summaryrefslogtreecommitdiff
path: root/object.h
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@osdl.org>2006-06-14 23:45:13 (GMT)
committerJunio C Hamano <junkio@cox.net>2006-06-18 01:49:18 (GMT)
commit885a86abe2e9f7b96a4e2012183c6751635840aa (patch)
treeb3fc0545d874cf62bee7e02ae1673722e434f8ad /object.h
parent210a0be504829bad5a2821488d3c25cc406fed4a (diff)
downloadgit-885a86abe2e9f7b96a4e2012183c6751635840aa.zip
git-885a86abe2e9f7b96a4e2012183c6751635840aa.tar.gz
git-885a86abe2e9f7b96a4e2012183c6751635840aa.tar.bz2
Shrink "struct object" a bit
This shrinks "struct object" by a small amount, by getting rid of the "struct type *" pointer and replacing it with a 3-bit bitfield instead. In addition, we merge the bitfields and the "flags" field, which incidentally should also remove a useless 4-byte padding from the object when in 64-bit mode. Now, our "struct object" is still too damn large, but it's now less obviously bloated, and of the remaining fields, only the "util" (which is not used by most things) is clearly something that should be eventually discarded. This shrinks the "git-rev-list --all" memory use by about 2.5% on the kernel archive (and, perhaps more importantly, on the larger mozilla archive). That may not sound like much, but I suspect it's more on a 64-bit platform. There are other remaining inefficiencies (the parent lists, for example, probably have horrible malloc overhead), but this was pretty obvious. Most of the patch is just changing the comparison of the "type" pointer from one of the constant string pointers to the appropriate new TYPE_xxx small integer constant. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
Diffstat (limited to 'object.h')
-rw-r--r--object.h20
1 files changed, 18 insertions, 2 deletions
diff --git a/object.h b/object.h
index e08afbd..a0762b6 100644
--- a/object.h
+++ b/object.h
@@ -12,12 +12,22 @@ struct object_refs {
struct object *ref[FLEX_ARRAY]; /* more */
};
+#define TYPE_BITS 3
+#define FLAG_BITS 27
+
+#define TYPE_NONE 0
+#define TYPE_BLOB 1
+#define TYPE_TREE 2
+#define TYPE_COMMIT 3
+#define TYPE_TAG 4
+#define TYPE_BAD 5
+
struct object {
unsigned parsed : 1;
unsigned used : 1;
- unsigned int flags;
+ unsigned type : TYPE_BITS;
+ unsigned flags : FLAG_BITS;
unsigned char sha1[20];
- const char *type;
struct object_refs *refs;
void *util;
};
@@ -25,6 +35,12 @@ struct object {
extern int track_object_refs;
extern int obj_allocs;
extern struct object **objs;
+extern const char *type_names[];
+
+static inline const char *typename(unsigned int type)
+{
+ return type_names[type > TYPE_TAG ? TYPE_BAD : type];
+}
/** Internal only **/
struct object *lookup_object(const unsigned char *sha1);