From e843ae5928125a64a32bd16d331063cc947e3fef Mon Sep 17 00:00:00 2001
From: Harlow Ward <harlow@hward.com>
Date: Sat, 30 Apr 2016 18:05:04 -0700
Subject: [PATCH] Remove poll interval in favor of aws retry backoff

---
 README.md   |  1 -
 consumer.go | 42 +++++++++++++++++++-----------------------
 2 files changed, 19 insertions(+), 24 deletions(-)

diff --git a/README.md b/README.md
index 97a49e8..2787075 100644
--- a/README.md
+++ b/README.md
@@ -25,7 +25,6 @@ func main() {
 
   // override default values
   c.Set("maxBatchCount", 200)
-  c.Set("pollInterval", "3s")
 
   // start consuming records from the queues
   c.Start(connector.HandlerFunc(func(b connector.Buffer) {
diff --git a/consumer.go b/consumer.go
index 5847c55..5491daa 100644
--- a/consumer.go
+++ b/consumer.go
@@ -2,7 +2,6 @@ package connector
 
 import (
 	"os"
-	"time"
 
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/aws/awserr"
@@ -11,7 +10,6 @@ import (
 )
 
 var (
-	pollInterval  = 1 * time.Second
 	maxBatchCount = 1000
 )
 
@@ -38,17 +36,9 @@ type Consumer struct {
 
 // Set `option` to `value`
 func (c *Consumer) Set(option string, value interface{}) {
-	var err error
-
 	switch option {
 	case "maxBatchCount":
 		maxBatchCount = value.(int)
-	case "pollInterval":
-		pollInterval, err = time.ParseDuration(value.(string))
-		if err != nil {
-			logger.Log("fatal", "ParseDuration", "msg", "unable to parse pollInterval value")
-			os.Exit(1)
-		}
 	default:
 		logger.Log("fatal", "Set", "msg", "unknown option")
 		os.Exit(1)
@@ -76,12 +66,20 @@ func (c *Consumer) Start(handler Handler) {
 }
 
 func (c *Consumer) handlerLoop(shardID string, handler Handler) {
+	buf := &Buffer{
+		MaxBatchCount: maxBatchCount,
+	}
+
+	checkpoint := &Checkpoint{
+		AppName:    c.appName,
+		StreamName: c.streamName,
+	}
+
 	params := &kinesis.GetShardIteratorInput{
 		ShardId:    aws.String(shardID),
 		StreamName: aws.String(c.streamName),
 	}
 
-	checkpoint := &Checkpoint{AppName: c.appName, StreamName: c.streamName}
 	if checkpoint.CheckpointExists(shardID) {
 		params.ShardIteratorType = aws.String("AFTER_SEQUENCE_NUMBER")
 		params.StartingSequenceNumber = aws.String(checkpoint.SequenceNumber())
@@ -97,13 +95,14 @@ func (c *Consumer) handlerLoop(shardID string, handler Handler) {
 		}
 	}
 
-	b := &Buffer{MaxBatchCount: maxBatchCount}
 	shardIterator := resp.ShardIterator
 
 	for {
-		resp, err := c.svc.GetRecords(&kinesis.GetRecordsInput{
-			ShardIterator: shardIterator,
-		})
+		resp, err := c.svc.GetRecords(
+			&kinesis.GetRecordsInput{
+				ShardIterator: shardIterator,
+			},
+		)
 
 		if err != nil {
 			awsErr, _ := err.(awserr.Error)
@@ -113,20 +112,17 @@ func (c *Consumer) handlerLoop(shardID string, handler Handler) {
 
 		if len(resp.Records) > 0 {
 			for _, r := range resp.Records {
-				b.AddRecord(r)
+				buf.AddRecord(r)
 
-				if b.ShouldFlush() {
-					handler.HandleRecords(*b)
-					checkpoint.SetCheckpoint(shardID, b.LastSeq())
-					b.Flush()
+				if buf.ShouldFlush() {
+					handler.HandleRecords(*buf)
+					checkpoint.SetCheckpoint(shardID, buf.LastSeq())
+					buf.Flush()
 				}
 			}
 		} else if resp.NextShardIterator == aws.String("") || shardIterator == resp.NextShardIterator {
 			logger.Log("fatal", "nextShardIterator", "msg", err.Error())
 			os.Exit(1)
-		} else {
-			logger.Log("info", "sleeping", "msg", "no records to process")
-			time.Sleep(pollInterval)
 		}
 
 		shardIterator = resp.NextShardIterator