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-rw-r--r--fetch-pack.c789
1 files changed, 789 insertions, 0 deletions
diff --git a/fetch-pack.c b/fetch-pack.c
new file mode 100644
index 0000000000..06f4aeced4
--- /dev/null
+++ b/fetch-pack.c
@@ -0,0 +1,789 @@
+#include "cache.h"
+#include "refs.h"
+#include "pkt-line.h"
+#include "commit.h"
+#include "tag.h"
+#include "exec_cmd.h"
+#include "pack.h"
+#include "sideband.h"
+
+static int keep_pack;
+static int transfer_unpack_limit = -1;
+static int fetch_unpack_limit = -1;
+static int unpack_limit = 100;
+static int quiet;
+static int verbose;
+static int fetch_all;
+static int depth;
+static int no_progress;
+static const char fetch_pack_usage[] =
+"git-fetch-pack [--all] [--quiet|-q] [--keep|-k] [--thin] [--upload-pack=<git-upload-pack>] [--depth=<n>] [--no-progress] [-v] [<host>:]<directory> [<refs>...]";
+static const char *uploadpack = "git-upload-pack";
+
+#define COMPLETE (1U << 0)
+#define COMMON (1U << 1)
+#define COMMON_REF (1U << 2)
+#define SEEN (1U << 3)
+#define POPPED (1U << 4)
+
+/*
+ * After sending this many "have"s if we do not get any new ACK , we
+ * give up traversing our history.
+ */
+#define MAX_IN_VAIN 256
+
+static struct commit_list *rev_list;
+static int non_common_revs, multi_ack, use_thin_pack, use_sideband;
+
+static void rev_list_push(struct commit *commit, int mark)
+{
+ if (!(commit->object.flags & mark)) {
+ commit->object.flags |= mark;
+
+ if (!(commit->object.parsed))
+ parse_commit(commit);
+
+ insert_by_date(commit, &rev_list);
+
+ if (!(commit->object.flags & COMMON))
+ non_common_revs++;
+ }
+}
+
+static int rev_list_insert_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
+{
+ struct object *o = deref_tag(parse_object(sha1), path, 0);
+
+ if (o && o->type == OBJ_COMMIT)
+ rev_list_push((struct commit *)o, SEEN);
+
+ return 0;
+}
+
+/*
+ This function marks a rev and its ancestors as common.
+ In some cases, it is desirable to mark only the ancestors (for example
+ when only the server does not yet know that they are common).
+*/
+
+static void mark_common(struct commit *commit,
+ int ancestors_only, int dont_parse)
+{
+ if (commit != NULL && !(commit->object.flags & COMMON)) {
+ struct object *o = (struct object *)commit;
+
+ if (!ancestors_only)
+ o->flags |= COMMON;
+
+ if (!(o->flags & SEEN))
+ rev_list_push(commit, SEEN);
+ else {
+ struct commit_list *parents;
+
+ if (!ancestors_only && !(o->flags & POPPED))
+ non_common_revs--;
+ if (!o->parsed && !dont_parse)
+ parse_commit(commit);
+
+ for (parents = commit->parents;
+ parents;
+ parents = parents->next)
+ mark_common(parents->item, 0, dont_parse);
+ }
+ }
+}
+
+/*
+ Get the next rev to send, ignoring the common.
+*/
+
+static const unsigned char* get_rev(void)
+{
+ struct commit *commit = NULL;
+
+ while (commit == NULL) {
+ unsigned int mark;
+ struct commit_list* parents;
+
+ if (rev_list == NULL || non_common_revs == 0)
+ return NULL;
+
+ commit = rev_list->item;
+ if (!(commit->object.parsed))
+ parse_commit(commit);
+ commit->object.flags |= POPPED;
+ if (!(commit->object.flags & COMMON))
+ non_common_revs--;
+
+ parents = commit->parents;
+
+ if (commit->object.flags & COMMON) {
+ /* do not send "have", and ignore ancestors */
+ commit = NULL;
+ mark = COMMON | SEEN;
+ } else if (commit->object.flags & COMMON_REF)
+ /* send "have", and ignore ancestors */
+ mark = COMMON | SEEN;
+ else
+ /* send "have", also for its ancestors */
+ mark = SEEN;
+
+ while (parents) {
+ if (!(parents->item->object.flags & SEEN))
+ rev_list_push(parents->item, mark);
+ if (mark & COMMON)
+ mark_common(parents->item, 1, 0);
+ parents = parents->next;
+ }
+
+ rev_list = rev_list->next;
+ }
+
+ return commit->object.sha1;
+}
+
+static int find_common(int fd[2], unsigned char *result_sha1,
+ struct ref *refs)
+{
+ int fetching;
+ int count = 0, flushes = 0, retval;
+ const unsigned char *sha1;
+ unsigned in_vain = 0;
+ int got_continue = 0;
+
+ for_each_ref(rev_list_insert_ref, NULL);
+
+ fetching = 0;
+ for ( ; refs ; refs = refs->next) {
+ unsigned char *remote = refs->old_sha1;
+ struct object *o;
+
+ /*
+ * If that object is complete (i.e. it is an ancestor of a
+ * local ref), we tell them we have it but do not have to
+ * tell them about its ancestors, which they already know
+ * about.
+ *
+ * We use lookup_object here because we are only
+ * interested in the case we *know* the object is
+ * reachable and we have already scanned it.
+ */
+ if (((o = lookup_object(remote)) != NULL) &&
+ (o->flags & COMPLETE)) {
+ continue;
+ }
+
+ if (!fetching)
+ packet_write(fd[1], "want %s%s%s%s%s%s%s\n",
+ sha1_to_hex(remote),
+ (multi_ack ? " multi_ack" : ""),
+ (use_sideband == 2 ? " side-band-64k" : ""),
+ (use_sideband == 1 ? " side-band" : ""),
+ (use_thin_pack ? " thin-pack" : ""),
+ (no_progress ? " no-progress" : ""),
+ " ofs-delta");
+ else
+ packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
+ fetching++;
+ }
+ if (is_repository_shallow())
+ write_shallow_commits(fd[1], 1);
+ if (depth > 0)
+ packet_write(fd[1], "deepen %d", depth);
+ packet_flush(fd[1]);
+ if (!fetching)
+ return 1;
+
+ if (depth > 0) {
+ char line[1024];
+ unsigned char sha1[20];
+ int len;
+
+ while ((len = packet_read_line(fd[0], line, sizeof(line)))) {
+ if (!prefixcmp(line, "shallow ")) {
+ if (get_sha1_hex(line + 8, sha1))
+ die("invalid shallow line: %s", line);
+ register_shallow(sha1);
+ continue;
+ }
+ if (!prefixcmp(line, "unshallow ")) {
+ if (get_sha1_hex(line + 10, sha1))
+ die("invalid unshallow line: %s", line);
+ if (!lookup_object(sha1))
+ die("object not found: %s", line);
+ /* make sure that it is parsed as shallow */
+ parse_object(sha1);
+ if (unregister_shallow(sha1))
+ die("no shallow found: %s", line);
+ continue;
+ }
+ die("expected shallow/unshallow, got %s", line);
+ }
+ }
+
+ flushes = 0;
+ retval = -1;
+ while ((sha1 = get_rev())) {
+ packet_write(fd[1], "have %s\n", sha1_to_hex(sha1));
+ if (verbose)
+ fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
+ in_vain++;
+ if (!(31 & ++count)) {
+ int ack;
+
+ packet_flush(fd[1]);
+ flushes++;
+
+ /*
+ * We keep one window "ahead" of the other side, and
+ * will wait for an ACK only on the next one
+ */
+ if (count == 32)
+ continue;
+
+ do {
+ ack = get_ack(fd[0], result_sha1);
+ if (verbose && ack)
+ fprintf(stderr, "got ack %d %s\n", ack,
+ sha1_to_hex(result_sha1));
+ if (ack == 1) {
+ flushes = 0;
+ multi_ack = 0;
+ retval = 0;
+ goto done;
+ } else if (ack == 2) {
+ struct commit *commit =
+ lookup_commit(result_sha1);
+ mark_common(commit, 0, 1);
+ retval = 0;
+ in_vain = 0;
+ got_continue = 1;
+ }
+ } while (ack);
+ flushes--;
+ if (got_continue && MAX_IN_VAIN < in_vain) {
+ if (verbose)
+ fprintf(stderr, "giving up\n");
+ break; /* give up */
+ }
+ }
+ }
+done:
+ packet_write(fd[1], "done\n");
+ if (verbose)
+ fprintf(stderr, "done\n");
+ if (retval != 0) {
+ multi_ack = 0;
+ flushes++;
+ }
+ while (flushes || multi_ack) {
+ int ack = get_ack(fd[0], result_sha1);
+ if (ack) {
+ if (verbose)
+ fprintf(stderr, "got ack (%d) %s\n", ack,
+ sha1_to_hex(result_sha1));
+ if (ack == 1)
+ return 0;
+ multi_ack = 1;
+ continue;
+ }
+ flushes--;
+ }
+ return retval;
+}
+
+static struct commit_list *complete;
+
+static int mark_complete(const char *path, const unsigned char *sha1, int flag, void *cb_data)
+{
+ struct object *o = parse_object(sha1);
+
+ while (o && o->type == OBJ_TAG) {
+ struct tag *t = (struct tag *) o;
+ if (!t->tagged)
+ break; /* broken repository */
+ o->flags |= COMPLETE;
+ o = parse_object(t->tagged->sha1);
+ }
+ if (o && o->type == OBJ_COMMIT) {
+ struct commit *commit = (struct commit *)o;
+ commit->object.flags |= COMPLETE;
+ insert_by_date(commit, &complete);
+ }
+ return 0;
+}
+
+static void mark_recent_complete_commits(unsigned long cutoff)
+{
+ while (complete && cutoff <= complete->item->date) {
+ if (verbose)
+ fprintf(stderr, "Marking %s as complete\n",
+ sha1_to_hex(complete->item->object.sha1));
+ pop_most_recent_commit(&complete, COMPLETE);
+ }
+}
+
+static void filter_refs(struct ref **refs, int nr_match, char **match)
+{
+ struct ref **return_refs;
+ struct ref *newlist = NULL;
+ struct ref **newtail = &newlist;
+ struct ref *ref, *next;
+ struct ref *fastarray[32];
+
+ if (nr_match && !fetch_all) {
+ if (ARRAY_SIZE(fastarray) < nr_match)
+ return_refs = xcalloc(nr_match, sizeof(struct ref *));
+ else {
+ return_refs = fastarray;
+ memset(return_refs, 0, sizeof(struct ref *) * nr_match);
+ }
+ }
+ else
+ return_refs = NULL;
+
+ for (ref = *refs; ref; ref = next) {
+ next = ref->next;
+ if (!memcmp(ref->name, "refs/", 5) &&
+ check_ref_format(ref->name + 5))
+ ; /* trash */
+ else if (fetch_all &&
+ (!depth || prefixcmp(ref->name, "refs/tags/") )) {
+ *newtail = ref;
+ ref->next = NULL;
+ newtail = &ref->next;
+ continue;
+ }
+ else {
+ int order = path_match(ref->name, nr_match, match);
+ if (order) {
+ return_refs[order-1] = ref;
+ continue; /* we will link it later */
+ }
+ }
+ free(ref);
+ }
+
+ if (!fetch_all) {
+ int i;
+ for (i = 0; i < nr_match; i++) {
+ ref = return_refs[i];
+ if (ref) {
+ *newtail = ref;
+ ref->next = NULL;
+ newtail = &ref->next;
+ }
+ }
+ if (return_refs != fastarray)
+ free(return_refs);
+ }
+ *refs = newlist;
+}
+
+static int everything_local(struct ref **refs, int nr_match, char **match)
+{
+ struct ref *ref;
+ int retval;
+ unsigned long cutoff = 0;
+
+ track_object_refs = 0;
+ save_commit_buffer = 0;
+
+ for (ref = *refs; ref; ref = ref->next) {
+ struct object *o;
+
+ o = parse_object(ref->old_sha1);
+ if (!o)
+ continue;
+
+ /* We already have it -- which may mean that we were
+ * in sync with the other side at some time after
+ * that (it is OK if we guess wrong here).
+ */
+ if (o->type == OBJ_COMMIT) {
+ struct commit *commit = (struct commit *)o;
+ if (!cutoff || cutoff < commit->date)
+ cutoff = commit->date;
+ }
+ }
+
+ if (!depth) {
+ for_each_ref(mark_complete, NULL);
+ if (cutoff)
+ mark_recent_complete_commits(cutoff);
+ }
+
+ /*
+ * Mark all complete remote refs as common refs.
+ * Don't mark them common yet; the server has to be told so first.
+ */
+ for (ref = *refs; ref; ref = ref->next) {
+ struct object *o = deref_tag(lookup_object(ref->old_sha1),
+ NULL, 0);
+
+ if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
+ continue;
+
+ if (!(o->flags & SEEN)) {
+ rev_list_push((struct commit *)o, COMMON_REF | SEEN);
+
+ mark_common((struct commit *)o, 1, 1);
+ }
+ }
+
+ filter_refs(refs, nr_match, match);
+
+ for (retval = 1, ref = *refs; ref ; ref = ref->next) {
+ const unsigned char *remote = ref->old_sha1;
+ unsigned char local[20];
+ struct object *o;
+
+ o = lookup_object(remote);
+ if (!o || !(o->flags & COMPLETE)) {
+ retval = 0;
+ if (!verbose)
+ continue;
+ fprintf(stderr,
+ "want %s (%s)\n", sha1_to_hex(remote),
+ ref->name);
+ continue;
+ }
+
+ hashcpy(ref->new_sha1, local);
+ if (!verbose)
+ continue;
+ fprintf(stderr,
+ "already have %s (%s)\n", sha1_to_hex(remote),
+ ref->name);
+ }
+ return retval;
+}
+
+static pid_t setup_sideband(int fd[2], int xd[2])
+{
+ pid_t side_pid;
+
+ if (!use_sideband) {
+ fd[0] = xd[0];
+ fd[1] = xd[1];
+ return 0;
+ }
+ /* xd[] is talking with upload-pack; subprocess reads from
+ * xd[0], spits out band#2 to stderr, and feeds us band#1
+ * through our fd[0].
+ */
+ if (pipe(fd) < 0)
+ die("fetch-pack: unable to set up pipe");
+ side_pid = fork();
+ if (side_pid < 0)
+ die("fetch-pack: unable to fork off sideband demultiplexer");
+ if (!side_pid) {
+ /* subprocess */
+ close(fd[0]);
+ if (xd[0] != xd[1])
+ close(xd[1]);
+ if (recv_sideband("fetch-pack", xd[0], fd[1], 2))
+ exit(1);
+ exit(0);
+ }
+ close(xd[0]);
+ close(fd[1]);
+ fd[1] = xd[1];
+ return side_pid;
+}
+
+static int get_pack(int xd[2])
+{
+ int status;
+ pid_t pid, side_pid;
+ int fd[2];
+ const char *argv[20];
+ char keep_arg[256];
+ char hdr_arg[256];
+ const char **av;
+ int do_keep = keep_pack;
+
+ side_pid = setup_sideband(fd, xd);
+
+ av = argv;
+ *hdr_arg = 0;
+ if (unpack_limit) {
+ struct pack_header header;
+
+ if (read_pack_header(fd[0], &header))
+ die("protocol error: bad pack header");
+ snprintf(hdr_arg, sizeof(hdr_arg), "--pack_header=%u,%u",
+ ntohl(header.hdr_version), ntohl(header.hdr_entries));
+ if (ntohl(header.hdr_entries) < unpack_limit)
+ do_keep = 0;
+ else
+ do_keep = 1;
+ }
+
+ if (do_keep) {
+ *av++ = "index-pack";
+ *av++ = "--stdin";
+ if (!quiet && !no_progress)
+ *av++ = "-v";
+ if (use_thin_pack)
+ *av++ = "--fix-thin";
+ if (keep_pack > 1 || unpack_limit) {
+ int s = sprintf(keep_arg,
+ "--keep=fetch-pack %d on ", getpid());
+ if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
+ strcpy(keep_arg + s, "localhost");
+ *av++ = keep_arg;
+ }
+ }
+ else {
+ *av++ = "unpack-objects";
+ if (quiet)
+ *av++ = "-q";
+ }
+ if (*hdr_arg)
+ *av++ = hdr_arg;
+ *av++ = NULL;
+
+ pid = fork();
+ if (pid < 0)
+ die("fetch-pack: unable to fork off %s", argv[0]);
+ if (!pid) {
+ dup2(fd[0], 0);
+ close(fd[0]);
+ close(fd[1]);
+ execv_git_cmd(argv);
+ die("%s exec failed", argv[0]);
+ }
+ close(fd[0]);
+ close(fd[1]);
+ while (waitpid(pid, &status, 0) < 0) {
+ if (errno != EINTR)
+ die("waiting for %s: %s", argv[0], strerror(errno));
+ }
+ if (WIFEXITED(status)) {
+ int code = WEXITSTATUS(status);
+ if (code)
+ die("%s died with error code %d", argv[0], code);
+ return 0;
+ }
+ if (WIFSIGNALED(status)) {
+ int sig = WTERMSIG(status);
+ die("%s died of signal %d", argv[0], sig);
+ }
+ die("%s died of unnatural causes %d", argv[0], status);
+}
+
+static int fetch_pack(int fd[2], int nr_match, char **match)
+{
+ struct ref *ref;
+ unsigned char sha1[20];
+
+ get_remote_heads(fd[0], &ref, 0, NULL, 0);
+ if (is_repository_shallow() && !server_supports("shallow"))
+ die("Server does not support shallow clients");
+ if (server_supports("multi_ack")) {
+ if (verbose)
+ fprintf(stderr, "Server supports multi_ack\n");
+ multi_ack = 1;
+ }
+ if (server_supports("side-band-64k")) {
+ if (verbose)
+ fprintf(stderr, "Server supports side-band-64k\n");
+ use_sideband = 2;
+ }
+ else if (server_supports("side-band")) {
+ if (verbose)
+ fprintf(stderr, "Server supports side-band\n");
+ use_sideband = 1;
+ }
+ if (!ref) {
+ packet_flush(fd[1]);
+ die("no matching remote head");
+ }
+ if (everything_local(&ref, nr_match, match)) {
+ packet_flush(fd[1]);
+ goto all_done;
+ }
+ if (find_common(fd, sha1, ref) < 0)
+ if (keep_pack != 1)
+ /* When cloning, it is not unusual to have
+ * no common commit.
+ */
+ fprintf(stderr, "warning: no common commits\n");
+
+ if (get_pack(fd))
+ die("git-fetch-pack: fetch failed.");
+
+ all_done:
+ while (ref) {
+ printf("%s %s\n",
+ sha1_to_hex(ref->old_sha1), ref->name);
+ ref = ref->next;
+ }
+ return 0;
+}
+
+static int remove_duplicates(int nr_heads, char **heads)
+{
+ int src, dst;
+
+ for (src = dst = 0; src < nr_heads; src++) {
+ /* If heads[src] is different from any of
+ * heads[0..dst], push it in.
+ */
+ int i;
+ for (i = 0; i < dst; i++) {
+ if (!strcmp(heads[i], heads[src]))
+ break;
+ }
+ if (i < dst)
+ continue;
+ if (src != dst)
+ heads[dst] = heads[src];
+ dst++;
+ }
+ heads[dst] = 0;
+ return dst;
+}
+
+static int fetch_pack_config(const char *var, const char *value)
+{
+ if (strcmp(var, "fetch.unpacklimit") == 0) {
+ fetch_unpack_limit = git_config_int(var, value);
+ return 0;
+ }
+
+ if (strcmp(var, "transfer.unpacklimit") == 0) {
+ transfer_unpack_limit = git_config_int(var, value);
+ return 0;
+ }
+
+ return git_default_config(var, value);
+}
+
+static struct lock_file lock;
+
+int main(int argc, char **argv)
+{
+ int i, ret, nr_heads;
+ char *dest = NULL, **heads;
+ int fd[2];
+ pid_t pid;
+ struct stat st;
+
+ setup_git_directory();
+ git_config(fetch_pack_config);
+
+ if (0 <= transfer_unpack_limit)
+ unpack_limit = transfer_unpack_limit;
+ else if (0 <= fetch_unpack_limit)
+ unpack_limit = fetch_unpack_limit;
+
+ nr_heads = 0;
+ heads = NULL;
+ for (i = 1; i < argc; i++) {
+ char *arg = argv[i];
+
+ if (*arg == '-') {
+ if (!prefixcmp(arg, "--upload-pack=")) {
+ uploadpack = arg + 14;
+ continue;
+ }
+ if (!prefixcmp(arg, "--exec=")) {
+ uploadpack = arg + 7;
+ continue;
+ }
+ if (!strcmp("--quiet", arg) || !strcmp("-q", arg)) {
+ quiet = 1;
+ continue;
+ }
+ if (!strcmp("--keep", arg) || !strcmp("-k", arg)) {
+ keep_pack++;
+ unpack_limit = 0;
+ continue;
+ }
+ if (!strcmp("--thin", arg)) {
+ use_thin_pack = 1;
+ continue;
+ }
+ if (!strcmp("--all", arg)) {
+ fetch_all = 1;
+ continue;
+ }
+ if (!strcmp("-v", arg)) {
+ verbose = 1;
+ continue;
+ }
+ if (!prefixcmp(arg, "--depth=")) {
+ depth = strtol(arg + 8, NULL, 0);
+ if (stat(git_path("shallow"), &st))
+ st.st_mtime = 0;
+ continue;
+ }
+ if (!strcmp("--no-progress", arg)) {
+ no_progress = 1;
+ continue;
+ }
+ usage(fetch_pack_usage);
+ }
+ dest = arg;
+ heads = argv + i + 1;
+ nr_heads = argc - i - 1;
+ break;
+ }
+ if (!dest)
+ usage(fetch_pack_usage);
+ pid = git_connect(fd, dest, uploadpack);
+ if (pid < 0)
+ return 1;
+ if (heads && nr_heads)
+ nr_heads = remove_duplicates(nr_heads, heads);
+ ret = fetch_pack(fd, nr_heads, heads);
+ close(fd[0]);
+ close(fd[1]);
+ ret |= finish_connect(pid);
+
+ if (!ret && nr_heads) {
+ /* If the heads to pull were given, we should have
+ * consumed all of them by matching the remote.
+ * Otherwise, 'git-fetch remote no-such-ref' would
+ * silently succeed without issuing an error.
+ */
+ for (i = 0; i < nr_heads; i++)
+ if (heads[i] && heads[i][0]) {
+ error("no such remote ref %s", heads[i]);
+ ret = 1;
+ }
+ }
+
+ if (!ret && depth > 0) {
+ struct cache_time mtime;
+ char *shallow = git_path("shallow");
+ int fd;
+
+ mtime.sec = st.st_mtime;
+#ifdef USE_NSEC
+ mtime.usec = st.st_mtim.usec;
+#endif
+ if (stat(shallow, &st)) {
+ if (mtime.sec)
+ die("shallow file was removed during fetch");
+ } else if (st.st_mtime != mtime.sec
+#ifdef USE_NSEC
+ || st.st_mtim.usec != mtime.usec
+#endif
+ )
+ die("shallow file was changed during fetch");
+
+ fd = hold_lock_file_for_update(&lock, shallow, 1);
+ if (!write_shallow_commits(fd, 0)) {
+ unlink(shallow);
+ rollback_lock_file(&lock);
+ } else {
+ close(fd);
+ commit_lock_file(&lock);
+ }
+ }
+
+ return !!ret;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-18 10:20:57 +0000