show-branch: optionally use unique prefix as name.

git-show-branch acquires two new options. --sha1-name to name
commits using the unique prefix of their object names, and
--no-name to not to show names at all.

This was outlined in <7vk6gpyuyr.fsf@assigned-by-dhcp.cox.net>

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/Documentation/git-show-branch.txt b/Documentation/git-show-branch.txt
index e0dce7e..c6c97b2 100644 (file)
--- a/Documentation/git-show-branch.txt
+++ b/Documentation/git-show-branch.txt
@@ -7,7 +7,7 @@ git-show-branch - Show branches and their commits.
 
 SYNOPSIS
 --------
-'git-show-branch [--all] [--heads] [--tags] [--more=<n> | --list | --independent | --merge-base] <reference>...'
+'git-show-branch [--all] [--heads] [--tags] [--more=<n> | --list | --independent | --merge-base] [--no-name | --sha1-name] <reference>...'
 
 DESCRIPTION
 -----------
@@ -44,6 +44,15 @@ OPTIONS
        Among the <reference>s given, display only the ones that
        cannot be reached from any other <reference>.
 
+--no-name::
+       Do not show naming strings for each commit.
+
+--sha1-name::
+       Instead of naming the commits using the path to reach
+       them from heads (e.g. "master~2" to mean the grandparent
+       of "master"), name them with the unique prefix of their
+       object names.
+
 Note that --more, --list, --independent and --merge-base options
 are mutually exclusive.
 
@@ -88,21 +97,6 @@ whose commit message is "Add 'git show-branch'.  "fixes" branch
 adds one commit 'Introduce "reset type"'.  "mhf" branch has many
 other commits.
 
-When only one head is given, the output format changes slightly
-to conserve space.  The '+' sign to show which commit is
-reachable from which head and the first N lines to show the list
-of heads being displayed are both meaningless so they are
-omitted.  Also the label given to each commit does not repeat
-the name of the branch because it is obvious.
-
-------------------------------------------------
-$ git show-branch --more=4 master
-[master] Add 'git show-branch'.
-[~1] Add a new extended SHA1 syntax <name>~<num>
-[~2] Fix "git-diff A B"
-[~3] git-ls-files: generalized pathspecs
-[~4] Make "git-ls-files" work in subdirectories
-------------------------------------------------
 
 Author
 ------

diff --git a/cache.h b/cache.h
index 64cbcac..41cc22c 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -194,6 +194,7 @@ extern char *git_path(const char *fmt, ...) __attribute__((format (printf, 1, 2)
 extern char *sha1_file_name(const unsigned char *sha1);
 extern char *sha1_pack_name(const unsigned char *sha1);
 extern char *sha1_pack_index_name(const unsigned char *sha1);
+extern const char *find_unique_abbrev(const unsigned char *sha1, int);
 extern const unsigned char null_sha1[20];
 
 int git_mkstemp(char *path, size_t n, const char *template);

diff --git a/sha1_name.c b/sha1_name.c
index f64755f..4e9a052 100644 (file)
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -119,6 +119,9 @@ static int find_short_packed_object(int len, const unsigned char *match, unsigne
        return found;
 }
 
+#define SHORT_NAME_NOT_FOUND (-1)
+#define SHORT_NAME_AMBIGUOUS (-2)
+
 static int find_unique_short_object(int len, char *canonical,
                                    unsigned char *res, unsigned char *sha1)
 {
@@ -128,23 +131,24 @@ static int find_unique_short_object(int len, char *canonical,
        has_unpacked = find_short_object_filename(len, canonical, unpacked_sha1);
        has_packed = find_short_packed_object(len, res, packed_sha1);
        if (!has_unpacked && !has_packed)
-               return -1;
+               return SHORT_NAME_NOT_FOUND;
        if (1 < has_unpacked || 1 < has_packed)
-               return error("short SHA1 %.*s is ambiguous.", len, canonical);
+               return SHORT_NAME_AMBIGUOUS;
        if (has_unpacked != has_packed) {
                memcpy(sha1, (has_packed ? packed_sha1 : unpacked_sha1), 20);
                return 0;
        }
        /* Both have unique ones -- do they match? */
        if (memcmp(packed_sha1, unpacked_sha1, 20))
-               return error("short SHA1 %.*s is ambiguous.", len, canonical);
+               return -2;
        memcpy(sha1, packed_sha1, 20);
        return 0;
 }
 
-static int get_short_sha1(const char *name, int len, unsigned char *sha1)
+static int get_short_sha1(const char *name, int len, unsigned char *sha1,
+                         int quietly)
 {
-       int i;
+       int i, status;
        char canonical[40];
        unsigned char res[20];
 
@@ -171,7 +175,29 @@ static int get_short_sha1(const char *name, int len, unsigned char *sha1)
                res[i >> 1] |= val;
        }
 
-       return find_unique_short_object(i, canonical, res, sha1);
+       status = find_unique_short_object(i, canonical, res, sha1);
+       if (!quietly && (status == SHORT_NAME_AMBIGUOUS))
+               return error("short SHA1 %.*s is ambiguous.", len, canonical);
+       return status;
+}
+
+const char *find_unique_abbrev(const unsigned char *sha1, int len)
+{
+       int status;
+       static char hex[41];
+       memcpy(hex, sha1_to_hex(sha1), 40);
+       while (len < 40) {
+               unsigned char sha1_ret[20];
+               status = get_short_sha1(hex, len, sha1_ret, 1);
+               if (!status) {
+                       hex[len] = 0;
+                       return hex;
+               }
+               if (status != SHORT_NAME_AMBIGUOUS)
+                       return NULL;
+               len++;
+       }
+       return NULL;
 }
 
 static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
@@ -292,7 +318,7 @@ static int get_sha1_1(const char *name, int len, unsigned char *sha1)
        ret = get_sha1_basic(name, len, sha1);
        if (!ret)
                return 0;
-       return get_short_sha1(name, len, sha1);
+       return get_short_sha1(name, len, sha1, 0);
 }
 
 /*

diff --git a/show-branch.c b/show-branch.c
index 8429c17..bb14c86 100644 (file)
--- a/show-branch.c
+++ b/show-branch.c
@@ -133,25 +133,28 @@ static void name_commits(struct commit_list *list,
                        nth = 0;
                        while (parents) {
                                struct commit *p = parents->item;
-                               char newname[1000];
+                               char newname[1000], *en;
                                parents = parents->next;
                                nth++;
                                if (p->object.util)
                                        continue;
+                               en = newname;
                                switch (n->generation) {
                                case 0:
-                                       sprintf(newname, "%s^%d",
-                                               n->head_name, nth);
+                                       en += sprintf(en, "%s", n->head_name);
                                        break;
                                case 1:
-                                       sprintf(newname, "%s^^%d",
-                                               n->head_name, nth);
+                                       en += sprintf(en, "%s^", n->head_name);
                                        break;
                                default:
-                                       sprintf(newname, "%s~%d^%d",
-                                               n->head_name, n->generation,
-                                               nth);
+                                       en += sprintf(en, "%s~%d",
+                                               n->head_name, n->generation);
+                                       break;
                                }
+                               if (nth == 1)
+                                       en += sprintf(en, "^");
+                               else
+                                       en += sprintf(en, "^%d", nth);
                                name_commit(p, strdup(newname), 0);
                                i++;
                                name_first_parent_chain(p);
@@ -205,7 +208,7 @@ static void join_revs(struct commit_list **list_p,
        }
 }
 
-static void show_one_commit(struct commit *commit)
+static void show_one_commit(struct commit *commit, int no_name)
 {
        char pretty[128], *cp;
        struct commit_name *name = commit->object.util;
@@ -218,11 +221,21 @@ static void show_one_commit(struct commit *commit)
                cp = pretty + 8;
        else
                cp = pretty;
-       if (name && name->head_name) {
-               printf("[%s", name->head_name);
-               if (name->generation)
-                       printf("~%d", name->generation);
-               printf("] ");
+
+       if (!no_name) {
+               if (name && name->head_name) {
+                       printf("[%s", name->head_name);
+                       if (name->generation) {
+                               if (name->generation == 1)
+                                       printf("^");
+                               else
+                                       printf("~%d", name->generation);
+                       }
+                       printf("] ");
+               }
+               else
+                       printf("[%s] ",
+                              find_unique_abbrev(commit->object.sha1, 7));
        }
        puts(cp);
 }
@@ -354,7 +367,8 @@ int main(int ac, char **av)
        unsigned char head_sha1[20];
        int merge_base = 0;
        int independent = 0;
-       char **label;
+       int no_name = 0;
+       int sha1_name = 0;
 
        setup_git_directory();
 
@@ -370,6 +384,10 @@ int main(int ac, char **av)
                        extra = 1;
                else if (!strcmp(arg, "--list"))
                        extra = -1;
+               else if (!strcmp(arg, "--no-name"))
+                       no_name = 1;
+               else if (!strcmp(arg, "--sha1-name"))
+                       sha1_name = 1;
                else if (!strncmp(arg, "--more=", 7))
                        extra = atoi(arg + 7);
                else if (!strcmp(arg, "--merge-base"))
@@ -465,7 +483,8 @@ int main(int ac, char **av)
                                printf("%c [%s] ",
                                       is_head ? '*' : '!', ref_name[i]);
                        }
-                       show_one_commit(rev[i]);
+                       /* header lines never need name */
+                       show_one_commit(rev[i], 1);
                }
                if (0 <= extra) {
                        for (i = 0; i < num_rev; i++)
@@ -480,7 +499,8 @@ int main(int ac, char **av)
        sort_in_topological_order(&seen);
 
        /* Give names to commits */
-       name_commits(seen, rev, ref_name, num_rev);
+       if (!sha1_name && !no_name)
+               name_commits(seen, rev, ref_name, num_rev);
 
        all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
        all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
@@ -490,7 +510,6 @@ int main(int ac, char **av)
                struct commit *commit = pop_one_commit(&seen);
                int this_flag = commit->object.flags;
                int is_merge_point = (this_flag & all_revs) == all_revs;
-               static char *obvious[] = { "" };
 
                if (is_merge_point)
                        shown_merge_point = 1;
@@ -501,9 +520,7 @@ int main(int ac, char **av)
                                        ? '+' : ' ');
                        putchar(' ');
                }
-               show_one_commit(commit);
-               if (num_rev == 1)
-                       label = obvious;
+               show_one_commit(commit, no_name);
                if (shown_merge_point && is_merge_point)
                        if (--extra < 0)
                                break;