Mercurial > hg
view mercurial/httpclient/_readers.py @ 35616:706aa203b396
fileset: add a lightweight file filtering language
This patch was inspired by one that Jun Wu authored for the fb-experimental
repo, to avoid using matcher for efficiency[1]. We want a way to specify what
files will be converted to LFS at commit time. And per discussion, we also want
to specify what files to skip, text diff, or merge in another config option.
The current `lfs.threshold` config option could not satisfy complex needs. I'm
putting it in a core package because Augie floated the idea of also using it for
narrow and sparse.
Yuya suggested farming out to fileset.parse(), which added support for more
symbols. The only fileset element not supported here is 'negate'. (List isn't
supported by filesets either.) I also changed the 'always' token to the 'all()'
predicate for consistency, and introduced 'none()' to improve readability in a
future tracked file based config. The extension operator was changed from '.'
to '**', to match how recursive path globs are specified. Finally, I changed
the path matcher from '/' to 'path:' at Yuya's suggestion, for consistency with
matcher. Unfortunately, ':' is currently reserved in filesets, so this has to
be quoted to be processed as a string instead of a symbol[2]. We should
probably revisit that, because it's seriously ugly. But it's only used by an
experimental extension, and I think using a file based config for LFS may drive
some more tweaks, so I'm settling for this for now.
I reserved all of the glob characters in fileset except '.' and '_' for the
extension test because those are likely valid extension characters.
Sample filter settings:
all() # everything
size(">20MB") # larger than 20MB
!**.txt # except for .txt files
**.zip | **.tar.gz | **.7z # some types of compressed files
"path:bin" # files under "bin" in the project root
[1] https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-December/109387.html
[2] https://www.mercurial-scm.org/pipermail/mercurial-devel/2018-January/109729.html
author | Matt Harbison <matt_harbison@yahoo.com> |
---|---|
date | Wed, 10 Jan 2018 22:23:34 -0500 |
parents | 456609cbd840 |
children |
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# Copyright 2011, Google Inc. # All rights reserved. # # Redistribution and use in source and binary forms, with or without # modification, are permitted provided that the following conditions are # met: # # * Redistributions of source code must retain the above copyright # notice, this list of conditions and the following disclaimer. # * Redistributions in binary form must reproduce the above # copyright notice, this list of conditions and the following disclaimer # in the documentation and/or other materials provided with the # distribution. # * Neither the name of Google Inc. nor the names of its # contributors may be used to endorse or promote products derived from # this software without specific prior written permission. # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. """Reader objects to abstract out different body response types. This module is package-private. It is not expected that these will have any clients outside of httpplus. """ from __future__ import absolute_import try: import httplib httplib.HTTPException except ImportError: import http.client as httplib import logging logger = logging.getLogger(__name__) class ReadNotReady(Exception): """Raised when read() is attempted but not enough data is loaded.""" class HTTPRemoteClosedError(httplib.HTTPException): """The server closed the remote socket in the middle of a response.""" class AbstractReader(object): """Abstract base class for response readers. Subclasses must implement _load, and should implement _close if it's not an error for the server to close their socket without some termination condition being detected during _load. """ def __init__(self): self._finished = False self._done_chunks = [] self.available_data = 0 def _addchunk(self, data): self._done_chunks.append(data) self.available_data += len(data) def _pushchunk(self, data): self._done_chunks.insert(0, data) self.available_data += len(data) def _popchunk(self): b = self._done_chunks.pop(0) self.available_data -= len(b) return b def done(self): """Returns true if the response body is entirely read.""" return self._finished def read(self, amt): """Read amt bytes from the response body.""" if self.available_data < amt and not self._finished: raise ReadNotReady() blocks = [] need = amt while self._done_chunks: b = self._popchunk() if len(b) > need: nb = b[:need] self._pushchunk(b[need:]) b = nb blocks.append(b) need -= len(b) if need == 0: break result = b''.join(blocks) assert len(result) == amt or (self._finished and len(result) < amt) return result def readto(self, delimstr, blocks = None): """return available data chunks up to the first one in which delimstr occurs. No data will be returned after delimstr -- the chunk in which it occurs will be split and the remainder pushed back onto the available data queue. If blocks is supplied chunks will be added to blocks, otherwise a new list will be allocated. """ if blocks is None: blocks = [] while self._done_chunks: b = self._popchunk() i = b.find(delimstr) + len(delimstr) if i: if i < len(b): self._pushchunk(b[i:]) blocks.append(b[:i]) break else: blocks.append(b) return blocks def _load(self, data): # pragma: no cover """Subclasses must implement this. As data is available to be read out of this object, it should be placed into the _done_chunks list. Subclasses should not rely on data remaining in _done_chunks forever, as it may be reaped if the client is parsing data as it comes in. """ raise NotImplementedError def _close(self): """Default implementation of close. The default implementation assumes that the reader will mark the response as finished on the _finished attribute once the entire response body has been read. In the event that this is not true, the subclass should override the implementation of close (for example, close-is-end responses have to set self._finished in the close handler.) """ if not self._finished: raise HTTPRemoteClosedError( 'server appears to have closed the socket mid-response') class AbstractSimpleReader(AbstractReader): """Abstract base class for simple readers that require no response decoding. Examples of such responses are Connection: Close (close-is-end) and responses that specify a content length. """ def _load(self, data): if data: assert not self._finished, ( 'tried to add data (%r) to a closed reader!' % data) logger.debug('%s read an additional %d data', self.name, len(data)) # pylint: disable=E1101 self._addchunk(data) class CloseIsEndReader(AbstractSimpleReader): """Reader for responses that specify Connection: Close for length.""" name = 'close-is-end' def _close(self): logger.info('Marking close-is-end reader as closed.') self._finished = True class ContentLengthReader(AbstractSimpleReader): """Reader for responses that specify an exact content length.""" name = 'content-length' def __init__(self, amount): AbstractSimpleReader.__init__(self) self._amount = amount if amount == 0: self._finished = True self._amount_seen = 0 def _load(self, data): AbstractSimpleReader._load(self, data) self._amount_seen += len(data) if self._amount_seen >= self._amount: self._finished = True logger.debug('content-length read complete') class ChunkedReader(AbstractReader): """Reader for chunked transfer encoding responses.""" def __init__(self, eol): AbstractReader.__init__(self) self._eol = eol self._leftover_skip_amt = 0 self._leftover_data = '' def _load(self, data): assert not self._finished, 'tried to add data to a closed reader!' logger.debug('chunked read an additional %d data', len(data)) position = 0 if self._leftover_data: logger.debug( 'chunked reader trying to finish block from leftover data') # TODO: avoid this string concatenation if possible data = self._leftover_data + data position = self._leftover_skip_amt self._leftover_data = '' self._leftover_skip_amt = 0 datalen = len(data) while position < datalen: split = data.find(self._eol, position) if split == -1: self._leftover_data = data self._leftover_skip_amt = position return amt = int(data[position:split], base=16) block_start = split + len(self._eol) # If the whole data chunk plus the eol trailer hasn't # loaded, we'll wait for the next load. if block_start + amt + len(self._eol) > len(data): self._leftover_data = data self._leftover_skip_amt = position return if amt == 0: self._finished = True logger.debug('closing chunked reader due to chunk of length 0') return self._addchunk(data[block_start:block_start + amt]) position = block_start + amt + len(self._eol) # no-check-code