Re: [RFC PATCH 00/19] object-store refactoring 3 (replace objects, main ref store)
- From
René Scharfe <l.s.r@web.de>
- Date
- Apr 7, 2018, 04:58 UTC
- Message-ID
- <38962a15-1081-bbdb-b4c4-6b46222b5f64@web.de>
- In-Reply-To
- <20180406232136.253950-1-sbeller@google.com>
Am 07.04.2018 um 01:21 schrieb Stefan Beller:
> This applies on top of 464416a2eaadf84d2bfdf795007863d03b222b7c > (sb/packfiles-in-repository). > It is also available at https://github.com/stefanbeller/git/tree/object-store-3
This series conflicts with 1731a1e239 (replace_object: convert struct replace_object to object_id) and b383a13cc0 (Convert lookup_replace_object to struct object_id), which are in next.
> This series will bring the replacement mechanism (git replace) > into the object store.
Good idea.
Show 24 quoted lines
> $ git diff 464416a2eaadf84d2bfdf795007863d03b222b7c..HEAD -- object-store.h repository.h
> diff --git a/object-store.h b/object-store.h
> index fef33f345f..be90c02db6 100644
> --- a/object-store.h
> +++ b/object-store.h
> @@ -93,6 +93,22 @@ struct raw_object_store {
> struct alternate_object_database *alt_odb_list;
> struct alternate_object_database **alt_odb_tail;
>
> + /*
> + * Objects that should be substituted by other objects
> + * (see git-replace(1)).
> + */
> + struct replace_objects {
> + /*
> + * An array of replacements. The array is kept sorted by the original
> + * sha1.
> + */
> + struct replace_object **items;
> +
> + int alloc, nr;
> +
> + unsigned prepared : 1;
> + } replacements;An oidmap would be a better fit -- lookups should be quicker and memory consumption not much worse. I meant to submit something like this eventually after Brian's series lands:
-- >8 -- Subject: [PATCH] replace_object: use oidmap
Load the replace objects into an oidmap to allow for easy lookups in constant time.
Signed-off-by: Rene Scharfe <l.s.r@web.de> --- This is on top of next.
replace_object.c | 76 ++++++++++-------------------------------------- 1 file changed, 16 insertions(+), 60 deletions(-)
diff --git a/replace_object.c b/replace_object.c index 336357394d..a757a5ebf2 100644 --- a/replace_object.c +++ b/replace_object.c @@ -1,54 +1,14 @@ #include "cache.h" -#include "sha1-lookup.h" +#include "oidmap.h" #include "refs.h" #include "commit.h" -/* - * An array of replacements. The array is kept sorted by the original - * sha1. - */ -static struct replace_object { - struct object_id original; +struct replace_object { + struct oidmap_entry original; struct object_id replacement; -} **replace_object; - -static int replace_object_alloc, replace_object_nr; +}; -static const unsigned char *replace_sha1_access(size_t index, void *table) -{ - struct replace_object **replace = table; - return replace[index]->original.hash; -} - -static int replace_object_pos(const unsigned char *sha1) -{ - return sha1_pos(sha1, replace_object, replace_object_nr, - replace_sha1_access); -} - -static int register_replace_object(struct replace_object *replace, - int ignore_dups) -{ - int pos = replace_object_pos(replace->original.hash); - - if (0 <= pos) { - if (ignore_dups) - free(replace); - else { - free(replace_object[pos]); - replace_object[pos] = replace; - } - return 1; - } - pos = -pos - 1; - ALLOC_GROW(replace_object, replace_object_nr + 1, replace_object_alloc); - replace_object_nr++; - if (pos < replace_object_nr) - MOVE_ARRAY(replace_object + pos + 1, replace_object + pos, - replace_object_nr - pos - 1); - replace_object[pos] = replace; - return 0; -} +static struct oidmap replace_map = OIDMAP_INIT; static int register_replace_ref(const char *refname, const struct object_id *oid, @@ -59,7 +19,7 @@ static int register_replace_ref(const char *refname, const char *hash = slash ? slash + 1 : refname; struct replace_object *repl_obj = xmalloc(sizeof(*repl_obj)); - if (get_oid_hex(hash, &repl_obj->original)) { + if (get_oid_hex(hash, &repl_obj->original.oid)) { free(repl_obj); warning("bad replace ref name: %s", refname); return 0; @@ -69,7 +29,7 @@ static int register_replace_ref(const char *refname, oidcpy(&repl_obj->replacement, oid); /* Register new object */ - if (register_replace_object(repl_obj, 1)) + if (oidmap_put(&replace_map, repl_obj)) die("duplicate replace ref: %s", refname); return 0; @@ -84,7 +44,7 @@ static void prepare_replace_object(void) for_each_replace_ref(register_replace_ref, NULL); replace_object_prepared = 1; - if (!replace_object_nr) + if (!replace_map.map.tablesize) check_replace_refs = 0; } @@ -100,21 +60,17 @@ static void prepare_replace_object(void) */ const struct object_id *do_lookup_replace_object(const struct object_id *oid) { - int pos, depth = MAXREPLACEDEPTH; + int depth = MAXREPLACEDEPTH; const struct object_id *cur = oid; prepare_replace_object(); /* Try to recursively replace the object */ - do { - if (--depth < 0) - die("replace depth too high for object %s", - oid_to_hex(oid)); - - pos = replace_object_pos(cur->hash); - if (0 <= pos) - cur = &replace_object[pos]->replacement; - } while (0 <= pos); - - return cur; + while (depth-- > 0) { + struct replace_object *repl_obj = oidmap_get(&replace_map, cur); + if (!repl_obj) + return cur; + cur = &repl_obj->replacement; + } + die("replace depth too high for object %s", oid_to_hex(oid)); }
-- 2.17.0