Repository format version check.
[gitweb.git] / fetch-pack.c
index e9035a1dc1e71fbac6e530eda3810848404f0f2d..65659826601eb9c850266539f6c9e7807a0b467e 100644 (file)
 #include "cache.h"
+#include "refs.h"
 #include "pkt-line.h"
+#include "commit.h"
+#include "tag.h"
+#include <time.h>
+#include <sys/wait.h>
 
-static const char fetch_pack_usage[] = "git-fetch-pack [host:]directory [heads]* < mycommitlist";
+static int quiet;
+static int verbose;
+static const char fetch_pack_usage[] =
+"git-fetch-pack [-q] [-v] [--exec=upload-pack] [host:]directory <refs>...";
 static const char *exec = "git-upload-pack";
 
-static int get_ack(int fd, unsigned char *result_sha1)
+#define COMPLETE       (1U << 0)
+#define COMMON         (1U << 1)
+#define COMMON_REF     (1U << 2)
+#define SEEN           (1U << 3)
+#define POPPED         (1U << 4)
+
+static struct commit_list *rev_list = NULL;
+static int non_common_revs = 0, multi_ack = 0;
+
+static void rev_list_push(struct commit *commit, int mark)
 {
-       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 0;
-       if (!strncmp(line, "ACK ", 3)) {
-               if (!get_sha1_hex(line+4, result_sha1))
-                       return 1;
+       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++;
        }
-       die("git-fetch_pack: expected ACK/NAK, got '%s'", line);
 }
 
-static int find_common(int fd[2], unsigned char *result_sha1)
+static int rev_list_insert_ref(const char *path, const unsigned char *sha1)
 {
-       static char line[1000];
-       int count = 0, flushes = 0;
+       struct object *o = deref_tag(parse_object(sha1), path, 0);
+
+       if (o && o->type == commit_type)
+               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()
+{
+       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;
+               }
 
-       while (fgets(line, sizeof(line), stdin) != NULL) {
-               unsigned char sha1[20];
-               if (get_sha1_hex(line, sha1))
-                       die("git-fetch-pack: expected object name, got crud");
+               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;
+
+       for_each_ref(rev_list_insert_ref);
+
+       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;
+               }
+
+               packet_write(fd[1], "want %s%s\n", sha1_to_hex(remote),
+                       multi_ack ? " multi_ack" : "");
+               fetching++;
+       }
+       packet_flush(fd[1]);
+       if (!fetching)
+               return 1;
+
+       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));
                if (!(31 & ++count)) {
+                       int ack;
+
                        packet_flush(fd[1]);
                        flushes++;
 
@@ -42,53 +183,238 @@ static int find_common(int fd[2], unsigned char *result_sha1)
                         */
                        if (count == 32)
                                continue;
-                       if (get_ack(fd[0], result_sha1))
-                               return 0;
+
+                       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;
+                               }
+                       } while (ack);
                        flushes--;
                }
        }
-       flushes++;
-       packet_flush(fd[1]);
-       while (flushes) {
+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--;
-               if (get_ack(fd[0], result_sha1))
-                       return 0;
        }
-       return -1;
+       return retval;
 }
 
-static int get_remote_heads(int fd, int nr_match, char **match)
+static struct commit_list *complete = NULL;
+
+static int mark_complete(const char *path, const unsigned char *sha1)
 {
-       for (;;) {
-               static char line[1000];
-               unsigned char sha1[20];
-               char *refname;
-               int len;
-
-               len = packet_read_line(fd, line, sizeof(line));
-               if (!len)
-                       break;
-               if (line[len-1] == '\n')
-                       line[--len] = 0;
-               if (len < 42 || get_sha1_hex(line, sha1))
-                       die("git-fetch-pack: protocol error - expected ref descriptor, got '%sä'", line);
-               refname = line+41;
-               if (nr_match && !path_match(refname, nr_match, match))
-                       continue;
-               printf("%s %s\n", sha1_to_hex(sha1), refname);
+       struct object *o = parse_object(sha1);
+
+       while (o && o->type == tag_type) {
+               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 == commit_type) {
+               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 *prev, *current, *next;
+
+       if (!nr_match)
+               return;
+
+       for (prev = NULL, current = *refs; current; current = next) {
+               next = current->next;
+               if ((!memcmp(current->name, "refs/", 5) &&
+                                       check_ref_format(current->name + 5)) ||
+                               !path_match(current->name, nr_match, match)) {
+                       if (prev == NULL)
+                               *refs = next;
+                       else
+                               prev->next = next;
+                       free(current);
+               } else
+                       prev = current;
+       }
+}
+
+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 == commit_type) {
+                       struct commit *commit = (struct commit *)o;
+                       if (!cutoff || cutoff < commit->date)
+                               cutoff = commit->date;
+               }
+       }
+
+       for_each_ref(mark_complete);
+       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 != commit_type || !(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;
+               }
+
+               memcpy(ref->new_sha1, local, 20);
+               if (!verbose)
+                       continue;
+               fprintf(stderr,
+                       "already have %s (%s)\n", sha1_to_hex(remote),
+                       ref->name);
+       }
+       return retval;
+}
+
 static int fetch_pack(int fd[2], int nr_match, char **match)
 {
+       struct ref *ref;
        unsigned char sha1[20];
+       int status;
+       pid_t pid;
 
-       get_remote_heads(fd[0], nr_match, match);
-       if (find_common(fd, sha1) < 0)
-               die("git-fetch-pack: no common commits");
-       printf("common commit: %s\n", sha1_to_hex(sha1));
-       return 0;
+       get_remote_heads(fd[0], &ref, 0, NULL, 0);
+       if (server_supports("multi_ack")) {
+               if (verbose)
+                       fprintf(stderr, "Server supports multi_ack\n");
+               multi_ack = 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)
+               fprintf(stderr, "warning: no common commits\n");
+       pid = fork();
+       if (pid < 0)
+               die("git-fetch-pack: unable to fork off git-unpack-objects");
+       if (!pid) {
+               dup2(fd[0], 0);
+               close(fd[0]);
+               close(fd[1]);
+               execlp("git-unpack-objects", "git-unpack-objects",
+                      quiet ? "-q" : NULL, NULL);
+               die("git-unpack-objects exec failed");
+       }
+       close(fd[0]);
+       close(fd[1]);
+       while (waitpid(pid, &status, 0) < 0) {
+               if (errno != EINTR)
+                       die("waiting for git-unpack-objects: %s", strerror(errno));
+       }
+       if (WIFEXITED(status)) {
+               int code = WEXITSTATUS(status);
+               if (code)
+                       die("git-unpack-objects died with error code %d", code);
+all_done:
+               while (ref) {
+                       printf("%s %s\n",
+                              sha1_to_hex(ref->old_sha1), ref->name);
+                       ref = ref->next;
+               }
+               return 0;
+       }
+       if (WIFSIGNALED(status)) {
+               int sig = WTERMSIG(status);
+               die("git-unpack-objects died of signal %d", sig);
+       }
+       die("Sherlock Holmes! git-unpack-objects died of unnatural causes %d!", status);
 }
 
 int main(int argc, char **argv)
@@ -104,7 +430,18 @@ int main(int argc, char **argv)
                char *arg = argv[i];
 
                if (*arg == '-') {
-                       /* Arguments go here */
+                       if (!strncmp("--exec=", arg, 7)) {
+                               exec = arg + 7;
+                               continue;
+                       }
+                       if (!strcmp("-q", arg)) {
+                               quiet = 1;
+                               continue;
+                       }
+                       if (!strcmp("-v", arg)) {
+                               verbose = 1;
+                               continue;
+                       }
                        usage(fetch_pack_usage);
                }
                dest = arg;
@@ -121,5 +458,19 @@ int main(int argc, char **argv)
        close(fd[0]);
        close(fd[1]);
        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;
+                       }
+       }
+
        return ret;
 }