summaryrefslogtreecommitdiff
path: root/diff.c
diff options
context:
space:
mode:
Diffstat (limited to 'diff.c')
-rw-r--r--diff.c87
1 files changed, 66 insertions, 21 deletions
diff --git a/diff.c b/diff.c
index a4d2b2d726..8dfa624432 100644
--- a/diff.c
+++ b/diff.c
@@ -83,7 +83,7 @@ static void builtin_diff(const char *name,
{
int i, next_at;
const char *diff_cmd = "diff -L'%s%s' -L'%s%s'";
- const char *diff_arg = "'%s' '%s'";
+ const char *diff_arg = "'%s' '%s'||:"; /* "||:" is to return 0 */
const char *input_name_sq[2];
const char *path0[2];
const char *path1[2];
@@ -132,11 +132,50 @@ static void builtin_diff(const char *name,
execlp("/bin/sh","sh", "-c", cmd, NULL);
}
+/*
+ * Given a name and sha1 pair, if the dircache tells us the file in
+ * the work tree has that object contents, return true, so that
+ * prepare_temp_file() does not have to inflate and extract.
+ */
+static int work_tree_matches(const char *name, const unsigned char *sha1)
+{
+ 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
+ * two linux-2.6 kernel trees in an already checked out work
+ * tree. This is because most diff-tree comparison deals with
+ * only a small number of files, while reading the cache is
+ * expensive for a large project, and its cost outweighs the
+ * savings we get by not inflating the object to a temporary
+ * file. Practically, this code only helps when we are used
+ * by diff-cache --cached, which does read the cache before
+ * calling us.
+ */
+ if (!active_cache)
+ return 0;
+
+ len = strlen(name);
+ pos = cache_name_pos(name, len);
+ if (pos < 0)
+ return 0;
+ ce = active_cache[pos];
+ if ((stat(name, &st) < 0) ||
+ cache_match_stat(ce, &st) ||
+ memcmp(sha1, ce->sha1, 20))
+ return 0;
+ return 1;
+}
+
static void prepare_temp_file(const char *name,
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:
@@ -150,20 +189,22 @@ static void prepare_temp_file(const char *name,
}
if (one->sha1_valid &&
- !memcmp(one->u.sha1, null_sha1, sizeof(null_sha1))) {
- one->sha1_valid = 0;
- one->u.name = name;
- }
+ (!memcmp(one->blob_sha1, null_sha1, sizeof(null_sha1)) ||
+ work_tree_matches(name, one->blob_sha1)))
+ use_work_tree = 1;
- if (!one->sha1_valid) {
+ if (!one->sha1_valid || use_work_tree) {
struct stat st;
- temp->name = one->u.name;
+ temp->name = name;
if (stat(temp->name, &st) < 0) {
if (errno == ENOENT)
goto not_a_valid_file;
die("stat(%s): %s", temp->name, strerror(errno));
}
- strcpy(temp->hex, sha1_to_hex(null_sha1));
+ if (!one->sha1_valid)
+ strcpy(temp->hex, sha1_to_hex(null_sha1));
+ else
+ strcpy(temp->hex, sha1_to_hex(one->blob_sha1));
sprintf(temp->mode, "%06o",
S_IFREG |ce_permissions(st.st_mode));
}
@@ -173,10 +214,10 @@ static void prepare_temp_file(const char *name,
char type[20];
unsigned long size;
- blob = read_sha1_file(one->u.sha1, type, &size);
+ blob = read_sha1_file(one->blob_sha1, type, &size);
if (!blob || strcmp(type, "blob"))
die("unable to read blob object for %s (%s)",
- name, sha1_to_hex(one->u.sha1));
+ name, sha1_to_hex(one->blob_sha1));
strcpy(temp->tmp_path, ".diff_XXXXXX");
fd = mkstemp(temp->tmp_path);
@@ -187,7 +228,7 @@ static void prepare_temp_file(const char *name,
close(fd);
free(blob);
temp->name = temp->tmp_path;
- strcpy(temp->hex, sha1_to_hex(one->u.sha1));
+ strcpy(temp->hex, sha1_to_hex(one->blob_sha1));
temp->hex[40] = 0;
sprintf(temp->mode, "%06o", one->mode);
}
@@ -261,16 +302,20 @@ void run_external_diff(const char *name,
printf("* Unmerged path %s\n", name);
exit(0);
}
- if (waitpid(pid, &status, 0) < 0 || !WIFEXITED(status)) {
- /* We do not check the exit status because typically
+ if (waitpid(pid, &status, 0) < 0 ||
+ !WIFEXITED(status) || WEXITSTATUS(status)) {
+ /* Earlier we did not check the exit status because
* diff exits non-zero if files are different, and
- * we are not interested in knowing that. We *knew*
- * they are different and that's why we ran diff
- * in the first place! However if it dies by a signal,
- * we stop processing immediately.
+ * we are not interested in knowing that. It was a
+ * mistake which made it harder to quit a diff-*
+ * session that uses the git-apply-patch-script as
+ * the GIT_EXTERNAL_DIFF. A custom GIT_EXTERNAL_DIFF
+ * should also exit non-zero only when it wants to
+ * abort the entire diff-* session.
*/
remove_tempfile();
- die("external diff died unexpectedly.\n");
+ fprintf(stderr, "external diff died, stopping at %s.\n", name);
+ exit(1);
}
remove_tempfile();
}
@@ -282,7 +327,7 @@ void diff_addremove(int addremove, unsigned mode,
char concatpath[PATH_MAX];
struct diff_spec spec[2], *one, *two;
- memcpy(spec[0].u.sha1, sha1, 20);
+ memcpy(spec[0].blob_sha1, sha1, 20);
spec[0].mode = mode;
spec[0].sha1_valid = spec[0].file_valid = 1;
spec[1].file_valid = 0;
@@ -307,9 +352,9 @@ void diff_change(unsigned old_mode, unsigned new_mode,
char concatpath[PATH_MAX];
struct diff_spec spec[2];
- memcpy(spec[0].u.sha1, old_sha1, 20);
+ memcpy(spec[0].blob_sha1, old_sha1, 20);
spec[0].mode = old_mode;
- memcpy(spec[1].u.sha1, new_sha1, 20);
+ 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;