fsck: avoid reading every object twice

During verify_pack() all objects are read for SHA-1 check. Then
fsck_sha1() is called on every object, which read the object again
(fsck_sha1 -> parse_object -> read_sha1_file).

Avoid reading an object twice, do fsck_sha1 while we have an object
uncompressed data in verify_pack.

On git.git, with this patch I got:

$ /usr/bin/time ./git fsck >/dev/null
98.97user 0.90system 1:40.01elapsed 99%CPU (0avgtext+0avgdata 616624maxresident)k
0inputs+0outputs (0major+194186minor)pagefaults 0swaps

Without it:

$ /usr/bin/time ./git fsck >/dev/null
231.23user 2.35system 3:53.82elapsed 99%CPU (0avgtext+0avgdata 636688maxresident)k
0inputs+0outputs (0major+461629minor)pagefaults 0swaps

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/fsck.c b/builtin/fsck.c
index 4ead98dcab276b4177fad302ed062a3fb584c9ea..0603f6444e1b5057193b6dba5e6489e6935ca119 100644 (file)
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -282,14 +282,8 @@ static void check_connectivity(void)
        }
 }
 
-static int fsck_sha1(const unsigned char *sha1)
+static int fsck_obj(struct object *obj)
 {
-       struct object *obj = parse_object(sha1);
-       if (!obj) {
-               errors_found |= ERROR_OBJECT;
-               return error("%s: object corrupt or missing",
-                            sha1_to_hex(sha1));
-       }
        if (obj->flags & SEEN)
                return 0;
        obj->flags |= SEEN;
@@ -332,6 +326,29 @@ static int fsck_sha1(const unsigned char *sha1)
        return 0;
 }
 
+static int fsck_sha1(const unsigned char *sha1)
+{
+       struct object *obj = parse_object(sha1);
+       if (!obj) {
+               errors_found |= ERROR_OBJECT;
+               return error("%s: object corrupt or missing",
+                            sha1_to_hex(sha1));
+       }
+       return fsck_obj(obj);
+}
+
+static int fsck_obj_buffer(const unsigned char *sha1, enum object_type type,
+                          unsigned long size, void *buffer, int *eaten)
+{
+       struct object *obj;
+       obj = parse_object_buffer(sha1, type, size, buffer, eaten);
+       if (!obj) {
+               errors_found |= ERROR_OBJECT;
+               return error("%s: object corrupt or missing", sha1_to_hex(sha1));
+       }
+       return fsck_obj(obj);
+}
+
 /*
  * This is the sorting chunk size: make it reasonably
  * big so that we can sort well..
@@ -627,17 +644,8 @@ int cmd_fsck(int argc, const char **argv, const char *prefix)
                prepare_packed_git();
                for (p = packed_git; p; p = p->next)
                        /* verify gives error messages itself */
-                       if (verify_pack(p))
+                       if (verify_pack(p, fsck_obj_buffer))
                                errors_found |= ERROR_PACK;
-
-               for (p = packed_git; p; p = p->next) {
-                       uint32_t j, num;
-                       if (open_pack_index(p))
-                               continue;
-                       num = p->num_objects;
-                       for (j = 0; j < num; j++)
-                               fsck_sha1(nth_packed_object_sha1(p, j));
-               }
        }
 
        heads = 0;

diff --git a/pack-check.c b/pack-check.c
index 7ac9b3a6815f2b6f7c017b54f10e8a4b5f8070d6..3b48b86156347e35b30cd9eddab270063073478e 100644 (file)
--- a/pack-check.c
+++ b/pack-check.c
@@ -42,7 +42,8 @@ int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
 }
 
 static int verify_packfile(struct packed_git *p,
-               struct pack_window **w_curs)
+                          struct pack_window **w_curs,
+                          verify_fn fn)
 {
        off_t index_size = p->index_size;
        const unsigned char *index_base = p->index_data;
@@ -120,6 +121,12 @@ static int verify_packfile(struct packed_git *p,
                else if (check_sha1_signature(entries[i].sha1, data, size, typename(type)))
                        err = error("packed %s from %s is corrupt",
                                    sha1_to_hex(entries[i].sha1), p->pack_name);
+               else if (fn) {
+                       int eaten = 0;
+                       fn(entries[i].sha1, type, size, data, &eaten);
+                       if (eaten)
+                               data = NULL;
+               }
                free(data);
        }
        free(entries);
@@ -150,7 +157,7 @@ int verify_pack_index(struct packed_git *p)
        return err;
 }
 
-int verify_pack(struct packed_git *p)
+int verify_pack(struct packed_git *p, verify_fn fn)
 {
        int err = 0;
        struct pack_window *w_curs = NULL;
@@ -159,7 +166,7 @@ int verify_pack(struct packed_git *p)
        if (!p->index_data)
                return -1;
 
-       err |= verify_packfile(p, &w_curs);
+       err |= verify_packfile(p, &w_curs, fn);
        unuse_pack(&w_curs);
 
        return err;

diff --git a/pack.h b/pack.h
index 722a54e00a2cb7d9514c12f799fb1ec15930cf5d..70f3c29bea152e90257f5fc64fb128f1978a7652 100644 (file)
--- a/pack.h
+++ b/pack.h
@@ -70,10 +70,13 @@ struct pack_idx_entry {
        off_t offset;
 };
 
+
+typedef int (*verify_fn)(const unsigned char*, enum object_type, unsigned long, void*, int*);
+
 extern const char *write_idx_file(const char *index_name, struct pack_idx_entry **objects, int nr_objects, const struct pack_idx_option *, unsigned char *sha1);
 extern int check_pack_crc(struct packed_git *p, struct pack_window **w_curs, off_t offset, off_t len, unsigned int nr);
 extern int verify_pack_index(struct packed_git *);
-extern int verify_pack(struct packed_git *);
+extern int verify_pack(struct packed_git *, verify_fn fn);
 extern void fixup_pack_header_footer(int, unsigned char *, const char *, uint32_t, unsigned char *, off_t);
 extern char *index_pack_lockfile(int fd);
 extern int encode_in_pack_object_header(enum object_type, uintmax_t, unsigned char *);