[PATCH v5 27/35] transport-helper: introduce stateless-connect
- From
- Brandon Williams <bmwill@google.com>
- Date
- Mar 14, 2018, 18:32 UTC
- Message-ID
- <20180314183213.223440-28-bmwill@google.com>
- In-Reply-To
- <20180314183213.223440-1-bmwill@google.com>
Introduce the transport-helper capability 'stateless-connect'. This capability indicates that the transport-helper can be requested to run the 'stateless-connect' command which should attempt to make a stateless connection with a remote end. Once established, the connection can be used by the git client to communicate with the remote end natively in a stateless-rpc manner as supported by protocol v2. This means that the client must send everything the server needs in a single request as the client must not assume any state-storing on the part of the server or transport.
If a stateless connection cannot be established then the remote-helper will respond in the same manner as the 'connect' command indicating that the client should fallback to using the dumb remote-helper commands.
A future patch will implement the 'stateless-connect' capability in our http remote-helper (remote-curl) so that protocol v2 can be used using the http transport.
Signed-off-by: Brandon Williams <bmwill@google.com> --- Documentation/gitremote-helpers.txt | 32 +++++++++++++++++++++++++++++ transport-helper.c | 11 ++++++++++ transport.c | 1 + transport.h | 6 ++++++ 4 files changed, 50 insertions(+)
diff --git a/Documentation/gitremote-helpers.txt b/Documentation/gitremote-helpers.txt index 4a584f3c5d..cd9b34d230 100644 --- a/Documentation/gitremote-helpers.txt +++ b/Documentation/gitremote-helpers.txt @@ -102,6 +102,14 @@ Capabilities for Pushing + Supported commands: 'connect'. +'stateless-connect':: + Experimental; for internal use only. + Can attempt to connect to a remote server for communication + using git's wire-protocol version 2. See the documentation + for the stateless-connect command for more information. ++ +Supported commands: 'stateless-connect'. + 'push':: Can discover remote refs and push local commits and the history leading up to them to new or existing remote refs. @@ -136,6 +144,14 @@ Capabilities for Fetching + Supported commands: 'connect'. +'stateless-connect':: + Experimental; for internal use only. + Can attempt to connect to a remote server for communication + using git's wire-protocol version 2. See the documentation + for the stateless-connect command for more information. ++ +Supported commands: 'stateless-connect'. + 'fetch':: Can discover remote refs and transfer objects reachable from them to the local object store. @@ -375,6 +391,22 @@ Supported if the helper has the "export" capability. + Supported if the helper has the "connect" capability. +'stateless-connect' <service>:: + Experimental; for internal use only. + Connects to the given remote service for communication using + git's wire-protocol version 2. Valid replies to this command + are empty line (connection established), 'fallback' (no smart + transport support, fall back to dumb transports) and just + exiting with error message printed (can't connect, don't bother + trying to fall back). After line feed terminating the positive + (empty) response, the output of the service starts. Messages + (both request and response) must consist of zero or more + PKT-LINEs, terminating in a flush packet. The client must not + expect the server to store any state in between request-response + pairs. After the connection ends, the remote helper exits. ++ +Supported if the helper has the "stateless-connect" capability. + If a fatal error occurs, the program writes the error message to stderr and exits. The caller should expect that a suitable error message has been printed if the child closes the connection without diff --git a/transport-helper.c b/transport-helper.c index 830f21f0a9..aecbc4a845 100644 --- a/transport-helper.c +++ b/transport-helper.c @@ -12,6 +12,7 @@ #include "argv-array.h" #include "refs.h" #include "transport-internal.h" +#include "protocol.h" static int debug; @@ -26,6 +27,7 @@ struct helper_data { option : 1, push : 1, connect : 1, + stateless_connect : 1, signed_tags : 1, check_connectivity : 1, no_disconnect_req : 1, @@ -188,6 +190,8 @@ static struct child_process *get_helper(struct transport *transport) refspecs[refspec_nr++] = xstrdup(arg); } else if (!strcmp(capname, "connect")) { data->connect = 1; + } else if (!strcmp(capname, "stateless-connect")) { + data->stateless_connect = 1; } else if (!strcmp(capname, "signed-tags")) { data->signed_tags = 1; } else if (skip_prefix(capname, "export-marks ", &arg)) { @@ -612,6 +616,13 @@ static int process_connect_service(struct transport *transport, if (data->connect) { strbuf_addf(&cmdbuf, "connect %s\n", name); ret = run_connect(transport, &cmdbuf); + } else if (data->stateless_connect && + (get_protocol_version_config() == protocol_v2) && + !strcmp("git-upload-pack", name)) { + strbuf_addf(&cmdbuf, "stateless-connect %s\n", name); + ret = run_connect(transport, &cmdbuf); + if (ret) + transport->stateless_rpc = 1; } strbuf_release(&cmdbuf); diff --git a/transport.c b/transport.c index 9152a45b38..342db492ca 100644 --- a/transport.c +++ b/transport.c @@ -252,6 +252,7 @@ static int fetch_refs_via_pack(struct transport *transport, data->options.check_self_contained_and_connected; args.cloning = transport->cloning; args.update_shallow = data->options.update_shallow; + args.stateless_rpc = transport->stateless_rpc; if (!data->got_remote_heads) refs_tmp = get_refs_via_connect(transport, 0, NULL); diff --git a/transport.h b/transport.h index 83992a4257..0e602d4d47 100644 --- a/transport.h +++ b/transport.h @@ -55,6 +55,12 @@ struct transport { */ unsigned cloning : 1; + /* + * Indicates that the transport is connected via a half-duplex + * connection and should operate in stateless-rpc mode. + */ + unsigned stateless_rpc : 1; + /* * These strings will be passed to the {pre, post}-receive hook, * on the remote side, if both sides support the push options capability.
-- 2.16.2.804.g6dcf76e118-goog