##// END OF EJS Templates
wireproto: add streams to frame-based protocol...
wireproto: add streams to frame-based protocol Previously, the frame-based protocol was just a series of frames, with each frame associated with a request ID. In order to scale the protocol, we'll want to enable the use of compression. While it is possible to enable compression at the socket/pipe level, this has its disadvantages. The big one is it undermines the point of frames being standalone, atomic units that can be read and written: if you add compression above the framing protocol, you are back to having a stream-based protocol as opposed to something frame-based. So in order to preserve frames, compression needs to occur at the frame payload level. Compressing each frame's payload individually will limit compression ratios because the window size of the compressor will be limited by the max frame size, which is 32-64kb as currently defined. It will also add CPU overhead, as it is more efficient for compressors to operate on fewer, larger blocks of data than more, smaller blocks. So compressing each frame independently is out. This means we need to compress each frame's payload as if it is part of a larger stream. The simplest approach is to have 1 stream per connection. This could certainly work. However, it has disadvantages (documented below). We could also have 1 stream per RPC/command invocation. (This is the model HTTP/2 goes with.) This also has disadvantages. The main disadvantage to one global stream is that it has the very real potential to create CPU bottlenecks doing compression. Networks are only getting faster and the performance of single CPU cores has been relatively flat. Newer compression formats like zstandard offer better CPU cycle efficiency than predecessors like zlib. But it still all too common to saturate your CPU with compression overhead long before you saturate the network pipe. The main disadvantage with streams per request is that you can't reap the benefits of the compression context for multiple requests. For example, if you send 1000 RPC requests (or HTTP/2 requests for that matter), the response to each would have its own compression context. The overall size of the raw responses would be larger because compression contexts wouldn't be able to reference data from another request or response. The approach for streams as implemented in this commit is to support N streams per connection and for streams to potentially span requests and responses. As explained by the added internals docs, this facilitates servers and clients delegating independent streams and compression to independent threads / CPU cores. This helps alleviate the CPU bottleneck of compression. This design also allows compression contexts to be reused across requests/responses. This can result in improved compression ratios and less overhead for compressors and decompressors having to build new contexts. Another feature that was defined was the ability for individual frames within a stream to declare whether that individual frame's payload uses the content encoding (read: compression) defined by the stream. The idea here is that some servers may serve data from a combination of caches and dynamic resolution. Data coming from caches may be pre-compressed. We want to facilitate servers being able to essentially stream bytes from caches to the wire with minimal overhead. Being able to mix and match with frames are compressed within a stream enables these types of advanced server functionality. This commit defines the new streams mechanism. Basic code for supporting streams in frames has been added. But that code is seriously lacking and doesn't fully conform to the defined protocol. For example, we don't close any streams. And support for content encoding within streams is not yet implemented. The change was rather invasive and I didn't think it would be reasonable to implement the entire feature in a single commit. For the record, I would have loved to reuse an existing multiplexing protocol to build the new wire protocol on top of. However, I couldn't find a protocol that offers the performance and scaling characteristics that I desired. Namely, it should support multiple compression contexts to facilitate scaling out to multiple CPU cores and compression contexts should be able to live longer than single RPC requests. HTTP/2 *almost* fits the bill. But the semantics of HTTP message exchange state that streams can only live for a single request-response. We /could/ tunnel on top of HTTP/2 streams and frames with HEADER and DATA frames. But there's no guarantee that HTTP/2 libraries and proxies would allow us to use HTTP/2 streams and frames without the HTTP message exchange semantics defined in RFC 7540 Section 8. Other RPC protocols like gRPC tunnel are built on top of HTTP/2 and thus preserve its semantics of stream per RPC invocation. Even QUIC does this. We could attempt to invent a higher-level stream that spans HTTP/2 streams. But this would be violating HTTP/2 because there is no guarantee that HTTP/2 streams are routed to the same server. The best we can do - which is what this protocol does - is shoehorn all request and response data into a single HTTP message and create streams within. At that point, we've defined a Content-Type in HTTP parlance. It just so happens our media type can also work as a standalone, stream-based protocol, without leaning on HTTP or similar protocol. Differential Revision: https://phab.mercurial-scm.org/D2907

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error.py
307 lines | 9.7 KiB | text/x-python | PythonLexer
Martin Geisler
put license and copyright info into comment blocks
r8226 # error.py - Mercurial exceptions
#
# Copyright 2005-2008 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
Matt Mackall
Update license to GPLv2+
r10263 # GNU General Public License version 2 or any later version.
Matt Mackall
errors: move revlog errors...
r7633
Martin Geisler
turn some comments back into module docstrings
r8227 """Mercurial exceptions.
This allows us to catch exceptions at higher levels without forcing
imports.
"""
Gregory Szorc
error: use absolute_import
r25945 from __future__ import absolute_import
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 # Do not import anything but pycompat here, please
from . import pycompat
def _tobytes(exc):
"""Byte-stringify exception in the same way as BaseException_str()"""
if not exc.args:
return b''
if len(exc.args) == 1:
return pycompat.bytestr(exc.args[0])
return b'(%s)' % b', '.join(b"'%s'" % pycompat.bytestr(a) for a in exc.args)
Matt Mackall
errors: move revlog errors...
r7633
Yuya Nishihara
error: make HintException a mix-in class not derived from BaseException (API)...
r29509 class Hint(object):
"""Mix-in to provide a hint of an error
Yuya Nishihara
error: make hintable exceptions reject unknown keyword arguments (API)...
r29510 This should come first in the inheritance list to consume a hint and
pass remaining arguments to the exception class.
Yuya Nishihara
error: make HintException a mix-in class not derived from BaseException (API)...
r29509 """
Jordi Gutiérrez Hermoso
error: refactor common hint-pattern into a common base class...
r25248 def __init__(self, *args, **kw):
Augie Fackler
error: use r-string to properly pop hints from **kw...
r31503 self.hint = kw.pop(r'hint', None)
Yuya Nishihara
error: make hintable exceptions reject unknown keyword arguments (API)...
r29510 super(Hint, self).__init__(*args, **kw)
Jordi Gutiérrez Hermoso
error: refactor common hint-pattern into a common base class...
r25248
Yuya Nishihara
error: make HintException a mix-in class not derived from BaseException (API)...
r29509 class RevlogError(Hint, Exception):
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 __bytes__ = _tobytes
Matt Mackall
errors: move revlog errors...
r7633
Pierre-Yves David
repoview: add a FilteredIndexError class...
r23014 class FilteredIndexError(IndexError):
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 __bytes__ = _tobytes
Pierre-Yves David
repoview: add a FilteredIndexError class...
r23014
Matt Mackall
errors: move revlog errors...
r7633 class LookupError(RevlogError, KeyError):
def __init__(self, name, index, message):
self.name = name
Martin von Zweigbergk
error: store filename and message on LookupError for later...
r24038 self.index = index
Siddharth Agarwal
error.LookupError: rename 'message' property to something else...
r24137 # this can't be called 'message' because at least some installs of
# Python 2.6+ complain about the 'message' property being deprecated
self.lookupmessage = message
Augie Fackler
error: fix isinstnace check to use bytes instead of str...
r36559 if isinstance(name, bytes) and len(name) == 20:
Gregory Szorc
error: use absolute_import
r25945 from .node import short
Matt Mackall
errors: move revlog errors...
r7633 name = short(name)
RevlogError.__init__(self, '%s@%s: %s' % (index, name, message))
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 def __bytes__(self):
return RevlogError.__bytes__(self)
Matt Mackall
errors: move revlog errors...
r7633 def __str__(self):
return RevlogError.__str__(self)
Matt Mackall
error: move ParseError
r7636
Pierre-Yves David
repoview: add a FilteredLookupError class...
r23015 class FilteredLookupError(LookupError):
pass
Takumi IINO
hgweb: show correct error message for i18n environment...
r18855 class ManifestLookupError(LookupError):
pass
Matt Mackall
error: change ParseError to CommandError
r11287 class CommandError(Exception):
Matt Mackall
error: move ParseError
r7636 """Exception raised on errors in parsing the command line."""
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 __bytes__ = _tobytes
Matt Mackall
error: move repo errors...
r7637
Yuya Nishihara
error: make HintException a mix-in class not derived from BaseException (API)...
r29509 class InterventionRequired(Hint, Exception):
Augie Fackler
error: introduce new InterventionRequired exception...
r18931 """Exception raised when a command requires human intervention."""
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 __bytes__ = _tobytes
Augie Fackler
error: introduce new InterventionRequired exception...
r18931
Yuya Nishihara
error: make HintException a mix-in class not derived from BaseException (API)...
r29509 class Abort(Hint, Exception):
Matt Mackall
error: add new ParseError for various parsing errors
r11288 """Raised if a command needs to print an error and exit."""
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 __bytes__ = _tobytes
Matt Mackall
error: add new ParseError for various parsing errors
r11288
Siddharth Agarwal
hook: raise a separate exception for when loading a hook fails...
r26692 class HookLoadError(Abort):
"""raised when loading a hook fails, aborting an operation
Exists to allow more specialized catching."""
Pierre-Yves David
hook: raise a more specialized HookAbort exception when a hook fails...
r23415 class HookAbort(Abort):
"""raised when a validation hook fails, aborting an operation
Exists to allow more specialized catching."""
Matt Mackall
error: add new ParseError for various parsing errors
r11288 class ConfigError(Abort):
Mike Edgar
error: use docstrings, not bare strings, for error classes
r22359 """Exception raised when parsing config files"""
Matt Mackall
ui: introduce new config parser
r8144
Pierre-Yves David
update: introduce a 'UpdateAbort' exception...
r26683 class UpdateAbort(Abort):
"""Raised when an update is aborted for destination issue"""
Pierre-Yves David
destutil: add more precise error classes for destmerge...
r28141 class MergeDestAbort(Abort):
"""Raised when an update is aborted for destination issues"""
class NoMergeDestAbort(MergeDestAbort):
"""Raised when an update is aborted because there is nothing to merge"""
class ManyMergeDestAbort(MergeDestAbort):
Mads Kiilerich
spelling: fixes of non-dictionary words
r30332 """Raised when an update is aborted because destination is ambiguous"""
Pierre-Yves David
destutil: add more precise error classes for destmerge...
r28141
Siddharth Agarwal
error: add structured exception for EOF at prompt...
r26896 class ResponseExpected(Abort):
"""Raised when an EOF is received for a prompt"""
def __init__(self):
from .i18n import _
Abort.__init__(self, _('response expected'))
Yuya Nishihara
error: make HintException a mix-in class not derived from BaseException (API)...
r29509 class OutOfBandError(Hint, Exception):
Mike Edgar
error: use docstrings, not bare strings, for error classes
r22359 """Exception raised when a remote repo reports failure"""
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 __bytes__ = _tobytes
Andrew Pritchard
wireproto: add out-of-band error class to allow remote repo to report errors...
r15017
Yuya Nishihara
error: make HintException a mix-in class not derived from BaseException (API)...
r29509 class ParseError(Hint, Exception):
Augie Fackler
error: update docstring on ParseError...
r24040 """Raised when parsing config files and {rev,file}sets (msg[, pos])"""
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 __bytes__ = _tobytes
Matt Mackall
error: add new ParseError for various parsing errors
r11288
Yuya Nishihara
error: move patch.PatchError so it can easily implement __bytes__ (API)
r34252 class PatchError(Exception):
__bytes__ = _tobytes
Augie Fackler
error: add a new UnknownIdentifier error type...
r24217 class UnknownIdentifier(ParseError):
"""Exception raised when a {rev,file}set references an unknown identifier"""
def __init__(self, function, symbols):
Gregory Szorc
error: use absolute_import
r25945 from .i18n import _
Augie Fackler
error: add a new UnknownIdentifier error type...
r24217 ParseError.__init__(self, _("unknown identifier: %s") % function)
self.function = function
self.symbols = symbols
Yuya Nishihara
error: make HintException a mix-in class not derived from BaseException (API)...
r29509 class RepoError(Hint, Exception):
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 __bytes__ = _tobytes
Matt Mackall
error: move repo errors...
r7637
Matt Mackall
Make distinct lookup error for localrepo.lookup...
r9423 class RepoLookupError(RepoError):
pass
Pierre-Yves David
repoview: add a FilteredRepoLookupError...
r23016 class FilteredRepoLookupError(RepoLookupError):
pass
Matt Mackall
error: move repo errors...
r7637 class CapabilityError(RepoError):
pass
Matt Mackall
error: move lock errors...
r7640
Adrian Buehlmann
introduce new RequirementError (issue2649)...
r13447 class RequirementError(RepoError):
"""Exception raised if .hg/requires has an unknown entry."""
Bryan O'Sullivan
stdio: add machinery to identify failed stdout/stderr writes...
r31959 class StdioError(IOError):
"""Raised if I/O to stdout or stderr fails"""
def __init__(self, err):
IOError.__init__(self, err.errno, err.strerror)
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 # no __bytes__() because error message is derived from the standard IOError
Siddharth Agarwal
error: add a structured exception for unsupported merge records...
r26985 class UnsupportedMergeRecords(Abort):
def __init__(self, recordtypes):
from .i18n import _
self.recordtypes = sorted(recordtypes)
s = ' '.join(self.recordtypes)
Abort.__init__(
self, _('unsupported merge state records: %s') % s,
hint=_('see https://mercurial-scm.org/wiki/MergeStateRecords for '
'more information'))
obsolete: raise richer exception on unknown version...
r32591 class UnknownVersion(Abort):
"""generic exception for aborting from an encounter with an unknown version
"""
def __init__(self, msg, hint=None, version=None):
self.version = version
super(UnknownVersion, self).__init__(msg, hint=hint)
Matt Mackall
error: move lock errors...
r7640 class LockError(IOError):
def __init__(self, errno, strerror, filename, desc):
IOError.__init__(self, errno, strerror, filename)
self.desc = desc
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 # no __bytes__() because error message is derived from the standard IOError
Matt Mackall
error: move lock errors...
r7640 class LockHeld(LockError):
def __init__(self, errno, filename, desc, locker):
LockError.__init__(self, errno, 'Lock held', filename, desc)
self.locker = locker
class LockUnavailable(LockError):
pass
Matt Mackall
error: move UnexpectedOutput (now ResponseError)
r7641
Siddharth Agarwal
error: add an exception to indicate lock inheritance API contract violations
r26355 # LockError is for errors while acquiring the lock -- this is unrelated
Siddharth Agarwal
error: make lock inheritance contract violations a subclass of RuntimeError...
r26438 class LockInheritanceContractViolation(RuntimeError):
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 __bytes__ = _tobytes
Siddharth Agarwal
error: add an exception to indicate lock inheritance API contract violations
r26355
Matt Mackall
error: move UnexpectedOutput (now ResponseError)
r7641 class ResponseError(Exception):
"""Raised to print an error with part of output and exit."""
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 __bytes__ = _tobytes
Matt Mackall
error: move UnexpectedOutput (now ResponseError)
r7641
Matt Mackall
error: move UnknownCommand and AmbiguousCommand
r7643 class UnknownCommand(Exception):
"""Exception raised if command is not in the command table."""
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 __bytes__ = _tobytes
Matt Mackall
error: move UnknownCommand and AmbiguousCommand
r7643
class AmbiguousCommand(Exception):
"""Exception raised if command shortcut matches more than one command."""
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 __bytes__ = _tobytes
Matt Mackall
error: move UnknownCommand and AmbiguousCommand
r7643
Matt Mackall
error: move SignalInterrupt...
r7644 # derived from KeyboardInterrupt to simplify some breakout code
class SignalInterrupt(KeyboardInterrupt):
"""Exception raised on SIGTERM and SIGHUP."""
Matt Mackall
error: move SignatureError
r7646
class SignatureError(Exception):
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 __bytes__ = _tobytes
Pierre-Yves David
bundle2: fix raising errors during heads checking...
r21184
class PushRaced(RuntimeError):
"""An exception raised during unbundling that indicate a push race"""
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 __bytes__ = _tobytes
Pierre-Yves David
bundle2: fix raising errors during heads checking...
r21184
Yuya Nishihara
error: add hint to ProgrammingError...
r32340 class ProgrammingError(Hint, RuntimeError):
Jun Wu
error: make it clear that ProgrammingError is for mercurial developers...
r30585 """Raised if a mercurial (core or extension) developer made a mistake"""
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 __bytes__ = _tobytes
Jun Wu
error: add ProgrammingError...
r30573
Pulkit Goyal
error: add a new exception named WdirUnsupported...
r32401 class WdirUnsupported(Exception):
"""An exception which is raised when 'wdir()' is not supported"""
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 __bytes__ = _tobytes
Pulkit Goyal
error: add a new exception named WdirUnsupported...
r32401
Pierre-Yves David
bundle2: move exception classes into the error module...
r21618 # bundle2 related errors
class BundleValueError(ValueError):
Pierre-Yves David
bundle2: introduce a ``params`` attribute to BundleValueError...
r21621 """error raised when bundle2 cannot be processed"""
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 __bytes__ = _tobytes
Pierre-Yves David
bundle2: introduce a parttype attribute to BundleValueError...
r21620
Pierre-Yves David
bundle2: rename error exception class for unsupported feature...
r26393 class BundleUnknownFeatureError(BundleValueError):
Pierre-Yves David
bundle2: allow to specify unsupported value on error...
r26394 def __init__(self, parttype=None, params=(), values=()):
Pierre-Yves David
bundle2: introduce a parttype attribute to BundleValueError...
r21620 self.parttype = parttype
Pierre-Yves David
bundle2: introduce a ``params`` attribute to BundleValueError...
r21621 self.params = params
Pierre-Yves David
bundle2: allow to specify unsupported value on error...
r26394 self.values = values
Pierre-Yves David
bundle2: support None parttype in BundleValueError...
r21627 if self.parttype is None:
msg = 'Stream Parameter'
else:
msg = parttype
Pierre-Yves David
bundle2: allow to specify unsupported value on error...
r26394 entries = self.params
if self.params and self.values:
assert len(self.params) == len(self.values)
entries = []
for idx, par in enumerate(self.params):
val = self.values[idx]
if val is None:
entries.append(val)
else:
entries.append("%s=%r" % (par, val))
if entries:
msg = '%s - %s' % (msg, ', '.join(entries))
Brendan Cully
error: restore python 2.4 compatibility for BundleValueError...
r21747 ValueError.__init__(self, msg)
Pierre-Yves David
bundle2: move exception classes into the error module...
r21618
class ReadOnlyPartError(RuntimeError):
"""error raised when code tries to alter a part being generated"""
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 __bytes__ = _tobytes
Pierre-Yves David
bundle2: move exception classes into the error module...
r21618
Pierre-Yves David
bundle2: introduce a PushkeyFail error to abort unbundle on pushkey error...
r25484 class PushkeyFailed(Abort):
"""error raised when a pushkey part failed to update a value"""
def __init__(self, partid, namespace=None, key=None, new=None, old=None,
ret=None):
self.partid = partid
self.namespace = namespace
self.key = key
self.new = new
self.old = old
self.ret = ret
# no i18n expected to be processed into a better message
Abort.__init__(self, 'failed to update value for "%s/%s"'
% (namespace, key))
Mike Edgar
error: add CensoredNodeError, will be thrown when content deliberately erased...
r22595 class CensoredNodeError(RevlogError):
Mike Edgar
changegroup: emit full-replacement deltas if either revision is censored...
r24190 """error raised when content verification fails on a censored node
Mike Edgar
error: add CensoredNodeError, will be thrown when content deliberately erased...
r22595
Mike Edgar
changegroup: emit full-replacement deltas if either revision is censored...
r24190 Also contains the tombstone data substituted for the uncensored data.
"""
def __init__(self, filename, node, tombstone):
Gregory Szorc
error: use absolute_import
r25945 from .node import short
Mike Edgar
error: add CensoredNodeError, will be thrown when content deliberately erased...
r22595 RevlogError.__init__(self, '%s:%s' % (filename, short(node)))
Mike Edgar
changegroup: emit full-replacement deltas if either revision is censored...
r24190 self.tombstone = tombstone
Mike Edgar
revlog: in addgroup, reject ill-formed deltas based on censored nodes...
r24120
class CensoredBaseError(RevlogError):
"""error raised when a delta is rejected because its base is censored
A delta based on a censored revision must be formed as single patch
operation which replaces the entire base with new content. This ensures
the delta may be applied by clones which have not censored the base.
"""
Gregory Szorc
exchange: refactor bundle specification parsing...
r26640
class InvalidBundleSpecification(Exception):
"""error raised when a bundle specification is invalid.
This is used for syntax errors as opposed to support errors.
"""
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 __bytes__ = _tobytes
Gregory Szorc
exchange: refactor bundle specification parsing...
r26640
class UnsupportedBundleSpecification(Exception):
"""error raised when a bundle specification is not supported."""
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 __bytes__ = _tobytes
Kostia Balytskyi
shelve: make unshelve be able to abort in any case
r29536
class CorruptedState(Exception):
"""error raised when a command is not able to read its state from file"""
Yuya Nishihara
py3: implement __bytes__() on most of our exception classes...
r32616 __bytes__ = _tobytes
Gregory Szorc
httppeer: wrap HTTPResponse.read() globally...
r32002
Gregory Szorc
error: rename RichIOError to PeerTransportError...
r32023 class PeerTransportError(Abort):
"""Transport-level I/O error when communicating with a peer repo."""
Phil Cohen
error: add InMemoryMergeConflictsError...
r35104
class InMemoryMergeConflictsError(Exception):
"""Exception raised when merge conflicts arose during an in-memory merge."""
__bytes__ = _tobytes