package main // TODO: have logs go somewhere useful, like email // TODO: check if images are prebinarised and if so skip multiple binarisation import ( "errors" "fmt" "log" "os" "os/exec" "path/filepath" "strings" "time" "rescribe.xyz/go.git/preproc" ) const usage = `Usage: bookpipeline [-v] Watches the preprocess, ocr and analyse queues for book names. When one is found this general process is followed: - The book name is hidden from the queue, and a 'heartbeat' is started which keeps it hidden (this will time out after 2 minutes if the program is terminated) - The necessary files from bookname/ are downloaded - The files are processed - The resulting files are uploaded to bookname/ - The heartbeat is stopped - The book name is removed from the queue it was taken from, and added to the next queue for future processing -v verbose ` const training = "rescribealphav5" // TODO: allow to set on cmdline // 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 = 3 * time.Minute type Clouder interface { Init() error ListObjects(bucket string, prefix string) ([]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 ListToPreprocess(bookname string) ([]string, error) ListToOCR(bookname string) ([]string, error) DownloadFromInProgress(key string, fn string) error UploadToInProgress(key string, path string) error CheckPreQueue() (Qmsg, error) CheckOCRQueue() (Qmsg, error) CheckAnalyseQueue() (Qmsg, error) AddToOCRQueue(msg string) error AddToAnalyseQueue(msg string) error DelFromPreQueue(handle string) error DelFromOCRQueue(handle string) error PreQueueHeartbeat(t *time.Ticker, msgHandle string) error OCRQueueHeartbeat(t *time.Ticker, msgHandle string) error Logger() *log.Logger } type Qmsg struct { Handle, Body string } func download(dl chan string, process chan string, conn Pipeliner, dir string, errc chan error) { for key := range dl { fn := filepath.Join(dir, filepath.Base(key)) err := conn.DownloadFromInProgress(key, fn) if err != nil { close(process) errc <- err return } process <- fn } close(process) } func up(c chan string, done chan bool, conn Pipeliner, bookname string, errc chan error) { for path := range c { name := filepath.Base(path) key := filepath.Join(bookname, name) err := conn.UploadToInProgress(key, path) if err != nil { errc <- err return } } done <- true } func preprocess(pre chan string, up chan string, logger *log.Logger, errc chan error) { 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 { close(up) errc <- err return } for _, p := range done { up <- p } } close(up) } // TODO: use Tesseract API rather than calling the executable func ocr(toocr chan string, up chan string, logger *log.Logger, errc chan error) { for path := range toocr { logger.Println("OCRing", path) name := strings.Replace(path, ".png", "", 1) // TODO: handle any file extension cmd := exec.Command("tesseract", "-l", training, path, name, "hocr") err := cmd.Run() if err != nil { close(up) errc <- errors.New(fmt.Sprintf("Error ocring %s: %s", path, err)) return } up <- name + ".hocr" } close(up) } func preprocBook(msg Qmsg, conn Pipeliner) error { 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 { t.Stop() return errors.New(fmt.Sprintf("Failed to create directory %s: %s", d, err)) } dl := make(chan string) pre := make(chan string) upc := make(chan string) done := make(chan bool) errc := make(chan error) // these functions will do their jobs when their channels have data go download(dl, pre, conn, d, errc) go preprocess(pre, upc, conn.Logger(), errc) go up(upc, done, conn, bookname, errc) conn.Logger().Println("Getting list of objects to download") todl, err := conn.ListToPreprocess(bookname) if err != nil { t.Stop() _ = os.RemoveAll(d) return errors.New(fmt.Sprintf("Failed to get list of files for book %s: %s", bookname, err)) } for _, d := range todl { dl <- d } close(dl) // wait for either the done or errc channel to be sent to select { case err = <-errc: t.Stop() _ = os.RemoveAll(d) return err case <-done: } conn.Logger().Println("Sending", bookname, "to OCR queue") err = conn.AddToOCRQueue(bookname) if err != nil { t.Stop() _ = os.RemoveAll(d) return errors.New(fmt.Sprintf("Error adding to ocr queue %s: %s", bookname, err)) } t.Stop() conn.Logger().Println("Deleting original message from preprocessing queue") err = conn.DelFromPreQueue(msg.Handle) if err != nil { _ = os.RemoveAll(d) return errors.New(fmt.Sprintf("Error deleting message from preprocessing queue: %s", err)) } err = os.RemoveAll(d) if err != nil { return errors.New(fmt.Sprintf("Failed to remove directory %s: %s", d, err)) } return nil } // TODO: this is very similar to preprocBook; try to at least mostly merge them func ocrBook(msg Qmsg, conn Pipeliner) error { bookname := msg.Body t := time.NewTicker(HeartbeatTime * time.Second) go conn.OCRQueueHeartbeat(t, msg.Handle) d := filepath.Join(os.TempDir(), bookname) err := os.MkdirAll(d, 0755) if err != nil { t.Stop() return errors.New(fmt.Sprintf("Failed to create directory %s: %s", d, err)) } dl := make(chan string) ocrc := make(chan string) upc := make(chan string) done := make(chan bool) errc := make(chan error) // these functions will do their jobs when their channels have data go download(dl, ocrc, conn, d, errc) go ocr(ocrc, upc, conn.Logger(), errc) go up(upc, done, conn, bookname, errc) conn.Logger().Println("Getting list of objects to download") todl, err := conn.ListToOCR(bookname) if err != nil { t.Stop() _ = os.RemoveAll(d) return errors.New(fmt.Sprintf("Failed to get list of files for book %s: %s", bookname, err)) } for _, a := range todl { dl <- a } close(dl) // wait for either the done or errc channel to be sent to select { case err = <-errc: t.Stop() _ = os.RemoveAll(d) return err case <-done: } conn.Logger().Println("Sending", bookname, "to analyse queue") err = conn.AddToAnalyseQueue(bookname) if err != nil { t.Stop() _ = os.RemoveAll(d) return errors.New(fmt.Sprintf("Error adding to analyse queue %s: %s", bookname, err)) } t.Stop() conn.Logger().Println("Deleting original message from OCR queue") err = conn.DelFromOCRQueue(msg.Handle) if err != nil { _ = os.RemoveAll(d) return errors.New(fmt.Sprintf("Error deleting message from OCR queue: %s", err)) } err = os.RemoveAll(d) if err != nil { return errors.New(fmt.Sprintf("Failed to remove directory %s: %s", d, err)) } return nil } 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) } verboselog.Println("Finished setting up AWS session") var checkPreQueue <-chan time.Time var checkOCRQueue <-chan time.Time checkPreQueue = time.After(0) checkOCRQueue = time.After(0) for { select { case <- checkPreQueue: msg, err := conn.CheckPreQueue() checkPreQueue = time.After(PauseBetweenChecks) if err != nil { log.Println("Error checking preprocess queue", err) continue } if msg.Handle == "" { verboselog.Println("No message received on preprocess queue, sleeping") continue } err = preprocBook(msg, conn) if err != nil { log.Println("Error during preprocess", err) } case <- checkOCRQueue: msg, err := conn.CheckOCRQueue() checkOCRQueue = time.After(PauseBetweenChecks) if err != nil { log.Println("Error checking OCR queue", err) continue } if msg.Handle == "" { verboselog.Println("No message received on OCR queue, sleeping") continue } err = ocrBook(msg, conn) if err != nil { log.Println("Error during OCR process", err) } } } }