Implement key providers

Author: mxpv

pkg/feed/key.go

@@ -0,0 +1,51 @@
+package feed
+
+import (
+	"sync"
+
+	"github.com/pkg/errors"
+)
+
+type KeyProvider interface {
+	Get() string
+}
+
+type FixedKeyProvider struct {
+	key string
+}
+
+func NewFixedKey(key string) (KeyProvider, error) {
+	if key == "" {
+		return nil, errors.New("key can't be empty")
+	}
+
+	return &FixedKeyProvider{key: key}, nil
+}
+
+func (p FixedKeyProvider) Get() string {
+	return p.key
+}
+
+type RotatedKeyProvider struct {
+	keys  []string
+	lock  sync.Mutex
+	index int
+}
+
+func NewRotatedKeys(keys []string) (KeyProvider, error) {
+	if len(keys) < 2 {
+		return nil, errors.Errorf("at least 2 keys required (got %d)", len(keys))
+	}
+
+	return &RotatedKeyProvider{keys: keys, index: 0}, nil
+}
+
+func (p *RotatedKeyProvider) Get() string {
+	p.lock.Lock()
+	defer p.lock.Unlock()
+
+	current := p.index % len(p.keys)
+	p.index++
+
+	return p.keys[current]
+}

pkg/feed/key_test.go

@@ -0,0 +1,26 @@
+package feed
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNewFixedKey(t *testing.T) {
+	key, err := NewFixedKey("123")
+	assert.NoError(t, err)
+
+	assert.EqualValues(t, "123", key.Get())
+	assert.EqualValues(t, "123", key.Get())
+}
+
+func TestNewRotatedKeys(t *testing.T) {
+	key, err := NewRotatedKeys([]string{"123", "456"})
+	assert.NoError(t, err)
+
+	assert.EqualValues(t, "123", key.Get())
+	assert.EqualValues(t, "456", key.Get())
+
+	assert.EqualValues(t, "123", key.Get())
+	assert.EqualValues(t, "456", key.Get())
+}