ((BITS(nbits) & BYTE(bitmap, nbits)) != BITS(nbits))) {
+               return false;
+       }
+       return true;
+}
+
+static inline bool bitmap_empty(void *bitmap, int nbits)
+{
+       int n = 0;
+
+       while ((nbits - n) >= BITS_PER_LONG) {
+               if (LONG(bitmap, n))
+                       return false;
+               n += BITS_PER_LONG;
+       }
+       while ((nbits - n) >= 8) {
+               if (BYTE(bitmap, n))
+                       return false;
+               n += 8;
+       }
+       if (BITS(nbits) && ((BITS(nbits) & BYTE(bitmap, nbits)))) {
+               return false;
+       }
+       return true;
+}
+
+
+static inline void *bitmap_alloc(int nbits)
+{
+       return malloc((nbits + 7) / 8);
+}
+
+#undef BYTE
+#undef LONG
+#undef BIT
+#undef BYTES
+#undef BITS
+
+#endif /* CCAN_BITMAP_H_ */