]> git.ipfire.org Git - thirdparty/git.git/commitdiff
fetch-pack: move core code to libgit.a
authorNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Fri, 26 Oct 2012 15:53:55 +0000 (22:53 +0700)
committerJeff King <peff@peff.net>
Mon, 29 Oct 2012 07:40:29 +0000 (03:40 -0400)
fetch_pack() is used by transport.c, part of libgit.a while it stays
in builtin/fetch-pack.c. Move it to fetch-pack.c so that we won't get
undefined reference if a program that uses libgit.a happens to pull it
in.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Makefile
builtin/fetch-pack.c
fetch-pack.c [new file with mode: 0644]

index 357ab3ba0b05c847b8ceebb40c57b343d8270f4c..53a766e283652d3f0e4602065ec73ea7e675836c 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -746,6 +746,7 @@ LIB_OBJS += editor.o
 LIB_OBJS += entry.o
 LIB_OBJS += environment.o
 LIB_OBJS += exec_cmd.o
+LIB_OBJS += fetch-pack.o
 LIB_OBJS += fsck.o
 LIB_OBJS += gettext.o
 LIB_OBJS += gpg-interface.o
index d0fd7076efe414e3fdc15c4b0e751331684d0a37..940ae35dc2ce4923a248896eb764f145312d71b4 100644 (file)
 #include "builtin.h"
-#include "refs.h"
 #include "pkt-line.h"
-#include "commit.h"
-#include "tag.h"
-#include "exec_cmd.h"
-#include "pack.h"
-#include "sideband.h"
 #include "fetch-pack.h"
-#include "remote.h"
-#include "run-command.h"
-#include "transport.h"
-#include "version.h"
-
-static int transfer_unpack_limit = -1;
-static int fetch_unpack_limit = -1;
-static int unpack_limit = 100;
-static int prefer_ofs_delta = 1;
-static int no_done;
-static int fetch_fsck_objects = -1;
-static int transfer_fsck_objects = -1;
-static int agent_supported;
 
 static const char fetch_pack_usage[] =
 "git fetch-pack [--all] [--stdin] [--quiet|-q] [--keep|-k] [--thin] "
 "[--include-tag] [--upload-pack=<git-upload-pack>] [--depth=<n>] "
 "[--no-progress] [-v] [<host>:]<directory> [<refs>...]";
 
-#define COMPLETE       (1U << 0)
-#define COMMON         (1U << 1)
-#define COMMON_REF     (1U << 2)
-#define SEEN           (1U << 3)
-#define POPPED         (1U << 4)
-
-static int marked;
-
-/*
- * 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_sideband;
-
-static void rev_list_push(struct commit *commit, int mark)
-{
-       if (!(commit->object.flags & mark)) {
-               commit->object.flags |= mark;
-
-               if (!(commit->object.parsed))
-                       if (parse_commit(commit))
-                               return;
-
-               commit_list_insert_by_date(commit, &rev_list);
-
-               if (!(commit->object.flags & COMMON))
-                       non_common_revs++;
-       }
-}
-
-static int rev_list_insert_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
-{
-       struct object *o = deref_tag(parse_object(sha1), refname, 0);
-
-       if (o && o->type == OBJ_COMMIT)
-               rev_list_push((struct commit *)o, SEEN);
-
-       return 0;
-}
-
-static int clear_marks(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
-{
-       struct object *o = deref_tag(parse_object(sha1), refname, 0);
-
-       if (o && o->type == OBJ_COMMIT)
-               clear_commit_marks((struct commit *)o,
-                                  COMMON | COMMON_REF | SEEN | POPPED);
-       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)
-                               if (parse_commit(commit))
-                                       return;
-
-                       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);
-               parents = commit->parents;
-
-               commit->object.flags |= POPPED;
-               if (!(commit->object.flags & COMMON))
-                       non_common_revs--;
-
-               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;
-}
-
-enum ack_type {
-       NAK = 0,
-       ACK,
-       ACK_continue,
-       ACK_common,
-       ACK_ready
-};
-
-static void consume_shallow_list(struct fetch_pack_args *args, int fd)
-{
-       if (args->stateless_rpc && args->depth > 0) {
-               /* If we sent a depth we will get back "duplicate"
-                * shallow and unshallow commands every time there
-                * is a block of have lines exchanged.
-                */
-               char line[1000];
-               while (packet_read_line(fd, line, sizeof(line))) {
-                       if (!prefixcmp(line, "shallow "))
-                               continue;
-                       if (!prefixcmp(line, "unshallow "))
-                               continue;
-                       die("git fetch-pack: expected shallow list");
-               }
-       }
-}
-
-struct write_shallow_data {
-       struct strbuf *out;
-       int use_pack_protocol;
-       int count;
-};
-
-static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
-{
-       struct write_shallow_data *data = cb_data;
-       const char *hex = sha1_to_hex(graft->sha1);
-       data->count++;
-       if (data->use_pack_protocol)
-               packet_buf_write(data->out, "shallow %s", hex);
-       else {
-               strbuf_addstr(data->out, hex);
-               strbuf_addch(data->out, '\n');
-       }
-       return 0;
-}
-
-static int write_shallow_commits(struct strbuf *out, int use_pack_protocol)
-{
-       struct write_shallow_data data;
-       data.out = out;
-       data.use_pack_protocol = use_pack_protocol;
-       data.count = 0;
-       for_each_commit_graft(write_one_shallow, &data);
-       return data.count;
-}
-
-static enum ack_type get_ack(int fd, unsigned char *result_sha1)
-{
-       static char line[1000];
-       int len = packet_read_line(fd, line, sizeof(line));
-
-       if (!len)
-               die("git fetch-pack: expected ACK/NAK, got EOF");
-       if (line[len-1] == '\n')
-               line[--len] = 0;
-       if (!strcmp(line, "NAK"))
-               return NAK;
-       if (!prefixcmp(line, "ACK ")) {
-               if (!get_sha1_hex(line+4, result_sha1)) {
-                       if (strstr(line+45, "continue"))
-                               return ACK_continue;
-                       if (strstr(line+45, "common"))
-                               return ACK_common;
-                       if (strstr(line+45, "ready"))
-                               return ACK_ready;
-                       return ACK;
-               }
-       }
-       die("git fetch_pack: expected ACK/NAK, got '%s'", line);
-}
-
-static void send_request(struct fetch_pack_args *args,
-                        int fd, struct strbuf *buf)
-{
-       if (args->stateless_rpc) {
-               send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
-               packet_flush(fd);
-       } else
-               safe_write(fd, buf->buf, buf->len);
-}
-
-static void insert_one_alternate_ref(const struct ref *ref, void *unused)
-{
-       rev_list_insert_ref(NULL, ref->old_sha1, 0, NULL);
-}
-
-#define INITIAL_FLUSH 16
-#define PIPESAFE_FLUSH 32
-#define LARGE_FLUSH 1024
-
-static int next_flush(struct fetch_pack_args *args, int count)
-{
-       int flush_limit = args->stateless_rpc ? LARGE_FLUSH : PIPESAFE_FLUSH;
-
-       if (count < flush_limit)
-               count <<= 1;
-       else
-               count += flush_limit;
-       return count;
-}
-
-static int find_common(struct fetch_pack_args *args,
-                      int fd[2], unsigned char *result_sha1,
-                      struct ref *refs)
-{
-       int fetching;
-       int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
-       const unsigned char *sha1;
-       unsigned in_vain = 0;
-       int got_continue = 0;
-       int got_ready = 0;
-       struct strbuf req_buf = STRBUF_INIT;
-       size_t state_len = 0;
-
-       if (args->stateless_rpc && multi_ack == 1)
-               die("--stateless-rpc requires multi_ack_detailed");
-       if (marked)
-               for_each_ref(clear_marks, NULL);
-       marked = 1;
-
-       for_each_ref(rev_list_insert_ref, NULL);
-       for_each_alternate_ref(insert_one_alternate_ref, NULL);
-
-       fetching = 0;
-       for ( ; refs ; refs = refs->next) {
-               unsigned char *remote = refs->old_sha1;
-               const char *remote_hex;
-               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;
-               }
-
-               remote_hex = sha1_to_hex(remote);
-               if (!fetching) {
-                       struct strbuf c = STRBUF_INIT;
-                       if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
-                       if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
-                       if (no_done)            strbuf_addstr(&c, " no-done");
-                       if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
-                       if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
-                       if (args->use_thin_pack) strbuf_addstr(&c, " thin-pack");
-                       if (args->no_progress)   strbuf_addstr(&c, " no-progress");
-                       if (args->include_tag)   strbuf_addstr(&c, " include-tag");
-                       if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
-                       if (agent_supported)    strbuf_addf(&c, " agent=%s",
-                                                           git_user_agent_sanitized());
-                       packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
-                       strbuf_release(&c);
-               } else
-                       packet_buf_write(&req_buf, "want %s\n", remote_hex);
-               fetching++;
-       }
-
-       if (!fetching) {
-               strbuf_release(&req_buf);
-               packet_flush(fd[1]);
-               return 1;
-       }
-
-       if (is_repository_shallow())
-               write_shallow_commits(&req_buf, 1);
-       if (args->depth > 0)
-               packet_buf_write(&req_buf, "deepen %d", args->depth);
-       packet_buf_flush(&req_buf);
-       state_len = req_buf.len;
-
-       if (args->depth > 0) {
-               char line[1024];
-               unsigned char sha1[20];
-
-               send_request(args, fd[1], &req_buf);
-               while (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 */
-                               if (!parse_object(sha1))
-                                       die("error in object: %s", line);
-                               if (unregister_shallow(sha1))
-                                       die("no shallow found: %s", line);
-                               continue;
-                       }
-                       die("expected shallow/unshallow, got %s", line);
-               }
-       } else if (!args->stateless_rpc)
-               send_request(args, fd[1], &req_buf);
-
-       if (!args->stateless_rpc) {
-               /* If we aren't using the stateless-rpc interface
-                * we don't need to retain the headers.
-                */
-               strbuf_setlen(&req_buf, 0);
-               state_len = 0;
-       }
-
-       flushes = 0;
-       retval = -1;
-       while ((sha1 = get_rev())) {
-               packet_buf_write(&req_buf, "have %s\n", sha1_to_hex(sha1));
-               if (args->verbose)
-                       fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
-               in_vain++;
-               if (flush_at <= ++count) {
-                       int ack;
-
-                       packet_buf_flush(&req_buf);
-                       send_request(args, fd[1], &req_buf);
-                       strbuf_setlen(&req_buf, state_len);
-                       flushes++;
-                       flush_at = next_flush(args, count);
-
-                       /*
-                        * We keep one window "ahead" of the other side, and
-                        * will wait for an ACK only on the next one
-                        */
-                       if (!args->stateless_rpc && count == INITIAL_FLUSH)
-                               continue;
-
-                       consume_shallow_list(args, fd[0]);
-                       do {
-                               ack = get_ack(fd[0], result_sha1);
-                               if (args->verbose && ack)
-                                       fprintf(stderr, "got ack %d %s\n", ack,
-                                                       sha1_to_hex(result_sha1));
-                               switch (ack) {
-                               case ACK:
-                                       flushes = 0;
-                                       multi_ack = 0;
-                                       retval = 0;
-                                       goto done;
-                               case ACK_common:
-                               case ACK_ready:
-                               case ACK_continue: {
-                                       struct commit *commit =
-                                               lookup_commit(result_sha1);
-                                       if (!commit)
-                                               die("invalid commit %s", sha1_to_hex(result_sha1));
-                                       if (args->stateless_rpc
-                                        && ack == ACK_common
-                                        && !(commit->object.flags & COMMON)) {
-                                               /* We need to replay the have for this object
-                                                * on the next RPC request so the peer knows
-                                                * it is in common with us.
-                                                */
-                                               const char *hex = sha1_to_hex(result_sha1);
-                                               packet_buf_write(&req_buf, "have %s\n", hex);
-                                               state_len = req_buf.len;
-                                       }
-                                       mark_common(commit, 0, 1);
-                                       retval = 0;
-                                       in_vain = 0;
-                                       got_continue = 1;
-                                       if (ack == ACK_ready) {
-                                               rev_list = NULL;
-                                               got_ready = 1;
-                                       }
-                                       break;
-                                       }
-                               }
-                       } while (ack);
-                       flushes--;
-                       if (got_continue && MAX_IN_VAIN < in_vain) {
-                               if (args->verbose)
-                                       fprintf(stderr, "giving up\n");
-                               break; /* give up */
-                       }
-               }
-       }
-done:
-       if (!got_ready || !no_done) {
-               packet_buf_write(&req_buf, "done\n");
-               send_request(args, fd[1], &req_buf);
-       }
-       if (args->verbose)
-               fprintf(stderr, "done\n");
-       if (retval != 0) {
-               multi_ack = 0;
-               flushes++;
-       }
-       strbuf_release(&req_buf);
-
-       consume_shallow_list(args, fd[0]);
-       while (flushes || multi_ack) {
-               int ack = get_ack(fd[0], result_sha1);
-               if (ack) {
-                       if (args->verbose)
-                               fprintf(stderr, "got ack (%d) %s\n", ack,
-                                       sha1_to_hex(result_sha1));
-                       if (ack == ACK)
-                               return 0;
-                       multi_ack = 1;
-                       continue;
-               }
-               flushes--;
-       }
-       /* it is no error to fetch into a completely empty repo */
-       return count ? retval : 0;
-}
-
-static struct commit_list *complete;
-
-static int mark_complete(const char *refname, 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;
-               if (!(commit->object.flags & COMPLETE)) {
-                       commit->object.flags |= COMPLETE;
-                       commit_list_insert_by_date(commit, &complete);
-               }
-       }
-       return 0;
-}
-
-static void mark_recent_complete_commits(struct fetch_pack_args *args,
-                                        unsigned long cutoff)
-{
-       while (complete && cutoff <= complete->item->date) {
-               if (args->verbose)
-                       fprintf(stderr, "Marking %s as complete\n",
-                               sha1_to_hex(complete->item->object.sha1));
-               pop_most_recent_commit(&complete, COMPLETE);
-       }
-}
-
-static int non_matching_ref(struct string_list_item *item, void *unused)
-{
-       if (item->util) {
-               item->util = NULL;
-               return 0;
-       }
-       else
-               return 1;
-}
-
-static void filter_refs(struct fetch_pack_args *args,
-                       struct ref **refs, struct string_list *sought)
-{
-       struct ref *newlist = NULL;
-       struct ref **newtail = &newlist;
-       struct ref *ref, *next;
-       int sought_pos;
-
-       sought_pos = 0;
-       for (ref = *refs; ref; ref = next) {
-               int keep = 0;
-               next = ref->next;
-               if (!memcmp(ref->name, "refs/", 5) &&
-                   check_refname_format(ref->name + 5, 0))
-                       ; /* trash */
-               else {
-                       while (sought_pos < sought->nr) {
-                               int cmp = strcmp(ref->name, sought->items[sought_pos].string);
-                               if (cmp < 0)
-                                       break; /* definitely do not have it */
-                               else if (cmp == 0) {
-                                       keep = 1; /* definitely have it */
-                                       sought->items[sought_pos++].util = "matched";
-                                       break;
-                               }
-                               else
-                                       sought_pos++; /* might have it; keep looking */
-                       }
-               }
-
-               if (! keep && args->fetch_all &&
-                   (!args->depth || prefixcmp(ref->name, "refs/tags/")))
-                       keep = 1;
-
-               if (keep) {
-                       *newtail = ref;
-                       ref->next = NULL;
-                       newtail = &ref->next;
-               } else {
-                       free(ref);
-               }
-       }
-
-       filter_string_list(sought, 0, non_matching_ref, NULL);
-       *refs = newlist;
-}
-
-static void mark_alternate_complete(const struct ref *ref, void *unused)
-{
-       mark_complete(NULL, ref->old_sha1, 0, NULL);
-}
-
-static int everything_local(struct fetch_pack_args *args,
-                           struct ref **refs, struct string_list *sought)
-{
-       struct ref *ref;
-       int retval;
-       unsigned long cutoff = 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 (!args->depth) {
-               for_each_ref(mark_complete, NULL);
-               for_each_alternate_ref(mark_alternate_complete, NULL);
-               if (cutoff)
-                       mark_recent_complete_commits(args, 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(args, refs, sought);
-
-       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 (!args->verbose)
-                               continue;
-                       fprintf(stderr,
-                               "want %s (%s)\n", sha1_to_hex(remote),
-                               ref->name);
-                       continue;
-               }
-
-               hashcpy(ref->new_sha1, local);
-               if (!args->verbose)
-                       continue;
-               fprintf(stderr,
-                       "already have %s (%s)\n", sha1_to_hex(remote),
-                       ref->name);
-       }
-       return retval;
-}
-
-static int sideband_demux(int in, int out, void *data)
-{
-       int *xd = data;
-
-       int ret = recv_sideband("fetch-pack", xd[0], out);
-       close(out);
-       return ret;
-}
-
-static int get_pack(struct fetch_pack_args *args,
-                   int xd[2], char **pack_lockfile)
-{
-       struct async demux;
-       const char *argv[20];
-       char keep_arg[256];
-       char hdr_arg[256];
-       const char **av;
-       int do_keep = args->keep_pack;
-       struct child_process cmd;
-
-       memset(&demux, 0, sizeof(demux));
-       if (use_sideband) {
-               /* xd[] is talking with upload-pack; subprocess reads from
-                * xd[0], spits out band#2 to stderr, and feeds us band#1
-                * through demux->out.
-                */
-               demux.proc = sideband_demux;
-               demux.data = xd;
-               demux.out = -1;
-               if (start_async(&demux))
-                       die("fetch-pack: unable to fork off sideband"
-                           " demultiplexer");
-       }
-       else
-               demux.out = xd[0];
-
-       memset(&cmd, 0, sizeof(cmd));
-       cmd.argv = argv;
-       av = argv;
-       *hdr_arg = 0;
-       if (!args->keep_pack && unpack_limit) {
-               struct pack_header header;
-
-               if (read_pack_header(demux.out, &header))
-                       die("protocol error: bad pack header");
-               snprintf(hdr_arg, sizeof(hdr_arg),
-                        "--pack_header=%"PRIu32",%"PRIu32,
-                        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) {
-               if (pack_lockfile)
-                       cmd.out = -1;
-               *av++ = "index-pack";
-               *av++ = "--stdin";
-               if (!args->quiet && !args->no_progress)
-                       *av++ = "-v";
-               if (args->use_thin_pack)
-                       *av++ = "--fix-thin";
-               if (args->lock_pack || unpack_limit) {
-                       int s = sprintf(keep_arg,
-                                       "--keep=fetch-pack %"PRIuMAX " on ", (uintmax_t) getpid());
-                       if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
-                               strcpy(keep_arg + s, "localhost");
-                       *av++ = keep_arg;
-               }
-       }
-       else {
-               *av++ = "unpack-objects";
-               if (args->quiet || args->no_progress)
-                       *av++ = "-q";
-       }
-       if (*hdr_arg)
-               *av++ = hdr_arg;
-       if (fetch_fsck_objects >= 0
-           ? fetch_fsck_objects
-           : transfer_fsck_objects >= 0
-           ? transfer_fsck_objects
-           : 0)
-               *av++ = "--strict";
-       *av++ = NULL;
-
-       cmd.in = demux.out;
-       cmd.git_cmd = 1;
-       if (start_command(&cmd))
-               die("fetch-pack: unable to fork off %s", argv[0]);
-       if (do_keep && pack_lockfile) {
-               *pack_lockfile = index_pack_lockfile(cmd.out);
-               close(cmd.out);
-       }
-
-       if (finish_command(&cmd))
-               die("%s failed", argv[0]);
-       if (use_sideband && finish_async(&demux))
-               die("error in sideband demultiplexer");
-       return 0;
-}
-
-static struct ref *do_fetch_pack(struct fetch_pack_args *args,
-                                int fd[2],
-                                const struct ref *orig_ref,
-                                struct string_list *sought,
-                                char **pack_lockfile)
-{
-       struct ref *ref = copy_ref_list(orig_ref);
-       unsigned char sha1[20];
-       const char *agent_feature;
-       int agent_len;
-
-       sort_ref_list(&ref, ref_compare_name);
-
-       if (is_repository_shallow() && !server_supports("shallow"))
-               die("Server does not support shallow clients");
-       if (server_supports("multi_ack_detailed")) {
-               if (args->verbose)
-                       fprintf(stderr, "Server supports multi_ack_detailed\n");
-               multi_ack = 2;
-               if (server_supports("no-done")) {
-                       if (args->verbose)
-                               fprintf(stderr, "Server supports no-done\n");
-                       if (args->stateless_rpc)
-                               no_done = 1;
-               }
-       }
-       else if (server_supports("multi_ack")) {
-               if (args->verbose)
-                       fprintf(stderr, "Server supports multi_ack\n");
-               multi_ack = 1;
-       }
-       if (server_supports("side-band-64k")) {
-               if (args->verbose)
-                       fprintf(stderr, "Server supports side-band-64k\n");
-               use_sideband = 2;
-       }
-       else if (server_supports("side-band")) {
-               if (args->verbose)
-                       fprintf(stderr, "Server supports side-band\n");
-               use_sideband = 1;
-       }
-       if (!server_supports("thin-pack"))
-               args->use_thin_pack = 0;
-       if (!server_supports("no-progress"))
-               args->no_progress = 0;
-       if (!server_supports("include-tag"))
-               args->include_tag = 0;
-       if (server_supports("ofs-delta")) {
-               if (args->verbose)
-                       fprintf(stderr, "Server supports ofs-delta\n");
-       } else
-               prefer_ofs_delta = 0;
-
-       if ((agent_feature = server_feature_value("agent", &agent_len))) {
-               agent_supported = 1;
-               if (args->verbose && agent_len)
-                       fprintf(stderr, "Server version is %.*s\n",
-                               agent_len, agent_feature);
-       }
-
-       if (everything_local(args, &ref, sought)) {
-               packet_flush(fd[1]);
-               goto all_done;
-       }
-       if (find_common(args, fd, sha1, ref) < 0)
-               if (!args->keep_pack)
-                       /* When cloning, it is not unusual to have
-                        * no common commit.
-                        */
-                       warning("no common commits");
-
-       if (args->stateless_rpc)
-               packet_flush(fd[1]);
-       if (get_pack(args, fd, pack_lockfile))
-               die("git fetch-pack: fetch failed.");
-
- all_done:
-       return ref;
-}
-
-static int fetch_pack_config(const char *var, const char *value, void *cb)
-{
-       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;
-       }
-
-       if (strcmp(var, "repack.usedeltabaseoffset") == 0) {
-               prefer_ofs_delta = git_config_bool(var, value);
-               return 0;
-       }
-
-       if (!strcmp(var, "fetch.fsckobjects")) {
-               fetch_fsck_objects = git_config_bool(var, value);
-               return 0;
-       }
-
-       if (!strcmp(var, "transfer.fsckobjects")) {
-               transfer_fsck_objects = git_config_bool(var, value);
-               return 0;
-       }
-
-       return git_default_config(var, value, cb);
-}
-
-static struct lock_file lock;
-
-static void fetch_pack_setup(void)
-{
-       static int did_setup;
-       if (did_setup)
-               return;
-       git_config(fetch_pack_config, NULL);
-       if (0 <= transfer_unpack_limit)
-               unpack_limit = transfer_unpack_limit;
-       else if (0 <= fetch_unpack_limit)
-               unpack_limit = fetch_unpack_limit;
-       did_setup = 1;
-}
-
 int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 {
        int i, ret;
@@ -1046,64 +159,3 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 
        return ret;
 }
-
-struct ref *fetch_pack(struct fetch_pack_args *args,
-                      int fd[], struct child_process *conn,
-                      const struct ref *ref,
-                      const char *dest,
-                      struct string_list *sought,
-                      char **pack_lockfile)
-{
-       struct stat st;
-       struct ref *ref_cpy;
-
-       fetch_pack_setup();
-       if (args->depth > 0) {
-               if (stat(git_path("shallow"), &st))
-                       st.st_mtime = 0;
-       }
-
-       if (sought->nr) {
-               sort_string_list(sought);
-               string_list_remove_duplicates(sought, 0);
-       }
-
-       if (!ref) {
-               packet_flush(fd[1]);
-               die("no matching remote head");
-       }
-       ref_cpy = do_fetch_pack(args, fd, ref, sought, pack_lockfile);
-
-       if (args->depth > 0) {
-               struct cache_time mtime;
-               struct strbuf sb = STRBUF_INIT;
-               char *shallow = git_path("shallow");
-               int fd;
-
-               mtime.sec = st.st_mtime;
-               mtime.nsec = ST_MTIME_NSEC(st);
-               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_MTIME_NSEC(st) != mtime.nsec
-#endif
-                         )
-                       die("shallow file was changed during fetch");
-
-               fd = hold_lock_file_for_update(&lock, shallow,
-                                              LOCK_DIE_ON_ERROR);
-               if (!write_shallow_commits(&sb, 0)
-                || write_in_full(fd, sb.buf, sb.len) != sb.len) {
-                       unlink_or_warn(shallow);
-                       rollback_lock_file(&lock);
-               } else {
-                       commit_lock_file(&lock);
-               }
-               strbuf_release(&sb);
-       }
-
-       reprepare_packed_git();
-       return ref_cpy;
-}
diff --git a/fetch-pack.c b/fetch-pack.c
new file mode 100644 (file)
index 0000000..099ff4d
--- /dev/null
@@ -0,0 +1,951 @@
+#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"
+#include "fetch-pack.h"
+#include "remote.h"
+#include "run-command.h"
+#include "transport.h"
+#include "version.h"
+
+static int transfer_unpack_limit = -1;
+static int fetch_unpack_limit = -1;
+static int unpack_limit = 100;
+static int prefer_ofs_delta = 1;
+static int no_done;
+static int fetch_fsck_objects = -1;
+static int transfer_fsck_objects = -1;
+static int agent_supported;
+
+#define COMPLETE       (1U << 0)
+#define COMMON         (1U << 1)
+#define COMMON_REF     (1U << 2)
+#define SEEN           (1U << 3)
+#define POPPED         (1U << 4)
+
+static int marked;
+
+/*
+ * 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_sideband;
+
+static void rev_list_push(struct commit *commit, int mark)
+{
+       if (!(commit->object.flags & mark)) {
+               commit->object.flags |= mark;
+
+               if (!(commit->object.parsed))
+                       if (parse_commit(commit))
+                               return;
+
+               commit_list_insert_by_date(commit, &rev_list);
+
+               if (!(commit->object.flags & COMMON))
+                       non_common_revs++;
+       }
+}
+
+static int rev_list_insert_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
+{
+       struct object *o = deref_tag(parse_object(sha1), refname, 0);
+
+       if (o && o->type == OBJ_COMMIT)
+               rev_list_push((struct commit *)o, SEEN);
+
+       return 0;
+}
+
+static int clear_marks(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
+{
+       struct object *o = deref_tag(parse_object(sha1), refname, 0);
+
+       if (o && o->type == OBJ_COMMIT)
+               clear_commit_marks((struct commit *)o,
+                                  COMMON | COMMON_REF | SEEN | POPPED);
+       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)
+                               if (parse_commit(commit))
+                                       return;
+
+                       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);
+               parents = commit->parents;
+
+               commit->object.flags |= POPPED;
+               if (!(commit->object.flags & COMMON))
+                       non_common_revs--;
+
+               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;
+}
+
+enum ack_type {
+       NAK = 0,
+       ACK,
+       ACK_continue,
+       ACK_common,
+       ACK_ready
+};
+
+static void consume_shallow_list(struct fetch_pack_args *args, int fd)
+{
+       if (args->stateless_rpc && args->depth > 0) {
+               /* If we sent a depth we will get back "duplicate"
+                * shallow and unshallow commands every time there
+                * is a block of have lines exchanged.
+                */
+               char line[1000];
+               while (packet_read_line(fd, line, sizeof(line))) {
+                       if (!prefixcmp(line, "shallow "))
+                               continue;
+                       if (!prefixcmp(line, "unshallow "))
+                               continue;
+                       die("git fetch-pack: expected shallow list");
+               }
+       }
+}
+
+struct write_shallow_data {
+       struct strbuf *out;
+       int use_pack_protocol;
+       int count;
+};
+
+static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
+{
+       struct write_shallow_data *data = cb_data;
+       const char *hex = sha1_to_hex(graft->sha1);
+       data->count++;
+       if (data->use_pack_protocol)
+               packet_buf_write(data->out, "shallow %s", hex);
+       else {
+               strbuf_addstr(data->out, hex);
+               strbuf_addch(data->out, '\n');
+       }
+       return 0;
+}
+
+static int write_shallow_commits(struct strbuf *out, int use_pack_protocol)
+{
+       struct write_shallow_data data;
+       data.out = out;
+       data.use_pack_protocol = use_pack_protocol;
+       data.count = 0;
+       for_each_commit_graft(write_one_shallow, &data);
+       return data.count;
+}
+
+static enum ack_type get_ack(int fd, unsigned char *result_sha1)
+{
+       static char line[1000];
+       int len = packet_read_line(fd, line, sizeof(line));
+
+       if (!len)
+               die("git fetch-pack: expected ACK/NAK, got EOF");
+       if (line[len-1] == '\n')
+               line[--len] = 0;
+       if (!strcmp(line, "NAK"))
+               return NAK;
+       if (!prefixcmp(line, "ACK ")) {
+               if (!get_sha1_hex(line+4, result_sha1)) {
+                       if (strstr(line+45, "continue"))
+                               return ACK_continue;
+                       if (strstr(line+45, "common"))
+                               return ACK_common;
+                       if (strstr(line+45, "ready"))
+                               return ACK_ready;
+                       return ACK;
+               }
+       }
+       die("git fetch_pack: expected ACK/NAK, got '%s'", line);
+}
+
+static void send_request(struct fetch_pack_args *args,
+                        int fd, struct strbuf *buf)
+{
+       if (args->stateless_rpc) {
+               send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
+               packet_flush(fd);
+       } else
+               safe_write(fd, buf->buf, buf->len);
+}
+
+static void insert_one_alternate_ref(const struct ref *ref, void *unused)
+{
+       rev_list_insert_ref(NULL, ref->old_sha1, 0, NULL);
+}
+
+#define INITIAL_FLUSH 16
+#define PIPESAFE_FLUSH 32
+#define LARGE_FLUSH 1024
+
+static int next_flush(struct fetch_pack_args *args, int count)
+{
+       int flush_limit = args->stateless_rpc ? LARGE_FLUSH : PIPESAFE_FLUSH;
+
+       if (count < flush_limit)
+               count <<= 1;
+       else
+               count += flush_limit;
+       return count;
+}
+
+static int find_common(struct fetch_pack_args *args,
+                      int fd[2], unsigned char *result_sha1,
+                      struct ref *refs)
+{
+       int fetching;
+       int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
+       const unsigned char *sha1;
+       unsigned in_vain = 0;
+       int got_continue = 0;
+       int got_ready = 0;
+       struct strbuf req_buf = STRBUF_INIT;
+       size_t state_len = 0;
+
+       if (args->stateless_rpc && multi_ack == 1)
+               die("--stateless-rpc requires multi_ack_detailed");
+       if (marked)
+               for_each_ref(clear_marks, NULL);
+       marked = 1;
+
+       for_each_ref(rev_list_insert_ref, NULL);
+       for_each_alternate_ref(insert_one_alternate_ref, NULL);
+
+       fetching = 0;
+       for ( ; refs ; refs = refs->next) {
+               unsigned char *remote = refs->old_sha1;
+               const char *remote_hex;
+               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;
+               }
+
+               remote_hex = sha1_to_hex(remote);
+               if (!fetching) {
+                       struct strbuf c = STRBUF_INIT;
+                       if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
+                       if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
+                       if (no_done)            strbuf_addstr(&c, " no-done");
+                       if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
+                       if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
+                       if (args->use_thin_pack) strbuf_addstr(&c, " thin-pack");
+                       if (args->no_progress)   strbuf_addstr(&c, " no-progress");
+                       if (args->include_tag)   strbuf_addstr(&c, " include-tag");
+                       if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
+                       if (agent_supported)    strbuf_addf(&c, " agent=%s",
+                                                           git_user_agent_sanitized());
+                       packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
+                       strbuf_release(&c);
+               } else
+                       packet_buf_write(&req_buf, "want %s\n", remote_hex);
+               fetching++;
+       }
+
+       if (!fetching) {
+               strbuf_release(&req_buf);
+               packet_flush(fd[1]);
+               return 1;
+       }
+
+       if (is_repository_shallow())
+               write_shallow_commits(&req_buf, 1);
+       if (args->depth > 0)
+               packet_buf_write(&req_buf, "deepen %d", args->depth);
+       packet_buf_flush(&req_buf);
+       state_len = req_buf.len;
+
+       if (args->depth > 0) {
+               char line[1024];
+               unsigned char sha1[20];
+
+               send_request(args, fd[1], &req_buf);
+               while (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 */
+                               if (!parse_object(sha1))
+                                       die("error in object: %s", line);
+                               if (unregister_shallow(sha1))
+                                       die("no shallow found: %s", line);
+                               continue;
+                       }
+                       die("expected shallow/unshallow, got %s", line);
+               }
+       } else if (!args->stateless_rpc)
+               send_request(args, fd[1], &req_buf);
+
+       if (!args->stateless_rpc) {
+               /* If we aren't using the stateless-rpc interface
+                * we don't need to retain the headers.
+                */
+               strbuf_setlen(&req_buf, 0);
+               state_len = 0;
+       }
+
+       flushes = 0;
+       retval = -1;
+       while ((sha1 = get_rev())) {
+               packet_buf_write(&req_buf, "have %s\n", sha1_to_hex(sha1));
+               if (args->verbose)
+                       fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
+               in_vain++;
+               if (flush_at <= ++count) {
+                       int ack;
+
+                       packet_buf_flush(&req_buf);
+                       send_request(args, fd[1], &req_buf);
+                       strbuf_setlen(&req_buf, state_len);
+                       flushes++;
+                       flush_at = next_flush(args, count);
+
+                       /*
+                        * We keep one window "ahead" of the other side, and
+                        * will wait for an ACK only on the next one
+                        */
+                       if (!args->stateless_rpc && count == INITIAL_FLUSH)
+                               continue;
+
+                       consume_shallow_list(args, fd[0]);
+                       do {
+                               ack = get_ack(fd[0], result_sha1);
+                               if (args->verbose && ack)
+                                       fprintf(stderr, "got ack %d %s\n", ack,
+                                                       sha1_to_hex(result_sha1));
+                               switch (ack) {
+                               case ACK:
+                                       flushes = 0;
+                                       multi_ack = 0;
+                                       retval = 0;
+                                       goto done;
+                               case ACK_common:
+                               case ACK_ready:
+                               case ACK_continue: {
+                                       struct commit *commit =
+                                               lookup_commit(result_sha1);
+                                       if (!commit)
+                                               die("invalid commit %s", sha1_to_hex(result_sha1));
+                                       if (args->stateless_rpc
+                                        && ack == ACK_common
+                                        && !(commit->object.flags & COMMON)) {
+                                               /* We need to replay the have for this object
+                                                * on the next RPC request so the peer knows
+                                                * it is in common with us.
+                                                */
+                                               const char *hex = sha1_to_hex(result_sha1);
+                                               packet_buf_write(&req_buf, "have %s\n", hex);
+                                               state_len = req_buf.len;
+                                       }
+                                       mark_common(commit, 0, 1);
+                                       retval = 0;
+                                       in_vain = 0;
+                                       got_continue = 1;
+                                       if (ack == ACK_ready) {
+                                               rev_list = NULL;
+                                               got_ready = 1;
+                                       }
+                                       break;
+                                       }
+                               }
+                       } while (ack);
+                       flushes--;
+                       if (got_continue && MAX_IN_VAIN < in_vain) {
+                               if (args->verbose)
+                                       fprintf(stderr, "giving up\n");
+                               break; /* give up */
+                       }
+               }
+       }
+done:
+       if (!got_ready || !no_done) {
+               packet_buf_write(&req_buf, "done\n");
+               send_request(args, fd[1], &req_buf);
+       }
+       if (args->verbose)
+               fprintf(stderr, "done\n");
+       if (retval != 0) {
+               multi_ack = 0;
+               flushes++;
+       }
+       strbuf_release(&req_buf);
+
+       consume_shallow_list(args, fd[0]);
+       while (flushes || multi_ack) {
+               int ack = get_ack(fd[0], result_sha1);
+               if (ack) {
+                       if (args->verbose)
+                               fprintf(stderr, "got ack (%d) %s\n", ack,
+                                       sha1_to_hex(result_sha1));
+                       if (ack == ACK)
+                               return 0;
+                       multi_ack = 1;
+                       continue;
+               }
+               flushes--;
+       }
+       /* it is no error to fetch into a completely empty repo */
+       return count ? retval : 0;
+}
+
+static struct commit_list *complete;
+
+static int mark_complete(const char *refname, 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;
+               if (!(commit->object.flags & COMPLETE)) {
+                       commit->object.flags |= COMPLETE;
+                       commit_list_insert_by_date(commit, &complete);
+               }
+       }
+       return 0;
+}
+
+static void mark_recent_complete_commits(struct fetch_pack_args *args,
+                                        unsigned long cutoff)
+{
+       while (complete && cutoff <= complete->item->date) {
+               if (args->verbose)
+                       fprintf(stderr, "Marking %s as complete\n",
+                               sha1_to_hex(complete->item->object.sha1));
+               pop_most_recent_commit(&complete, COMPLETE);
+       }
+}
+
+static int non_matching_ref(struct string_list_item *item, void *unused)
+{
+       if (item->util) {
+               item->util = NULL;
+               return 0;
+       }
+       else
+               return 1;
+}
+
+static void filter_refs(struct fetch_pack_args *args,
+                       struct ref **refs, struct string_list *sought)
+{
+       struct ref *newlist = NULL;
+       struct ref **newtail = &newlist;
+       struct ref *ref, *next;
+       int sought_pos;
+
+       sought_pos = 0;
+       for (ref = *refs; ref; ref = next) {
+               int keep = 0;
+               next = ref->next;
+               if (!memcmp(ref->name, "refs/", 5) &&
+                   check_refname_format(ref->name + 5, 0))
+                       ; /* trash */
+               else {
+                       while (sought_pos < sought->nr) {
+                               int cmp = strcmp(ref->name, sought->items[sought_pos].string);
+                               if (cmp < 0)
+                                       break; /* definitely do not have it */
+                               else if (cmp == 0) {
+                                       keep = 1; /* definitely have it */
+                                       sought->items[sought_pos++].util = "matched";
+                                       break;
+                               }
+                               else
+                                       sought_pos++; /* might have it; keep looking */
+                       }
+               }
+
+               if (! keep && args->fetch_all &&
+                   (!args->depth || prefixcmp(ref->name, "refs/tags/")))
+                       keep = 1;
+
+               if (keep) {
+                       *newtail = ref;
+                       ref->next = NULL;
+                       newtail = &ref->next;
+               } else {
+                       free(ref);
+               }
+       }
+
+       filter_string_list(sought, 0, non_matching_ref, NULL);
+       *refs = newlist;
+}
+
+static void mark_alternate_complete(const struct ref *ref, void *unused)
+{
+       mark_complete(NULL, ref->old_sha1, 0, NULL);
+}
+
+static int everything_local(struct fetch_pack_args *args,
+                           struct ref **refs, struct string_list *sought)
+{
+       struct ref *ref;
+       int retval;
+       unsigned long cutoff = 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 (!args->depth) {
+               for_each_ref(mark_complete, NULL);
+               for_each_alternate_ref(mark_alternate_complete, NULL);
+               if (cutoff)
+                       mark_recent_complete_commits(args, 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(args, refs, sought);
+
+       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 (!args->verbose)
+                               continue;
+                       fprintf(stderr,
+                               "want %s (%s)\n", sha1_to_hex(remote),
+                               ref->name);
+                       continue;
+               }
+
+               hashcpy(ref->new_sha1, local);
+               if (!args->verbose)
+                       continue;
+               fprintf(stderr,
+                       "already have %s (%s)\n", sha1_to_hex(remote),
+                       ref->name);
+       }
+       return retval;
+}
+
+static int sideband_demux(int in, int out, void *data)
+{
+       int *xd = data;
+
+       int ret = recv_sideband("fetch-pack", xd[0], out);
+       close(out);
+       return ret;
+}
+
+static int get_pack(struct fetch_pack_args *args,
+                   int xd[2], char **pack_lockfile)
+{
+       struct async demux;
+       const char *argv[20];
+       char keep_arg[256];
+       char hdr_arg[256];
+       const char **av;
+       int do_keep = args->keep_pack;
+       struct child_process cmd;
+
+       memset(&demux, 0, sizeof(demux));
+       if (use_sideband) {
+               /* xd[] is talking with upload-pack; subprocess reads from
+                * xd[0], spits out band#2 to stderr, and feeds us band#1
+                * through demux->out.
+                */
+               demux.proc = sideband_demux;
+               demux.data = xd;
+               demux.out = -1;
+               if (start_async(&demux))
+                       die("fetch-pack: unable to fork off sideband"
+                           " demultiplexer");
+       }
+       else
+               demux.out = xd[0];
+
+       memset(&cmd, 0, sizeof(cmd));
+       cmd.argv = argv;
+       av = argv;
+       *hdr_arg = 0;
+       if (!args->keep_pack && unpack_limit) {
+               struct pack_header header;
+
+               if (read_pack_header(demux.out, &header))
+                       die("protocol error: bad pack header");
+               snprintf(hdr_arg, sizeof(hdr_arg),
+                        "--pack_header=%"PRIu32",%"PRIu32,
+                        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) {
+               if (pack_lockfile)
+                       cmd.out = -1;
+               *av++ = "index-pack";
+               *av++ = "--stdin";
+               if (!args->quiet && !args->no_progress)
+                       *av++ = "-v";
+               if (args->use_thin_pack)
+                       *av++ = "--fix-thin";
+               if (args->lock_pack || unpack_limit) {
+                       int s = sprintf(keep_arg,
+                                       "--keep=fetch-pack %"PRIuMAX " on ", (uintmax_t) getpid());
+                       if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
+                               strcpy(keep_arg + s, "localhost");
+                       *av++ = keep_arg;
+               }
+       }
+       else {
+               *av++ = "unpack-objects";
+               if (args->quiet || args->no_progress)
+                       *av++ = "-q";
+       }
+       if (*hdr_arg)
+               *av++ = hdr_arg;
+       if (fetch_fsck_objects >= 0
+           ? fetch_fsck_objects
+           : transfer_fsck_objects >= 0
+           ? transfer_fsck_objects
+           : 0)
+               *av++ = "--strict";
+       *av++ = NULL;
+
+       cmd.in = demux.out;
+       cmd.git_cmd = 1;
+       if (start_command(&cmd))
+               die("fetch-pack: unable to fork off %s", argv[0]);
+       if (do_keep && pack_lockfile) {
+               *pack_lockfile = index_pack_lockfile(cmd.out);
+               close(cmd.out);
+       }
+
+       if (finish_command(&cmd))
+               die("%s failed", argv[0]);
+       if (use_sideband && finish_async(&demux))
+               die("error in sideband demultiplexer");
+       return 0;
+}
+
+static struct ref *do_fetch_pack(struct fetch_pack_args *args,
+                                int fd[2],
+                                const struct ref *orig_ref,
+                                struct string_list *sought,
+                                char **pack_lockfile)
+{
+       struct ref *ref = copy_ref_list(orig_ref);
+       unsigned char sha1[20];
+       const char *agent_feature;
+       int agent_len;
+
+       sort_ref_list(&ref, ref_compare_name);
+
+       if (is_repository_shallow() && !server_supports("shallow"))
+               die("Server does not support shallow clients");
+       if (server_supports("multi_ack_detailed")) {
+               if (args->verbose)
+                       fprintf(stderr, "Server supports multi_ack_detailed\n");
+               multi_ack = 2;
+               if (server_supports("no-done")) {
+                       if (args->verbose)
+                               fprintf(stderr, "Server supports no-done\n");
+                       if (args->stateless_rpc)
+                               no_done = 1;
+               }
+       }
+       else if (server_supports("multi_ack")) {
+               if (args->verbose)
+                       fprintf(stderr, "Server supports multi_ack\n");
+               multi_ack = 1;
+       }
+       if (server_supports("side-band-64k")) {
+               if (args->verbose)
+                       fprintf(stderr, "Server supports side-band-64k\n");
+               use_sideband = 2;
+       }
+       else if (server_supports("side-band")) {
+               if (args->verbose)
+                       fprintf(stderr, "Server supports side-band\n");
+               use_sideband = 1;
+       }
+       if (!server_supports("thin-pack"))
+               args->use_thin_pack = 0;
+       if (!server_supports("no-progress"))
+               args->no_progress = 0;
+       if (!server_supports("include-tag"))
+               args->include_tag = 0;
+       if (server_supports("ofs-delta")) {
+               if (args->verbose)
+                       fprintf(stderr, "Server supports ofs-delta\n");
+       } else
+               prefer_ofs_delta = 0;
+
+       if ((agent_feature = server_feature_value("agent", &agent_len))) {
+               agent_supported = 1;
+               if (args->verbose && agent_len)
+                       fprintf(stderr, "Server version is %.*s\n",
+                               agent_len, agent_feature);
+       }
+
+       if (everything_local(args, &ref, sought)) {
+               packet_flush(fd[1]);
+               goto all_done;
+       }
+       if (find_common(args, fd, sha1, ref) < 0)
+               if (!args->keep_pack)
+                       /* When cloning, it is not unusual to have
+                        * no common commit.
+                        */
+                       warning("no common commits");
+
+       if (args->stateless_rpc)
+               packet_flush(fd[1]);
+       if (get_pack(args, fd, pack_lockfile))
+               die("git fetch-pack: fetch failed.");
+
+ all_done:
+       return ref;
+}
+
+static int fetch_pack_config(const char *var, const char *value, void *cb)
+{
+       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;
+       }
+
+       if (strcmp(var, "repack.usedeltabaseoffset") == 0) {
+               prefer_ofs_delta = git_config_bool(var, value);
+               return 0;
+       }
+
+       if (!strcmp(var, "fetch.fsckobjects")) {
+               fetch_fsck_objects = git_config_bool(var, value);
+               return 0;
+       }
+
+       if (!strcmp(var, "transfer.fsckobjects")) {
+               transfer_fsck_objects = git_config_bool(var, value);
+               return 0;
+       }
+
+       return git_default_config(var, value, cb);
+}
+
+static struct lock_file lock;
+
+static void fetch_pack_setup(void)
+{
+       static int did_setup;
+       if (did_setup)
+               return;
+       git_config(fetch_pack_config, NULL);
+       if (0 <= transfer_unpack_limit)
+               unpack_limit = transfer_unpack_limit;
+       else if (0 <= fetch_unpack_limit)
+               unpack_limit = fetch_unpack_limit;
+       did_setup = 1;
+}
+
+struct ref *fetch_pack(struct fetch_pack_args *args,
+                      int fd[], struct child_process *conn,
+                      const struct ref *ref,
+                      const char *dest,
+                      struct string_list *sought,
+                      char **pack_lockfile)
+{
+       struct stat st;
+       struct ref *ref_cpy;
+
+       fetch_pack_setup();
+       if (args->depth > 0) {
+               if (stat(git_path("shallow"), &st))
+                       st.st_mtime = 0;
+       }
+
+       if (sought->nr) {
+               sort_string_list(sought);
+               string_list_remove_duplicates(sought, 0);
+       }
+
+       if (!ref) {
+               packet_flush(fd[1]);
+               die("no matching remote head");
+       }
+       ref_cpy = do_fetch_pack(args, fd, ref, sought, pack_lockfile);
+
+       if (args->depth > 0) {
+               struct cache_time mtime;
+               struct strbuf sb = STRBUF_INIT;
+               char *shallow = git_path("shallow");
+               int fd;
+
+               mtime.sec = st.st_mtime;
+               mtime.nsec = ST_MTIME_NSEC(st);
+               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_MTIME_NSEC(st) != mtime.nsec
+#endif
+                         )
+                       die("shallow file was changed during fetch");
+
+               fd = hold_lock_file_for_update(&lock, shallow,
+                                              LOCK_DIE_ON_ERROR);
+               if (!write_shallow_commits(&sb, 0)
+                || write_in_full(fd, sb.buf, sb.len) != sb.len) {
+                       unlink_or_warn(shallow);
+                       rollback_lock_file(&lock);
+               } else {
+                       commit_lock_file(&lock);
+               }
+               strbuf_release(&sb);
+       }
+
+       reprepare_packed_git();
+       return ref_cpy;
+}