-import logging
-import re
+# Copyright (C) The Arvados Authors. All rights reserved.
+#
+# SPDX-License-Identifier: AGPL-3.0
+
import json
import llfuse
+import logging
+import re
+import time
from fresh import FreshBase, convertTime
class File(FreshBase):
"""Base for file objects."""
+ __slots__ = ("inode", "parent_inode", "_mtime")
+
def __init__(self, parent_inode, _mtime=0):
super(File, self).__init__()
self.inode = None
def mtime(self):
return self._mtime
- def clear(self, force=False):
- return True
+ def clear(self):
+ pass
def writable(self):
return False
class FuseArvadosFile(File):
"""Wraps a ArvadosFile."""
+ __slots__ = ('arvfile',)
+
def __init__(self, parent_inode, arvfile, _mtime):
super(FuseArvadosFile, self).__init__(parent_inode, _mtime)
self.arvfile = arvfile
return self.object_uuid
def update(self, obj=None):
+ if obj is None:
+ # TODO: retrieve the current record for self.object_uuid
+ # from the server. For now, at least don't crash when
+ # someone tells us it's a good time to update but doesn't
+ # pass us a fresh obj. See #8345
+ return
self._mtime = convertTime(obj['modified_at']) if 'modified_at' in obj else 0
self.contents = json.dumps(obj, indent=4, sort_keys=True) + "\n"
def persisted(self):
return True
+
+
+class FuncToJSONFile(StringFile):
+ """File content is the return value of a given function, encoded as JSON.
+
+ The function is called at the time the file is read. The result is
+ cached until invalidate() is called.
+ """
+ def __init__(self, parent_inode, func):
+ super(FuncToJSONFile, self).__init__(parent_inode, "", 0)
+ self.func = func
+
+ # invalidate_inode() is asynchronous with no callback to wait for. In
+ # order to guarantee userspace programs don't get stale data that was
+ # generated before the last invalidate(), we must disallow inode
+ # caching entirely.
+ self.allow_attr_cache = False
+
+ def size(self):
+ self._update()
+ return super(FuncToJSONFile, self).size()
+
+ def readfrom(self, *args, **kwargs):
+ self._update()
+ return super(FuncToJSONFile, self).readfrom(*args, **kwargs)
+
+ def _update(self):
+ if not self.stale():
+ return
+ self._mtime = time.time()
+ obj = self.func()
+ self.contents = json.dumps(obj, indent=4, sort_keys=True) + "\n"
+ self.fresh()