forked from jacobsa/gcloud
/
conn.go
85 lines (69 loc) · 2 KB
/
conn.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
// 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 gcsfake
import (
"fmt"
"golang.org/x/net/context"
"github.com/jacobsa/gcloud/gcs"
"github.com/jacobsa/syncutil"
"github.com/jacobsa/timeutil"
)
// Create an "in-memory GCS" that allows access to buckets of any name, each
// initially with empty contents. The supplied clock will be used for
// generating timestamps.
func NewConn(clock timeutil.Clock) (c gcs.Conn) {
typed := &conn{
clock: clock,
buckets: make(map[string]gcs.Bucket),
}
typed.mu = syncutil.NewInvariantMutex(typed.checkInvariants)
c = typed
return
}
////////////////////////////////////////////////////////////////////////
// Implementation
////////////////////////////////////////////////////////////////////////
type conn struct {
clock timeutil.Clock
mu syncutil.InvariantMutex
// INVARIANT: For each k, v: v.Name() == k
//
// GUARDED_BY(mu)
buckets map[string]gcs.Bucket
}
// LOCKS_REQUIRED(c.mu)
func (c *conn) checkInvariants() {
// INVARIANT: For each k, v: v.Name() == k
for k, v := range c.buckets {
if v.Name() != k {
panic(fmt.Sprintf("Name mismatch: %q vs. %q", v.Name(), k))
}
}
}
// LOCKS_EXCLUDED(c.mu)
func (c *conn) OpenBucket(
ctx context.Context,
name string) (b gcs.Bucket, err error) {
c.mu.Lock()
defer c.mu.Unlock()
// Do we already know this bucket name?
b = c.buckets[name]
if b != nil {
return
}
// Create it.
b = NewFakeBucket(c.clock, name)
c.buckets[name] = b
return
}