80 lines
2.5 KiB
Go
80 lines
2.5 KiB
Go
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// Copyright 2015 Google Inc. All Rights Reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package cachingfs
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import (
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"time"
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"github.com/jacobsa/fuse"
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"github.com/jacobsa/fuse/fuseutil"
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)
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// Constants that define the relative offsets of the inodes exported by the
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// file system. See notes on the RenumberInodes method.
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const (
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FooInodeOffset = iota
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DirInodeOffset
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BarInodeOffset
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)
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// A file system with a fixed structure that looks like this:
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//
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// foo
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// dir/
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// bar
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//
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// The file system is configured with durations that specify how long to allow
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// inode entries and attributes to be cached, used when responding to fuse
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// requests. It also exposes methods for renumbering inodes and updating mtimes
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// that are useful in testing that these durations are honored.
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type CachingFS struct {
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fuseutil.NotImplementedFileSystem
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}
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var _ fuse.FileSystem = &CachingFS{}
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// Create a file system that issues cacheable responses according to the
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// following rules:
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//
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// * LookUpInodeResponse.Entry.EntryExpiration is set according to
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// lookupEntryTimeout.
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//
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// * GetInodeAttributesResponse.AttributesExpiration is set according to
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// getattrTimeout.
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//
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// * Nothing else is marked cacheable. (In particular, the attributes
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// returned by LookUpInode are not cacheable.)
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//
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func NewCachingFS(
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lookupEntryTimeout time.Duration,
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getattrTimeout time.Duration) (fs *CachingFS, err error)
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// Cause inodes to receive IDs according to the following rules in further
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// responses to fuse:
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//
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// * The ID of "foo" is base + FooInodeOffset.
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// * The ID of "dir" is base + DirInodeOffset.
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// * The ID of "dir/bar" is base + BarInodeOffset.
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//
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// If this method has never been called, the file system behaves as if it were
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// called with base set to fuse.RootInodeID + 1.
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//
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// REQUIRES: base > fuse.RootInodeID
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func (fs *CachingFS) RenumberInodes(base fuse.InodeID)
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// Cause further queries for the attributes of inodes to use the supplied time
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// as the inode's mtime.
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func (fs *CachingFS) SetMtime(mtime time.Time)
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