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git/builtin/tag.c
Jeff King ffc4b8012d tag: speed up --contains calculation
When we want to know if commit A contains commit B (or any
one of a set of commits, B through Z), we generally
calculate the merge bases and see if B is a merge base of A
(or for a set, if any of the commits B through Z have that
property).

When we are going to check a series of commits A1 through An
to see whether each contains B (e.g., because we are
deciding which tags to show with "git tag --contains"), we
do a series of merge base calculations. This can be very
expensive, as we repeat a lot of traversal work.

Instead, let's leverage the fact that we are going to use
the same --contains list for each tag, and mark areas of the
commit graph is definitely containing those commits, or
definitely not containing those commits. Later tags can then
stop traversing as soon as they see a previously calculated
answer.

This sped up "git tag --contains HEAD~200" in the linux-2.6
repository from:

  real    0m15.417s
  user    0m15.197s
  sys     0m0.220s

to:

  real    0m5.329s
  user    0m5.144s
  sys     0m0.184s

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-06-11 22:32:25 -07:00

532 lines
12 KiB
C

/*
* Builtin "git tag"
*
* Copyright (c) 2007 Kristian Høgsberg <krh@redhat.com>,
* Carlos Rica <jasampler@gmail.com>
* Based on git-tag.sh and mktag.c by Linus Torvalds.
*/
#include "cache.h"
#include "builtin.h"
#include "refs.h"
#include "tag.h"
#include "run-command.h"
#include "parse-options.h"
#include "diff.h"
#include "revision.h"
static const char * const git_tag_usage[] = {
"git tag [-a|-s|-u <key-id>] [-f] [-m <msg>|-F <file>] <tagname> [<head>]",
"git tag -d <tagname>...",
"git tag -l [-n[<num>]] [<pattern>]",
"git tag -v <tagname>...",
NULL
};
static char signingkey[1000];
struct tag_filter {
const char *pattern;
int lines;
struct commit_list *with_commit;
};
#define PGP_SIGNATURE "-----BEGIN PGP SIGNATURE-----"
static int in_commit_list(const struct commit_list *want, struct commit *c)
{
for (; want; want = want->next)
if (!hashcmp(want->item->object.sha1, c->object.sha1))
return 1;
return 0;
}
static int contains_recurse(struct commit *candidate,
const struct commit_list *want)
{
struct commit_list *p;
/* was it previously marked as containing a want commit? */
if (candidate->object.flags & TMP_MARK)
return 1;
/* or marked as not possibly containing a want commit? */
if (candidate->object.flags & UNINTERESTING)
return 0;
/* or are we it? */
if (in_commit_list(want, candidate))
return 1;
if (parse_commit(candidate) < 0)
return 0;
/* Otherwise recurse and mark ourselves for future traversals. */
for (p = candidate->parents; p; p = p->next) {
if (contains_recurse(p->item, want)) {
candidate->object.flags |= TMP_MARK;
return 1;
}
}
candidate->object.flags |= UNINTERESTING;
return 0;
}
static int contains(struct commit *candidate, const struct commit_list *want)
{
return contains_recurse(candidate, want);
}
static int show_reference(const char *refname, const unsigned char *sha1,
int flag, void *cb_data)
{
struct tag_filter *filter = cb_data;
if (!fnmatch(filter->pattern, refname, 0)) {
int i;
unsigned long size;
enum object_type type;
char *buf, *sp, *eol;
size_t len;
if (filter->with_commit) {
struct commit *commit;
commit = lookup_commit_reference_gently(sha1, 1);
if (!commit)
return 0;
if (!contains(commit, filter->with_commit))
return 0;
}
if (!filter->lines) {
printf("%s\n", refname);
return 0;
}
printf("%-15s ", refname);
buf = read_sha1_file(sha1, &type, &size);
if (!buf || !size)
return 0;
/* skip header */
sp = strstr(buf, "\n\n");
if (!sp) {
free(buf);
return 0;
}
/* only take up to "lines" lines, and strip the signature */
for (i = 0, sp += 2;
i < filter->lines && sp < buf + size &&
prefixcmp(sp, PGP_SIGNATURE "\n");
i++) {
if (i)
printf("\n ");
eol = memchr(sp, '\n', size - (sp - buf));
len = eol ? eol - sp : size - (sp - buf);
fwrite(sp, len, 1, stdout);
if (!eol)
break;
sp = eol + 1;
}
putchar('\n');
free(buf);
}
return 0;
}
static int list_tags(const char *pattern, int lines,
struct commit_list *with_commit)
{
struct tag_filter filter;
if (pattern == NULL)
pattern = "*";
filter.pattern = pattern;
filter.lines = lines;
filter.with_commit = with_commit;
for_each_tag_ref(show_reference, (void *) &filter);
return 0;
}
typedef int (*each_tag_name_fn)(const char *name, const char *ref,
const unsigned char *sha1);
static int for_each_tag_name(const char **argv, each_tag_name_fn fn)
{
const char **p;
char ref[PATH_MAX];
int had_error = 0;
unsigned char sha1[20];
for (p = argv; *p; p++) {
if (snprintf(ref, sizeof(ref), "refs/tags/%s", *p)
>= sizeof(ref)) {
error("tag name too long: %.*s...", 50, *p);
had_error = 1;
continue;
}
if (!resolve_ref(ref, sha1, 1, NULL)) {
error("tag '%s' not found.", *p);
had_error = 1;
continue;
}
if (fn(*p, ref, sha1))
had_error = 1;
}
return had_error;
}
static int delete_tag(const char *name, const char *ref,
const unsigned char *sha1)
{
if (delete_ref(ref, sha1, 0))
return 1;
printf("Deleted tag '%s' (was %s)\n", name, find_unique_abbrev(sha1, DEFAULT_ABBREV));
return 0;
}
static int verify_tag(const char *name, const char *ref,
const unsigned char *sha1)
{
const char *argv_verify_tag[] = {"verify-tag",
"-v", "SHA1_HEX", NULL};
argv_verify_tag[2] = sha1_to_hex(sha1);
if (run_command_v_opt(argv_verify_tag, RUN_GIT_CMD))
return error("could not verify the tag '%s'", name);
return 0;
}
static int do_sign(struct strbuf *buffer)
{
struct child_process gpg;
const char *args[4];
char *bracket;
int len;
int i, j;
if (!*signingkey) {
if (strlcpy(signingkey, git_committer_info(IDENT_ERROR_ON_NO_NAME),
sizeof(signingkey)) > sizeof(signingkey) - 1)
return error("committer info too long.");
bracket = strchr(signingkey, '>');
if (bracket)
bracket[1] = '\0';
}
/* When the username signingkey is bad, program could be terminated
* because gpg exits without reading and then write gets SIGPIPE. */
signal(SIGPIPE, SIG_IGN);
memset(&gpg, 0, sizeof(gpg));
gpg.argv = args;
gpg.in = -1;
gpg.out = -1;
args[0] = "gpg";
args[1] = "-bsau";
args[2] = signingkey;
args[3] = NULL;
if (start_command(&gpg))
return error("could not run gpg.");
if (write_in_full(gpg.in, buffer->buf, buffer->len) != buffer->len) {
close(gpg.in);
close(gpg.out);
finish_command(&gpg);
return error("gpg did not accept the tag data");
}
close(gpg.in);
len = strbuf_read(buffer, gpg.out, 1024);
close(gpg.out);
if (finish_command(&gpg) || !len || len < 0)
return error("gpg failed to sign the tag");
/* Strip CR from the line endings, in case we are on Windows. */
for (i = j = 0; i < buffer->len; i++)
if (buffer->buf[i] != '\r') {
if (i != j)
buffer->buf[j] = buffer->buf[i];
j++;
}
strbuf_setlen(buffer, j);
return 0;
}
static const char tag_template[] =
"\n"
"#\n"
"# Write a tag message\n"
"#\n";
static void set_signingkey(const char *value)
{
if (strlcpy(signingkey, value, sizeof(signingkey)) >= sizeof(signingkey))
die("signing key value too long (%.10s...)", value);
}
static int git_tag_config(const char *var, const char *value, void *cb)
{
if (!strcmp(var, "user.signingkey")) {
if (!value)
return config_error_nonbool(var);
set_signingkey(value);
return 0;
}
return git_default_config(var, value, cb);
}
static void write_tag_body(int fd, const unsigned char *sha1)
{
unsigned long size;
enum object_type type;
char *buf, *sp, *eob;
size_t len;
buf = read_sha1_file(sha1, &type, &size);
if (!buf)
return;
/* skip header */
sp = strstr(buf, "\n\n");
if (!sp || !size || type != OBJ_TAG) {
free(buf);
return;
}
sp += 2; /* skip the 2 LFs */
eob = strstr(sp, "\n" PGP_SIGNATURE "\n");
if (eob)
len = eob - sp;
else
len = buf + size - sp;
write_or_die(fd, sp, len);
free(buf);
}
static int build_tag_object(struct strbuf *buf, int sign, unsigned char *result)
{
if (sign && do_sign(buf) < 0)
return error("unable to sign the tag");
if (write_sha1_file(buf->buf, buf->len, tag_type, result) < 0)
return error("unable to write tag file");
return 0;
}
static void create_tag(const unsigned char *object, const char *tag,
struct strbuf *buf, int message, int sign,
unsigned char *prev, unsigned char *result)
{
enum object_type type;
char header_buf[1024];
int header_len;
char *path = NULL;
type = sha1_object_info(object, NULL);
if (type <= OBJ_NONE)
die("bad object type.");
header_len = snprintf(header_buf, sizeof(header_buf),
"object %s\n"
"type %s\n"
"tag %s\n"
"tagger %s\n\n",
sha1_to_hex(object),
typename(type),
tag,
git_committer_info(IDENT_ERROR_ON_NO_NAME));
if (header_len > sizeof(header_buf) - 1)
die("tag header too big.");
if (!message) {
int fd;
/* write the template message before editing: */
path = git_pathdup("TAG_EDITMSG");
fd = open(path, O_CREAT | O_TRUNC | O_WRONLY, 0600);
if (fd < 0)
die_errno("could not create file '%s'", path);
if (!is_null_sha1(prev))
write_tag_body(fd, prev);
else
write_or_die(fd, tag_template, strlen(tag_template));
close(fd);
if (launch_editor(path, buf, NULL)) {
fprintf(stderr,
"Please supply the message using either -m or -F option.\n");
exit(1);
}
}
stripspace(buf, 1);
if (!message && !buf->len)
die("no tag message?");
strbuf_insert(buf, 0, header_buf, header_len);
if (build_tag_object(buf, sign, result) < 0) {
if (path)
fprintf(stderr, "The tag message has been left in %s\n",
path);
exit(128);
}
if (path) {
unlink_or_warn(path);
free(path);
}
}
struct msg_arg {
int given;
struct strbuf buf;
};
static int parse_msg_arg(const struct option *opt, const char *arg, int unset)
{
struct msg_arg *msg = opt->value;
if (!arg)
return -1;
if (msg->buf.len)
strbuf_addstr(&(msg->buf), "\n\n");
strbuf_addstr(&(msg->buf), arg);
msg->given = 1;
return 0;
}
int cmd_tag(int argc, const char **argv, const char *prefix)
{
struct strbuf buf = STRBUF_INIT;
unsigned char object[20], prev[20];
char ref[PATH_MAX];
const char *object_ref, *tag;
struct ref_lock *lock;
int annotate = 0, sign = 0, force = 0, lines = -1,
list = 0, delete = 0, verify = 0;
const char *msgfile = NULL, *keyid = NULL;
struct msg_arg msg = { 0, STRBUF_INIT };
struct commit_list *with_commit = NULL;
struct option options[] = {
OPT_BOOLEAN('l', NULL, &list, "list tag names"),
{ OPTION_INTEGER, 'n', NULL, &lines, "n",
"print <n> lines of each tag message",
PARSE_OPT_OPTARG, NULL, 1 },
OPT_BOOLEAN('d', NULL, &delete, "delete tags"),
OPT_BOOLEAN('v', NULL, &verify, "verify tags"),
OPT_GROUP("Tag creation options"),
OPT_BOOLEAN('a', NULL, &annotate,
"annotated tag, needs a message"),
OPT_CALLBACK('m', NULL, &msg, "msg",
"message for the tag", parse_msg_arg),
OPT_FILENAME('F', NULL, &msgfile, "message in a file"),
OPT_BOOLEAN('s', NULL, &sign, "annotated and GPG-signed tag"),
OPT_STRING('u', NULL, &keyid, "key-id",
"use another key to sign the tag"),
OPT_BOOLEAN('f', "force", &force, "replace the tag if exists"),
OPT_GROUP("Tag listing options"),
{
OPTION_CALLBACK, 0, "contains", &with_commit, "commit",
"print only tags that contain the commit",
PARSE_OPT_LASTARG_DEFAULT,
parse_opt_with_commit, (intptr_t)"HEAD",
},
OPT_END()
};
git_config(git_tag_config, NULL);
argc = parse_options(argc, argv, prefix, options, git_tag_usage, 0);
if (keyid) {
sign = 1;
set_signingkey(keyid);
}
if (sign)
annotate = 1;
if (argc == 0 && !(delete || verify))
list = 1;
if ((annotate || msg.given || msgfile || force) &&
(list || delete || verify))
usage_with_options(git_tag_usage, options);
if (list + delete + verify > 1)
usage_with_options(git_tag_usage, options);
if (list)
return list_tags(argv[0], lines == -1 ? 0 : lines,
with_commit);
if (lines != -1)
die("-n option is only allowed with -l.");
if (with_commit)
die("--contains option is only allowed with -l.");
if (delete)
return for_each_tag_name(argv, delete_tag);
if (verify)
return for_each_tag_name(argv, verify_tag);
if (msg.given || msgfile) {
if (msg.given && msgfile)
die("only one -F or -m option is allowed.");
annotate = 1;
if (msg.given)
strbuf_addbuf(&buf, &(msg.buf));
else {
if (!strcmp(msgfile, "-")) {
if (strbuf_read(&buf, 0, 1024) < 0)
die_errno("cannot read '%s'", msgfile);
} else {
if (strbuf_read_file(&buf, msgfile, 1024) < 0)
die_errno("could not open or read '%s'",
msgfile);
}
}
}
tag = argv[0];
object_ref = argc == 2 ? argv[1] : "HEAD";
if (argc > 2)
die("too many params");
if (get_sha1(object_ref, object))
die("Failed to resolve '%s' as a valid ref.", object_ref);
if (snprintf(ref, sizeof(ref), "refs/tags/%s", tag) > sizeof(ref) - 1)
die("tag name too long: %.*s...", 50, tag);
if (check_ref_format(ref))
die("'%s' is not a valid tag name.", tag);
if (!resolve_ref(ref, prev, 1, NULL))
hashclr(prev);
else if (!force)
die("tag '%s' already exists", tag);
if (annotate)
create_tag(object, tag, &buf, msg.given || msgfile,
sign, prev, object);
lock = lock_any_ref_for_update(ref, prev, 0);
if (!lock)
die("%s: cannot lock the ref", ref);
if (write_ref_sha1(lock, object, NULL) < 0)
die("%s: cannot update the ref", ref);
if (force && hashcmp(prev, object))
printf("Updated tag '%s' (was %s)\n", tag, find_unique_abbrev(prev, DEFAULT_ABBREV));
strbuf_release(&buf);
return 0;
}