--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/mercurial/httpclient/_readers.py Fri May 04 16:00:33 2012 -0500
@@ -0,0 +1,195 @@
+# 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.
+"""
+
+import httplib
+import itertools
+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 = []
+
+ @property
+ def available_data(self):
+ return sum(map(len, self._done_chunks))
+
+ def done(self):
+ return self._finished
+
+ def read(self, amt):
+ if self.available_data < amt and not self._finished:
+ raise ReadNotReady()
+ need = [amt]
+ def pred(s):
+ needed = need[0] > 0
+ need[0] -= len(s)
+ return needed
+ blocks = list(itertools.takewhile(pred, self._done_chunks))
+ self._done_chunks = self._done_chunks[len(blocks):]
+ over_read = sum(map(len, blocks)) - amt
+ if over_read > 0 and blocks:
+ logger.debug('need to reinsert %d data into done chunks', over_read)
+ last = blocks[-1]
+ blocks[-1], reinsert = last[:-over_read], last[-over_read:]
+ self._done_chunks.insert(0, reinsert)
+ result = ''.join(blocks)
+ assert len(result) == amt or (self._finished and len(result) < amt)
+ return result
+
+ 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 addtional %d data', self.name, len(data))
+ self._done_chunks.append(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):
+ AbstractReader.__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 addtional %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 redaer due to chunk of length 0')
+ return
+ self._done_chunks.append(data[block_start:block_start + amt])
+ position = block_start + amt + len(self._eol)
+# no-check-code