-
Notifications
You must be signed in to change notification settings - Fork 0
/
state.go
191 lines (156 loc) · 4.17 KB
/
state.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
182
183
184
185
186
187
188
189
190
191
// Copyright 2012 Aaron Jacobs. All Rights Reserved.
// Author: aaronjjacobs@gmail.com (Aaron Jacobs)
//
// 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 main
import (
"context"
"fmt"
"io/ioutil"
"log"
"os"
"sync"
"time"
"github.com/jacobsa/comeback/internal/state"
"github.com/jacobsa/comeback/internal/util"
"github.com/jacobsa/comeback/internal/wiring"
"github.com/jacobsa/gcloud/gcs"
)
var g_stateOnce sync.Once
var g_state state.State
var g_saveStateMutex sync.Mutex
func buildExistingScores(
ctx context.Context,
bucket gcs.Bucket) (existingScores util.StringSet, err error) {
// List into a slice.
slice, err := listAllScores(
ctx,
bucket,
wiring.BlobObjectNamePrefix)
if err != nil {
err = fmt.Errorf("listAllScores: %v", err)
return
}
// Build a set.
existingScores = util.NewStringSet()
for _, score := range slice {
existingScores.Add(score.Hex())
}
return
}
func makeState(ctx context.Context) (s state.State, err error) {
cfg := getConfig()
bucket := getBucket(ctx)
// Open the specified file.
f, err := os.Open(cfg.StateFile)
switch {
// Special case: if the error is that the file doesn't exist, ignore it.
case os.IsNotExist(err):
err = nil
log.Println("No state file found. Using fresh state.")
case err != nil:
return
}
// If we opened a file above, load from it.
if f != nil {
defer f.Close()
s, err = state.LoadState(f)
if err != nil {
err = fmt.Errorf("LoadState: %v", err)
return
}
}
// Throw out the existing score cache if requested.
if *g_discardScoreCache {
s.ScoresForFiles = state.NewScoreMap()
}
// Make sure there are no nil interface values.
if s.ScoresForFiles == nil {
s.ScoresForFiles = state.NewScoreMap()
}
// If we don't know the set of hex scores in the store, or the set of scores
// is stale, re-list.
age := time.Now().Sub(s.RelistTime)
const maxAge = 30 * 24 * time.Hour
if s.ExistingScores == nil || age > maxAge {
log.Println("Listing existing scores...")
s.RelistTime = time.Now()
s.ExistingScores, err = buildExistingScores(ctx, bucket)
if err != nil {
err = fmt.Errorf("buildExistingScores: %v", err)
return
}
}
return
}
func initState(ctx context.Context) {
var err error
// Load the state struct.
log.Println("Loading from state file...")
g_state, err = makeState(ctx)
if err != nil {
log.Fatalln(err)
}
// Save it back to the file, in case makeState changed it (e.g. by listing
// existing scores).
log.Println("Saving to state file...")
err = saveStateStruct(getConfig().StateFile, &g_state)
if err != nil {
log.Fatalf("saveStateStruct: %v", err)
}
log.Println("Finished saving to state file.")
}
func getState(ctx context.Context) *state.State {
g_stateOnce.Do(func() { initState(ctx) })
return &g_state
}
func saveStateStruct(dst string, s *state.State) (err error) {
// Create a temporary file.
f, err := ioutil.TempFile("", "comeback_state")
if err != nil {
err = fmt.Errorf("TempFile: %v", err)
return
}
defer f.Close()
tempFilePath := f.Name()
// Write to the file.
err = state.SaveState(f, *s)
if err != nil {
err = fmt.Errorf("SaveState: %v", err)
return
}
// Close the file.
err = f.Close()
if err != nil {
err = fmt.Errorf("Close: %v", err)
return
}
// Rename the file into the new location.
err = os.Rename(tempFilePath, dst)
if err != nil {
err = fmt.Errorf("Rename: %v", err)
return
}
return
}
func saveState(ctx context.Context) {
// Make sure only one run can happen at a time.
g_saveStateMutex.Lock()
defer g_saveStateMutex.Unlock()
cfg := getConfig()
stateStruct := getState(ctx)
err := saveStateStruct(cfg.StateFile, stateStruct)
if err != nil {
log.Fatalf("saveStateStruct: %v", err)
}
}