-
Notifications
You must be signed in to change notification settings - Fork 337
/
memory.go
181 lines (146 loc) · 3.95 KB
/
memory.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
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
/*
Copyright 2022 Codenotary 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 memory
import (
"bytes"
"context"
"errors"
"fmt"
"io"
"io/ioutil"
"math/rand"
"sort"
"strings"
"sync"
"time"
remotestorage "github.com/codenotary/immudb/embedded/remotestorage"
)
var (
ErrInvalidArguments = errors.New("invalid arguments")
)
// Storage implements a simple in-memory remote storage
type Storage struct {
mutex sync.RWMutex
objects map[string][]byte
randomPutDelayMinMs, randomPutDelayMaxMs int
}
func Open() *Storage {
return &Storage{
objects: map[string][]byte{},
}
}
func (r *Storage) Kind() string {
return "memory"
}
func (r *Storage) String() string {
return fmt.Sprintf("memory(%p):", r)
}
// Get opens a stream of data for given object
func (r *Storage) Get(ctx context.Context, name string, offs, size int64) (io.ReadCloser, error) {
if offs < 0 || size == 0 {
return nil, ErrInvalidArguments
}
r.mutex.RLock()
defer r.mutex.RUnlock()
object, exists := r.objects[name]
if !exists {
return nil, remotestorage.ErrNotFound
}
objectLen := int64(len(object))
if offs > objectLen {
offs = objectLen
}
if size < 0 || offs+size > objectLen {
size = objectLen - offs
}
return ioutil.NopCloser(bytes.NewReader(object[offs : offs+size])), nil
}
func (r *Storage) randomPutDelay() time.Duration {
delayMs := r.randomPutDelayMinMs + rand.Intn(r.randomPutDelayMaxMs-r.randomPutDelayMinMs+1)
return time.Millisecond * time.Duration(delayMs)
}
// Put writes a remote s3 resource
func (r *Storage) Put(ctx context.Context, name string, fileName string) error {
object, err := ioutil.ReadFile(fileName)
if err != nil {
return err
}
store := func() {
r.mutex.Lock()
r.objects[name] = object
r.mutex.Unlock()
}
delay := r.randomPutDelay()
if delay > 0 {
// Asynchronous store
go func() {
time.Sleep(delay)
store()
}()
} else {
// Synchronous store
store()
}
return nil
}
// Exists checks if a remove resource exists and can be read
// Note that due to an asynchronous nature of cluod storage,
// a resource stored with the Put method may not be immediately accessible
func (r *Storage) Exists(ctx context.Context, name string) (bool, error) {
r.mutex.RLock()
defer r.mutex.RUnlock()
_, exists := r.objects[name]
return exists, nil
}
func (r *Storage) ListEntries(ctx context.Context, path string) ([]remotestorage.EntryInfo, []string, error) {
r.mutex.Lock()
defer r.mutex.Unlock()
if path != "" {
if !strings.HasSuffix(path, "/") ||
strings.Contains(path, "//") ||
path == "/" {
return nil, nil, ErrInvalidArguments
}
}
subPathSet := map[string]struct{}{}
entries := []remotestorage.EntryInfo{}
for k := range r.objects {
if !strings.HasPrefix(k, path) {
continue
}
kWithoutPath := k[len(path):]
nextSlash := strings.IndexRune(kWithoutPath, '/')
if nextSlash == -1 {
entries = append(entries, remotestorage.EntryInfo{
Name: kWithoutPath,
Size: int64(len(r.objects[k])),
})
} else {
subPathSet[kWithoutPath[:nextSlash]] = struct{}{}
}
}
sort.Slice(entries, func(i, j int) bool { return entries[i].Name < entries[j].Name })
subPaths := []string{}
for k := range subPathSet {
subPaths = append(subPaths, k)
}
sort.Strings(subPaths)
return entries, subPaths, nil
}
func (r *Storage) SetRandomPutDelays(minMs, maxMs int) {
r.mutex.Lock()
defer r.mutex.Unlock()
r.randomPutDelayMinMs = minMs
r.randomPutDelayMaxMs = maxMs
}
var _ remotestorage.Storage = (*Storage)(nil)