Blame - docs/oauth2client.locked_file.html - platform/external/python/google-api-python-client

><a href=".">index</a> <a href="file:/home/jcgregorio/projects/clean/oauth2client/locked_file.py">/home/jcgregorio/projects/clean/oauth2client/locked_file.py</a></td></tr></table>

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<tt>Locked file interface that should work on Unix and Windows pythons.

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This module first tries to use fcntl locking to ensure serialized access

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to a file, then falls back on a lock file if that is unavialable.

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Usage:

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f = <a href="#LockedFile">LockedFile</a>('filename', 'r+b', 'rb')

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f.open_and_lock()

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if f.is_locked():

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print 'Acquired filename with r+b mode'

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f.file_handle().write('locked data')

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else:

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print 'Aquired filename with rb mode'

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f.unlock_and_close()</tt>

<big>Modules</big></td></tr>

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<td width="100%"><table width="100%" summary="list"><tr><td width="25%" valign=top><a href="errno.html">errno</a>

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<a href="fcntl.html">fcntl</a>

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</td><td width="25%" valign=top><a href="logging.html">logging</a>

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</td><td width="25%" valign=top><a href="time.html">time</a>

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</td><td width="25%" valign=top></td></tr></table></td></tr></table>

<big>Classes</big></td></tr>

<dt><a href="__builtin__.html#object">__builtin__.object</a>

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</dt><dd>

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<dl>

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<dt><a href="oauth2client.locked_file.html#LockedFile">LockedFile</a>

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</dt></dl>

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</dd>

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<dt><a href="exceptions.html#Exception">exceptions.Exception</a>(<a href="exceptions.html#BaseException">exceptions.BaseException</a>)

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</dt><dd>

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<dl>

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<dt><a href="oauth2client.locked_file.html#AlreadyLockedException">AlreadyLockedException</a>

</dt></dl>

</dd>

</dl>

<a name="AlreadyLockedException">class AlreadyLockedException</a>(<a href="exceptions.html#Exception">exceptions.Exception</a>)</td></tr>

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<td colspan=2><tt>Trying to lock a file that has already been locked by the <a href="#LockedFile">LockedFile</a>.  </tt></td></tr>

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<td width="100%"><dl><dt>Method resolution order:</dt>

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<dd><a href="oauth2client.locked_file.html#AlreadyLockedException">AlreadyLockedException</a></dd>

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<dd><a href="exceptions.html#Exception">exceptions.Exception</a></dd>

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<dd><a href="exceptions.html#BaseException">exceptions.BaseException</a></dd>

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<dd><a href="__builtin__.html#object">__builtin__.object</a></dd>

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</dl>

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<hr>

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Data descriptors defined here:

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<dl><dt>__weakref__</dt>

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<dd><tt>list of weak references to the object (if defined)</tt></dd>

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</dl>

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<hr>

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Methods inherited from <a href="exceptions.html#Exception">exceptions.Exception</a>:

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<dl><dt><a name="AlreadyLockedException-__init__">__init__</a>(...)</dt><dd><tt>x.<a href="#AlreadyLockedException-__init__">__init__</a>(...) initializes x; see x.__class__.__doc__ for signature</tt></dd></dl>

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<hr>

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Data and other attributes inherited from <a href="exceptions.html#Exception">exceptions.Exception</a>:

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<dl><dt>__new__ = <built-in method __new__ of type object><dd><tt>T.<a href="#AlreadyLockedException-__new__">__new__</a>(S, ...) -> a new <a href="__builtin__.html#object">object</a> with type S, a subtype of T</tt></dl>

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<hr>

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Methods inherited from <a href="exceptions.html#BaseException">exceptions.BaseException</a>:

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<dl><dt><a name="AlreadyLockedException-__delattr__">__delattr__</a>(...)</dt><dd><tt>x.<a href="#AlreadyLockedException-__delattr__">__delattr__</a>('name') <==> del x.name</tt></dd></dl>

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<dl><dt><a name="AlreadyLockedException-__getattribute__">__getattribute__</a>(...)</dt><dd><tt>x.<a href="#AlreadyLockedException-__getattribute__">__getattribute__</a>('name') <==> x.name</tt></dd></dl>

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<dl><dt><a name="AlreadyLockedException-__getitem__">__getitem__</a>(...)</dt><dd><tt>x.<a href="#AlreadyLockedException-__getitem__">__getitem__</a>(y) <==> x[y]</tt></dd></dl>

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<dl><dt><a name="AlreadyLockedException-__getslice__">__getslice__</a>(...)</dt><dd><tt>x.<a href="#AlreadyLockedException-__getslice__">__getslice__</a>(i, j) <==> x[i:j]

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Use of negative indices is not supported.</tt></dd></dl>

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<dl><dt><a name="AlreadyLockedException-__reduce__">__reduce__</a>(...)</dt></dl>

<dl><dt><a name="AlreadyLockedException-__setattr__">__setattr__</a>(...)</dt><dd><tt>x.<a href="#AlreadyLockedException-__setattr__">__setattr__</a>('name', value) <==> x.name = value</tt></dd></dl>

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<dl><dt><a name="AlreadyLockedException-__setstate__">__setstate__</a>(...)</dt></dl>

<dl><dt><a name="AlreadyLockedException-__unicode__">__unicode__</a>(...)</dt></dl>

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<hr>

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Data descriptors inherited from <a href="exceptions.html#BaseException">exceptions.BaseException</a>:

</dl>

</dl>

<dl><dt>message</dt>

</dl>

</td></tr></table>

<a name="LockedFile">class LockedFile</a>(<a href="__builtin__.html#object">__builtin__.object</a>)</td></tr>

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<td colspan=2><tt>Represent a file that has exclusive access.  </tt></td></tr>

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<td width="100%">Methods defined here:

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<dl><dt><a name="LockedFile-__init__">__init__</a>(self, filename, mode, fallback_mode, use_fcntl=True)</dt><dd><tt>Construct a <a href="#LockedFile">LockedFile</a>.

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Args:

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filename: string, The path of the file to open.

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mode: string, The mode to try to open the file with.

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fallback_mode: string, The mode to use if locking fails.

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use_fcntl: string, Whether or not fcntl-based locking should be used.</tt></dd></dl>

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<dl><dt><a name="LockedFile-file_handle">file_handle</a>(self)</dt><dd><tt>Return the file_handle to the opened file.</tt></dd></dl>

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<dl><dt><a name="LockedFile-filename">filename</a>(self)</dt><dd><tt>Return the filename we were constructed with.</tt></dd></dl>

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<dl><dt><a name="LockedFile-is_locked">is_locked</a>(self)</dt><dd><tt>Return whether we successfully locked the file.</tt></dd></dl>

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<dl><dt><a name="LockedFile-open_and_lock">open_and_lock</a>(self, timeout=0, delay=0.050000000000000003)</dt><dd><tt>Open the file, trying to lock it.

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Args:

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timeout: float, The number of seconds to try to acquire the lock.

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delay: float, The number of seconds to wait between retry attempts.

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Raises:

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<a href="#AlreadyLockedException">AlreadyLockedException</a>: if the lock is already acquired.