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authorJunio C Hamano <junkio@cox.net>2005-08-21 09:51:10 (GMT)
committerJunio C Hamano <junkio@cox.net>2005-08-23 01:34:10 (GMT)
commitf76412ed6dbf2f9863115ee38f4198368dbaf7b1 (patch)
tree49eb364c591e842ff81e206911cb96d4e566ee2b /show-branch.c
parent4f7599ac2543e1d59f2b2b865ecff272ae5f4ea5 (diff)
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[PATCH] Add 'git show-branch'.
The 'git show-branches' command turns out to be reasonably useful, but painfully slow. So rewrite it in C, using ideas from merge-base while enhancing it a bit more. - Unlike show-branches, it can take --heads (show me all my heads), --tags (show me all my tags), or --all (both). - It can take --more=<number> to show beyond the merge-base. - It shows the short name for each commit in the extended SHA1 syntax. - It can find merge-base for more than two heads. Examples: $ git show-branch --more=6 HEAD is almost the same as "git log --pretty=oneline --max-count=6". $ git show-branch --merge-base master mhf misc finds the merge base of the three given heads. $ git show-branch master mhf misc shows logs from the top of these three branch heads, up to their common ancestor commit is shown. $ git show-branch --all --more=10 is poor-man's gitk, showing all the tags and heads, and going back 10 commits beyond the merge base of those refs. Signed-off-by: Junio C Hamano <junkio@cox.net>
Diffstat (limited to 'show-branch.c')
-rw-r--r--show-branch.c325
1 files changed, 325 insertions, 0 deletions
diff --git a/show-branch.c b/show-branch.c
new file mode 100644
index 0000000..c9a6fce
--- /dev/null
+++ b/show-branch.c
@@ -0,0 +1,325 @@
+#include <stdlib.h>
+#include "cache.h"
+#include "commit.h"
+#include "refs.h"
+
+static const char show_branch_usage[] =
+"git-show-branch [--all] [--heads] [--tags] [--more=count] [<refs>...]";
+
+#define UNINTERESTING 01
+
+#define REV_SHIFT 2
+#define MAX_REVS 29 /* should not exceed bits_per_int - REV_SHIFT */
+
+static struct commit *interesting(struct commit_list *list)
+{
+ while (list) {
+ struct commit *commit = list->item;
+ list = list->next;
+ if (commit->object.flags & UNINTERESTING)
+ continue;
+ return commit;
+ }
+ return NULL;
+}
+
+static struct commit *pop_one_commit(struct commit_list **list_p)
+{
+ struct commit *commit;
+ struct commit_list *list;
+ list = *list_p;
+ commit = list->item;
+ *list_p = list->next;
+ free(list);
+ return commit;
+}
+
+struct commit_name {
+ int head_rev; /* which head's ancestor? */
+ int generation; /* how many parents away from head_rev */
+};
+
+/* Name the commit as nth generation ancestor of head_rev;
+ * we count only the first-parent relationship for naming purposes.
+ */
+static void name_commit(struct commit *commit, int head_rev, int nth)
+{
+ struct commit_name *name;
+ if (!commit->object.util)
+ commit->object.util = xmalloc(sizeof(struct commit_name));
+ name = commit->object.util;
+ name->head_rev = head_rev;
+ name->generation = nth;
+}
+
+/* Parent is the first parent of the commit. We may name it
+ * as (n+1)th generation ancestor of the same head_rev as
+ * commit is nth generation ancestore of, if that generation
+ * number is better than the name it already has.
+ */
+static void name_parent(struct commit *commit, struct commit *parent)
+{
+ struct commit_name *commit_name = commit->object.util;
+ struct commit_name *parent_name = parent->object.util;
+ if (!commit_name)
+ return;
+ if (!parent_name ||
+ commit_name->generation + 1 < parent_name->generation)
+ name_commit(parent, commit_name->head_rev,
+ commit_name->generation + 1);
+}
+
+static int mark_seen(struct commit *commit, struct commit_list **seen_p)
+{
+ if (!commit->object.flags) {
+ insert_by_date(commit, seen_p);
+ return 1;
+ }
+ return 0;
+}
+
+static void join_revs(struct commit_list **list_p,
+ struct commit_list **seen_p,
+ int num_rev, int extra)
+{
+ int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
+ int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
+
+ while (*list_p) {
+ struct commit_list *parents;
+ struct commit *commit = pop_one_commit(list_p);
+ int flags = commit->object.flags & all_mask;
+ int nth_parent = 0;
+ int still_interesting = !!interesting(*list_p);
+
+ if (!still_interesting && extra < 0)
+ break;
+
+ mark_seen(commit, seen_p);
+ if ((flags & all_revs) == all_revs)
+ flags |= UNINTERESTING;
+ parents = commit->parents;
+
+ while (parents) {
+ struct commit *p = parents->item;
+ int this_flag = p->object.flags;
+ parents = parents->next;
+ nth_parent++;
+ if (nth_parent == 1)
+ name_parent(commit, p);
+
+ if ((this_flag & flags) == flags)
+ continue;
+ parse_commit(p);
+ if (mark_seen(p, seen_p) && !still_interesting)
+ extra--;
+ p->object.flags |= flags;
+ insert_by_date(p, list_p);
+ }
+ }
+}
+
+static void show_one_commit(struct commit *commit, char **head_name)
+{
+ char pretty[128], *cp;
+ struct commit_name *name = commit->object.util;
+ pretty_print_commit(CMIT_FMT_ONELINE, commit->buffer, ~0,
+ pretty, sizeof(pretty));
+ if (!strncmp(pretty, "[PATCH] ", 8))
+ cp = pretty + 8;
+ else
+ cp = pretty;
+ if (name && head_name) {
+ printf("[%s", head_name[name->head_rev]);
+ if (name->generation)
+ printf("~%d", name->generation);
+ printf("] ");
+ }
+ puts(cp);
+}
+
+static char *ref_name[MAX_REVS + 1];
+static int ref_name_cnt;
+
+static int append_ref(const char *refname, const unsigned char *sha1)
+{
+ struct commit *commit = lookup_commit_reference_gently(sha1, 1);
+ if (!commit)
+ return 0;
+ if (MAX_REVS < ref_name_cnt) {
+ fprintf(stderr, "warning: ignoring %s; "
+ "cannot handle more than %d refs",
+ refname, MAX_REVS);
+ return 0;
+ }
+ ref_name[ref_name_cnt++] = strdup(refname);
+ ref_name[ref_name_cnt] = NULL;
+ return 0;
+}
+
+static int append_head_ref(const char *refname, const unsigned char *sha1)
+{
+ if (strncmp(refname, "refs/heads/", 11))
+ return 0;
+ return append_ref(refname + 5, sha1);
+}
+
+static int append_tag_ref(const char *refname, const unsigned char *sha1)
+{
+ if (strncmp(refname, "refs/tags/", 10))
+ return 0;
+ return append_ref(refname + 5, sha1);
+}
+
+static void snarf_refs(int head, int tag)
+{
+ if (head)
+ for_each_ref(append_head_ref);
+ if (tag)
+ for_each_ref(append_tag_ref);
+}
+
+static int rev_is_head(char *head_path, int headlen,
+ char *name,
+ unsigned char *head_sha1, unsigned char *sha1)
+{
+ int namelen;
+ if ((!head_path[0]) || memcmp(head_sha1, sha1, 20))
+ return 0;
+ namelen = strlen(name);
+ if ((headlen < namelen) ||
+ memcmp(head_path + headlen - namelen, name, namelen))
+ return 0;
+ if (headlen == namelen ||
+ head_path[headlen - namelen - 1] == '/')
+ return 1;
+ return 0;
+}
+
+static int show_merge_base(struct commit_list *seen, int num_rev)
+{
+ int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
+ int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
+
+ while (seen) {
+ struct commit *commit = pop_one_commit(&seen);
+ int flags = commit->object.flags & all_mask;
+ if (!(flags & UNINTERESTING) &&
+ ((flags & all_revs) == all_revs)) {
+ puts(sha1_to_hex(commit->object.sha1));
+ return 0;
+ }
+ }
+ return 1;
+}
+
+int main(int ac, char **av)
+{
+ struct commit *rev[MAX_REVS], *commit;
+ struct commit_list *list = NULL, *seen = NULL;
+ int num_rev, i, extra = 0;
+ int all_heads = 0, all_tags = 0;
+ char head_path[128];
+ int head_path_len;
+ unsigned char head_sha1[20];
+ int merge_base = 0;
+
+ while (1 < ac && av[1][0] == '-') {
+ char *arg = av[1];
+ if (!strcmp(arg, "--all"))
+ all_heads = all_tags = 1;
+ else if (!strcmp(arg, "--heads"))
+ all_heads = 1;
+ else if (!strcmp(arg, "--tags"))
+ all_tags = 1;
+ else if (!strcmp(arg, "--more"))
+ extra = 1;
+ else if (!strncmp(arg, "--more=", 7)) {
+ extra = atoi(arg + 7);
+ if (extra < 0)
+ usage(show_branch_usage);
+ }
+ else if (!strcmp(arg, "--merge-base"))
+ merge_base = 1;
+ else
+ usage(show_branch_usage);
+ ac--; av++;
+ }
+ ac--; av++;
+
+ if (all_heads + all_tags)
+ snarf_refs(all_heads, all_tags);
+
+ while (0 < ac) {
+ unsigned char revkey[20];
+ if (get_sha1(*av, revkey))
+ die("bad sha1 reference %s", *av);
+ append_ref(*av, revkey);
+ ac--; av++;
+ }
+
+ /* If still no revs, then add heads */
+ if (!ref_name_cnt)
+ snarf_refs(1, 0);
+
+ for (num_rev = 0; ref_name[num_rev]; num_rev++) {
+ unsigned char revkey[20];
+
+ if (MAX_REVS <= num_rev)
+ die("cannot handle more than %d revs.", MAX_REVS);
+ if (get_sha1(ref_name[num_rev], revkey))
+ usage(show_branch_usage);
+ commit = lookup_commit_reference(revkey);
+ if (!commit)
+ die("cannot find commit %s (%s)",
+ ref_name[num_rev], revkey);
+ parse_commit(commit);
+ if (!commit->object.util)
+ name_commit(commit, num_rev, 0);
+ mark_seen(commit, &seen);
+
+ /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
+ * and so on. REV_SHIFT bits from bit 0 are used for
+ * internal bookkeeping.
+ */
+ commit->object.flags |= 1u << (num_rev + REV_SHIFT);
+ insert_by_date(commit, &list);
+ rev[num_rev] = commit;
+ }
+ join_revs(&list, &seen, num_rev, extra);
+
+ head_path_len = readlink(".git/HEAD", head_path, sizeof(head_path)-1);
+ if ((head_path_len < 0) || get_sha1("HEAD", head_sha1))
+ head_path[0] = 0;
+ else
+ head_path[head_path_len] = 0;
+
+ if (merge_base)
+ return show_merge_base(seen, num_rev);
+
+ if (1 < num_rev)
+ for (i = 0; i < num_rev; i++) {
+ int j;
+ int is_head = rev_is_head(head_path,
+ head_path_len,
+ ref_name[i],
+ head_sha1,
+ rev[i]->object.sha1);
+ for (j = 0; j < i; j++)
+ putchar(' ');
+ printf("%c [%s] ", is_head ? '*' : '!', ref_name[i]);
+ show_one_commit(rev[i], NULL);
+ }
+ while (seen) {
+ struct commit *commit = pop_one_commit(&seen);
+ int this_flag = commit->object.flags;
+ if ((this_flag & UNINTERESTING) && (--extra < 0))
+ break;
+ for (i = 0; i < num_rev; i++)
+ putchar((this_flag & (1u << (i + REV_SHIFT)))
+ ? '+' : ' ');
+ putchar(' ');
+ show_one_commit(commit, ref_name);
+ }
+ return 0;
+}