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Viewing changes to bzrlib/transport/__init__.py

  • Committer: Canonical.com Patch Queue Manager
  • Date: 2006-03-09 06:39:13 UTC
  • mfrom: (1596.2.6 integration)
  • Revision ID: pqm@pqm.ubuntu.com-20060309063913-6d8ce700706d0802
Merge knit performance stage 1.

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bzrlib/transport/__init__.py
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"""
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import errno
 
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from collections import deque
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from copy import deepcopy
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from stat import *
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import sys
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        """
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        raise NotImplementedError
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    def readv(self, relpath, offsets):
 
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        """Get parts of the file at the given relative path.
 
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        :offsets: A list of (offset, size) tuples.
 
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        :return: A list or generator of (offset, data) tuples
 
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        """
 
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        def do_combined_read(combined_offsets):
 
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            total_size = 0
 
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            for offset, size in combined_offsets:
 
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                total_size += size
 
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            mutter('readv coalesced %d reads.', len(combined_offsets))
 
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            offset = combined_offsets[0][0]
 
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            fp.seek(offset)
 
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            data = fp.read(total_size)
 
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            pos = 0
 
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            for offset, size in combined_offsets:
 
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                yield offset, data[pos:pos + size]
 
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                pos += size
 
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        if not len(offsets):
 
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            return
 
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        fp = self.get(relpath)
 
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        pending_offsets = deque(offsets)
 
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        combined_offsets = []
 
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        while len(pending_offsets):
 
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            offset, size = pending_offsets.popleft()
 
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            if not combined_offsets:
 
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                combined_offsets = [[offset, size]]
 
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            else:
 
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                if (len (combined_offsets) < 50 and
 
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                    combined_offsets[-1][0] + combined_offsets[-1][1] == offset):
 
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                    # combatible offset:
 
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                    combined_offsets.append([offset, size])
 
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                else:
 
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                    # incompatible, or over the threshold issue a read and yield
 
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                    pending_offsets.appendleft((offset, size))
 
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                    for result in do_combined_read(combined_offsets):
 
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                        yield result
 
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                    combined_offsets = []
 
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        # whatever is left is a single coalesced request
 
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        if len(combined_offsets):
 
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            for result in do_combined_read(combined_offsets):
 
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                yield result
 
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    def get_multi(self, relpaths, pb=None):
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        """Get a list of file-like objects, one for each entry in relpaths.
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                # from running this test
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                pass
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        return result
 
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class TransportLogger(object):
 
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    """Adapt a transport to get clear logging data on api calls.
 
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    Feel free to extend to log whatever calls are of interest.
 
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    """
 
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    def __init__(self, adapted):
 
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        self._adapted = adapted
 
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        self._calls = []
 
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    def get(self, name):
 
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        self._calls.append((name,))
 
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        return self._adapted.get(name)
 
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    def __getattr__(self, name):
 
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        """Thunk all undefined access through to self._adapted."""
 
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        # raise AttributeError, name 
 
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        return getattr(self._adapted, name)
 
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    def readv(self, name, offsets):
 
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        self._calls.append((name, offsets))
 
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        return self._adapted.readv(name, offsets)
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# None is the default transport, for things with no url scheme