added dequeue

diff --git a/kdq.h b/kdq.h
new file mode 100644 (file)
index 0000000..edd55b5
--- /dev/null
+++ b/kdq.h
@@ -0,0 +1,128 @@
+#ifndef __AC_KDQ_H
+#define __AC_KDQ_H
+
+#include <stdlib.h>
+#include <string.h>
+
+#define __KDQ_TYPE(type) \
+       typedef struct { \
+               size_t front:58, bits:6, count, mask; \
+               type *a; \
+       } kdq_##type##_t;
+
+#define kdq_t(type) kdq_##type##_t
+#define kdq_size(q) ((q)->count)
+#define kdq_first(q) ((q)->a[(q)->front])
+#define kdq_last(q) ((q)->a[((q)->front + (q)->count - 1) & (q)->mask])
+#define kdq_at(q, i) ((q)->a[((q)->front + (i)) & (q)->mask])
+
+#define __KDQ_IMPL(type, SCOPE) \
+       SCOPE kdq_##type##_t *kdq_init_##type() \
+       { \
+               kdq_##type##_t *q; \
+               q = (kdq_##type##_t*)calloc(1, sizeof(kdq_##type##_t)); \
+               q->bits = 2, q->mask = (1ULL<<q->bits) - 1; \
+               q->a = (type*)malloc((1<<q->bits) * sizeof(type)); \
+               return q; \
+       } \
+       SCOPE void kdq_destroy_##type(kdq_##type##_t *q) \
+       { \
+               if (q == 0) return; \
+               free(q->a); free(q); \
+       } \
+       SCOPE int kdq_resize_##type(kdq_##type##_t *q, int new_bits) \
+       { \
+               size_t new_size = 1ULL<<new_bits, old_size = 1ULL<<q->bits; \
+               if (new_size < q->count) { /* not big enough */ \
+                       int i; \
+                       for (i = 0; i < 64; ++i) \
+                               if (1ULL<<i > q->count) break; \
+                       new_bits = i, new_size = 1ULL<<new_bits; \
+               } \
+               if (new_bits == q->bits) return q->bits; /* unchanged */ \
+               if (new_bits > q->bits) q->a = (type*)realloc(q->a, (1ULL<<new_bits) * sizeof(type)); \
+               if (q->front + q->count <= old_size) { /* unwrapped */ \
+                       if (q->front + q->count > new_size) /* only happens for shrinking */ \
+                               memmove(q->a, q->a + new_size, (q->front + q->count - new_size) * sizeof(type)); \
+               } else { /* wrapped */ \
+                       memmove(q->a + (new_size - (old_size - q->front)), q->a + q->front, (old_size - q->front) * sizeof(type)); \
+                       q->front = new_size - (old_size - q->front); \
+               } \
+               q->bits = new_bits, q->mask = (1ULL<<q->bits) - 1; \
+               if (new_bits < q->bits) q->a = (type*)realloc(q->a, (1ULL<<new_bits) * sizeof(type)); \
+               return q->bits; \
+       } \
+       SCOPE type *kdq_pushp_##type(kdq_##type##_t *q) \
+       { \
+               if (q->count == 1ULL<<q->bits) kdq_resize_##type(q, q->bits + 1); \
+               return &q->a[((q->count++) + q->front) & (q)->mask]; \
+       } \
+       SCOPE void kdq_push_##type(kdq_##type##_t *q, type v) \
+       { \
+               if (q->count == 1ULL<<q->bits) kdq_resize_##type(q, q->bits + 1); \
+               q->a[((q->count++) + q->front) & (q)->mask] = v; \
+       } \
+       SCOPE type *kdq_unshiftp_##type(kdq_##type##_t *q) \
+       { \
+               if (q->count == 1ULL<<q->bits) kdq_resize_##type(q, q->bits + 1); \
+               ++q->count; \
+               q->front = q->front? q->front - 1 : (1ULL<<q->bits) - 1; \
+               return &q->a[q->front]; \
+       } \
+       SCOPE void kdq_unshift_##type(kdq_##type##_t *q, type v) \
+       { \
+               type *p; \
+               p = kdq_unshiftp_##type(q); \
+               *p = v; \
+       } \
+       SCOPE type *kdq_pop_##type(kdq_##type##_t *q) \
+       { \
+               return q->count? &q->a[((--q->count) + q->front) & q->mask] : 0; \
+       } \
+       SCOPE type *kdq_shift_##type(kdq_##type##_t *q) \
+       { \
+               type *d = 0; \
+               if (q->count == 0) return 0; \
+               d = &q->a[q->front++]; \
+               q->front &= q->mask; \
+               --q->count; \
+               return d; \
+       }
+
+#define KDQ_INIT2(type, SCOPE) \
+       __KDQ_TYPE(type) \
+       __KDQ_IMPL(type, SCOPE)
+
+#ifndef klib_unused
+#if (defined __clang__ && __clang_major__ >= 3) || (defined __GNUC__ && __GNUC__ >= 3)
+#define klib_unused __attribute__ ((__unused__))
+#else
+#define klib_unused
+#endif
+#endif /* klib_unused */
+
+#define KDQ_INIT(type) KDQ_INIT2(type, static inline klib_unused)
+
+#define KDQ_DECLARE(type) \
+       __KDQ_TYPE(type) \
+       kdq_##type##_t *kdq_init_##type(); \
+       void kdq_destroy_##type(kdq_##type##_t *q); \
+       int kdq_resize_##type(kdq_##type##_t *q, int new_bits); \
+       type *kdq_pushp_##type(kdq_##type##_t *q); \
+       void kdq_push_##type(kdq_##type##_t *q, type v); \
+       type *kdq_unshiftp_##type(kdq_##type##_t *q); \
+       void kdq_unshift_##type(kdq_##type##_t *q, type v); \
+       type *kdq_pop_##type(kdq_##type##_t *q); \
+       type *kdq_shift_##type(kdq_##type##_t *q);
+
+#define kdq_init(type) kdq_init_##type()
+#define kdq_destroy(type, q) kdq_destroy_##type(q)
+#define kdq_resize(type, q, new_bits) kdq_resize_##type(q, new_bits)
+#define kdq_pushp(type, q) kdq_pushp_##type(q)
+#define kdq_push(type, q, v) kdq_push_##type(q, v)
+#define kdq_pop(type, q) kdq_pop_##type(q)
+#define kdq_unshiftp(type, q) kdq_unshiftp_##type(q)
+#define kdq_unshift(type, q, v) kdq_unshift_##type(q, v)
+#define kdq_shift(type, q) kdq_shift_##type(q)
+
+#endif