[PATCH] Detect renames in diff family.
This rips out the rename detection engine from diff-helper and moves it
to the diff core, and updates the internal calling convention used by
diff-tree family into the diff core. In order to give the same option
name to diff-tree family as well as to diff-helper, I've changed the
earlier diff-helper '-r' option to '-M' (stands for Move; sorry but the
natural abbreviation 'r' for 'rename' is already taken for 'recursive').
Although I did a fair amount of test with the git-diff-tree with
existing rename commits in the core GIT repository, this should still be
considered beta (preview) release. This patch depends on the diff-delta
infrastructure just committed.
This implements almost everything I wanted to see in this series of
patch, except a few minor cleanups in the calling convention into diff
core, but that will be a separate cleanup patch.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/Documentation/git-diff-cache.txt b/Documentation/git-diff-cache.txt
index b54b822..9cd6103 100644
--- a/Documentation/git-diff-cache.txt
+++ b/Documentation/git-diff-cache.txt
@@ -9,7 +9,7 @@
SYNOPSIS
--------
-'git-diff-cache' [-p] [-r] [-z] [-m] [--cached] <tree-ish>
+'git-diff-cache' [-p] [-r] [-z] [-m] [-M] [--cached] <tree-ish>
DESCRIPTION
-----------
@@ -33,6 +33,9 @@
-z::
\0 line termination on output
+-M::
+ Detect renames; implies -p.
+
--cached::
do not consider the on-disk file at all
diff --git a/Documentation/git-diff-files.txt b/Documentation/git-diff-files.txt
index 0ad2f89..166238f 100644
--- a/Documentation/git-diff-files.txt
+++ b/Documentation/git-diff-files.txt
@@ -9,7 +9,7 @@
SYNOPSIS
--------
-'git-diff-files' [-p] [-q] [-r] [-z] [<pattern>...]
+'git-diff-files' [-p] [-q] [-r] [-z] [-M] [<pattern>...]
DESCRIPTION
-----------
@@ -26,6 +26,9 @@
-q::
Remain silent even on nonexisting files
+-M::
+ Detect renames; implies -p.
+
-r::
This flag does not mean anything. It is there only to match
git-diff-tree. Unlike git-diff-tree, git-diff-files always looks
diff --git a/Documentation/git-diff-helper.txt b/Documentation/git-diff-helper.txt
index e930f97..3c5d8fd 100644
--- a/Documentation/git-diff-helper.txt
+++ b/Documentation/git-diff-helper.txt
@@ -9,7 +9,7 @@
SYNOPSIS
--------
-'git-diff-helper' [-z] [-R] [-r]
+'git-diff-helper' [-z] [-R] [-M]
DESCRIPTION
-----------
@@ -31,7 +31,7 @@
would show a diff to bring the working file back to what
is in the <tree>.
--r::
+-M::
Detect renames.
diff --git a/Documentation/git-diff-tree.txt b/Documentation/git-diff-tree.txt
index ff7f25f..4c45c26 100644
--- a/Documentation/git-diff-tree.txt
+++ b/Documentation/git-diff-tree.txt
@@ -9,7 +9,7 @@
SYNOPSIS
--------
-'git-diff-tree' [-p] [-r] [-z] [--stdin] [-m] [-s] [-v] <tree-ish> <tree-ish> [<pattern>]\*
+'git-diff-tree' [-p] [-r] [-z] [--stdin] [-M] [-m] [-s] [-v] <tree-ish> <tree-ish> [<pattern>]\*
DESCRIPTION
-----------
@@ -33,6 +33,9 @@
generate patch (see section on generating patches). For
git-diff-tree, this flag implies '-r' as well.
+-M::
+ Detect renames; implies -p, in turn implying also '-r'.
+
-r::
recurse
diff --git a/diff-cache.c b/diff-cache.c
index 4cfbcdb..2bdea9c 100644
--- a/diff-cache.c
+++ b/diff-cache.c
@@ -5,6 +5,7 @@
static int generate_patch = 0;
static int match_nonexisting = 0;
static int line_termination = '\n';
+static int detect_rename = 0;
/* A file entry went away or appeared */
static void show_file(const char *prefix, struct cache_entry *ce, unsigned char *sha1, unsigned int mode)
@@ -165,13 +166,14 @@
}
static char *diff_cache_usage =
-"git-diff-cache [-p] [-r] [-z] [-m] [--cached] <tree sha1>";
+"git-diff-cache [-p] [-r] [-z] [-m] [-M] [--cached] <tree-ish>";
int main(int argc, char **argv)
{
unsigned char tree_sha1[20];
void *tree;
unsigned long size;
+ int ret;
read_cache();
while (argc > 2) {
@@ -186,6 +188,10 @@
generate_patch = 1;
continue;
}
+ if (!strcmp(arg, "-M")) {
+ generate_patch = detect_rename = 1;
+ continue;
+ }
if (!strcmp(arg, "-z")) {
line_termination = '\0';
continue;
@@ -204,6 +210,9 @@
if (argc != 2 || get_sha1(argv[1], tree_sha1))
usage(diff_cache_usage);
+ if (generate_patch)
+ diff_setup(detect_rename, 0, 0, 0, 0);
+
mark_merge_entries();
tree = read_object_with_reference(tree_sha1, "tree", &size, 0);
@@ -212,5 +221,8 @@
if (read_tree(tree, size, 1))
die("unable to read tree object %s", argv[1]);
- return diff_cache(active_cache, active_nr);
+ ret = diff_cache(active_cache, active_nr);
+ if (generate_patch)
+ diff_flush();
+ return ret;
}
diff --git a/diff-files.c b/diff-files.c
index d556b96..7ffe663 100644
--- a/diff-files.c
+++ b/diff-files.c
@@ -7,10 +7,11 @@
#include "diff.h"
static const char *diff_files_usage =
-"diff-files [-p] [-q] [-r] [-z] [paths...]";
+"diff-files [-p] [-q] [-r] [-z] [-M] [paths...]";
static int generate_patch = 0;
static int line_termination = '\n';
+static int detect_rename = 0;
static int silent = 0;
static int matches_pathspec(struct cache_entry *ce, char **spec, int cnt)
@@ -79,6 +80,9 @@
; /* no-op */
else if (!strcmp(argv[1], "-z"))
line_termination = 0;
+ else if (!strcmp(argv[1], "-M")) {
+ detect_rename = generate_patch = 1;
+ }
else
usage(diff_files_usage);
argv++; argc--;
@@ -92,6 +96,9 @@
exit(1);
}
+ if (generate_patch)
+ diff_setup(detect_rename, 0, 0, 0, 0);
+
for (i = 0; i < entries; i++) {
struct stat st;
unsigned int oldmode, mode;
@@ -132,5 +139,7 @@
show_modified(oldmode, mode, ce->sha1, null_sha1,
ce->name);
}
+ if (generate_patch)
+ diff_flush();
return 0;
}
diff --git a/diff-helper.c b/diff-helper.c
index 2877ddc..5b0feb1 100644
--- a/diff-helper.c
+++ b/diff-helper.c
@@ -6,160 +6,23 @@
#include "strbuf.h"
#include "diff.h"
-static int matches_pathspec(const char *name, const char **spec, int cnt)
-{
- int i;
- int namelen = strlen(name);
- for (i = 0; i < cnt; i++) {
- int speclen = strlen(spec[i]);
- if (! strncmp(spec[i], name, speclen) &&
- speclen <= namelen &&
- (name[speclen] == 0 ||
- name[speclen] == '/'))
- return 1;
- }
- return 0;
-}
-
static int detect_rename = 0;
-/*
- * We do not detect circular renames. Just hold created and deleted
- * entries and later attempt to match them up. If they do not match,
- * then spit them out as deletes or creates as original.
- */
-
-static struct diff_spec_hold {
- struct diff_spec_hold *next;
- struct diff_spec_hold *matched;
- struct diff_spec old, new;
- char path[1];
-} *createdfile, *deletedfile;
-
-static void hold_spec(const char *path,
- struct diff_spec *old, struct diff_spec *new)
+static int parse_oneside_change(const char *cp, int *mode,
+ unsigned char *sha1, char *path)
{
- struct diff_spec_hold **list, *elem;
- list = (! old->file_valid) ? &createdfile : &deletedfile;
- elem = xmalloc(sizeof(*elem) + strlen(path));
- strcpy(elem->path, path);
- elem->next = *list;
- *list = elem;
- elem->old = *old;
- elem->new = *new;
- elem->matched = 0;
-}
+ int ch, m;
-#define MINIMUM_SCORE 7000
-int estimate_similarity(struct diff_spec *one, struct diff_spec *two)
-{
- /* Return how similar they are, representing the score as an
- * integer between 0 and 10000.
- *
- * This version is very dumb and detects exact matches only.
- * Wnen Nico's delta stuff gets in, I'll use the delta
- * algorithm to estimate the similarity score in core.
- */
-
- if (one->sha1_valid && two->sha1_valid &&
- !memcmp(one->blob_sha1, two->blob_sha1, 20))
- return 10000;
- return 0;
-}
-
-static void flush_renames(const char **spec, int cnt, int reverse)
-{
- struct diff_spec_hold *rename_src, *rename_dst, *elem;
- struct diff_spec_hold *leftover = NULL;
- int score, best_score;
-
- while (createdfile) {
- rename_dst = createdfile;
- createdfile = rename_dst->next;
- best_score = MINIMUM_SCORE;
- rename_src = NULL;
- for (elem = deletedfile;
- elem;
- elem = elem->next) {
- if (elem->matched)
- continue;
- score = estimate_similarity(&elem->old,
- &rename_dst->new);
- if (best_score < score) {
- rename_src = elem;
- best_score = score;
- }
- }
- if (rename_src) {
- rename_src->matched = rename_dst;
- rename_dst->matched = rename_src;
-
- if (!cnt ||
- matches_pathspec(rename_src->path, spec, cnt) ||
- matches_pathspec(rename_dst->path, spec, cnt)) {
- if (reverse)
- run_external_diff(rename_dst->path,
- rename_src->path,
- &rename_dst->new,
- &rename_src->old);
- else
- run_external_diff(rename_src->path,
- rename_dst->path,
- &rename_src->old,
- &rename_dst->new);
- }
- }
- else {
- rename_dst->next = leftover;
- leftover = rename_dst;
- }
- }
-
- /* unmatched deletes */
- for (elem = deletedfile; elem; elem = elem->next) {
- if (elem->matched)
- continue;
- if (!cnt ||
- matches_pathspec(elem->path, spec, cnt)) {
- if (reverse)
- run_external_diff(elem->path, NULL,
- &elem->new, &elem->old);
- else
- run_external_diff(elem->path, NULL,
- &elem->old, &elem->new);
- }
- }
-
- /* unmatched creates */
- for (elem = leftover; elem; elem = elem->next) {
- if (!cnt ||
- matches_pathspec(elem->path, spec, cnt)) {
- if (reverse)
- run_external_diff(elem->path, NULL,
- &elem->new, &elem->old);
- else
- run_external_diff(elem->path, NULL,
- &elem->old, &elem->new);
- }
- }
-}
-
-static int parse_oneside_change(const char *cp, struct diff_spec *one,
- char *path)
-{
- int ch;
-
- one->file_valid = one->sha1_valid = 1;
- one->mode = 0;
+ m = 0;
while ((ch = *cp) && '0' <= ch && ch <= '7') {
- one->mode = (one->mode << 3) | (ch - '0');
+ m = (m << 3) | (ch - '0');
cp++;
}
-
+ *mode = m;
if (strncmp(cp, "\tblob\t", 6))
return -1;
cp += 6;
- if (get_sha1_hex(cp, one->blob_sha1))
+ if (get_sha1_hex(cp, sha1))
return -1;
cp += 40;
if (*cp++ != '\t')
@@ -168,79 +31,63 @@
return 0;
}
-static int parse_diff_raw_output(const char *buf,
- const char **spec, int cnt, int reverse)
+static int parse_diff_raw_output(const char *buf)
{
- struct diff_spec old, new;
char path[PATH_MAX];
+ unsigned char old_sha1[20], new_sha1[20];
const char *cp = buf;
- int ch;
+ int ch, old_mode, new_mode;
switch (*cp++) {
case 'U':
- if (!cnt || matches_pathspec(cp + 1, spec, cnt))
- diff_unmerge(cp + 1);
- return 0;
+ diff_unmerge(cp + 1);
+ break;
case '+':
- old.file_valid = 0;
- parse_oneside_change(cp, &new, path);
+ parse_oneside_change(cp, &new_mode, new_sha1, path);
+ diff_addremove('+', new_mode, new_sha1, path, NULL);
break;
case '-':
- new.file_valid = 0;
- parse_oneside_change(cp, &old, path);
+ parse_oneside_change(cp, &old_mode, old_sha1, path);
+ diff_addremove('-', old_mode, old_sha1, path, NULL);
break;
case '*':
- old.file_valid = old.sha1_valid =
- new.file_valid = new.sha1_valid = 1;
- old.mode = new.mode = 0;
+ old_mode = new_mode = 0;
while ((ch = *cp) && ('0' <= ch && ch <= '7')) {
- old.mode = (old.mode << 3) | (ch - '0');
+ old_mode = (old_mode << 3) | (ch - '0');
cp++;
}
if (strncmp(cp, "->", 2))
return -1;
cp += 2;
while ((ch = *cp) && ('0' <= ch && ch <= '7')) {
- new.mode = (new.mode << 3) | (ch - '0');
+ new_mode = (new_mode << 3) | (ch - '0');
cp++;
}
if (strncmp(cp, "\tblob\t", 6))
return -1;
cp += 6;
- if (get_sha1_hex(cp, old.blob_sha1))
+ if (get_sha1_hex(cp, old_sha1))
return -1;
cp += 40;
if (strncmp(cp, "->", 2))
return -1;
cp += 2;
- if (get_sha1_hex(cp, new.blob_sha1))
+ if (get_sha1_hex(cp, new_sha1))
return -1;
cp += 40;
if (*cp++ != '\t')
return -1;
strcpy(path, cp);
+ diff_change(old_mode, new_mode, old_sha1, new_sha1, path, 0);
break;
default:
return -1;
}
-
- if (detect_rename && old.file_valid != new.file_valid) {
- /* hold these */
- hold_spec(path, &old, &new);
- return 0;
- }
-
- if (!cnt || matches_pathspec(path, spec, cnt)) {
- if (reverse)
- run_external_diff(path, NULL, &new, &old);
- else
- run_external_diff(path, NULL, &old, &new);
- }
return 0;
}
static const char *diff_helper_usage =
- "git-diff-helper [-r] [-R] [-z] paths...";
+ "git-diff-helper [-z] [-R] [-M] paths...";
int main(int ac, const char **av) {
struct strbuf sb;
@@ -254,7 +101,7 @@
reverse = 1;
else if (av[1][1] == 'z')
line_termination = 0;
- else if (av[1][1] == 'r')
+ else if (av[1][1] == 'M')
detect_rename = 1;
else
usage(diff_helper_usage);
@@ -262,18 +109,20 @@
}
/* the remaining parameters are paths patterns */
+ diff_setup(detect_rename, 0, reverse, av+1, ac-1);
+
while (1) {
int status;
read_line(&sb, stdin, line_termination);
if (sb.eof)
break;
- status = parse_diff_raw_output(sb.buf, av+1, ac-1, reverse);
+ status = parse_diff_raw_output(sb.buf);
if (status) {
- flush_renames(av+1, ac-1, reverse);
+ diff_flush();
printf("%s%c", sb.buf, line_termination);
}
}
- flush_renames(av+1, ac-1, reverse);
+ diff_flush();
return 0;
}
diff --git a/diff-tree.c b/diff-tree.c
index 59d12f2..34c868d 100644
--- a/diff-tree.c
+++ b/diff-tree.c
@@ -9,6 +9,7 @@
static int read_stdin = 0;
static int line_termination = '\n';
static int generate_patch = 0;
+static int detect_rename = 0;
static const char *header = NULL;
static const char *header_prefix = "";
@@ -281,6 +282,18 @@
return retval;
}
+static int diff_tree_sha1_top(const unsigned char *old,
+ const unsigned char *new, const char *base)
+{
+ int ret;
+ if (generate_patch)
+ diff_setup(detect_rename, 0, 0, 0, 0);
+ ret = diff_tree_sha1(old, new, base);
+ if (generate_patch)
+ diff_flush();
+ return ret;
+}
+
static int get_one_line(const char *msg, unsigned long len)
{
int ret = 0;
@@ -377,7 +390,7 @@
if (get_sha1_hex(buf + offset + 7, parent))
return -1;
header = generate_header(name, sha1_to_hex(parent), buf, size);
- diff_tree_sha1(parent, commit, "");
+ diff_tree_sha1_top(parent, commit, "");
if (!header && verbose_header)
header_prefix = "\ndiff-tree ";
offset += 48;
@@ -401,14 +414,14 @@
line[81] = 0;
sprintf(this_header, "%s (from %s)\n", line, line+41);
header = this_header;
- return diff_tree_sha1(parent, commit, "");
+ return diff_tree_sha1_top(parent, commit, "");
}
line[40] = 0;
return diff_tree_commit(commit, line);
}
static char *diff_tree_usage =
-"diff-tree [-p] [-r] [-z] [--stdin] [-m] [-s] [-v] <tree sha1> <tree sha1>";
+"diff-tree [-p] [-r] [-z] [--stdin] [-M] [-m] [-s] [-v] <tree-ish> <tree-ish>";
int main(int argc, char **argv)
{
@@ -447,6 +460,10 @@
recursive = generate_patch = 1;
continue;
}
+ if (!strcmp(arg, "-M")) {
+ detect_rename = recursive = generate_patch = 1;
+ continue;
+ }
if (!strcmp(arg, "-z")) {
line_termination = '\0';
continue;
@@ -490,7 +507,7 @@
diff_tree_commit(sha1[0], NULL);
break;
case 2:
- diff_tree_sha1(sha1[0], sha1[1], "");
+ diff_tree_sha1_top(sha1[0], sha1[1], "");
break;
}
diff --git a/diff.c b/diff.c
index 74004e5..1f9cfa8 100644
--- a/diff.c
+++ b/diff.c
@@ -7,8 +7,10 @@
#include <limits.h>
#include "cache.h"
#include "diff.h"
+#include "delta.h"
static const char *diff_opts = "-pu";
+static unsigned char null_sha1[20] = { 0, };
static const char *external_diff(void)
{
@@ -79,6 +81,18 @@
char tmp_path[50];
} diff_temp[2];
+struct diff_spec {
+ unsigned char blob_sha1[20];
+ unsigned short mode; /* file mode */
+ unsigned sha1_valid : 1; /* if true, use blob_sha1 and trust mode;
+ * however with a NULL SHA1, read them
+ * from the file system.
+ * if false, use the name and read mode from
+ * the filesystem.
+ */
+ unsigned file_valid : 1; /* if false the file does not even exist */
+};
+
static void builtin_diff(const char *name_a,
const char *name_b,
struct diff_tempfile *temp)
@@ -160,7 +174,7 @@
struct cache_entry *ce;
struct stat st;
int pos, len;
-
+
/* We do not read the cache ourselves here, because the
* benchmark with my previous version that always reads cache
* shows that it makes things worse for diff-tree comparing
@@ -214,9 +228,6 @@
struct diff_tempfile *temp,
struct diff_spec *one)
{
- static unsigned char null_sha1[20] = { 0, };
- int use_work_tree = 0;
-
if (!one->file_valid) {
not_a_valid_file:
/* A '-' entry produces this for file-2, and
@@ -228,12 +239,8 @@
return;
}
- if (one->sha1_valid &&
- (!memcmp(one->blob_sha1, null_sha1, sizeof(null_sha1)) ||
- work_tree_matches(name, one->blob_sha1)))
- use_work_tree = 1;
-
- if (!one->sha1_valid || use_work_tree) {
+ if (!one->sha1_valid ||
+ work_tree_matches(name, one->blob_sha1)) {
struct stat st;
temp->name = name;
if (lstat(temp->name, &st) < 0) {
@@ -295,22 +302,59 @@
remove_tempfile();
}
+static int detect_rename;
+static int reverse_diff;
+static const char **pathspec;
+static int speccnt;
+static int diff_rename_minimum_score;
+
+static int matches_pathspec(const char *name)
+{
+ int i;
+ int namelen;
+
+ if (speccnt == 0)
+ return 1;
+
+ namelen = strlen(name);
+ for (i = 0; i < speccnt; i++) {
+ int speclen = strlen(pathspec[i]);
+ if (! strncmp(pathspec[i], name, speclen) &&
+ speclen <= namelen &&
+ (name[speclen] == 0 || name[speclen] == '/'))
+ return 1;
+ }
+ return 0;
+}
+
/* An external diff command takes:
*
* diff-cmd name infile1 infile1-sha1 infile1-mode \
- * infile2 infile2-sha1 infile2-mode.
+ * infile2 infile2-sha1 infile2-mode [ rename-to ]
*
*/
-void run_external_diff(const char *name,
- const char *other,
- struct diff_spec *one,
- struct diff_spec *two)
+static void run_external_diff(const char *name,
+ const char *other,
+ struct diff_spec *one,
+ struct diff_spec *two)
{
struct diff_tempfile *temp = diff_temp;
pid_t pid;
int status;
static int atexit_asked = 0;
+ if (reverse_diff) {
+ struct diff_spec *tmp_spec;
+ tmp_spec = one; one = two; two = tmp_spec;
+ if (other) {
+ const char *tmp;
+ tmp = name; name = other; other = tmp;
+ }
+ }
+
+ if (!matches_pathspec(name) && (!other || !matches_pathspec(other)))
+ return;
+
if (one && two) {
prepare_temp_file(name, &temp[0], one);
prepare_temp_file(other ? : name, &temp[1], two);
@@ -329,14 +373,23 @@
die("unable to fork");
if (!pid) {
const char *pgm = external_diff();
- /* not passing rename patch to external ones */
- if (!other && pgm) {
- if (one && two)
- execlp(pgm, pgm,
- name,
- temp[0].name, temp[0].hex, temp[0].mode,
- temp[1].name, temp[1].hex, temp[1].mode,
- NULL);
+ if (pgm) {
+ if (one && two) {
+ const char *exec_arg[9];
+ const char **arg = &exec_arg[0];
+ *arg++ = pgm;
+ *arg++ = name;
+ *arg++ = temp[0].name;
+ *arg++ = temp[0].hex;
+ *arg++ = temp[0].mode;
+ *arg++ = temp[1].name;
+ *arg++ = temp[1].hex;
+ *arg++ = temp[1].mode;
+ if (other)
+ *arg++ = other;
+ *arg = 0;
+ execvp(pgm, (char *const*) exec_arg);
+ }
else
execlp(pgm, pgm, name, NULL);
}
@@ -367,6 +420,293 @@
remove_tempfile();
}
+/*
+ * We do not detect circular renames. Just hold created and deleted
+ * entries and later attempt to match them up. If they do not match,
+ * then spit them out as deletes or creates as original.
+ */
+
+static struct diff_spec_hold {
+ struct diff_spec_hold *next;
+ struct diff_spec it;
+ unsigned long size;
+ int flags;
+#define MATCHED 1
+#define SHOULD_FREE 2
+#define SHOULD_MUNMAP 4
+ void *data;
+ char path[1];
+} *createdfile, *deletedfile;
+
+static void hold_diff(const char *name,
+ struct diff_spec *one,
+ struct diff_spec *two)
+{
+ struct diff_spec_hold **list, *elem;
+
+ if (one->file_valid && two->file_valid)
+ die("internal error");
+
+ if (!detect_rename) {
+ run_external_diff(name, NULL, one, two);
+ return;
+ }
+ elem = xmalloc(sizeof(*elem) + strlen(name));
+ strcpy(elem->path, name);
+ elem->size = 0;
+ elem->data = NULL;
+ elem->flags = 0;
+ if (one->file_valid) {
+ list = &deletedfile;
+ elem->it = *one;
+ }
+ else {
+ list = &createdfile;
+ elem->it = *two;
+ }
+ elem->next = *list;
+ *list = elem;
+}
+
+static int populate_data(struct diff_spec_hold *s)
+{
+ char type[20];
+
+ if (s->data)
+ return 0;
+ if (s->it.sha1_valid) {
+ s->data = read_sha1_file(s->it.blob_sha1, type, &s->size);
+ s->flags |= SHOULD_FREE;
+ }
+ else {
+ struct stat st;
+ int fd;
+ fd = open(s->path, O_RDONLY);
+ if (fd < 0)
+ return -1;
+ if (fstat(fd, &st)) {
+ close(fd);
+ return -1;
+ }
+ s->size = st.st_size;
+ s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
+ close(fd);
+ if (!s->size)
+ s->data = "";
+ else
+ s->flags |= SHOULD_MUNMAP;
+ }
+ return 0;
+}
+
+static void free_data(struct diff_spec_hold *s)
+{
+ if (s->flags & SHOULD_FREE)
+ free(s->data);
+ else if (s->flags & SHOULD_MUNMAP)
+ munmap(s->data, s->size);
+ s->flags &= ~(SHOULD_FREE|SHOULD_MUNMAP);
+}
+
+static void flush_remaining_diff(struct diff_spec_hold *elem,
+ int on_created_list)
+{
+ static struct diff_spec null_file_spec;
+
+ null_file_spec.file_valid = 0;
+ for ( ; elem ; elem = elem->next) {
+ free_data(elem);
+ if (elem->flags & MATCHED)
+ continue;
+ if (on_created_list)
+ run_external_diff(elem->path, NULL,
+ &null_file_spec, &elem->it);
+ else
+ run_external_diff(elem->path, NULL,
+ &elem->it, &null_file_spec);
+ }
+}
+
+static int is_exact_match(struct diff_spec_hold *src,
+ struct diff_spec_hold *dst)
+{
+ if (src->it.sha1_valid && dst->it.sha1_valid &&
+ !memcmp(src->it.blob_sha1, dst->it.blob_sha1, 20))
+ return 1;
+ if (populate_data(src) || populate_data(dst))
+ /* this is an error but will be caught downstream */
+ return 0;
+ if (src->size == dst->size &&
+ !memcmp(src->data, dst->data, src->size))
+ return 1;
+ return 0;
+}
+
+#define MINIMUM_SCORE 5000
+int estimate_similarity(struct diff_spec_hold *src, struct diff_spec_hold *dst)
+{
+ /* src points at a deleted file and dst points at a created
+ * file. They may be quite similar, in which case we want to
+ * say src is renamed to dst.
+ *
+ * Compare them and return how similar they are, representing
+ * the score as an integer between 0 and 10000. 10000 is
+ * reserved for the case where they match exactly.
+ */
+ void *delta;
+ unsigned long delta_size;
+
+ delta_size = ((src->size < dst->size) ?
+ (dst->size - src->size) : (src->size - dst->size));
+
+ /* We would not consider rename followed by more than
+ * 20% edits; that is, delta_size must be smaller than
+ * (src->size + dst->size)/2 * 0.2, which means...
+ */
+ if ((src->size + dst->size) < delta_size * 10)
+ return 0;
+
+ delta = diff_delta(src->data, src->size,
+ dst->data, dst->size,
+ &delta_size);
+ free(delta);
+
+ /* This "delta" is really xdiff with adler32 and all the
+ * overheads but it is a quick and dirty approximation.
+ *
+ * Now we will give some score to it. Let's say 20% edit gets
+ * 5000 points and 0% edit gets 9000 points. That is, every
+ * 1/20000 edit gets 1 point penalty. The amount of penalty is:
+ *
+ * (delta_size * 2 / (src->size + dst->size)) * 20000
+ *
+ */
+ return 9000 - (40000 * delta_size / (src->size+dst->size));
+}
+
+struct diff_score {
+ struct diff_spec_hold *src;
+ struct diff_spec_hold *dst;
+ int score;
+};
+
+static int score_compare(const void *a_, const void *b_)
+{
+ const struct diff_score *a = a_, *b = b_;
+ return b->score - a->score;
+}
+
+static void flush_rename_pair(struct diff_spec_hold *src,
+ struct diff_spec_hold *dst)
+{
+ src->flags |= MATCHED;
+ dst->flags |= MATCHED;
+ free_data(src);
+ free_data(dst);
+ run_external_diff(src->path, dst->path,
+ &src->it, &dst->it);
+}
+
+static void free_held_diff(struct diff_spec_hold *list)
+{
+ struct diff_spec_hold *h;
+ for (h = list; list; list = h) {
+ h = list->next;
+ free_data(list);
+ free(list);
+ }
+}
+
+void diff_flush(void)
+{
+ int num_create, num_delete, c, d;
+ struct diff_spec_hold *elem, *src, *dst;
+ struct diff_score *mx;
+
+ /* We really want to cull the candidates list early
+ * with cheap tests in order to avoid doing deltas.
+ */
+ for (dst = createdfile; dst; dst = dst->next) {
+ for (src = deletedfile; src; src = src->next) {
+ if (! is_exact_match(src, dst))
+ continue;
+ flush_rename_pair(src, dst);
+ break;
+ }
+ }
+
+ /* Count surviving candidates */
+ for (num_create = 0, elem = createdfile; elem; elem = elem->next)
+ if (!(elem->flags & MATCHED))
+ num_create++;
+
+ for (num_delete = 0, elem = deletedfile; elem; elem = elem->next)
+ if (!(elem->flags & MATCHED))
+ num_delete++;
+
+ if (num_create == 0 || num_delete == 0)
+ goto exit_path;
+
+ mx = xmalloc(sizeof(*mx) * num_create * num_delete);
+ for (c = 0, dst = createdfile; dst; dst = dst->next) {
+ int base = c * num_delete;
+ if (dst->flags & MATCHED)
+ continue;
+ for (d = 0, src = deletedfile; src; src = src->next) {
+ struct diff_score *m = &mx[base+d];
+ if (src->flags & MATCHED)
+ continue;
+ m->src = src;
+ m->dst = dst;
+ m->score = estimate_similarity(src, dst);
+ d++;
+ }
+ c++;
+ }
+ qsort(mx, num_create*num_delete, sizeof(*mx), score_compare);
+
+ for (c = 0; c < num_create * num_delete; c++) {
+ src = mx[c].src;
+ dst = mx[c].dst;
+ if ((src->flags & MATCHED) || (dst->flags & MATCHED))
+ continue;
+ fprintf(stderr,
+ "**score ** %d %s %s\n",
+ mx[c].score, src->path, dst->path);
+ }
+
+ for (c = 0; c < num_create * num_delete; c++) {
+ src = mx[c].src;
+ dst = mx[c].dst;
+ if ((src->flags & MATCHED) || (dst->flags & MATCHED))
+ continue;
+ if (mx[c].score < diff_rename_minimum_score)
+ break;
+ flush_rename_pair(src, dst);
+ }
+
+ exit_path:
+ flush_remaining_diff(createdfile, 1);
+ flush_remaining_diff(deletedfile, 0);
+ free_held_diff(createdfile);
+ free_held_diff(deletedfile);
+ createdfile = deletedfile = NULL;
+}
+
+void diff_setup(int detect_rename_, int minimum_score_, int reverse_diff_,
+ const char **pathspec_, int speccnt_)
+{
+ free_held_diff(createdfile);
+ free_held_diff(deletedfile);
+ createdfile = deletedfile = NULL;
+
+ detect_rename = detect_rename_;
+ reverse_diff = reverse_diff_;
+ pathspec = pathspec_;
+ speccnt = speccnt_;
+ diff_rename_minimum_score = minimum_score_ ? : MINIMUM_SCORE;
+}
+
void diff_addremove(int addremove, unsigned mode,
const unsigned char *sha1,
const char *base, const char *path)
@@ -376,7 +716,8 @@
memcpy(spec[0].blob_sha1, sha1, 20);
spec[0].mode = mode;
- spec[0].sha1_valid = spec[0].file_valid = 1;
+ spec[0].sha1_valid = !!memcmp(sha1, null_sha1, 20);
+ spec[0].file_valid = 1;
spec[1].file_valid = 0;
if (addremove == '+') {
@@ -384,12 +725,12 @@
} else {
one = spec; two = one + 1;
}
-
+
if (path) {
strcpy(concatpath, base);
strcat(concatpath, path);
}
- run_external_diff(path ? concatpath : base, NULL, one, two);
+ hold_diff(path ? concatpath : base, one, two);
}
void diff_change(unsigned old_mode, unsigned new_mode,
@@ -399,17 +740,22 @@
char concatpath[PATH_MAX];
struct diff_spec spec[2];
- memcpy(spec[0].blob_sha1, old_sha1, 20);
- spec[0].mode = old_mode;
- memcpy(spec[1].blob_sha1, new_sha1, 20);
- spec[1].mode = new_mode;
- spec[0].sha1_valid = spec[0].file_valid = 1;
- spec[1].sha1_valid = spec[1].file_valid = 1;
-
if (path) {
strcpy(concatpath, base);
strcat(concatpath, path);
}
+
+ memcpy(spec[0].blob_sha1, old_sha1, 20);
+ spec[0].mode = old_mode;
+ memcpy(spec[1].blob_sha1, new_sha1, 20);
+ spec[1].mode = new_mode;
+ spec[0].sha1_valid = !!memcmp(old_sha1, null_sha1, 20);
+ spec[1].sha1_valid = !!memcmp(new_sha1, null_sha1, 20);
+ spec[1].file_valid = spec[0].file_valid = 1;
+
+ /* We do not look at changed files as candidate for
+ * rename detection ever.
+ */
run_external_diff(path ? concatpath : base, NULL, &spec[0], &spec[1]);
}
diff --git a/diff.h b/diff.h
index 815987d..cce4649 100644
--- a/diff.h
+++ b/diff.h
@@ -17,21 +17,10 @@
extern void diff_unmerge(const char *path);
-/* These are for diff-helper */
+extern void diff_setup(int detect_rename, int minimum_score,
+ int reverse,
+ const char **spec, int cnt);
-struct diff_spec {
- unsigned char blob_sha1[20];
- unsigned short mode; /* file mode */
- unsigned sha1_valid : 1; /* if true, use blob_sha1 and trust mode;
- * however with a NULL SHA1, read them
- * from the file system.
- * if false, use the name and read mode from
- * the filesystem.
- */
- unsigned file_valid : 1; /* if false the file does not even exist */
-};
-
-extern void run_external_diff(const char *name, const char *other,
- struct diff_spec *, struct diff_spec *);
+extern void diff_flush(void);
#endif /* DIFF_H */
diff --git a/git-apply-patch-script b/git-apply-patch-script
index 0849a3e..171c9f5 100755
--- a/git-apply-patch-script
+++ b/git-apply-patch-script
@@ -11,6 +11,9 @@
1)
echo >&2 "cannot handle unmerged diff on path $1."
exit 1 ;;
+8)
+ echo >&2 "cannot handle rename diff between $1 and $8 yet."
+ exit 1 ;;
esac
name="$1" tmp1="$2" hex1="$3" mode1="$4" tmp2="$5" hex2="$6" mode2="$7"
diff --git a/t/t4001-diff-rename.sh b/t/t4001-diff-rename.sh
new file mode 100644
index 0000000..44225f7
--- /dev/null
+++ b/t/t4001-diff-rename.sh
@@ -0,0 +1,60 @@
+#!/bin/sh
+#
+# Copyright (c) 2005 Junio C Hamano
+#
+
+test_description='Test rename detection in diff engine.
+
+'
+. ./test-lib.sh
+
+echo >path0 'Line 1
+Line 2
+Line 3
+Line 4
+Line 5
+Line 6
+Line 7
+Line 8
+Line 9
+Line 10
+line 11
+Line 12
+Line 13
+Line 14
+Line 15
+'
+
+test_expect_success \
+ 'update-cache --add a file.' \
+ 'git-update-cache --add path0'
+
+test_expect_success \
+ 'write that tree.' \
+ 'tree=$(git-write-tree)'
+
+sed -e 's/line/Line/' <path0 >path1
+rm -f path0
+test_expect_success \
+ 'renamed and edited the file.' \
+ 'git-update-cache --add --remove path0 path1'
+
+test_expect_success \
+ 'git-diff-cache -p -M after rename and editing.' \
+ 'git-diff-cache -p -M $tree >current'
+cat >expected <<\EOF
+diff --git a/path0 b/path1
+rename old path0
+rename new path1
+--- a/path0
++++ b/path1
+@@ -8,7 +8,7 @@ Line 7
+ Line 8
+ Line 9
+ Line 10
+-line 11
++Line 11
+ Line 12
+ Line 13
+ Line 14
+EOF
