Adds queue

Author: ashishkujoy

internal/queue/queue.go

@@ -0,0 +1,27 @@
+package queueinternal
+
+import "ashishkujoy/queue/internal/storage"
+
+type Queue struct {
+	segments *storage.Segments
+}
+
+func NewQueue(config *storage.Config) (*Queue, error) {
+	segments, err := storage.NewSegments(config, storage.NewIndex())
+	if err != nil {
+		return nil, err
+	}
+	return &Queue{segments: segments}, nil
+}
+
+func (q *Queue) Enqueue(data []byte) (int, error) {
+	return q.segments.Append(data)
+}
+
+func (q *Queue) Dequeue(id int) ([]byte, error) {
+	return q.segments.Read(id)
+}
+
+func (q *Queue) Close() error {
+	return q.segments.Close()
+}

internal/queue/queue_test.go

@@ -0,0 +1,35 @@
+package queueinternal
+
+import (
+	"ashishkujoy/queue/internal/storage"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func createTempDir(suffix string) string {
+	dir := os.TempDir() + "/" + suffix
+	os.MkdirAll(dir, 0755)
+	return dir
+}
+
+func removeTempDir(suffix string) {
+	dir := os.TempDir() + "/" + suffix
+	os.RemoveAll(dir)
+}
+
+func TestEnqueueSingleElement(t *testing.T) {
+	config := storage.NewConfig(createTempDir("TestEnqueueSingleElement"), 1000)
+	defer removeTempDir("TestEnqueueSingleElement")
+	queue, err := NewQueue(config)
+	assert.NoError(t, err)
+	defer queue.Close()
+
+	id, err := queue.Enqueue([]byte("First Message"))
+	assert.NoError(t, err)
+
+	data, err := queue.Dequeue(id)
+	assert.NoError(t, err)
+	assert.Equal(t, data, []byte("First Message"))
+}

internal/storage/config.go

@@ -4,3 +4,10 @@ type Config struct {
 	segmentsRoot          string
 	maxSegmentSizeInBytes int
 }
+
+func NewConfig(segmentsRoot string, maxSegmentSizeInBytes int) *Config {
+	return &Config{
+		segmentsRoot:          segmentsRoot,
+		maxSegmentSizeInBytes: maxSegmentSizeInBytes,
+	}
+}

internal/storage/segments.go

@@ -77,3 +77,15 @@ func (s *Segments) rollOverSegment() error {
 	s.active = newActiveSegment
 	return nil
 }
+
+func (s *Segments) Close() error {
+	if err := s.active.Close(); err != nil {
+		return err
+	}
+	for _, segment := range s.closedSegments {
+		if err := segment.Close(); err != nil {
+			return err
+		}
+	}
+	return nil
+}