1 files changed, 76 insertions, 0 deletions
diff --git a/alloc.c b/alloc.c
new file mode 100644
index 000000000..216c23a6f
--- /dev/null
+++ b/alloc.c
@@ -0,0 +1,76 @@
+/*
+ * alloc.c  - specialized allocator for internal objects
+ *
+ * Copyright (C) 2006 Linus Torvalds
+ *
+ * The standard malloc/free wastes too much space for objects, partly because
+ * it maintains all the allocation infrastructure (which isn't needed, since
+ * we never free an object descriptor anyway), but even more because it ends
+ * up with maximal alignment because it doesn't know what the object alignment
+ * for the new allocation is.
+ */
+#include "cache.h"
+#include "object.h"
+#include "blob.h"
+#include "tree.h"
+#include "commit.h"
+#include "tag.h"
+
+#define BLOCKING 1024
+
+#define DEFINE_ALLOCATOR(name, type)				\
+static unsigned int name##_allocs;				\
+void *alloc_##name##_node(void)					\
+{								\
+	static int nr;						\
+	static type *block;					\
+	void *ret;						\
+								\
+	if (!nr) {						\
+		nr = BLOCKING;					\
+		block = xmalloc(BLOCKING * sizeof(type));	\
+	}							\
+	nr--;							\
+	name##_allocs++;					\
+	ret = block++;						\
+	memset(ret, 0, sizeof(type));				\
+	return ret;						\
+}
+
+union any_object {
+	struct object object;
+	struct blob blob;
+	struct tree tree;
+	struct commit commit;
+	struct tag tag;
+};
+
+DEFINE_ALLOCATOR(blob, struct blob)
+DEFINE_ALLOCATOR(tree, struct tree)
+DEFINE_ALLOCATOR(commit, struct commit)
+DEFINE_ALLOCATOR(tag, struct tag)
+DEFINE_ALLOCATOR(object, union any_object)
+
+#ifdef NO_C99_FORMAT
+#define SZ_FMT "%u"
+#else
+#define SZ_FMT "%zu"
+#endif
+
+static void report(const char* name, unsigned int count, size_t size)
+{
+    fprintf(stderr, "%10s: %8u (" SZ_FMT " kB)\n", name, count, size);
+}
+
+#undef SZ_FMT
+
+#define REPORT(name)	\
+    report(#name, name##_allocs, name##_allocs*sizeof(struct name) >> 10)
+
+void alloc_report(void)
+{
+	REPORT(blob);
+	REPORT(tree);
+	REPORT(commit);
+	REPORT(tag);
+}