Add Emitters

* Add first s3 Emitter along with Emitter Interface.
* Replace setters with initializers.

buffers.go

@@ -1,10 +1,13 @@
 package etl
 
-import (
+import "bytes"
-	"bytes"
+
-	"fmt"
+type Buffer interface {
-	"time"
+	Data() []byte
-)
+	FirstSequenceNumber() string
+	LastSequenceNumber() string
+	NumMessagesInBuffer() int
+}
 
 type MsgBuffer struct {
 	buffer              bytes.Buffer
@@ -40,11 +43,6 @@ func (b MsgBuffer) SequenceExists(sequenceNumber string) bool {
 	return false
 }
 
-func (b MsgBuffer) FileName() string {
-	date := time.Now().UTC().Format("2006-01-02")
-	return fmt.Sprintf("/%v/%v-%v.txt", date, b.firstSequenceNumber, b.lastSequenceNumber)
-}
-
 func (b MsgBuffer) Data() []byte {
 	return b.buffer.Bytes()
 }

buffers_test.go

@@ -2,9 +2,7 @@ package etl
 
 import (
 	"bytes"
-	"fmt"
 	"testing"
-	"time"
 )
 
 func TestNumMessagesToBuffer(t *testing.T) {
@@ -139,18 +137,3 @@ func TestData(t *testing.T) {
 		t.Errorf("Data() want %v", body)
 	}
 }
-
-func TestFileName(t *testing.T) {
-	var r1, s1 = []byte("Record1"), "Seq1"
-	var r2, s2 = []byte("Record2"), "Seq2"
-	date := time.Now().UTC().Format("2006-01-02")
-	name := fmt.Sprintf("/%v/Seq1-Seq2.txt", date)
-
-	b := MsgBuffer{}
-	b.ConsumeRecord(r1, s1)
-	b.ConsumeRecord(r2, s2)
-
-	if b.FileName() != name {
-		t.Errorf("FileName() = want %v", b.FileName(), name)
-	}
-}

checkpoints.go

@@ -13,7 +13,7 @@ type Checkpoint interface {
 }
 
 type RedisCheckpoint struct {
-	appName        string
+	AppName        string
 	client         redis.Client
 	sequenceNumber string
 }
@@ -41,5 +41,5 @@ func (c *RedisCheckpoint) SetCheckpoint(streamName string, shardID string, seque
 }
 
 func (c RedisCheckpoint) keyGen(streamName string, shardID string) string {
-	return fmt.Sprintf("%v:checkpoint:%v:%v", c.appName, streamName, shardID)
+	return fmt.Sprintf("%v:checkpoint:%v:%v", c.AppName, streamName, shardID)
 }

checkpoints_test.go

@@ -7,7 +7,7 @@ import (
 
 func TestKeyGen(t *testing.T) {
 	k := "app:checkpoint:stream:shard"
-	c := RedisCheckpoint{appName: "app"}
+	c := RedisCheckpoint{AppName: "app"}
 
 	r := c.keyGen("stream", "shard")
 
@@ -20,7 +20,7 @@ func TestCheckpointExists(t *testing.T) {
 	var rc redis.Client
 	k := "app:checkpoint:stream:shard"
 	rc.Set(k, []byte("fakeSeqNum"))
-	c := RedisCheckpoint{appName: "app"}
+	c := RedisCheckpoint{AppName: "app"}
 
 	r := c.CheckpointExists("stream", "shard")
 
@@ -34,7 +34,7 @@ func TestCheckpointExists(t *testing.T) {
 func TestSetCheckpoint(t *testing.T) {
 	k := "app:checkpoint:stream:shard"
 	var rc redis.Client
-	c := RedisCheckpoint{appName: "app"}
+	c := RedisCheckpoint{AppName: "app"}
 	c.SetCheckpoint("stream", "shard", "fakeSeqNum")
 
 	r, _ := rc.Get(k)

emitters.go

@@ -0,0 +1,43 @@
+package etl
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/crowdmob/goamz/aws"
+	"github.com/crowdmob/goamz/s3"
+)
+
+type Emitter interface {
+	Emit(path string, data []byte)
+}
+
+type S3Emitter struct {
+	S3Bucket string
+}
+
+func (e S3Emitter) s3FileName(firstSeq string, lastSeq string) string {
+	date := time.Now().UTC().Format("2006-01-02")
+	return fmt.Sprintf("/%v/%v-%v.txt", date, firstSeq, lastSeq)
+}
+
+func (e S3Emitter) Emit(buffer Buffer) {
+	auth, _ := aws.EnvAuth()
+	s := s3.New(auth, aws.USEast)
+	b := s.Bucket(e.S3Bucket)
+	f := e.s3FileName(buffer.FirstSequenceNumber(), buffer.LastSequenceNumber())
+	r := b.Put(f, buffer.Data(), "text/plain", s3.Private, s3.Options{})
+	fmt.Printf("Successfully emitted %v records to S3 in s3://%v/%v", buffer.NumMessagesInBuffer(), b, f)
+	fmt.Println(r)
+}
+
+type RedshiftEmitter struct {
+}
+
+func (e RedshiftEmitter) Emit(path string, data []byte) {
+	// first call S3 bucket
+	// pg.query("COPY file_path TO table_name")
+	// pg.query("INSERT INTO imported_files VALUE file_path")
+	fmt.Printf("debug: emitting %v to Redshift\n", path)
+	fmt.Println(string(data))
+}

emitters_test.go

@@ -0,0 +1,18 @@
+package etl
+
+import (
+	"fmt"
+	"testing"
+	"time"
+)
+
+func TestPath(t *testing.T) {
+	d := time.Now().UTC().Format("2006-01-02")
+	n := fmt.Sprintf("/%v/a-b.txt", d)
+	e := S3Emitter{}
+	f := e.s3FileName("a", "b")
+
+	if f != n {
+		t.Errorf("s3FileName() = want %v", f, n)
+	}
+}

examples/consumer.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+
 	"github.com/harlow/go-etl"
 	"github.com/joho/godotenv"
 	"github.com/sendgridlabs/go-kinesis"
@@ -10,14 +11,10 @@ import (
 func main() {
 	godotenv.Load()
 
-	k := kinesis.New("", "", kinesis.Region{})
 	s := "inputStream"
-
+	k := kinesis.New("", "", kinesis.Region{})
-	c := etl.RedisCheckpoint{appName: "sampleApp"}
+	c := etl.RedisCheckpoint{AppName: "sampleApp"}
-
+	e := etl.S3Emitter{S3Bucket: "bucketName"}
-	e := etl.S3Emitter{}
-	e.SetBucketName("bucketName")
-
 	// t := etl.EventTransformer{}
 
 	args := kinesis.NewArgs()

utils.go

@@ -2,8 +2,8 @@ package etl
 
 import (
 	"fmt"
-	"time"
 	"github.com/sendgridlabs/go-kinesis"
+	"time"
 )
 
 func CreateAndWaitForStreamToBecomeAvailable(ksis *kinesis.Kinesis, streamName string, shardCount int) {
@@ -38,7 +38,11 @@ func CreateAndWaitForStreamToBecomeAvailable(ksis *kinesis.Kinesis, streamName s
 func StreamExists(ksis *kinesis.Kinesis, streamName string) bool {
 	args := kinesis.NewArgs()
 	resp, _ := ksis.ListStreams(args)
-  for _, name := range resp.StreamNames { if name == streamName { return true } }
+	for _, name := range resp.StreamNames {
+		if name == streamName {
+			return true
+		}
+	}
 	return false
 }