forked from GoogleCloudPlatform/gcsfuse
-
Notifications
You must be signed in to change notification settings - Fork 0
/
inode.go
100 lines (82 loc) · 2.83 KB
/
inode.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
// Copyright 2015 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package inode
import (
"sync"
"github.com/jacobsa/fuse/fuseops"
"golang.org/x/net/context"
)
type Inode interface {
// All methods below require the lock to be held unless otherwise documented.
sync.Locker
// Return the ID assigned to the inode.
//
// Does not require the lock to be held.
ID() fuseops.InodeID
// Return the name of the GCS object backing the inode. This may be "foo/bar"
// for a file, or "foo/bar/" for a directory.
//
// Does not require the lock to be held.
Name() string
// Increment the lookup count for the inode. For use in fuse operations where
// the kernel expects us to remember the inode.
IncrementLookupCount()
// Return up to date attributes for this inode.
Attributes(ctx context.Context) (fuseops.InodeAttributes, error)
// Decrement the lookup count for the inode by the given amount.
//
// If this method returns true, the lookup count has hit zero and the
// Destroy() method should be called to release any local resources, perhaps
// after releasing locks that should not be held while blocking.
DecrementLookupCount(n uint64) (destroy bool)
// Clean up any local resources used by the inode, putting it into an
// indeterminate state where no method should be called except Unlock.
//
// This method may block. Errors are for logging purposes only.
Destroy() (err error)
}
// An inode that is backed by a particular generation of a GCS object.
type GenerationBackedInode interface {
Inode
// Requires the inode lock.
SourceGeneration() Generation
}
// A particular generation of a GCS object, consisting of both a GCS object
// generation number and meta-generation number. Lexicographically ordered on
// the two.
//
// Cf. https://cloud.google.com/storage/docs/generations-preconditions
type Generation struct {
Object int64
Metadata int64
}
// Return -1, 0, or 1 according to whether g is less than, equal to, or greater
// than other.
func (g Generation) Compare(other Generation) int {
// Compare first on object generation number.
switch {
case g.Object < other.Object:
return -1
case g.Object > other.Object:
return 1
}
// Break ties on meta-generation.
switch {
case g.Metadata < other.Metadata:
return -1
case g.Metadata > other.Metadata:
return 1
}
return 0
}