Add a memory pool library implemented using cpp macros. The macro can
be used to create a type-specific memory pool API. The memory nodes
themselves are stored in a treap, using macros in trp.h. Taken
directly from David Michael Barr's svn-dump-fast-export repository.
Signed-off-by: Ramkumar Ramachandra <artagnon@xxxxxxxxx>
---
vcs-svn/obj_pool.h | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 61 insertions(+), 0 deletions(-)
create mode 100644 vcs-svn/obj_pool.h
diff --git a/vcs-svn/obj_pool.h b/vcs-svn/obj_pool.h
new file mode 100644
index 0000000..d8b0842
--- /dev/null
+++ b/vcs-svn/obj_pool.h
@@ -0,0 +1,61 @@
+#ifndef OBJ_POOL_H_
+#define OBJ_POOL_H_
+
+#include <stdint.h>
+#include <stdlib.h>
+
+/*
+ * The obj_pool_gen() macro generates a type-specific memory pool
+ * implementation.
+ *
+ * Arguments:
+ *
+ * pre : Prefix for generated functions (ex: string_).
+ * obj_t : Type for treap data structure (ex: char).
+ * intial_capacity : The initial size of the memory pool (ex: 4096).
+ *
+ */
+#define obj_pool_gen(pre, obj_t, initial_capacity) \
+static struct { \
+ uint32_t size; \
+ uint32_t capacity; \
+ obj_t *base; \
+} pre##_pool = { 0, 0, NULL}; \
+static uint32_t pre##_alloc(uint32_t count) \
+{ \
+ uint32_t offset; \
+ while (pre##_pool.size + count > pre##_pool.capacity) { \
+ if (pre##_pool.capacity) { \
+ pre##_pool.capacity *= 2; \
+ } else { \
+ pre##_pool.capacity = initial_capacity; \
+ } \
+ pre##_pool.base = \
+ realloc(pre##_pool.base, pre##_pool.capacity * sizeof(obj_t)); \
+ } \
+ offset = pre##_pool.size; \
+ pre##_pool.size += count; \
+ return offset; \
+} \
+static void pre##_free(uint32_t count) \
+{ \
+ pre##_pool.size -= count; \
+} \
+static uint32_t pre##_offset(obj_t *obj) \
+{ \
+ return obj == NULL ? ~0 : obj - pre##_pool.base; \
+} \
+static obj_t *pre##_pointer(uint32_t offset) \
+{ \
+ return offset >= pre##_pool.size ? NULL : &pre##_pool.base[offset]; \
+} \
+static void pre##_reset(void) \
+{ \
+ if (pre##_pool.base) \
+ free(pre##_pool.base); \
+ pre##_pool.base = NULL; \
+ pre##_pool.size = 0; \
+ pre##_pool.capacity = 0; \
+} \
+
+#endif
--
1.7.1
--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html