From d05de46ddec10d4b7f9968320d2cb5f54d14d2f4 Mon Sep 17 00:00:00 2001 From: Johan Dahlin Date: Mon, 8 Dec 2008 16:29:33 +0000 Subject: Dump the cache file to a temporary file and rename it the expected 2008-12-08 Johan Dahlin * giscanner/cachestore.py (CacheStore.store): Dump the cache file to a temporary file and rename it the expected filename only when it's completely written. This should make the cache more roboust when run in parallel, and hopefully avoid triggering bugs in Python. svn path=/trunk/; revision=985 --- ChangeLog | 8 ++++++++ giscanner/cachestore.py | 26 +++++++++++++++++++------- 2 files changed, 27 insertions(+), 7 deletions(-) diff --git a/ChangeLog b/ChangeLog index b5d6ba3c..ba52604a 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,11 @@ +2008-12-08 Johan Dahlin + + * giscanner/cachestore.py (CacheStore.store): Dump the cache + file to a temporary file and rename it the expected filename + only when it's completely written. + This should make the cache more roboust when run in parallel, + and hopefully avoid triggering bugs in Python. + 2008-12-03 Christophe Fergeau Bug 562971 – g-ir-scanner failure on libgpod headers diff --git a/giscanner/cachestore.py b/giscanner/cachestore.py index 4629e622..d9163464 100644 --- a/giscanner/cachestore.py +++ b/giscanner/cachestore.py @@ -18,11 +18,11 @@ # Boston, MA 02111-1307, USA. # +import errno import cPickle import hashlib import os -import errno - +import tempfile def _get_cachedir(): cachedir = os.path.join(os.environ['HOME'], '.cache') @@ -61,7 +61,7 @@ class CacheStore(object): return (os.stat(store_filename).st_mtime >= os.stat(filename).st_mtime) - def _purge_cache(self, filename): + def _remove_filename(filename): try: os.unlink(filename) except IOError, e: @@ -81,19 +81,31 @@ class CacheStore(object): store_filename = self._get_filename(filename) if store_filename is None: return + if (os.path.exists(store_filename) and self._cache_is_valid(store_filename, filename)): return None - fd = open(store_filename, 'w') + + tmp_fd, tmp_filename = tempfile.mkstemp(prefix='g-ir-scanner-cache-') try: - cPickle.dump(data, fd) + cPickle.dump(data, os.fdopen(tmp_fd, 'w')) except IOError, e: # No space left on device - if e.errno == e.ENOSPC: + if e.errno == errno.ENOSPC: + self._remove_filename(tmp_filename) return else: raise + try: + os.rename(tmp_filename, store_filename) + except OSError, e: + # Permission denied + if e.errno == errno.EACCES: + self._remove_filename(tmp_filename) + else: + raise + def load(self, filename): store_filename = self._get_filename(filename) if store_filename is None: @@ -111,6 +123,6 @@ class CacheStore(object): data = cPickle.load(fd) except (EOFError, ValueError, cPickle.BadPickleGet): # Broken cache entry, remove it - self._purge_cache(store_filename) + self._remove_filename(store_filename) data = None return data -- cgit v1.2.1