From c47e27ee5146b8c2dcf058ed58270ce691b43ff7 Mon Sep 17 00:00:00 2001
From: Nick White <git@njw.name>
Date: Wed, 4 Sep 2019 20:40:07 +0100
Subject: Rewrite heartbeat so errors during it will be reported, and the aws
 api doesn't rely on channels

---
 bookpipeline/aws.go                   | 25 +++++++++--------------
 bookpipeline/cmd/bookpipeline/main.go | 38 ++++++++++++++++++++++-------------
 2 files changed, 34 insertions(+), 29 deletions(-)

diff --git a/bookpipeline/aws.go b/bookpipeline/aws.go
index 7409434..a111ebf 100644
--- a/bookpipeline/aws.go
+++ b/bookpipeline/aws.go
@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"log"
 	"os"
-	"time"
 
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/aws/session"
@@ -15,7 +14,6 @@ import (
 )
 
 const PreprocPattern = `_bin[0-9].[0-9].png`
-const HeartbeatTime = 60
 
 type Qmsg struct {
         Handle, Body string
@@ -88,10 +86,10 @@ func (a *AwsConn) Init() error {
 	return nil
 }
 
-func (a *AwsConn) CheckQueue(url string) (Qmsg, error) {
+func (a *AwsConn) CheckQueue(url string, timeout int64) (Qmsg, error) {
 	msgResult, err := a.sqssvc.ReceiveMessage(&sqs.ReceiveMessageInput{
 		MaxNumberOfMessages: aws.Int64(1),
-		VisibilityTimeout:   aws.Int64(HeartbeatTime * 2),
+		VisibilityTimeout:   &timeout,
 		WaitTimeSeconds:     aws.Int64(20),
 		QueueUrl:            &url,
 	})
@@ -108,17 +106,14 @@ func (a *AwsConn) CheckQueue(url string) (Qmsg, error) {
 	}
 }
 
-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))
-		}
+func (a *AwsConn) QueueHeartbeat(msgHandle string, qurl string, duration int64) error {
+	_, 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
 }
diff --git a/bookpipeline/cmd/bookpipeline/main.go b/bookpipeline/cmd/bookpipeline/main.go
index c7dde5b..913ccc7 100644
--- a/bookpipeline/cmd/bookpipeline/main.go
+++ b/bookpipeline/cmd/bookpipeline/main.go
@@ -52,10 +52,10 @@ type Clouder interface {
 	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) (bookpipeline.Qmsg, error)
+	CheckQueue(url string, timeout int64) (bookpipeline.Qmsg, error)
 	AddToQueue(url string, msg string) error
 	DelFromQueue(url string, handle string) error
-	QueueHeartbeat(t *time.Ticker, msgHandle string, qurl string) error
+	QueueHeartbeat(msgHandle string, qurl string, duration int64) error
 }
 
 type Pipeliner interface {
@@ -225,24 +225,34 @@ func analyse(toanalyse chan string, up chan string, errc chan error, logger *log
 	close(up)
 }
 
+func heartbeat(conn Pipeliner, t *time.Ticker, msg string, queue string, errc chan error) {
+	for range t.C {
+		err := conn.QueueHeartbeat(msg, queue, HeartbeatTime * 2)
+		if err != nil {
+			errc <- err
+			t.Stop()
+			return
+		}
+	}
+}
+
 func processBook(msg bookpipeline.Qmsg, conn Pipeliner, process func(chan string, chan string, chan error, *log.Logger), match *regexp.Regexp, fromQueue string, toQueue string) error {
-	bookname := msg.Body
+	dl := make(chan string)
+	processc := make(chan string)
+	upc := make(chan string)
+	done := make(chan bool)
+	errc := make(chan error)
 
-	t := time.NewTicker(HeartbeatTime * time.Second)
-	go conn.QueueHeartbeat(t, msg.Handle, fromQueue)
+	bookname := msg.Body
 
 	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)
-	processc := make(chan string)
-	upc := make(chan string)
-	done := make(chan bool)
-	errc := make(chan error)
+	t := time.NewTicker(HeartbeatTime * time.Second)
+	go heartbeat(conn, t, msg.Handle, fromQueue, errc)
 
 	// these functions will do their jobs when their channels have data
 	go download(dl, processc, conn, d, errc, conn.GetLogger())
@@ -346,7 +356,7 @@ func main() {
 	for {
 		select {
 		case <-checkPreQueue:
-			msg, err := conn.CheckQueue(conn.PreQueueId())
+			msg, err := conn.CheckQueue(conn.PreQueueId(), HeartbeatTime * 2)
 			checkPreQueue = time.After(PauseBetweenChecks)
 			if err != nil {
 				log.Println("Error checking preprocess queue", err)
@@ -362,7 +372,7 @@ func main() {
 				log.Println("Error during preprocess", err)
 			}
 		case <-checkOCRQueue:
-			msg, err := conn.CheckQueue(conn.OCRQueueId())
+			msg, err := conn.CheckQueue(conn.OCRQueueId(), HeartbeatTime * 2)
 			checkOCRQueue = time.After(PauseBetweenChecks)
 			if err != nil {
 				log.Println("Error checking OCR queue", err)
@@ -378,7 +388,7 @@ func main() {
 				log.Println("Error during OCR process", err)
 			}
 		case <-checkAnalyseQueue:
-			msg, err := conn.CheckQueue(conn.AnalyseQueueId())
+			msg, err := conn.CheckQueue(conn.AnalyseQueueId(), HeartbeatTime * 2)
 			checkAnalyseQueue = time.After(PauseBetweenChecks)
 			if err != nil {
 				log.Println("Error checking analyse queue", err)
-- 
cgit v1.2.1-24-ge1ad