def _getOpenHdf5Blockfile(self, blockFilePath):
"""
Return a handle to the open hdf5File at the given path.
If we haven't opened the file yet, open it first.
"""
# Try once without locking
if blockFilePath in list(self._openBlockFiles.keys()):
return self._openBlockFiles[blockFilePath]
# Obtain the lock and try again
with self._lock:
if blockFilePath not in list(self._openBlockFiles.keys()):
try:
writeLock = FileLock(blockFilePath, timeout=10)
if self.mode == "a":
acquired = writeLock.acquire(blocking=False)
assert acquired, "Couldn't obtain an exclusive lock for writing to file: {}".format(
blockFilePath
)
self._fileLocks[blockFilePath] = writeLock
elif self.mode == "r":
assert writeLock.available(), "Can't read from a file that is being written to elsewhere."
else:
assert False, "Unsupported mode"
self._openBlockFiles[blockFilePath] = h5py.File(blockFilePath, self.mode)
except:
log_exception(logger, "Couldn't open {}".format(blockFilePath))
raise
return self._openBlockFiles[blockFilePath]
def isBlockLocked(self, blockstart):
"""
Return True if the block is locked for writing.
Note that both 'available' and 'not available' blocks might be locked.
"""
datasetPathComponents = self.getDatasetPathComponents(blockstart)
hdf5FilePath = datasetPathComponents.externalPath
testLock = FileLock(hdf5FilePath)
return not testLock.available()
