Re: Horrible re-packing?
From: Junio C Hamano <hidden>
Date: 2016-06-15 22:42:28
Subsystem:
the rest · Maintainer:
Linus Torvalds
Possibly related (same subject, not in this thread)
- 2016-06-15 · Horrible re-packing? · Linus Torvalds <torvalds@osdl.org>
- 2016-06-15 · Re: Horrible re-packing? · Linus Torvalds <torvalds@osdl.org>
- 2016-06-15 · Re: Horrible re-packing? · Linus Torvalds <torvalds@osdl.org>
- 2016-06-15 · Re: Horrible re-packing? · Junio C Hamano <hidden>
- 2016-06-15 · Re: Horrible re-packing? · Linus Torvalds <torvalds@osdl.org>
Junio C Hamano [off-list ref] writes:
- The output from rev-list --objects is fed to the function as its name parameter while path is set to NULL. When we allow a thin pack to be generated, rev-list --objects output also contains "-<commit-object-name>" lines. We read trees for these commits that are not going to be sent but can be used as base objects, and pass the pathname discovered from the tree using path and name pair (path is set to the linked list of struct name_path that describes the dirname, and name is set to the basename). This was done to reduce the need for allocating and copying the pathname in preparation for calling name_hash() function.
but it can trivially fixed by doing something like this. ---
diff --git a/pack-objects.c b/pack-objects.c
index 3590cd5..e0328f8 100644
--- a/pack-objects.c
+++ b/pack-objects.c@@ -463,17 +463,10 @@ static void rehash_objects(void) } } -struct name_path { - struct name_path *up; - const char *elem; - int len; -}; - #define DIRBITS 12 -static unsigned name_hash(struct name_path *path, const char *name) +static unsigned name_hash(const char *name) { - struct name_path *p = path; const char *n = name + strlen(name); unsigned hash = 0, name_hash = 0, name_done = 0;
@@ -492,14 +485,6 @@ static unsigned name_hash(struct name_pa name_hash = hash; hash = 0; } - for (p = path; p; p = p->up) { - hash = hash * 11 + '/'; - n = p->elem + p->len; - while (p->elem <= --n) { - unsigned char c = *n; - hash = hash * 11 + c; - } - } /* * Make sure "Makefile" and "t/Makefile" are hashed separately * but close enough.
@@ -686,9 +671,9 @@ static int name_cmp_len(const char *name } static void add_pbase_object(struct tree_desc *tree, - struct name_path *up, const char *name, - int cmplen) + int cmplen, + const char *fullname) { struct name_entry entry;
@@ -702,13 +687,12 @@ static void add_pbase_object(struct tree sha1_object_info(entry.sha1, type, &size)) continue; if (name[cmplen] != '/') { - unsigned hash = name_hash(up, name); + unsigned hash = name_hash(fullname); add_object_entry(entry.sha1, hash, 1); return; } if (!strcmp(type, tree_type)) { struct tree_desc sub; - struct name_path me; struct pbase_tree_cache *tree; const char *down = name+cmplen+1; int downlen = name_cmp_len(down);
@@ -719,10 +703,7 @@ static void add_pbase_object(struct tree sub.buf = tree->tree_data; sub.size = tree->tree_size; - me.up = up; - me.elem = entry.path; - me.len = entry.pathlen; - add_pbase_object(&sub, &me, down, downlen); + add_pbase_object(&sub, down, downlen, fullname); pbase_tree_put(tree); } }
@@ -778,14 +759,14 @@ static void add_preferred_base_object(ch for (it = pbase_tree; it; it = it->next) { if (cmplen == 0) { - hash = name_hash(NULL, ""); + hash = name_hash(""); add_object_entry(it->pcache.sha1, hash, 1); } else { struct tree_desc tree; tree.buf = it->pcache.tree_data; tree.size = it->pcache.tree_size; - add_pbase_object(&tree, NULL, name, cmplen); + add_pbase_object(&tree, name, cmplen, name); } } }
@@ -1328,7 +1309,7 @@ int main(int argc, char **argv) } if (get_sha1_hex(line, sha1)) die("expected sha1, got garbage:\n %s", line); - hash = name_hash(NULL, line+41); + hash = name_hash(line+41); add_preferred_base_object(line+41, hash); add_object_entry(sha1, hash, 0); }