D2858: wireproto: define and implement responses in framing protocol
indygreg (Gregory Szorc)
phabricator at mercurial-scm.org
Wed Mar 14 12:43:30 EDT 2018
indygreg updated this revision to Diff 7034.
REPOSITORY
rHG Mercurial
CHANGES SINCE LAST UPDATE
https://phab.mercurial-scm.org/D2858?vs=7032&id=7034
REVISION DETAIL
https://phab.mercurial-scm.org/D2858
AFFECTED FILES
mercurial/help/internals/wireprotocol.txt
mercurial/wireprotoframing.py
mercurial/wireprotoserver.py
tests/test-http-api-httpv2.t
CHANGE DETAILS
diff --git a/tests/test-http-api-httpv2.t b/tests/test-http-api-httpv2.t
--- a/tests/test-http-api-httpv2.t
+++ b/tests/test-http-api-httpv2.t
@@ -180,10 +180,14 @@
s> HTTP/1.1 200 OK\r\n
s> Server: testing stub value\r\n
s> Date: $HTTP_DATE$\r\n
- s> Content-Type: text/plain\r\n
- s> Content-Length: *\r\n (glob)
+ s> Content-Type: application/mercurial-exp-framing-0001\r\n
+ s> Transfer-Encoding: chunked\r\n
s> \r\n
- s> lookup branchmap pushkey known getbundle unbundlehash streamreqs=generaldelta,revlogv1 $USUAL_BUNDLE2_CAPS_SERVER$ unbundle=HG10GZ,HG10BZ,HG10UN
+ s> *\r\n (glob)
+ s> Y\x01\x00Blookup branchmap pushkey known getbundle unbundlehash streamreqs=generaldelta,revlogv1 $USUAL_BUNDLE2_CAPS_SERVER$ unbundle=HG10GZ,HG10BZ,HG10UN
+ s> \r\n
+ s> 0\r\n
+ s> \r\n
Request to read-write command fails because server is read-only by default
@@ -287,10 +291,14 @@
s> HTTP/1.1 200 OK\r\n
s> Server: testing stub value\r\n
s> Date: $HTTP_DATE$\r\n
- s> Content-Type: text/plain\r\n
- s> Content-Length: *\r\n (glob)
+ s> Content-Type: application/mercurial-exp-framing-0001\r\n
+ s> Transfer-Encoding: chunked\r\n
s> \r\n
- s> lookup branchmap pushkey known getbundle unbundlehash streamreqs=generaldelta,revlogv1 $USUAL_BUNDLE2_CAPS_SERVER$ unbundle=HG10GZ,HG10BZ,HG10UN
+ s> *\r\n (glob)
+ s> Y\x01\x00Blookup branchmap pushkey known getbundle unbundlehash streamreqs=generaldelta,revlogv1 $USUAL_BUNDLE2_CAPS_SERVER$ unbundle=HG10GZ,HG10BZ,HG10UN
+ s> \r\n
+ s> 0\r\n
+ s> \r\n
Authorized request for unknown command is rejected
diff --git a/mercurial/wireprotoserver.py b/mercurial/wireprotoserver.py
--- a/mercurial/wireprotoserver.py
+++ b/mercurial/wireprotoserver.py
@@ -497,15 +497,20 @@
rsp = wireproto.dispatch(repo, proto, command['command'])
- # TODO use proper response format.
res.status = b'200 OK'
- res.headers[b'Content-Type'] = b'text/plain'
+ res.headers[b'Content-Type'] = FRAMINGTYPE
if isinstance(rsp, wireprototypes.bytesresponse):
- res.setbodybytes(rsp.data)
+ action = reactor.onbytesresponseready(rsp.data)
else:
- res.setbodybytes(b'unhandled response type from wire proto '
- 'command')
+ action = reactor.onapplicationerror(
+ _('unhandled response type from wire proto command'))
+
+ if action['action'] == b'sendframes':
+ res.setbodygen(action['framegen'])
+ else:
+ raise error.ProgrammingError('unhandled event from reactor: %s' %
+ action['action'])
# Maps API name to metadata so custom API can be registered.
API_HANDLERS = {
diff --git a/mercurial/wireprotoframing.py b/mercurial/wireprotoframing.py
--- a/mercurial/wireprotoframing.py
+++ b/mercurial/wireprotoframing.py
@@ -20,15 +20,20 @@
)
FRAME_HEADER_SIZE = 4
+DEFAULT_MAX_FRAME_SIZE = 32768
FRAME_TYPE_COMMAND_NAME = 0x01
FRAME_TYPE_COMMAND_ARGUMENT = 0x02
FRAME_TYPE_COMMAND_DATA = 0x03
+FRAME_TYPE_BYTES_RESPONSE = 0x04
+FRAME_TYPE_ERROR_RESPONSE = 0x05
FRAME_TYPES = {
b'command-name': FRAME_TYPE_COMMAND_NAME,
b'command-argument': FRAME_TYPE_COMMAND_ARGUMENT,
b'command-data': FRAME_TYPE_COMMAND_DATA,
+ b'bytes-response': FRAME_TYPE_BYTES_RESPONSE,
+ b'error-response': FRAME_TYPE_ERROR_RESPONSE,
}
FLAG_COMMAND_NAME_EOS = 0x01
@@ -57,11 +62,29 @@
b'eos': FLAG_COMMAND_DATA_EOS,
}
+FLAG_BYTES_RESPONSE_CONTINUATION = 0x01
+FLAG_BYTES_RESPONSE_EOS = 0x02
+
+FLAGS_BYTES_RESPONSE = {
+ b'continuation': FLAG_BYTES_RESPONSE_CONTINUATION,
+ b'eos': FLAG_BYTES_RESPONSE_EOS,
+}
+
+FLAG_ERROR_RESPONSE_PROTOCOL = 0x01
+FLAG_ERROR_RESPONSE_APPLICATION = 0x02
+
+FLAGS_ERROR_RESPONSE = {
+ b'protocol': FLAG_ERROR_RESPONSE_PROTOCOL,
+ b'application': FLAG_ERROR_RESPONSE_APPLICATION,
+}
+
# Maps frame types to their available flags.
FRAME_TYPE_FLAGS = {
FRAME_TYPE_COMMAND_NAME: FLAGS_COMMAND,
FRAME_TYPE_COMMAND_ARGUMENT: FLAGS_COMMAND_ARGUMENT,
FRAME_TYPE_COMMAND_DATA: FLAGS_COMMAND_DATA,
+ FRAME_TYPE_BYTES_RESPONSE: FLAGS_BYTES_RESPONSE,
+ FRAME_TYPE_ERROR_RESPONSE: FLAGS_ERROR_RESPONSE,
}
ARGUMENT_FRAME_HEADER = struct.Struct(r'<HH')
@@ -147,10 +170,10 @@
if datafh:
while True:
- data = datafh.read(32768)
+ data = datafh.read(DEFAULT_MAX_FRAME_SIZE)
done = False
- if len(data) == 32768:
+ if len(data) == DEFAULT_MAX_FRAME_SIZE:
flags = FLAG_COMMAND_DATA_CONTINUATION
else:
flags = FLAG_COMMAND_DATA_EOS
@@ -162,6 +185,47 @@
if done:
break
+def createbytesresponseframesfrombytes(data,
+ maxframesize=DEFAULT_MAX_FRAME_SIZE):
+ """Create a raw frame to send a bytes response from static bytes input.
+
+ Returns a generator of bytearrays.
+ """
+
+ # Simple case of a single frame.
+ if len(data) <= maxframesize:
+ yield makeframe(FRAME_TYPE_BYTES_RESPONSE,
+ FLAG_BYTES_RESPONSE_EOS, data)
+ return
+
+ offset = 0
+ while True:
+ chunk = data[offset:maxframesize]
+ offset += len(chunk)
+ done = offset +1 == len(data)
+
+ if done:
+ flags = FLAG_BYTES_RESPONSE_EOS
+ else:
+ flags = FLAG_BYTES_RESPONSE_CONTINUATION
+
+ yield makeframe(FRAME_TYPE_BYTES_RESPONSE, flags, chunk)
+
+ if done:
+ break
+
+def createerrorframe(msg, protocol=False, application=False):
+ # TODO properly handle frame size limits.
+ assert len(msg) <= DEFAULT_MAX_FRAME_SIZE
+
+ flags = 0
+ if protocol:
+ flags |= FLAG_ERROR_RESPONSE_PROTOCOL
+ if application:
+ flags |= FLAG_ERROR_RESPONSE_APPLICATION
+
+ yield makeframe(FRAME_TYPE_ERROR_RESPONSE, flags, msg)
+
class serverreactor(object):
"""Holds state of a server handling frame-based protocol requests.
@@ -212,6 +276,22 @@
return meth(frametype, frameflags, payload)
+ def onbytesresponseready(self, data):
+ """Signal that a bytes response is ready to be sent to the client.
+
+ The raw bytes response is passed as an argument.
+ """
+ return {
+ 'action': 'sendframes',
+ 'framegen': createbytesresponseframesfrombytes(data),
+ }
+
+ def onapplicationerror(self, msg):
+ return {
+ 'action': 'sendframes',
+ 'framegen': createerrorframe(msg, application=True),
+ }
+
def _makeerrorresult(self, msg):
return {
'action': 'error',
diff --git a/mercurial/help/internals/wireprotocol.txt b/mercurial/help/internals/wireprotocol.txt
--- a/mercurial/help/internals/wireprotocol.txt
+++ b/mercurial/help/internals/wireprotocol.txt
@@ -591,6 +591,40 @@
server. The command has been fully issued and no new data for this
command will be sent. The next frame will belong to a new command.
+Bytes Response Data (``0x04``)
+------------------------------
+
+This frame contains raw bytes response data to an issued command.
+
+The following flag values are defined for this type:
+
+0x01
+ Data continuation. When set, an additional frame containing raw
+ response data will follow.
+0x02
+ End of data. When sent, the response data has been fully sent and
+ no additional frames for this response will be sent.
+
+The ``0x01`` flag is mutually exclusive with the ``0x02`` flag.
+
+Error Response (``0x05``)
+-------------------------
+
+An error occurred when processing a request. This could indicate
+a protocol-level failure or an application level failure depending
+on the flags for this message type.
+
+The payload for this type is an error message that should be
+displayed to the user.
+
+The following flag values are defined for this type:
+
+0x01
+ The error occurred at the transport/protocol level. If set, the
+ connection should be closed.
+0x02
+ The error occurred at the application level. e.g. invalid command.
+
Issuing Commands
----------------
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