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
|
package main
// TODO: have logs go somewhere useful, like email
// TODO: handle errors more smartly than just always fatal erroring
// - read the sdk guarantees on retrying and ensure we retry some times before giving up if necessary
// - cancel the current book processing rather than killing the program in the case of a nonrecoverable error
// TODO: check if images are prebinarised and if so skip multiple binarisation
import (
"log"
"os"
"path/filepath"
"time"
"rescribe.xyz/go.git/preproc"
)
const usage = "Usage: pipelinepreprocess [-v]\n\nContinuously checks the preprocess queue for books.\nWhen a book is found it's downloaded from the S3 inprogress bucket, preprocessed, and the results are uploaded to the S3 inprogress bucket. The book name is then added to the ocr queue, and removed from the preprocess queue.\n\n-v verbose\n"
// null writer to enable non-verbose logging to be discarded
type NullWriter bool
func (w NullWriter) Write(p []byte) (n int, err error) {
return len(p), nil
}
const PauseBetweenChecks = 60 * time.Second
// TODO: consider having the download etc functions return a channel like a generator, like in rob pike's talk
type Clouder interface {
Init() error
ListObjects(bucket string, prefix string, names chan string) error
Download(bucket string, key string, fn string) error
Upload(bucket string, key string, path string) error
CheckQueue(url string) (Qmsg, error)
AddToQueue(url string, msg string) error
DelFromQueue(url string, handle string) error
QueueHeartbeat(t *time.Ticker, msgHandle string, qurl string) error
}
type Pipeliner interface {
Clouder
ListInProgress(bookname string, names chan string) error
DownloadFromInProgress(key string, fn string) error
UploadToInProgress(key string, path string) error
CheckPreQueue() (Qmsg, error)
AddToOCRQueue(msg string) error
DelFromPreQueue(handle string) error
PreQueueHeartbeat(t *time.Ticker, msgHandle string) error
}
type Qmsg struct {
Handle, Body string
}
func download(dl chan string, pre chan string, conn Pipeliner, dir string) {
for key := range dl {
fn := filepath.Join(dir, filepath.Base(key))
err := conn.DownloadFromInProgress(key, fn)
if err != nil {
log.Fatalln("Failed to download", key, err)
}
pre <- fn
}
close(pre)
}
func preprocess(pre chan string, up chan string, logger *log.Logger) {
for path := range pre {
logger.Println("Preprocessing", path)
done, err := preproc.PreProcMulti(path, []float64{0.1, 0.2, 0.4, 0.5}, "binary", 0, true, 5, 30)
if err != nil {
log.Fatalln("Error preprocessing", path, err)
}
for _, p := range done {
up <- p
}
}
close(up)
}
func up(c chan string, done chan bool, conn Pipeliner, bookname string) {
for path := range c {
name := filepath.Base(path)
key := filepath.Join(bookname, name)
err := conn.UploadToInProgress(key, path)
if err != nil {
log.Fatalln("Failed to upload", path, err)
}
}
done <- true
}
func main() {
var verboselog *log.Logger
if len(os.Args) > 1 {
if os.Args[1] == "-v" {
verboselog = log.New(os.Stdout, "", log.LstdFlags)
} else {
log.Fatal(usage)
}
} else {
var n NullWriter
verboselog = log.New(n, "", log.LstdFlags)
}
var conn Pipeliner
conn = &awsConn{ region: "eu-west-2", logger: verboselog }
verboselog.Println("Setting up AWS session")
err := conn.Init()
if err != nil {
log.Fatalln("Error setting up cloud connection:", err)
}
for {
msg, err := conn.CheckPreQueue()
if err != nil {
log.Fatalln("Error checking preprocess queue", err)
}
if msg.Handle == "" {
verboselog.Println("No message received, sleeping")
time.Sleep(PauseBetweenChecks)
continue
}
bookname := msg.Body
t := time.NewTicker(HeartbeatTime * time.Second)
go conn.PreQueueHeartbeat(t, msg.Handle)
d := filepath.Join(os.TempDir(), bookname)
err = os.MkdirAll(d, 0755)
if err != nil {
log.Fatalln("Failed to create directory", d, err)
}
dl := make(chan string)
pre := make(chan string)
upc := make(chan string) // TODO: rename
done := make(chan bool) // this is just to communicate when up has finished, so the queues can be updated
// these functions will do their jobs when their channels have data
go download(dl, pre, conn, d)
go preprocess(pre, upc, verboselog)
go up(upc, done, conn, bookname)
verboselog.Println("Getting list of objects to download")
err = conn.ListInProgress(bookname, dl)
if err != nil {
log.Fatalln("Failed to get list of files for book", bookname, err)
}
// wait for the done channel to be posted to
<-done
verboselog.Println("Sending", bookname, "to OCR queue")
err = conn.AddToOCRQueue(bookname)
if err != nil {
log.Fatalln("Error adding to ocr queue", bookname, err)
}
t.Stop()
verboselog.Println("Deleting original message from preprocessing queue")
err = conn.DelFromPreQueue(msg.Handle)
if err != nil {
log.Fatalln("Error deleting message from preprocessing queue", err)
}
err = os.RemoveAll(d)
if err != nil {
log.Fatalln("Failed to remove directory", d, err)
}
}
}
|
