fetch-pack: Use a strbuf to compose the want list

This change is being offered as a refactoring to make later
commits in the smart HTTP series easier.

By changing the enabled capabilities to be formatted in a strbuf
it is easier to add a new capability to the set of supported
capabilities.

By formatting the want portion of the request into a strbuf and
writing it as a whole block we can later decide to hold onto
the req_buf (instead of releasing it) to recycle in stateless
communications.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin-fetch-pack.c b/builtin-fetch-pack.c
index 629735f54723a3bc3b24f8c91e9a6226ae28d742..783c2b0834c7532f747337e9e270b77a94297ebb 100644 (file)
--- a/builtin-fetch-pack.c
+++ b/builtin-fetch-pack.c
@@ -165,6 +165,7 @@ static int find_common(int fd[2], unsigned char *result_sha1,
        const unsigned char *sha1;
        unsigned in_vain = 0;
        int got_continue = 0;
+       struct strbuf req_buf = STRBUF_INIT;
 
        if (marked)
                for_each_ref(clear_marks, NULL);
@@ -175,6 +176,7 @@ static int find_common(int fd[2], unsigned char *result_sha1,
        fetching = 0;
        for ( ; refs ; refs = refs->next) {
                unsigned char *remote = refs->old_sha1;
+               const char *remote_hex;
                struct object *o;
 
                /*
@@ -192,27 +194,36 @@ static int find_common(int fd[2], unsigned char *result_sha1,
                        continue;
                }
 
-               if (!fetching)
-                       packet_write(fd[1], "want %s%s%s%s%s%s%s%s\n",
-                                    sha1_to_hex(remote),
-                                    (multi_ack ? " multi_ack" : ""),
-                                    (use_sideband == 2 ? " side-band-64k" : ""),
-                                    (use_sideband == 1 ? " side-band" : ""),
-                                    (args.use_thin_pack ? " thin-pack" : ""),
-                                    (args.no_progress ? " no-progress" : ""),
-                                    (args.include_tag ? " include-tag" : ""),
-                                    (prefer_ofs_delta ? " ofs-delta" : ""));
-               else
-                       packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
+               remote_hex = sha1_to_hex(remote);
+               if (!fetching) {
+                       struct strbuf c = STRBUF_INIT;
+                       if (multi_ack)          strbuf_addstr(&c, " multi_ack");
+                       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");
+                       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(fd[1], 1);
+               write_shallow_commits(&req_buf, 1);
        if (args.depth > 0)
-               packet_write(fd[1], "deepen %d", args.depth);
-       packet_flush(fd[1]);
-       if (!fetching)
-               return 1;
+               packet_buf_write(&req_buf, "deepen %d", args.depth);
+       packet_buf_flush(&req_buf);
+
+       safe_write(fd[1], req_buf.buf, req_buf.len);
 
        if (args.depth > 0) {
                char line[1024];
@@ -296,6 +307,8 @@ done:
                multi_ack = 0;
                flushes++;
        }
+       strbuf_release(&req_buf);
+
        while (flushes || multi_ack) {
                int ack = get_ack(fd[0], result_sha1);
                if (ack) {
@@ -809,6 +822,7 @@ struct ref *fetch_pack(struct fetch_pack_args *my_args,
 
        if (args.depth > 0) {
                struct cache_time mtime;
+               struct strbuf sb = STRBUF_INIT;
                char *shallow = git_path("shallow");
                int fd;
 
@@ -826,12 +840,14 @@ struct ref *fetch_pack(struct fetch_pack_args *my_args,
 
                fd = hold_lock_file_for_update(&lock, shallow,
                                               LOCK_DIE_ON_ERROR);
-               if (!write_shallow_commits(fd, 0)) {
+               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();

diff --git a/commit.c b/commit.c
index fedbd5e5267ec4beaf1f245a879918a2685c10b9..471efb0566368aaf589d6d8390d583bc21bed256 100644 (file)
--- a/commit.c
+++ b/commit.c
@@ -199,7 +199,7 @@ struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
        return commit_graft[pos];
 }
 
-int write_shallow_commits(int fd, int use_pack_protocol)
+int write_shallow_commits(struct strbuf *out, int use_pack_protocol)
 {
        int i, count = 0;
        for (i = 0; i < commit_graft_nr; i++)
@@ -208,12 +208,10 @@ int write_shallow_commits(int fd, int use_pack_protocol)
                                sha1_to_hex(commit_graft[i]->sha1);
                        count++;
                        if (use_pack_protocol)
-                               packet_write(fd, "shallow %s", hex);
+                               packet_buf_write(out, "shallow %s", hex);
                        else {
-                               if (write_in_full(fd, hex,  40) != 40)
-                                       break;
-                               if (write_str_in_full(fd, "\n") != 1)
-                                       break;
+                               strbuf_addstr(out, hex);
+                               strbuf_addch(out, '\n');
                        }
                }
        return count;

diff --git a/commit.h b/commit.h
index f4fc5c5589a3ae6f2b99e533c3dd0f3a7a7f418a..817c75c02f1c9825c60cd23c586e657b752d2933 100644 (file)
--- a/commit.h
+++ b/commit.h
@@ -131,7 +131,7 @@ extern struct commit_list *get_octopus_merge_bases(struct commit_list *in);
 
 extern int register_shallow(const unsigned char *sha1);
 extern int unregister_shallow(const unsigned char *sha1);
-extern int write_shallow_commits(int fd, int use_pack_protocol);
+extern int write_shallow_commits(struct strbuf *out, int use_pack_protocol);
 extern int is_repository_shallow(void);
 extern struct commit_list *get_shallow_commits(struct object_array *heads,
                int depth, int shallow_flag, int not_shallow_flag);