Update usage string, and comments

1 files changed, 269 insertions, 0 deletions

diff --git a/bookpipeline/aws.go b/bookpipeline/aws.go
new file mode 100644
index 0000000..1ac06de
--- /dev/null
+++ b/bookpipeline/aws.go
@@ -0,0 +1,269 @@
+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, analysequrl 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
+
+        a.logger.Println("Getting analyse queue URL")
+        result, err = a.sqssvc.GetQueueUrl(&sqs.GetQueueUrlInput{
+                QueueName: aws.String("rescribeanalyse"),
+        })
+        if err != nil {
+                return errors.New(fmt.Sprintf("Error getting analyse queue URL: %s", err))
+        }
+        a.analysequrl = *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) CheckOCRQueue() (Qmsg, error) {
+	a.logger.Println("Checking OCR queue for new messages")
+	return a.CheckQueue(a.ocrqurl)
+}
+
+func (a *awsConn) CheckAnalyseQueue() (Qmsg, error) {
+	a.logger.Println("Checking analyse queue for new messages")
+	return a.CheckQueue(a.ocrqurl)
+}
+
+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")
+	return a.QueueHeartbeat(t, msgHandle, a.prequrl)
+}
+
+func (a *awsConn) OCRQueueHeartbeat(t *time.Ticker, msgHandle string) error {
+	a.logger.Println("Starting ocr queue heartbeat")
+	return a.QueueHeartbeat(t, msgHandle, a.ocrqurl)
+}
+
+func (a *awsConn) ListObjects(bucket string, prefix string) ([]string, error) {
+	var names []string
+	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 {
+			names = append(names, *r.Key)
+		}
+		return true
+	})
+	return names, err
+}
+
+func (a *awsConn) ListToPreprocess(bookname string) ([]string, error) {
+	var names []string
+	preprocessed := regexp.MustCompile(PreprocPattern)
+	objs, err := a.ListObjects("rescribeinprogress", bookname)
+	if err != nil {
+		return names, err
+	}
+	// Filter out any object that looks like it's already been preprocessed
+	for _, n := range objs {
+		if preprocessed.MatchString(n) {
+			a.logger.Println("Skipping item that looks like it has already been processed", n)
+			continue
+		}
+		names = append(names, n)
+	}
+	return names, nil
+}
+
+func (a *awsConn) ListToOCR(bookname string) ([]string, error) {
+	var names []string
+	preprocessed := regexp.MustCompile(PreprocPattern)
+	objs, err := a.ListObjects("rescribeinprogress", bookname)
+	if err != nil {
+		return names, err
+	}
+	// Filter out any object that looks like it hasn't already been preprocessed
+	for _, n := range objs {
+		if ! preprocessed.MatchString(n) {
+			a.logger.Println("Skipping item that looks like it is not preprocessed", n)
+			continue
+		}
+		names = append(names, n)
+	}
+	return names, nil
+}
+
+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) AddToAnalyseQueue(msg string) error {
+	return a.AddToQueue(a.analysequrl, 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) DelFromOCRQueue(handle string) error {
+	return a.DelFromQueue(a.ocrqurl, 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 (a *awsConn) Logger() *log.Logger {
+	return a.logger
+}