git-upload-pack: More efficient usage of the has_sha1 array
[git.git] / fetch-pack.c
index 582f967..8566ab1 100644 (file)
@@ -1,6 +1,9 @@
 #include "cache.h"
 #include "refs.h"
 #include "pkt-line.h"
+#include "commit.h"
+#include "tag.h"
+#include <time.h>
 #include <sys/wait.h>
 
 static int quiet;
@@ -9,27 +12,66 @@ static const char fetch_pack_usage[] =
 "git-fetch-pack [-q] [-v] [--exec=upload-pack] [host:]directory <refs>...";
 static const char *exec = "git-upload-pack";
 
+#define COMPLETE       (1U << 0)
+
 static int find_common(int fd[2], unsigned char *result_sha1,
                       struct ref *refs)
 {
+       int fetching;
        static char line[1000];
-       int count = 0, flushes = 0, retval;
+       static char rev_command[1024];
+       int count = 0, flushes = 0, retval, rev_command_len;
        FILE *revs;
 
-       revs = popen("git-rev-list $(git-rev-parse --all)", "r");
-       if (!revs)
-               die("unable to run 'git-rev-list'");
-
-       while (refs) {
+       strcpy(rev_command, "git-rev-list $(git-rev-parse --all)");
+       rev_command_len = strlen(rev_command);
+       fetching = 0;
+       for ( ; refs ; refs = refs->next) {
                unsigned char *remote = refs->old_sha1;
-               if (verbose)
-                       fprintf(stderr,
-                               "want %s (%s)\n", sha1_to_hex(remote),
-                               refs->name);
+               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)) {
+                       struct commit_list *p;
+                       struct commit *commit =
+                               (struct commit *) (o = deref_tag(o));
+                       if (!o)
+                               goto repair;
+                       if (o->type != commit_type)
+                               continue;
+                       p = commit->parents;
+                       while (p &&
+                              rev_command_len + 44 < sizeof(rev_command)) {
+                               snprintf(rev_command + rev_command_len, 44,
+                                        " ^%s",
+                                        sha1_to_hex(p->item->object.sha1));
+                               rev_command_len += 43;
+                               p = p->next;
+                       }
+                       continue;
+               }
+       repair:
                packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
-               refs = refs->next;
+               fetching++;
        }
        packet_flush(fd[1]);
+       if (!fetching)
+               return 1;
+
+       revs = popen(rev_command, "r");
+       if (!revs)
+               die("unable to run 'git-rev-list'");
+
        flushes = 1;
        retval = -1;
        while (fgets(line, sizeof(line), revs) != NULL) {
@@ -74,6 +116,94 @@ static int find_common(int fd[2], unsigned char *result_sha1,
        return retval;
 }
 
+static struct commit_list *complete = NULL;
+
+static int mark_complete(const char *path, const unsigned char *sha1)
+{
+       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 int everything_local(struct ref *refs)
+{
+       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);
+
+       for (retval = 1; refs ; refs = refs->next) {
+               const unsigned char *remote = refs->old_sha1;
+               unsigned char local[20];
+               struct object *o;
+
+               o = parse_object(remote);
+               if (!o || !(o->flags & COMPLETE)) {
+                       retval = 0;
+                       if (!verbose)
+                               continue;
+                       fprintf(stderr,
+                               "want %s (%s)\n", sha1_to_hex(remote),
+                               refs->name);
+                       continue;
+               }
+
+               memcpy(refs->new_sha1, local, 20);
+               if (!verbose)
+                       continue;
+               fprintf(stderr,
+                       "already have %s (%s)\n", sha1_to_hex(remote),
+                       refs->name);
+       }
+       return retval;
+}
+
 static int fetch_pack(int fd[2], int nr_match, char **match)
 {
        struct ref *ref;
@@ -81,11 +211,15 @@ static int fetch_pack(int fd[2], int nr_match, char **match)
        int status;
        pid_t pid;
 
-       get_remote_heads(fd[0], &ref, nr_match, match);
+       get_remote_heads(fd[0], &ref, nr_match, match, 1);
        if (!ref) {
                packet_flush(fd[1]);
                die("no matching remote head");
        }
+       if (everything_local(ref)) {
+               packet_flush(fd[1]);
+               goto all_done;
+       }
        if (find_common(fd, sha1, ref) < 0)
                fprintf(stderr, "warning: no common commits\n");
        pid = fork();
@@ -109,6 +243,7 @@ static int fetch_pack(int fd[2], int nr_match, char **match)
                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);