From: Ronnie Sahlberg <sahlb...@google.com>

This adds support to the protocol between send-pack and receive-pack to
* allow receive-pack to inform the client that it has atomic push capability
* allow send-pack to request atomic push back.

There is currently no setting in send-pack to actually request that atomic
pushes are to be used yet. This only adds protocol capability not ability
for the user to activate it.

Signed-off-by: Ronnie Sahlberg <sahlb...@google.com>
Signed-off-by: Stefan Beller <sbel...@google.com>
---

Notes:
    Changes v1 -> v2:
        * Name it atomic instead of atomic-push. The name changes affects
          the flags send over the wire as well as the flags in
          struct send_pack_args
        * Add check, which was part of the later patch here:
        if (args->atomic && !atomic_supported) {
                fprintf(stderr, "Server does not support atomic push.");
                return -1;
        }
    
    v2 -> v3:
    More concise error reporting as suggested by Junio
    -           fprintf(stderr, "Server does not support atomic push.");
    -           return -1;
    +           return error("server does not support atomic push.");
    
    skipped v4 v5
    
    v6:
        * s/one single atomic transaction./one atomic transaction./
        * die(_( instead of return error(

 Documentation/technical/protocol-capabilities.txt | 13 +++++++++++--
 builtin/receive-pack.c                            |  6 +++++-
 send-pack.c                                       | 10 ++++++++++
 send-pack.h                                       |  3 ++-
 4 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/Documentation/technical/protocol-capabilities.txt 
b/Documentation/technical/protocol-capabilities.txt
index 6d5424c..4f8a7bf 100644
--- a/Documentation/technical/protocol-capabilities.txt
+++ b/Documentation/technical/protocol-capabilities.txt
@@ -18,8 +18,9 @@ was sent.  Server MUST NOT ignore capabilities that client 
requested
 and server advertised.  As a consequence of these rules, server MUST
 NOT advertise capabilities it does not understand.
 
-The 'report-status', 'delete-refs', 'quiet', and 'push-cert' capabilities
-are sent and recognized by the receive-pack (push to server) process.
+The 'atomic', 'report-status', 'delete-refs', 'quiet', and 'push-cert'
+capabilities are sent and recognized by the receive-pack (push to server)
+process.
 
 The 'ofs-delta' and 'side-band-64k' capabilities are sent and recognized
 by both upload-pack and receive-pack protocols.  The 'agent' capability
@@ -244,6 +245,14 @@ respond with the 'quiet' capability to suppress 
server-side progress
 reporting if the local progress reporting is also being suppressed
 (e.g., via `push -q`, or if stderr does not go to a tty).
 
+atomic
+------
+
+If the server sends the 'atomic' capability it is capable of accepting
+atomic pushes. If the pushing client requests this capability, the server
+will update the refs in one atomic transaction. Either all refs are
+updated or none.
+
 allow-tip-sha1-in-want
 ----------------------
 
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 32fc540..e76e5d5 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -40,6 +40,7 @@ static int transfer_unpack_limit = -1;
 static int unpack_limit = 100;
 static int report_status;
 static int use_sideband;
+static int use_atomic;
 static int quiet;
 static int prefer_ofs_delta = 1;
 static int auto_update_server_info;
@@ -171,7 +172,8 @@ static void show_ref(const char *path, const unsigned char 
*sha1)
                struct strbuf cap = STRBUF_INIT;
 
                strbuf_addstr(&cap,
-                             "report-status delete-refs side-band-64k quiet");
+                             "report-status delete-refs side-band-64k quiet "
+                             "atomic");
                if (prefer_ofs_delta)
                        strbuf_addstr(&cap, " ofs-delta");
                if (push_cert_nonce)
@@ -1179,6 +1181,8 @@ static struct command *read_head_info(struct sha1_array 
*shallow)
                                use_sideband = LARGE_PACKET_MAX;
                        if (parse_feature_request(feature_list, "quiet"))
                                quiet = 1;
+                       if (parse_feature_request(feature_list, "atomic"))
+                               use_atomic = 1;
                }
 
                if (!strcmp(line, "push-cert")) {
diff --git a/send-pack.c b/send-pack.c
index 949cb61..6646600 100644
--- a/send-pack.c
+++ b/send-pack.c
@@ -294,6 +294,8 @@ int send_pack(struct send_pack_args *args,
        int use_sideband = 0;
        int quiet_supported = 0;
        int agent_supported = 0;
+       int use_atomic;
+       int atomic_supported = 0;
        unsigned cmds_sent = 0;
        int ret;
        struct async demux;
@@ -314,6 +316,8 @@ int send_pack(struct send_pack_args *args,
                agent_supported = 1;
        if (server_supports("no-thin"))
                args->use_thin_pack = 0;
+       if (server_supports("atomic"))
+               atomic_supported = 1;
        if (args->push_cert) {
                int len;
 
@@ -328,6 +332,10 @@ int send_pack(struct send_pack_args *args,
                        "Perhaps you should specify a branch such as 
'master'.\n");
                return 0;
        }
+       if (args->atomic && !atomic_supported)
+               die(_("server does not support --atomic push"));
+
+       use_atomic = atomic_supported && args->atomic;
 
        if (status_report)
                strbuf_addstr(&cap_buf, " report-status");
@@ -335,6 +343,8 @@ int send_pack(struct send_pack_args *args,
                strbuf_addstr(&cap_buf, " side-band-64k");
        if (quiet_supported && (args->quiet || !args->progress))
                strbuf_addstr(&cap_buf, " quiet");
+       if (use_atomic)
+               strbuf_addstr(&cap_buf, " atomic");
        if (agent_supported)
                strbuf_addf(&cap_buf, " agent=%s", git_user_agent_sanitized());
 
diff --git a/send-pack.h b/send-pack.h
index 5635457..b664648 100644
--- a/send-pack.h
+++ b/send-pack.h
@@ -13,7 +13,8 @@ struct send_pack_args {
                use_ofs_delta:1,
                dry_run:1,
                push_cert:1,
-               stateless_rpc:1;
+               stateless_rpc:1,
+               atomic:1;
 };
 
 int send_pack(struct send_pack_args *args,
-- 
2.2.1.62.g3f15098

--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to