simplifying kv cache

cache/cache.go

@@ -7,11 +7,17 @@ import (
 )
 
 // Cache - generic cache interface
+// type Cache interface {
+// 	Put(ctx context.Context, key string, value []byte) error
+// 	Get(ctx context.Context, key string) (value []byte, err error)
+// 	Delete(ctx context.Context, key string) error
+// 	List(prefix string) ([][]byte, error)
+// }
 type Cache interface {
-	Put(ctx context.Context, key string, value []byte) error
-	Get(ctx context.Context, key string) (value []byte, err error)
-	Delete(ctx context.Context, key string) error
-	List(prefix string) ([][]byte, error)
+	Put(key string, value []byte) error
+	Get(key string) (value []byte, err error)
+	Delete(key string) error
+	List(prefix string) (map[string][]byte, error)
 }
 
 type expirationContextKeyType int

cache/memory/memory.go

@@ -1,7 +1,6 @@
 package memory
 
 import (
-	"context"
 	"fmt"
 	"strings"
 	"time"
@@ -84,7 +83,7 @@ func (c *Cache) service() {
 		req := <-c.requestChannel
 		resp := &response{}
 		switch req.requestType {
-		case GET:			
+		case GET:
 			val, ok := c.cache[req.key]
 			if !ok {
 				resp.error = cache.ErrNotFound
@@ -129,7 +128,7 @@ func (c *Cache) service() {
 }
 
 // Get - looks up value and returns it
-func (c *Cache) Get(ctx context.Context, key string) ([]byte, error) {
+func (c *Cache) Get(key string) ([]byte, error) {
 	respChannel := make(chan *response)
 	c.requestChannel <- &request{
 		requestType:     GET,
@@ -141,7 +140,7 @@ func (c *Cache) Get(ctx context.Context, key string) ([]byte, error) {
 }
 
 // Put - sets key/string. Overwrites existing key
-func (c *Cache) Put(ctx context.Context, key string, value []byte) error {
+func (c *Cache) Put(key string, value []byte) error {
 	respChannel := make(chan *response)
 	c.requestChannel <- &request{
 		requestType:     SET,
@@ -154,7 +153,7 @@ func (c *Cache) Put(ctx context.Context, key string, value []byte) error {
 }
 
 // Delete - deletes key
-func (c *Cache) Delete(ctx context.Context, key string) error {
+func (c *Cache) Delete(key string) error {
 	respChannel := make(chan *response)
 	c.requestChannel <- &request{
 		requestType:     DELETE,
@@ -166,7 +165,7 @@ func (c *Cache) Delete(ctx context.Context, key string) error {
 }
 
 // List all values for specified prefix
-func (c *Cache) List(prefix string) ([][]byte, error) {
+func (c *Cache) List(prefix string) (map[string][]byte, error) {
 	respChannel := make(chan *response)
 	c.requestChannel <- &request{
 		requestType:     COPY,
@@ -174,11 +173,11 @@ func (c *Cache) List(prefix string) ([][]byte, error) {
 	}
 	resp := <-respChannel
 
-	var list [][]byte
+	list := make(map[string][]byte)
 
 	for k, v := range resp.mapCopy {
 		if strings.HasPrefix(k, prefix) {
-			list = append(list, v)
+			list[k] = v
 		}
 	}
 	return list, nil

cache/memory/memory_test.go

@@ -1,7 +1,6 @@
 package memory
 
 import (
-	"context"
 	"log"
 	"testing"
 	"time"
@@ -10,12 +9,12 @@ import (
 func TestCacheSetGet(t *testing.T) {
 	c := NewMemoryCache(100*time.Millisecond, 100*time.Millisecond, 10*time.Millisecond)
 
-	err := c.Put(context.Background(), "a", []byte("b"))
+	err := c.Put("a", []byte("b"))
 	if err != nil {
 		t.Errorf("failed to SET a key, got error: %s", err)
 	}
 
-	val, err := c.Get(context.Background(), "a")
+	val, err := c.Get("a")
 	if err != nil {
 		t.Errorf("failed to GET a key, got error: %s", err)
 	}
@@ -33,12 +32,12 @@ func TestCacheSetGet(t *testing.T) {
 func TestCacheDel(t *testing.T) {
 	c := NewMemoryCache(100*time.Millisecond, 100*time.Millisecond, 10*time.Millisecond)
 
-	err := c.Put(context.Background(), "a", []byte("b"))
+	err := c.Put("a", []byte("b"))
 	if err != nil {
 		t.Errorf("failed to SET a key, got error: %s", err)
 	}
 
-	val, err := c.Get(context.Background(), "a")
+	val, err := c.Get("a")
 	if err != nil {
 		t.Errorf("failed to GET a key, got error: %s", err)
 	}
@@ -47,12 +46,12 @@ func TestCacheDel(t *testing.T) {
 		log.Panicf("value %v", val)
 	}
 
-	err = c.Delete(context.Background(), "a")
+	err = c.Delete("a")
 	if err != nil {
 		t.Errorf("faield to delete entry, got error: %s", err)
 	}
 
-	_, err = c.Get(context.Background(), "a")
+	_, err = c.Get("a")
 	if err == nil {
 		t.Errorf("expected to get an error after deletion, but got nil")
 	}
@@ -61,12 +60,12 @@ func TestCacheDel(t *testing.T) {
 func TestCacheExpiration(t *testing.T) {
 	c := NewMemoryCache(100*time.Millisecond, 100*time.Millisecond, 10*time.Millisecond)
 
-	err := c.Put(context.Background(), "a", []byte("b"))
+	err := c.Put("a", []byte("b"))
 	if err != nil {
 		t.Errorf("failed to SET a key, got error: %s", err)
 	}
 
-	val, err := c.Get(context.Background(), "a")
+	val, err := c.Get("a")
 	if err != nil {
 		t.Errorf("failed to GET a key, got error: %s", err)
 	}
@@ -77,7 +76,7 @@ func TestCacheExpiration(t *testing.T) {
 
 	time.Sleep(200 * time.Millisecond)
 
-	_, err = c.Get(context.Background(), "a")
+	_, err = c.Get("a")
 	if err == nil {
 		t.Errorf("expected to get an error after deletion, but got nil")
 	}