diff: round down similarity index
authorRené Scharfe <rene.scharfe@lsrfire.ath.cx>
Sun, 24 Jun 2007 22:23:34 +0000 (00:23 +0200)
committerJunio C Hamano <gitster@pobox.com>
Mon, 25 Jun 2007 08:51:21 +0000 (01:51 -0700)
Rounding down the printed (dis)similarity index allows us to use
"100%" as a special value that indicates complete rewrites and
fully equal file contents, respectively.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Documentation/diff-format.txt
diff.c
index 18d49d2c3baa81983b19a938598eb091fb7809ef..001503205b24d5c20ec10792c4ab6c4c7221bcb7 100644 (file)
@@ -126,6 +126,13 @@ the file that rename/copy produces, respectively.
     If there is need for such substitution then the whole
     pathname is put in double quotes.
 
     If there is need for such substitution then the whole
     pathname is put in double quotes.
 
+The similarity index is the percentage of unchanged lines, and
+the dissimilarity index is the percentage of changed lines.  It
+is a rounded down integer, followed by a percent sign.  The
+similarity index value of 100% is thus reserved for two equal
+files, while 100% dissimilarity means that no line from the old
+file made it into the new one.
+
 
 combined diff format
 --------------------
 
 combined diff format
 --------------------
diff --git a/diff.c b/diff.c
index 9938969fa50e8af2a4eabe96ae122111ae42fe75..e0edb98846753f39cab9e377c9ac4af2d7fdbf35 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -1813,6 +1813,11 @@ static void diff_fill_sha1_info(struct diff_filespec *one)
                hashclr(one->sha1);
 }
 
                hashclr(one->sha1);
 }
 
+static int similarity_index(struct diff_filepair *p)
+{
+       return p->score * 100 / MAX_SCORE;
+}
+
 static void run_diff(struct diff_filepair *p, struct diff_options *o)
 {
        const char *pgm = external_diff();
 static void run_diff(struct diff_filepair *p, struct diff_options *o)
 {
        const char *pgm = external_diff();
@@ -1847,23 +1852,20 @@ static void run_diff(struct diff_filepair *p, struct diff_options *o)
                                "similarity index %d%%\n"
                                "copy from %s\n"
                                "copy to %s\n",
                                "similarity index %d%%\n"
                                "copy from %s\n"
                                "copy to %s\n",
-                               (int)(0.5 + p->score * 100.0/MAX_SCORE),
-                               name_munged, other_munged);
+                               similarity_index(p), name_munged, other_munged);
                break;
        case DIFF_STATUS_RENAMED:
                len += snprintf(msg + len, sizeof(msg) - len,
                                "similarity index %d%%\n"
                                "rename from %s\n"
                                "rename to %s\n",
                break;
        case DIFF_STATUS_RENAMED:
                len += snprintf(msg + len, sizeof(msg) - len,
                                "similarity index %d%%\n"
                                "rename from %s\n"
                                "rename to %s\n",
-                               (int)(0.5 + p->score * 100.0/MAX_SCORE),
-                               name_munged, other_munged);
+                               similarity_index(p), name_munged, other_munged);
                break;
        case DIFF_STATUS_MODIFIED:
                if (p->score) {
                        len += snprintf(msg + len, sizeof(msg) - len,
                                        "dissimilarity index %d%%\n",
                break;
        case DIFF_STATUS_MODIFIED:
                if (p->score) {
                        len += snprintf(msg + len, sizeof(msg) - len,
                                        "dissimilarity index %d%%\n",
-                                       (int)(0.5 + p->score *
-                                             100.0/MAX_SCORE));
+                                       similarity_index(p));
                        complete_rewrite = 1;
                        break;
                }
                        complete_rewrite = 1;
                        break;
                }
@@ -2387,8 +2389,7 @@ static void diff_flush_raw(struct diff_filepair *p,
        }
 
        if (p->score)
        }
 
        if (p->score)
-               sprintf(status, "%c%03d", p->status,
-                       (int)(0.5 + p->score * 100.0/MAX_SCORE));
+               sprintf(status, "%c%03d", p->status, similarity_index(p));
        else {
                status[0] = p->status;
                status[1] = 0;
        else {
                status[0] = p->status;
                status[1] = 0;
@@ -2670,8 +2671,7 @@ static void show_rename_copy(const char *renamecopy, struct diff_filepair *p)
 {
        char *names = pprint_rename(p->one->path, p->two->path);
 
 {
        char *names = pprint_rename(p->one->path, p->two->path);
 
-       printf(" %s %s (%d%%)\n", renamecopy, names,
-              (int)(0.5 + p->score * 100.0/MAX_SCORE));
+       printf(" %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
        free(names);
        show_mode_change(p, 0);
 }
        free(names);
        show_mode_change(p, 0);
 }
@@ -2695,7 +2695,7 @@ static void diff_summary(struct diff_filepair *p)
                if (p->score) {
                        char *name = quote_one(p->two->path);
                        printf(" rewrite %s (%d%%)\n", name,
                if (p->score) {
                        char *name = quote_one(p->two->path);
                        printf(" rewrite %s (%d%%)\n", name,
-                               (int)(0.5 + p->score * 100.0/MAX_SCORE));
+                              similarity_index(p));
                        free(name);
                        show_mode_change(p, 0);
                } else  show_mode_change(p, 1);
                        free(name);
                        show_mode_change(p, 0);
                } else  show_mode_change(p, 1);