[PATCH 2 of 4] revlog: add a context manager to allow file handle reuse
yuya at tcha.org
Fri Nov 4 03:43:15 EDT 2016
On Tue, 01 Nov 2016 18:16:37 -0700, Gregory Szorc wrote:
> # HG changeset patch
> # User Gregory Szorc <gregory.szorc at gmail.com>
> # Date 1477099818 25200
> # Fri Oct 21 18:30:18 2016 -0700
> # Node ID d631065a702fa7eb956258e2289679d5902ccff6
> # Parent fb93d9a0a24db5a93a6a6758eacc6ba5ca37531e
> revlog: add a context manager to allow file handle reuse
> + @contextlib.contextmanager
> + def cachefilehandle(self):
> + """Maintain a persistent file handle during operations.
> + When this context manager is active, a file descriptor will be reused
> + for all read operations, ensuring the underlying revlog file isn't
> + reopened multiple times.
> + """
> + if self._readfh:
> + raise error.Abort('cachefilehandle already active')
> + # Inline revlogs have data chunks cached at open time. If we opened
> + # a file handle it wouldn't be read.
> + if self._inline:
> + yield
> + return
> + try:
> + self._readfh = self.opener(self.datafile)
> + yield
> + finally:
> + self._readfh.close()
> + self._readfh = None
This would crash if open() failed. It should be:
self._readfh = self.opener(self.datafile)
self._readfh = None
Should I fix it in flight? The other changes look good to me.
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