fsck: drop inode-sorting code

Fsck tries to access loose objects in order of inode number,
with the hope that this would make cold cache access faster
on a spinning disk. This dates back to 7e8c174 (fsck-cache:
sort entries by inode number, 2005-05-02), which predates
the invention of packfiles.

These days, there's not much point in trying to optimize
cold cache for a large number of loose objects. You are much
better off to simply pack the objects, which will reduce the
disk footprint _and_ provide better locality of data access.

So while you can certainly construct pathological cases
where this code might help, it is not worth the trouble
anymore.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/fsck.c b/builtin/fsck.c
index a019f4a2408ab4c549a91b7307b4356d0f27abb7..73c35963b831e857e6a4206e40acbac766d77fbc 100644 (file)
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -39,14 +39,6 @@ static int show_dangling = 1;
 #define ERROR_REACHABLE 02
 #define ERROR_PACK 04
 
-#ifdef NO_D_INO_IN_DIRENT
-#define SORT_DIRENT 0
-#define DIRENT_SORT_HINT(de) 0
-#else
-#define SORT_DIRENT 1
-#define DIRENT_SORT_HINT(de) ((de)->d_ino)
-#endif
-
 static int fsck_config(const char *var, const char *value, void *cb)
 {
        if (strcmp(var, "fsck.skiplist") == 0) {
@@ -373,64 +365,6 @@ static int fsck_obj_buffer(const unsigned char *sha1, enum object_type type,
        return fsck_obj(obj);
 }
 
-/*
- * This is the sorting chunk size: make it reasonably
- * big so that we can sort well..
- */
-#define MAX_SHA1_ENTRIES (1024)
-
-struct sha1_entry {
-       unsigned long ino;
-       unsigned char sha1[20];
-};
-
-static struct {
-       unsigned long nr;
-       struct sha1_entry *entry[MAX_SHA1_ENTRIES];
-} sha1_list;
-
-static int ino_compare(const void *_a, const void *_b)
-{
-       const struct sha1_entry *a = _a, *b = _b;
-       unsigned long ino1 = a->ino, ino2 = b->ino;
-       return ino1 < ino2 ? -1 : ino1 > ino2 ? 1 : 0;
-}
-
-static void fsck_sha1_list(void)
-{
-       int i, nr = sha1_list.nr;
-
-       if (SORT_DIRENT)
-               qsort(sha1_list.entry, nr,
-                     sizeof(struct sha1_entry *), ino_compare);
-       for (i = 0; i < nr; i++) {
-               struct sha1_entry *entry = sha1_list.entry[i];
-               unsigned char *sha1 = entry->sha1;
-
-               sha1_list.entry[i] = NULL;
-               if (fsck_sha1(sha1))
-                       errors_found |= ERROR_OBJECT;
-               free(entry);
-       }
-       sha1_list.nr = 0;
-}
-
-static void add_sha1_list(unsigned char *sha1, unsigned long ino)
-{
-       struct sha1_entry *entry = xmalloc(sizeof(*entry));
-       int nr;
-
-       entry->ino = ino;
-       hashcpy(entry->sha1, sha1);
-       nr = sha1_list.nr;
-       if (nr == MAX_SHA1_ENTRIES) {
-               fsck_sha1_list();
-               nr = 0;
-       }
-       sha1_list.entry[nr] = entry;
-       sha1_list.nr = ++nr;
-}
-
 static inline int is_loose_object_file(struct dirent *de,
                                       char *name, unsigned char *sha1)
 {
@@ -459,7 +393,8 @@ static void fsck_dir(int i, char *path)
                if (is_dot_or_dotdot(de->d_name))
                        continue;
                if (is_loose_object_file(de, name, sha1)) {
-                       add_sha1_list(sha1, DIRENT_SORT_HINT(de));
+                       if (fsck_sha1(sha1))
+                               errors_found |= ERROR_OBJECT;
                        continue;
                }
                if (starts_with(de->d_name, "tmp_obj_"))
@@ -573,7 +508,6 @@ static void fsck_object_dir(const char *path)
                display_progress(progress, i+1);
        }
        stop_progress(&progress);
-       fsck_sha1_list();
 }
 
 static int fsck_head_link(void)