Git's rename detection is good but still not perfect. There have been
a few times I wanted to correct git for better output but I
couldn't. This PoC WIP patch attempts to address that. It allows to
break/rearrange any file pairs. We can do something crazy like this:
attr.c => dir.c | 1786 ++++++++++++++++++++++++++++++++-----------------
dir.c => attr.c | 1788 +++++++++++++++++---------------------------------
t/t1306-xdg-files.sh | 39 ++
t/test-lib.sh | 1 +
4 files changed, 1828 insertions(+), 1786 deletions(-)
The above output is done with "git diff --manual-rename=foo A B"
and "foo" contains (probably not in the best format though)
-- 8< --
attr.c dir.c
dir.c attr.c
-- 8< --
The plan is to use git-notes to record rename corrections like above
so that "git log --patch" for example can make use of them. I'm not
sure what to do with merge commits yet (can we track renames in a
merge?). We can generate rename file from "diff -CM", then users can
edit and save it.
If you want to diff between two arbitrary trees, you'll have to feed
rename corrections via command line as git-notes are for commit diff
only.
In some cases, manual rename may be cheaper than --find-copies-harder,
so this feature could help reduce cpu usage. Though that's not my main
aim.
Oh and I think rename detection in diff other than tree-tree does not
work. Maybe I tested it the wrong way?
Comments?
-- 8< --
diff --git a/diff.c b/diff.c
index 62cbe14..c8d55d2 100644
--- a/diff.c
+++ b/diff.c
@@ -3547,6 +3547,12 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
DIFF_OPT_SET(options, RENAME_EMPTY);
else if (!strcmp(arg, "--no-rename-empty"))
DIFF_OPT_CLR(options, RENAME_EMPTY);
+ else if (!prefixcmp(arg, "--manual-rename=")) {
+ int ret = strbuf_read_file(&options->renames, arg + 16, 0);
+ if (ret == -1)
+ die("unable to read %s", arg + 16);
+ DIFF_OPT_SET(options, MANUAL_RENAME);
+ }
else if (!strcmp(arg, "--relative"))
DIFF_OPT_SET(options, RELATIVE_NAME);
else if (!prefixcmp(arg, "--relative=")) {
@@ -4621,6 +4627,8 @@ void diffcore_std(struct diff_options *options)
if (options->skip_stat_unmatch)
diffcore_skip_stat_unmatch(options);
if (!options->found_follow) {
+ if (DIFF_OPT_TST(options, MANUAL_RENAME))
+ diffcore_manual_rename(options);
/* See try_to_follow_renames() in tree-diff.c */
if (options->break_opt != -1)
diffcore_break(options->break_opt);
diff --git a/diff.h b/diff.h
index e027650..60d104e 100644
--- a/diff.h
+++ b/diff.h
@@ -61,6 +61,7 @@ typedef struct strbuf *(*diff_prefix_fn_t)(struct diff_options *opt, void *data)
#define DIFF_OPT_FIND_COPIES_HARDER (1 << 6)
#define DIFF_OPT_FOLLOW_RENAMES (1 << 7)
#define DIFF_OPT_RENAME_EMPTY (1 << 8)
+#define DIFF_OPT_MANUAL_RENAME (1 << 9)
/* (1 << 9) unused */
#define DIFF_OPT_HAS_CHANGES (1 << 10)
#define DIFF_OPT_QUICK (1 << 11)
@@ -147,6 +148,7 @@ struct diff_options {
int close_file;
struct pathspec pathspec;
+ struct strbuf renames;
change_fn_t change;
add_remove_fn_t add_remove;
diff_format_fn_t format_callback;
diff --git a/diffcore-rename.c b/diffcore-rename.c
index 216a7a4..05da99f 100644
--- a/diffcore-rename.c
+++ b/diffcore-rename.c
@@ -722,3 +722,148 @@ void diffcore_rename(struct diff_options *options)
rename_src_nr = rename_src_alloc = 0;
return;
}
+
+struct rename {
+ char *one, *two;
+ struct rename *next_one, *next_two;
+ struct diff_filespec *spec_one;
+ struct diff_filespec *spec_two;
+};
+
+static unsigned int string_hash(const char *s)
+{
+ unsigned int v = 1;
+ while (s && *s)
+ v += (unsigned char)*s++;
+ return v;
+}
+
+void diffcore_manual_rename(struct diff_options *options)
+{
+ struct rename *renames = NULL;
+ int i, nr = 0, alloc = 0;
+ const char *next, *p, *end;
+ struct hash_table hash_one, hash_two;
+ struct diff_queue_struct *q = &diff_queued_diff;
+ struct diff_queue_struct outq;
+
+ /* parse rename instructions */
+ end = options->renames.buf + options->renames.len;
+ for (p = options->renames.buf; p < end; p = next) {
+ struct rename *r;
+ const char *sep, *nl, *next_sep;
+
+ nl = strchr(p, '\n');
+ if (!nl)
+ nl = next = end;
+ else {
+ next = nl + 1;
+ if (p == nl)
+ continue;
+ }
+
+ /* one space to separate two paths (for now, quoting can come later) */
+ sep = strchr(p, ' ');
+ if (!sep || sep >= nl)
+ die("invalid syntax");
+ next_sep = strchr(sep + 1, ' ');
+ if (next_sep && next_sep < nl)
+ die("invalid syntax");
+
+ ALLOC_GROW(renames, nr + 1, alloc);
+ r = renames + nr++;
+ memset(r, 0, sizeof(*r));
+ if (p < sep)
+ r->one = xstrndup(p, sep - p);
+ if (sep < nl)
+ r->two = xstrndup(sep + 1, nl - (sep + 1));
+ }
+
+
+ /* initialize hash tables */
+ init_hash(&hash_one);
+ init_hash(&hash_two);
+ for (i = 0; i < nr; i++) {
+ struct rename *r = renames + i;
+ void** p;
+ p = insert_hash(string_hash(r->one), r, &hash_one);
+ if (p) {
+ r->next_one = *p;
+ *p = r;
+ }
+ p = insert_hash(string_hash(r->two), r, &hash_two);
+ if (p) {
+ r->next_two = *p;
+ *p = r;
+ }
+ }
+
+ /* rename */
+ DIFF_QUEUE_CLEAR(&outq);
+ for (i = 0; i < q->nr; i++) {
+ struct diff_filepair *p = q->queue[i];
+ struct rename *r1 = NULL, *r2 = NULL;
+ int hash, skip = 0;
+ if (DIFF_PAIR_UNMERGED(p))
+ continue;
+ if (DIFF_FILE_VALID(p->one)) {
+ hash = string_hash(p->one->path);
+ r1 = lookup_hash(hash, &hash_one);
+ while (r1) {
+ if (!strcmp(p->one->path, r1->one)) {
+ r1->spec_one = p->one;
+ skip = 1;
+ }
+ r1 = r1->next_one;
+ }
+ }
+ if (DIFF_FILE_VALID(p->two)) {
+ hash = string_hash(p->two->path);
+ r2 = lookup_hash(hash, &hash_two);
+ while (r2) {
+ if (!strcmp(p->two->path, r2->two)) {
+ r2->spec_two = p->two;
+ skip = 1;
+ }
+ r2 = r2->next_two;
+ }
+ }
+
+ /* This pair has nothing to do with manual renames,
+ reinsert it */
+ if (!skip)
+ diff_q(&outq, p);
+ }
+ free(q->queue);
+
+ for (i = 0; i < nr; i++) {
+ struct rename *r = renames + i;
+ struct diff_filepair *dp;
+ if (r->spec_one && r->spec_two) {
+ dp = diff_queue(&outq, r->spec_one, r->spec_two);
+ dp->renamed_pair = 1;
+ dp->score = MAX_SCORE;
+ } else if (r->spec_one && !r->two) {
+ dp = diff_queue(&outq, r->spec_one,
+ alloc_filespec(r->one));
+ } else if (!r->one && r->spec_two) {
+ dp = diff_queue(&outq, alloc_filespec(r->two),
+ r->spec_two);
+ } else {
+ die("incorrect rename %s %s", r->one, r->two);
+ }
+ }
+ *q = outq;
+ /* required? */
+ diffcore_fix_diff_index(options);
+
+ /* cleanup */
+ for (i = 0; i < nr; i++) {
+ struct rename *r = renames + i;
+ free(r->one);
+ free(r->two);
+ }
+ free(renames);
+ free_hash(&hash_one);
+ free_hash(&hash_two);
+}
diff --git a/diffcore.h b/diffcore.h
index be0739c..193bc67 100644
--- a/diffcore.h
+++ b/diffcore.h
@@ -107,6 +107,7 @@ extern void diff_q(struct diff_queue_struct *, struct diff_filepair *);
extern void diffcore_break(int);
extern void diffcore_rename(struct diff_options *);
+extern void diffcore_manual_rename(struct diff_options *);
extern void diffcore_merge_broken(void);
extern void diffcore_pickaxe(struct diff_options *);
extern void diffcore_order(const char *orderfile);
-- 8< --
--
Duy
--
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