Mercurial > hg
view mercurial/wireprototypes.py @ 37485:0b7475ea38cf
wireproto: port heads command to wire protocol v2
After much thought and consideration, wire protocol version 2's
commands will be defined in different functions from the existing
commands. This will make it easier to implement these commands
because it won't require shoehorning things like response formatting
and argument declaration into the same APIs.
For example, wire protocol version 1 requires that commands declare
a fixed and ordered list of argument names. It isn't really possible
to insert new arguments or have optional arguments without
breaking backwards compatibility. Wire protocol version 2, however,
uses CBOR maps for passing arguments. So arguments a) can be
optional b) can be added without BC c) can be strongly typed.
This commit starts our trek towards reimplementing the wire protocol
for version 2 with the heads command. It is pretty similar to the
existing heads command. One added feature is it can be told to
operate on only public phase changesets. This is useful for
making discovery faster when a repo has tens of thousands of
draft phase heads (such as Mozilla's "try" repository).
The HTTPv2 server-side protocol has had its `getargs()` implementation
updated to reflect that arguments are a map and not a list.
Differential Revision: https://phab.mercurial-scm.org/D3179
author | Gregory Szorc <gregory.szorc@gmail.com> |
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date | Wed, 28 Mar 2018 14:55:13 -0700 |
parents | 2d965bfeb8f6 |
children | 5e71dea79aae |
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# Copyright 2018 Gregory Szorc <gregory.szorc@gmail.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from __future__ import absolute_import from .thirdparty.zope import ( interface as zi, ) # Names of the SSH protocol implementations. SSHV1 = 'ssh-v1' # These are advertised over the wire. Increment the counters at the end # to reflect BC breakages. SSHV2 = 'exp-ssh-v2-0001' HTTPV2 = 'exp-http-v2-0001' # All available wire protocol transports. TRANSPORTS = { SSHV1: { 'transport': 'ssh', 'version': 1, }, SSHV2: { 'transport': 'ssh', # TODO mark as version 2 once all commands are implemented. 'version': 1, }, 'http-v1': { 'transport': 'http', 'version': 1, }, HTTPV2: { 'transport': 'http', 'version': 2, } } class bytesresponse(object): """A wire protocol response consisting of raw bytes.""" def __init__(self, data): self.data = data class ooberror(object): """wireproto reply: failure of a batch of operation Something failed during a batch call. The error message is stored in `self.message`. """ def __init__(self, message): self.message = message class pushres(object): """wireproto reply: success with simple integer return The call was successful and returned an integer contained in `self.res`. """ def __init__(self, res, output): self.res = res self.output = output class pusherr(object): """wireproto reply: failure The call failed. The `self.res` attribute contains the error message. """ def __init__(self, res, output): self.res = res self.output = output class streamres(object): """wireproto reply: binary stream The call was successful and the result is a stream. Accepts a generator containing chunks of data to be sent to the client. ``prefer_uncompressed`` indicates that the data is expected to be uncompressable and that the stream should therefore use the ``none`` engine. """ def __init__(self, gen=None, prefer_uncompressed=False): self.gen = gen self.prefer_uncompressed = prefer_uncompressed class streamreslegacy(object): """wireproto reply: uncompressed binary stream The call was successful and the result is a stream. Accepts a generator containing chunks of data to be sent to the client. Like ``streamres``, but sends an uncompressed data for "version 1" clients using the application/mercurial-0.1 media type. """ def __init__(self, gen=None): self.gen = gen class cborresponse(object): """Encode the response value as CBOR.""" def __init__(self, v): self.value = v class baseprotocolhandler(zi.Interface): """Abstract base class for wire protocol handlers. A wire protocol handler serves as an interface between protocol command handlers and the wire protocol transport layer. Protocol handlers provide methods to read command arguments, redirect stdio for the duration of the request, handle response types, etc. """ name = zi.Attribute( """The name of the protocol implementation. Used for uniquely identifying the transport type. """) def getargs(args): """return the value for arguments in <args> For version 1 transports, returns a list of values in the same order they appear in ``args``. For version 2 transports, returns a dict mapping argument name to value. """ def getprotocaps(): """Returns the list of protocol-level capabilities of client Returns a list of capabilities as declared by the client for the current request (or connection for stateful protocol handlers).""" def getpayload(): """Provide a generator for the raw payload. The caller is responsible for ensuring that the full payload is processed. """ def mayberedirectstdio(): """Context manager to possibly redirect stdio. The context manager yields a file-object like object that receives stdout and stderr output when the context manager is active. Or it yields ``None`` if no I/O redirection occurs. The intent of this context manager is to capture stdio output so it may be sent in the response. Some transports support streaming stdio to the client in real time. For these transports, stdio output won't be captured. """ def client(): """Returns a string representation of this client (as bytes).""" def addcapabilities(repo, caps): """Adds advertised capabilities specific to this protocol. Receives the list of capabilities collected so far. Returns a list of capabilities. The passed in argument can be returned. """ def checkperm(perm): """Validate that the client has permissions to perform a request. The argument is the permission required to proceed. If the client doesn't have that permission, the exception should raise or abort in a protocol specific manner. """