1
0
Fork 0
mirror of https://github.com/git/git.git synced 2024-05-19 05:56:30 +02:00
git/patch-ids.c
Jeff King 5a29cbc6e9 patch-ids: turn off rename detection
The patch-id code may be running inside another porcelain
like "git log" or "git format-patch", and therefore may have
set diff_detect_rename_default, either via the diff-ui
config, or by default since 5404c11 (diff: activate
diff.renames by default, 2016-02-25). This is the case even
if a command is run with `--no-renames`, as that is applied
only to the diff-options used by the command itself.

Rename detection doesn't help the patch-id results. It
_may_ actually hurt, as minor differences in the files that
would be overlooked by patch-id's canonicalization might
result in different renames (though I'd doubt that it ever
comes up in practice).

But mostly it is just a waste of CPU to compute these
renames.

Note that this does have one user-visible impact: the
prerequisite patches listed by "format-patch --base". There
may be some confusion between different versions of git as
older ones will enable renames, but newer ones will not.
However, this was already a problem, as people with
different settings for the "diff.renames" config would get
different results. After this patch, everyone should get the
same results, regardless of their config.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-09 14:13:53 -07:00

100 lines
2.8 KiB
C

#include "cache.h"
#include "diff.h"
#include "commit.h"
#include "sha1-lookup.h"
#include "patch-ids.h"
int commit_patch_id(struct commit *commit, struct diff_options *options,
unsigned char *sha1, int diff_header_only)
{
if (commit->parents)
diff_tree_sha1(commit->parents->item->object.oid.hash,
commit->object.oid.hash, "", options);
else
diff_root_tree_sha1(commit->object.oid.hash, "", options);
diffcore_std(options);
return diff_flush_patch_id(options, sha1, diff_header_only);
}
/*
* When we cannot load the full patch-id for both commits for whatever
* reason, the function returns -1 (i.e. return error(...)). Despite
* the "cmp" in the name of this function, the caller only cares about
* the return value being zero (a and b are equivalent) or non-zero (a
* and b are different), and returning non-zero would keep both in the
* result, even if they actually were equivalent, in order to err on
* the side of safety. The actual value being negative does not have
* any significance; only that it is non-zero matters.
*/
static int patch_id_cmp(struct patch_id *a,
struct patch_id *b,
struct diff_options *opt)
{
if (is_null_sha1(a->patch_id) &&
commit_patch_id(a->commit, opt, a->patch_id, 0))
return error("Could not get patch ID for %s",
oid_to_hex(&a->commit->object.oid));
if (is_null_sha1(b->patch_id) &&
commit_patch_id(b->commit, opt, b->patch_id, 0))
return error("Could not get patch ID for %s",
oid_to_hex(&b->commit->object.oid));
return hashcmp(a->patch_id, b->patch_id);
}
int init_patch_ids(struct patch_ids *ids)
{
memset(ids, 0, sizeof(*ids));
diff_setup(&ids->diffopts);
ids->diffopts.detect_rename = 0;
DIFF_OPT_SET(&ids->diffopts, RECURSIVE);
diff_setup_done(&ids->diffopts);
hashmap_init(&ids->patches, (hashmap_cmp_fn)patch_id_cmp, 256);
return 0;
}
int free_patch_ids(struct patch_ids *ids)
{
hashmap_free(&ids->patches, 1);
return 0;
}
static int init_patch_id_entry(struct patch_id *patch,
struct commit *commit,
struct patch_ids *ids)
{
unsigned char header_only_patch_id[GIT_SHA1_RAWSZ];
patch->commit = commit;
if (commit_patch_id(commit, &ids->diffopts, header_only_patch_id, 1))
return -1;
hashmap_entry_init(patch, sha1hash(header_only_patch_id));
return 0;
}
struct patch_id *has_commit_patch_id(struct commit *commit,
struct patch_ids *ids)
{
struct patch_id patch;
memset(&patch, 0, sizeof(patch));
if (init_patch_id_entry(&patch, commit, ids))
return NULL;
return hashmap_get(&ids->patches, &patch, &ids->diffopts);
}
struct patch_id *add_commit_patch_id(struct commit *commit,
struct patch_ids *ids)
{
struct patch_id *key = xcalloc(1, sizeof(*key));
if (init_patch_id_entry(key, commit, ids)) {
free(key);
return NULL;
}
hashmap_add(&ids->patches, key);
return key;
}