67 lines
2.0 KiB
Go
67 lines
2.0 KiB
Go
// Copyright 2015 Google Inc. All Rights Reserved.
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// Author: jacobsa@google.com (Aaron Jacobs)
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package memfs
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import (
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"github.com/jacobsa/fuse"
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"github.com/jacobsa/fuse/fuseutil"
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"github.com/jacobsa/gcloud/syncutil"
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)
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// Common attributes for files and directories.
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//
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// TODO(jacobsa): Add tests for interacting with a file/directory after it has
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// been unlinked, including creating a new file. Make sure we don't screw up
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// and reuse an inode ID while it is still in use.
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type inode struct {
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/////////////////////////
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// Constant data
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/////////////////////////
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// Is this a directory? If not, it is a file.
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dir bool
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/////////////////////////
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// Mutable state
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/////////////////////////
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mu syncutil.InvariantMutex
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// The current attributes of this inode.
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//
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// INVARIANT: No non-permission mode bits are set besides os.ModeDir
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// INVARIANT: If dir, then os.ModeDir is set
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// INVARIANT: If !dir, then os.ModeDir is not set
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attributes fuse.InodeAttributes // GUARDED_BY(mu)
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// For directories, entries describing the children of the directory.
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//
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// This array can never be shortened, nor can its elements be moved, because
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// we use its indices for Dirent.Offset, which is exposed to the user who
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// might be calling readdir in a loop while concurrently modifying the
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// directory. Unused entries can, however, be reused.
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//
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// TODO(jacobsa): Add good tests exercising concurrent modifications while
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// doing readdir, seekdir, etc. calls.
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//
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// INVARIANT: If dir is false, this is nil.
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// INVARIANT: For each i, entries[i].Offset == i+1
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entries []fuseutil.Dirent // GUARDED_BY(mu)
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// For files, the current contents of the file.
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//
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// INVARIANT: If dir is true, this is nil.
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contents []byte // GUARDED_BY(mu)
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}
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func newInode(dir bool) (inode *inode)
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func (inode *inode) checkInvariants()
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// Find an entry for the given child name and return its inode ID.
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//
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// REQUIRES: inode.dir
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// SHARED_LOCKS_REQUIRED(inode.mu)
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func (inode *inode) LookUpChild(name string) (id fuse.InodeID, ok bool)
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