In the Git pack protocol definition, an error packet may appear only in
a certain context. However, servers can face a runtime error (e.g. I/O
error) at an arbitrary timing. This patch changes the protocol to allow
an error packet to be sent instead of any packet.
Without this protocol spec change, when a server cannot process a
request, there's no way to tell that to a client. Since the server
cannot produce a valid response, it would be forced to cut a connection
without telling why. With this protocol spec change, the server can be
more gentle in this situation. An old client may see these error packets
as an unexpected packet, but this is not worse than having an unexpected
EOF.
Following this protocol spec change, the error packet handling code is
moved to pkt-line.c. Implementation wise, this implementation uses
pkt-line to communicate with a subprocess. Since this is not a part of
Git protocol, it's possible that a packet that is not supposed to be an
error packet is mistakenly parsed as an error packet. This error packet
handling is enabled only for the Git pack protocol parsing code
considering this.
Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce the "server-option" capability to protocol version 2. This
enables future clients the ability to send server specific options in
command requests when using protocol version 2.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When communicating with a v2 server, perform a fetch by requesting the
'fetch' command.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce the ls-refs server command. In protocol v2, the ls-refs
command is used to request the ref advertisement from the server. Since
it is a command which can be requested (as opposed to mandatory in v1),
a client can sent a number of parameters in its request to limit the ref
advertisement based on provided ref-prefixes.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce git-serve, the base server for protocol version 2.
Protocol version 2 is intended to be a replacement for Git's current
wire protocol. The intention is that it will be a simpler, less
wasteful protocol which can evolve over time.
Protocol version 2 improves upon version 1 by eliminating the initial
ref advertisement. In its place a server will export a list of
capabilities and commands which it supports in a capability
advertisement. A client can then request that a particular command be
executed by providing a number of capabilities and command specific
parameters. At the completion of a command, a client can request that
another command be executed or can terminate the connection by sending a
flush packet.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
