Split aws implementation from main.go in pipelinepreprocess

2 files changed, 205 insertions, 222 deletions

diff --git a/pipelinepreprocess/aws.go b/pipelinepreprocess/aws.go
new file mode 100644
index 0000000..bb969ed
--- /dev/null
+++ b/pipelinepreprocess/aws.go
@@ -0,0 +1,205 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"log"
+	"os"
+	"regexp"
+	"time"
+
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/session"
+	"github.com/aws/aws-sdk-go/service/s3"
+	"github.com/aws/aws-sdk-go/service/s3/s3manager"
+	"github.com/aws/aws-sdk-go/service/sqs"
+)
+
+const PreprocPattern = `_bin[0-9].[0-9].png`
+const HeartbeatTime = 60
+
+type awsConn struct {
+	// these need to be set before running Init()
+	region string
+	logger *log.Logger
+
+	// these are used internally
+	sess *session.Session
+        s3svc *s3.S3
+        sqssvc *sqs.SQS
+        downloader *s3manager.Downloader
+	uploader *s3manager.Uploader
+	prequrl, ocrqurl string
+}
+
+func (a *awsConn) Init() error {
+	if a.region == "" {
+		return errors.New("No region set")
+	}
+	if a.logger == nil {
+		return errors.New("No logger set")
+	}
+
+	var err error
+	a.sess, err = session.NewSession(&aws.Config{
+		Region: aws.String(a.region),
+	})
+	if err != nil {
+		return errors.New(fmt.Sprintf("Failed to set up aws session: %s", err))
+	}
+	a.s3svc = s3.New(a.sess)
+	a.sqssvc = sqs.New(a.sess)
+	a.downloader = s3manager.NewDownloader(a.sess)
+	a.uploader = s3manager.NewUploader(a.sess)
+
+        a.logger.Println("Getting preprocess queue URL")
+        result, err := a.sqssvc.GetQueueUrl(&sqs.GetQueueUrlInput{
+                QueueName: aws.String("rescribepreprocess"),
+        })
+        if err != nil {
+                return errors.New(fmt.Sprintf("Error getting preprocess queue URL: %s", err))
+        }
+        a.prequrl = *result.QueueUrl
+
+        a.logger.Println("Getting OCR queue URL")
+        result, err = a.sqssvc.GetQueueUrl(&sqs.GetQueueUrlInput{
+                QueueName: aws.String("rescribeocr"),
+        })
+        if err != nil {
+                return errors.New(fmt.Sprintf("Error getting OCR queue URL: %s", err))
+        }
+        a.ocrqurl = *result.QueueUrl
+	return nil
+}
+
+func (a *awsConn) CheckQueue(url string) (Qmsg, error) {
+	msgResult, err := a.sqssvc.ReceiveMessage(&sqs.ReceiveMessageInput{
+		MaxNumberOfMessages: aws.Int64(1),
+		VisibilityTimeout: aws.Int64(HeartbeatTime * 2),
+		WaitTimeSeconds: aws.Int64(20),
+		QueueUrl: &url,
+	})
+	if err != nil {
+		return Qmsg{}, err
+	}
+
+	if len(msgResult.Messages) > 0 {
+		msg := Qmsg{ Handle: *msgResult.Messages[0].ReceiptHandle, Body: *msgResult.Messages[0].Body }
+		a.logger.Println("Message received:", msg.Body)
+		return msg, nil
+	} else {
+		return Qmsg{}, nil
+	}
+}
+
+func (a *awsConn) CheckPreQueue() (Qmsg, error) {
+	a.logger.Println("Checking preprocessing queue for new messages")
+	return a.CheckQueue(a.prequrl)
+}
+
+func (a *awsConn) QueueHeartbeat(t *time.Ticker, msgHandle string, qurl string) error {
+	for _ = range t.C {
+		duration := int64(HeartbeatTime * 2)
+		_, err := a.sqssvc.ChangeMessageVisibility(&sqs.ChangeMessageVisibilityInput{
+			ReceiptHandle: &msgHandle,
+			QueueUrl: &qurl,
+			VisibilityTimeout: &duration,
+		})
+		if err != nil {
+			return errors.New(fmt.Sprintf("Heartbeat error updating queue duration: %s", err))
+		}
+	}
+	return nil
+}
+
+func (a *awsConn) PreQueueHeartbeat(t *time.Ticker, msgHandle string) error {
+	a.logger.Println("Starting preprocess queue heartbeat for", msgHandle)
+	return a.QueueHeartbeat(t, msgHandle, a.prequrl)
+}
+
+func (a *awsConn) ListObjects(bucket string, prefix string, names chan string) error {
+	alreadydone := regexp.MustCompile(PreprocPattern)
+	err := a.s3svc.ListObjectsV2Pages(&s3.ListObjectsV2Input{
+		Bucket: aws.String(bucket),
+		Prefix: aws.String(prefix),
+	}, func(page *s3.ListObjectsV2Output, last bool) bool {
+		for _, r := range page.Contents {
+			if alreadydone.MatchString(*r.Key) {
+				a.logger.Println("Skipping item that looks like it has already been processed", *r.Key)
+				continue
+			}
+			names <- *r.Key
+		}
+		return true
+	})
+	close(names)
+	return err
+}
+
+func (a *awsConn) ListInProgress(bookname string, names chan string) error {
+	return a.ListObjects("rescribeinprogress", bookname, names)
+}
+
+func (a *awsConn) AddToQueue(url string, msg string) error {
+	_, err := a.sqssvc.SendMessage(&sqs.SendMessageInput{
+		MessageBody: &msg,
+		QueueUrl: &url,
+	})
+	return err
+}
+
+func (a *awsConn) AddToOCRQueue(msg string) error {
+	return a.AddToQueue(a.ocrqurl, msg)
+}
+
+func (a *awsConn) DelFromQueue(url string, handle string) error {
+	_, err := a.sqssvc.DeleteMessage(&sqs.DeleteMessageInput{
+		QueueUrl: &url,
+		ReceiptHandle: &handle,
+	})
+	return err
+}
+
+func (a *awsConn) DelFromPreQueue(handle string) error {
+	return a.DelFromQueue(a.prequrl, handle)
+}
+
+func (a *awsConn) Download(bucket string, key string, path string) error {
+	f, err := os.Create(path)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	_, err = a.downloader.Download(f,
+		&s3.GetObjectInput{
+			Bucket: aws.String(bucket),
+			Key: &key,
+	})
+	return err
+}
+
+func (a *awsConn) DownloadFromInProgress(key string, path string) error {
+	a.logger.Println("Downloading", key)
+	return a.Download("rescribeinprogress", key, path)
+}
+
+func (a *awsConn) Upload(bucket string, key string, path string) error {
+	file, err := os.Open(path)
+	if err != nil {
+		log.Fatalln("Failed to open file", path, err)
+	}
+	defer file.Close()
+
+	_, err = a.uploader.Upload(&s3manager.UploadInput{
+		Bucket: aws.String(bucket),
+		Key:    aws.String(key),
+		Body:   file,
+	})
+	return err
+}
+
+func (a *awsConn) UploadToInProgress(key string, path string) error {
+	a.logger.Println("Uploading", path)
+	return a.Upload("rescribeinprogress", key, path)
+}
diff --git a/pipelinepreprocess/main.go b/pipelinepreprocess/main.go
index 407591f..a223d0b 100644
--- a/pipelinepreprocess/main.go
+++ b/pipelinepreprocess/main.go
@@ -6,20 +6,11 @@ package main
 // TODO: check if images are prebinarised and if so skip multiple binarisation
 
 import (
-	"errors"
-	"fmt"
 	"log"
 	"os"
 	"path/filepath"
-	"regexp"
 	"time"
 
-	"github.com/aws/aws-sdk-go/aws"
-	"github.com/aws/aws-sdk-go/aws/session"
-	"github.com/aws/aws-sdk-go/service/s3"
-	"github.com/aws/aws-sdk-go/service/s3/s3manager"
-	"github.com/aws/aws-sdk-go/service/sqs"
-
 	"rescribe.xyz/go.git/preproc"
 )
 
@@ -31,17 +22,8 @@ func (w NullWriter) Write(p []byte) (n int, err error) {
 	return len(p), nil
 }
 
-var alreadydone *regexp.Regexp
-
-const HeartbeatTime = 60
 const PauseBetweenChecks = 60 * time.Second
-const PreprocPattern = `_bin[0-9].[0-9].png`
 
-// TODO: could restructure like so:
-//       have the goroutine functions run outside of the main loop in the program,
-//       so use them for multiple books indefinitely. would require finding a way to
-//       signal when the queues need to be updated (e.g. when a book is finished)
-//
 // TODO: consider having the download etc functions return a channel like a generator, like in rob pike's talk
 
 type Clouder interface {
@@ -70,194 +52,6 @@ type Qmsg struct {
 	Handle, Body string
 }
 
-type awsConn struct {
-	// these need to be set before running Init()
-	region string
-	logger *log.Logger
-
-	// these are used internally
-	sess *session.Session
-        s3svc *s3.S3
-        sqssvc *sqs.SQS
-        downloader *s3manager.Downloader
-	uploader *s3manager.Uploader
-	prequrl, ocrqurl string
-}
-
-func (a *awsConn) Init() error {
-	if a.region == "" {
-		return errors.New("No region set")
-	}
-	if a.logger == nil {
-		return errors.New("No logger set")
-	}
-
-	var err error
-	a.sess, err = session.NewSession(&aws.Config{
-		Region: aws.String(a.region),
-	})
-	if err != nil {
-		return errors.New(fmt.Sprintf("Failed to set up aws session: %s", err))
-	}
-	a.s3svc = s3.New(a.sess)
-	a.sqssvc = sqs.New(a.sess)
-	a.downloader = s3manager.NewDownloader(a.sess)
-	a.uploader = s3manager.NewUploader(a.sess)
-
-        a.logger.Println("Getting preprocess queue URL")
-        result, err := a.sqssvc.GetQueueUrl(&sqs.GetQueueUrlInput{
-                QueueName: aws.String("rescribepreprocess"),
-        })
-        if err != nil {
-                return errors.New(fmt.Sprintf("Error getting preprocess queue URL: %s", err))
-        }
-        a.prequrl = *result.QueueUrl
-
-        a.logger.Println("Getting OCR queue URL")
-        result, err = a.sqssvc.GetQueueUrl(&sqs.GetQueueUrlInput{
-                QueueName: aws.String("rescribeocr"),
-        })
-        if err != nil {
-                return errors.New(fmt.Sprintf("Error getting OCR queue URL: %s", err))
-        }
-        a.ocrqurl = *result.QueueUrl
-	return nil
-}
-
-func (a *awsConn) CheckQueue(url string) (Qmsg, error) {
-	msgResult, err := a.sqssvc.ReceiveMessage(&sqs.ReceiveMessageInput{
-		MaxNumberOfMessages: aws.Int64(1),
-		VisibilityTimeout: aws.Int64(HeartbeatTime * 2),
-		WaitTimeSeconds: aws.Int64(20),
-		QueueUrl: &url,
-	})
-	if err != nil {
-		return Qmsg{}, err
-	}
-
-	if len(msgResult.Messages) > 0 {
-		msg := Qmsg{ Handle: *msgResult.Messages[0].ReceiptHandle, Body: *msgResult.Messages[0].Body }
-		a.logger.Println("Message received:", msg.Body)
-		return msg, nil
-	} else {
-		return Qmsg{}, nil
-	}
-}
-
-func (a *awsConn) CheckPreQueue() (Qmsg, error) {
-	a.logger.Println("Checking preprocessing queue for new messages")
-	return a.CheckQueue(a.prequrl)
-}
-
-func (a *awsConn) QueueHeartbeat(t *time.Ticker, msgHandle string, qurl string) error {
-	for _ = range t.C {
-		duration := int64(HeartbeatTime * 2)
-		_, err := a.sqssvc.ChangeMessageVisibility(&sqs.ChangeMessageVisibilityInput{
-			ReceiptHandle: &msgHandle,
-			QueueUrl: &qurl,
-			VisibilityTimeout: &duration,
-		})
-		if err != nil {
-			return errors.New(fmt.Sprintf("Heartbeat error updating queue duration: %s", err))
-		}
-	}
-	return nil
-}
-
-func (a *awsConn) PreQueueHeartbeat(t *time.Ticker, msgHandle string) error {
-	a.logger.Println("Starting preprocess queue heartbeat for", msgHandle)
-	return a.QueueHeartbeat(t, msgHandle, a.prequrl)
-}
-
-func (a *awsConn) ListObjects(bucket string, prefix string, names chan string) error {
-	err := a.s3svc.ListObjectsV2Pages(&s3.ListObjectsV2Input{
-		Bucket: aws.String(bucket),
-		Prefix: aws.String(prefix),
-	}, func(page *s3.ListObjectsV2Output, last bool) bool {
-		for _, r := range page.Contents {
-			if alreadydone.MatchString(*r.Key) {
-				a.logger.Println("Skipping item that looks like it has already been processed", *r.Key)
-				continue
-			}
-			names <- *r.Key
-		}
-		return true
-	})
-	close(names)
-	return err
-}
-
-func (a *awsConn) ListInProgress(bookname string, names chan string) error {
-	return a.ListObjects("rescribeinprogress", bookname, names)
-}
-
-func (a *awsConn) AddToQueue(url string, msg string) error {
-	_, err := a.sqssvc.SendMessage(&sqs.SendMessageInput{
-		MessageBody: &msg,
-		QueueUrl: &url,
-	})
-	return err
-}
-
-func (a *awsConn) AddToOCRQueue(msg string) error {
-	return a.AddToQueue(a.ocrqurl, msg)
-}
-
-func (a *awsConn) DelFromQueue(url string, handle string) error {
-	_, err := a.sqssvc.DeleteMessage(&sqs.DeleteMessageInput{
-		QueueUrl: &url,
-		ReceiptHandle: &handle,
-	})
-	return err
-}
-
-func (a *awsConn) DelFromPreQueue(handle string) error {
-	return a.DelFromQueue(a.prequrl, handle)
-}
-
-func (a *awsConn) Download(bucket string, key string, path string) error {
-	f, err := os.Create(path)
-	if err != nil {
-		return err
-	}
-	defer f.Close()
-
-	_, err = a.downloader.Download(f,
-		&s3.GetObjectInput{
-			Bucket: aws.String(bucket),
-			Key: &key,
-	})
-	return err
-}
-
-func (a *awsConn) DownloadFromInProgress(key string, path string) error {
-	a.logger.Println("Downloading", key)
-	return a.Download("rescribeinprogress", key, path)
-}
-
-func (a *awsConn) Upload(bucket string, key string, path string) error {
-	file, err := os.Open(path)
-	if err != nil {
-		log.Fatalln("Failed to open file", path, err)
-	}
-	defer file.Close()
-
-	_, err = a.uploader.Upload(&s3manager.UploadInput{
-		Bucket: aws.String(bucket),
-		Key:    aws.String(key),
-		Body:   file,
-	})
-	return err
-}
-
-func (a *awsConn) UploadToInProgress(key string, path string) error {
-	a.logger.Println("Uploading", path)
-	return a.Upload("rescribeinprogress", key, path)
-}
-
-
-
-
 func download(dl chan string, pre chan string, conn Pipeliner, dir string) {
 	for key := range dl {
 		fn := filepath.Join(dir, filepath.Base(key))
@@ -297,20 +91,6 @@ func up(c chan string, done chan bool, conn Pipeliner, bookname string) {
 	done <- true
 }
 
-func heartbeat(h *time.Ticker, msgHandle string, qurl string, sqssvc *sqs.SQS) {
-	for _ = range h.C {
-		duration := int64(HeartbeatTime * 2)
-		_, err := sqssvc.ChangeMessageVisibility(&sqs.ChangeMessageVisibilityInput{
-			ReceiptHandle: &msgHandle,
-			QueueUrl: &qurl,
-			VisibilityTimeout: &duration,
-		})
-		if err != nil {
-			log.Fatalln("Error updating queue duration:", err)
-		}
-	}
-}
-
 func main() {
 	var verboselog *log.Logger
 	if len(os.Args) > 1 {
@@ -324,8 +104,6 @@ func main() {
 		verboselog = log.New(n, "", log.LstdFlags)
 	}
 
-	alreadydone = regexp.MustCompile(PreprocPattern)
-
 	var conn Pipeliner
 	conn = &awsConn{ region: "eu-west-2", logger: verboselog }