fetch-pack: make negotiation-related vars local

Reduce the number of global variables by making the priority queue and
the count of non-common commits in it local, passing them as a struct to
various functions where necessary.

This also helps in the case that fetch_pack() is invoked twice in the
same process (when tag following is required when using a transport that
does not support tag following), in that different priority queues will
now be used in each invocation, instead of reusing the possibly
non-empty one.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/fetch-pack.c b/fetch-pack.c
index 806c40021f0d3602566f28344de4a4c08ffd649e..86252e1cf7d299eb7a4467bfdb8bf663b985d9db 100644 (file)
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -50,8 +50,12 @@ static int marked;
  */
 #define MAX_IN_VAIN 256
 
-static struct prio_queue rev_list = { compare_commits_by_commit_date };
-static int non_common_revs, multi_ack, use_sideband;
+struct negotiation_state {
+       struct prio_queue rev_list;
+       int non_common_revs;
+};
+
+static int multi_ack, use_sideband;
 /* Allow specifying sha1 if it is a ref tip. */
 #define ALLOW_TIP_SHA1 01
 /* Allow request of a sha1 if it is reachable from a ref (possibly hidden ref). */
@@ -93,7 +97,9 @@ static void cache_one_alternate(const char *refname,
        cache->items[cache->nr++] = obj;
 }
 
-static void for_each_cached_alternate(void (*cb)(struct object *))
+static void for_each_cached_alternate(struct negotiation_state *ns,
+                                     void (*cb)(struct negotiation_state *,
+                                                struct object *))
 {
        static int initialized;
        static struct alternate_object_cache cache;
@@ -105,10 +111,11 @@ static void for_each_cached_alternate(void (*cb)(struct object *))
        }
 
        for (i = 0; i < cache.nr; i++)
-               cb(cache.items[i]);
+               cb(ns, cache.items[i]);
 }
 
-static void rev_list_push(struct commit *commit, int mark)
+static void rev_list_push(struct negotiation_state *ns,
+                         struct commit *commit, int mark)
 {
        if (!(commit->object.flags & mark)) {
                commit->object.flags |= mark;
@@ -116,19 +123,21 @@ static void rev_list_push(struct commit *commit, int mark)
                if (parse_commit(commit))
                        return;
 
-               prio_queue_put(&rev_list, commit);
+               prio_queue_put(&ns->rev_list, commit);
 
                if (!(commit->object.flags & COMMON))
-                       non_common_revs++;
+                       ns->non_common_revs++;
        }
 }
 
-static int rev_list_insert_ref(const char *refname, const struct object_id *oid)
+static int rev_list_insert_ref(struct negotiation_state *ns,
+                              const char *refname,
+                              const struct object_id *oid)
 {
        struct object *o = deref_tag(parse_object(oid), refname, 0);
 
        if (o && o->type == OBJ_COMMIT)
-               rev_list_push((struct commit *)o, SEEN);
+               rev_list_push(ns, (struct commit *)o, SEEN);
 
        return 0;
 }
@@ -136,7 +145,7 @@ static int rev_list_insert_ref(const char *refname, const struct object_id *oid)
 static int rev_list_insert_ref_oid(const char *refname, const struct object_id *oid,
                                   int flag, void *cb_data)
 {
-       return rev_list_insert_ref(refname, oid);
+       return rev_list_insert_ref(cb_data, refname, oid);
 }
 
 static int clear_marks(const char *refname, const struct object_id *oid,
@@ -156,7 +165,7 @@ static int clear_marks(const char *refname, const struct object_id *oid,
    when only the server does not yet know that they are common).
 */
 
-static void mark_common(struct commit *commit,
+static void mark_common(struct negotiation_state *ns, struct commit *commit,
                int ancestors_only, int dont_parse)
 {
        if (commit != NULL && !(commit->object.flags & COMMON)) {
@@ -166,12 +175,12 @@ static void mark_common(struct commit *commit,
                        o->flags |= COMMON;
 
                if (!(o->flags & SEEN))
-                       rev_list_push(commit, SEEN);
+                       rev_list_push(ns, commit, SEEN);
                else {
                        struct commit_list *parents;
 
                        if (!ancestors_only && !(o->flags & POPPED))
-                               non_common_revs--;
+                               ns->non_common_revs--;
                        if (!o->parsed && !dont_parse)
                                if (parse_commit(commit))
                                        return;
@@ -179,7 +188,8 @@ static void mark_common(struct commit *commit,
                        for (parents = commit->parents;
                                        parents;
                                        parents = parents->next)
-                               mark_common(parents->item, 0, dont_parse);
+                               mark_common(ns, parents->item, 0,
+                                           dont_parse);
                }
        }
 }
@@ -188,7 +198,7 @@ static void mark_common(struct commit *commit,
   Get the next rev to send, ignoring the common.
 */
 
-static const struct object_id *get_rev(void)
+static const struct object_id *get_rev(struct negotiation_state *ns)
 {
        struct commit *commit = NULL;
 
@@ -196,16 +206,16 @@ static const struct object_id *get_rev(void)
                unsigned int mark;
                struct commit_list *parents;
 
-               if (rev_list.nr == 0 || non_common_revs == 0)
+               if (ns->rev_list.nr == 0 || ns->non_common_revs == 0)
                        return NULL;
 
-               commit = prio_queue_get(&rev_list);
+               commit = prio_queue_get(&ns->rev_list);
                parse_commit(commit);
                parents = commit->parents;
 
                commit->object.flags |= POPPED;
                if (!(commit->object.flags & COMMON))
-                       non_common_revs--;
+                       ns->non_common_revs--;
 
                if (commit->object.flags & COMMON) {
                        /* do not send "have", and ignore ancestors */
@@ -220,9 +230,9 @@ static const struct object_id *get_rev(void)
 
                while (parents) {
                        if (!(parents->item->object.flags & SEEN))
-                               rev_list_push(parents->item, mark);
+                               rev_list_push(ns, parents->item, mark);
                        if (mark & COMMON)
-                               mark_common(parents->item, 1, 0);
+                               mark_common(ns, parents->item, 1, 0);
                        parents = parents->next;
                }
        }
@@ -296,9 +306,10 @@ static void send_request(struct fetch_pack_args *args,
                write_or_die(fd, buf->buf, buf->len);
 }
 
-static void insert_one_alternate_object(struct object *obj)
+static void insert_one_alternate_object(struct negotiation_state *ns,
+                                       struct object *obj)
 {
-       rev_list_insert_ref(NULL, &obj->oid);
+       rev_list_insert_ref(ns, NULL, &obj->oid);
 }
 
 #define INITIAL_FLUSH 16
@@ -321,7 +332,8 @@ static int next_flush(int stateless_rpc, int count)
        return count;
 }
 
-static int find_common(struct fetch_pack_args *args,
+static int find_common(struct negotiation_state *ns,
+                      struct fetch_pack_args *args,
                       int fd[2], struct object_id *result_oid,
                       struct ref *refs)
 {
@@ -337,8 +349,8 @@ static int find_common(struct fetch_pack_args *args,
        if (args->stateless_rpc && multi_ack == 1)
                die(_("--stateless-rpc requires multi_ack_detailed"));
 
-       for_each_ref(rev_list_insert_ref_oid, NULL);
-       for_each_cached_alternate(insert_one_alternate_object);
+       for_each_ref(rev_list_insert_ref_oid, ns);
+       for_each_cached_alternate(ns, insert_one_alternate_object);
 
        fetching = 0;
        for ( ; refs ; refs = refs->next) {
@@ -456,7 +468,7 @@ static int find_common(struct fetch_pack_args *args,
        retval = -1;
        if (args->no_dependents)
                goto done;
-       while ((oid = get_rev())) {
+       while ((oid = get_rev(ns))) {
                packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
                print_verbose(args, "have %s", oid_to_hex(oid));
                in_vain++;
@@ -514,7 +526,7 @@ static int find_common(struct fetch_pack_args *args,
                                        } else if (!args->stateless_rpc
                                                   || ack != ACK_common)
                                                in_vain = 0;
-                                       mark_common(commit, 0, 1);
+                                       mark_common(ns, commit, 0, 1);
                                        retval = 0;
                                        got_continue = 1;
                                        if (ack == ACK_ready)
@@ -704,7 +716,8 @@ static void filter_refs(struct fetch_pack_args *args,
        *refs = newlist;
 }
 
-static void mark_alternate_complete(struct object *obj)
+static void mark_alternate_complete(struct negotiation_state *unused,
+                                   struct object *obj)
 {
        mark_complete(&obj->oid);
 }
@@ -741,7 +754,8 @@ static int add_loose_objects_to_set(const struct object_id *oid,
  * earliest commit time of the objects in refs that are commits and that we know
  * the commit time of.
  */
-static void mark_complete_and_common_ref(struct fetch_pack_args *args,
+static void mark_complete_and_common_ref(struct negotiation_state *ns,
+                                        struct fetch_pack_args *args,
                                         struct ref **refs)
 {
        struct ref *ref;
@@ -792,7 +806,7 @@ static void mark_complete_and_common_ref(struct fetch_pack_args *args,
        if (!args->no_dependents) {
                if (!args->deepen) {
                        for_each_ref(mark_complete_oid, NULL);
-                       for_each_cached_alternate(mark_alternate_complete);
+                       for_each_cached_alternate(NULL, mark_alternate_complete);
                        commit_list_sort_by_date(&complete);
                        if (cutoff)
                                mark_recent_complete_commits(args, cutoff);
@@ -810,9 +824,10 @@ static void mark_complete_and_common_ref(struct fetch_pack_args *args,
                                continue;
 
                        if (!(o->flags & SEEN)) {
-                               rev_list_push((struct commit *)o, COMMON_REF | SEEN);
+                               rev_list_push(ns, (struct commit *)o,
+                                             COMMON_REF | SEEN);
 
-                               mark_common((struct commit *)o, 1, 1);
+                               mark_common(ns, (struct commit *)o, 1, 1);
                        }
                }
        }
@@ -995,6 +1010,7 @@ static struct ref *do_fetch_pack(struct fetch_pack_args *args,
        struct object_id oid;
        const char *agent_feature;
        int agent_len;
+       struct negotiation_state ns = { { compare_commits_by_commit_date } };
 
        sort_ref_list(&ref, ref_compare_name);
        QSORT(sought, nr_sought, cmp_ref_by_name);
@@ -1070,13 +1086,13 @@ static struct ref *do_fetch_pack(struct fetch_pack_args *args,
        if (marked)
                for_each_ref(clear_marks, NULL);
        marked = 1;
-       mark_complete_and_common_ref(args, &ref);
+       mark_complete_and_common_ref(&ns, args, &ref);
        filter_refs(args, &ref, sought, nr_sought);
        if (everything_local(args, &ref)) {
                packet_flush(fd[1]);
                goto all_done;
        }
-       if (find_common(args, fd, &oid, ref) < 0)
+       if (find_common(&ns, args, fd, &oid, ref) < 0)
                if (!args->keep_pack)
                        /* When cloning, it is not unusual to have
                         * no common commit.
@@ -1096,7 +1112,7 @@ static struct ref *do_fetch_pack(struct fetch_pack_args *args,
                die(_("git fetch-pack: fetch failed."));
 
  all_done:
-       clear_prio_queue(&rev_list);
+       clear_prio_queue(&ns.rev_list);
        return ref;
 }
 
@@ -1158,13 +1174,14 @@ static void add_common(struct strbuf *req_buf, struct oidset *common)
        }
 }
 
-static int add_haves(struct strbuf *req_buf, int *haves_to_send, int *in_vain)
+static int add_haves(struct negotiation_state *ns, struct strbuf *req_buf,
+                    int *haves_to_send, int *in_vain)
 {
        int ret = 0;
        int haves_added = 0;
        const struct object_id *oid;
 
-       while ((oid = get_rev())) {
+       while ((oid = get_rev(ns))) {
                packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
                if (++haves_added >= *haves_to_send)
                        break;
@@ -1183,7 +1200,8 @@ static int add_haves(struct strbuf *req_buf, int *haves_to_send, int *in_vain)
        return ret;
 }
 
-static int send_fetch_request(int fd_out, const struct fetch_pack_args *args,
+static int send_fetch_request(struct negotiation_state *ns, int fd_out,
+                             const struct fetch_pack_args *args,
                              const struct ref *wants, struct oidset *common,
                              int *haves_to_send, int *in_vain)
 {
@@ -1239,7 +1257,7 @@ static int send_fetch_request(int fd_out, const struct fetch_pack_args *args,
                add_common(&req_buf, common);
 
                /* Add initial haves */
-               ret = add_haves(&req_buf, haves_to_send, in_vain);
+               ret = add_haves(ns, &req_buf, haves_to_send, in_vain);
        }
 
        /* Send request */
@@ -1276,7 +1294,9 @@ static int process_section_header(struct packet_reader *reader,
        return ret;
 }
 
-static int process_acks(struct packet_reader *reader, struct oidset *common)
+static int process_acks(struct negotiation_state *ns,
+                       struct packet_reader *reader,
+                       struct oidset *common)
 {
        /* received */
        int received_ready = 0;
@@ -1295,7 +1315,7 @@ static int process_acks(struct packet_reader *reader, struct oidset *common)
                                struct commit *commit;
                                oidset_insert(common, &oid);
                                commit = lookup_commit(&oid);
-                               mark_common(commit, 0, 1);
+                               mark_common(ns, commit, 0, 1);
                        }
                        continue;
                }
@@ -1373,6 +1393,7 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
        struct packet_reader reader;
        int in_vain = 0;
        int haves_to_send = INITIAL_FLUSH;
+       struct negotiation_state ns = { { compare_commits_by_commit_date } };
        packet_reader_init(&reader, fd[0], NULL, 0,
                           PACKET_READ_CHOMP_NEWLINE);
 
@@ -1393,18 +1414,19 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
                        marked = 1;
 
                        /* Filter 'ref' by 'sought' and those that aren't local */
-                       mark_complete_and_common_ref(args, &ref);
+                       mark_complete_and_common_ref(&ns, args, &ref);
                        filter_refs(args, &ref, sought, nr_sought);
                        if (everything_local(args, &ref))
                                state = FETCH_DONE;
                        else
                                state = FETCH_SEND_REQUEST;
 
-                       for_each_ref(rev_list_insert_ref_oid, NULL);
-                       for_each_cached_alternate(insert_one_alternate_object);
+                       for_each_ref(rev_list_insert_ref_oid, &ns);
+                       for_each_cached_alternate(&ns,
+                                                 insert_one_alternate_object);
                        break;
                case FETCH_SEND_REQUEST:
-                       if (send_fetch_request(fd[1], args, ref, &common,
+                       if (send_fetch_request(&ns, fd[1], args, ref, &common,
                                               &haves_to_send, &in_vain))
                                state = FETCH_GET_PACK;
                        else
@@ -1412,7 +1434,7 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
                        break;
                case FETCH_PROCESS_ACKS:
                        /* Process ACKs/NAKs */
-                       switch (process_acks(&reader, &common)) {
+                       switch (process_acks(&ns, &reader, &common)) {
                        case 2:
                                state = FETCH_GET_PACK;
                                break;
@@ -1441,7 +1463,7 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
                }
        }
 
-       clear_prio_queue(&rev_list);
+       clear_prio_queue(&ns.rev_list);
        oidset_clear(&common);
        return ref;
 }