add list keys to cache (#352)

* add list keys to cache

* add list keys example

cache/examples.json

@@ -62,5 +62,14 @@
             "key": "counter",
             "value": 0
         }
+    }],
+    "listKeys": [{
+        "title": "List the keys",
+        "description": "List all the stored keys",
+        "run_check": true,
+        "request": {},
+        "response": {
+            "keys": ["counter", "foo"]
+        }
     }]
 }

cache/handler/cache.go

@@ -120,3 +120,16 @@ func (c *Cache) Decrement(ctx context.Context, req *pb.DecrementRequest, rsp *pb
 
 	return nil
 }
+
+func (c *Cache) ListKeys(ctx context.Context, req *pb.ListKeysRequest, rsp *pb.ListKeysResponse) error {
+	keys, err := cache.Context(ctx).ListKeys()
+
+	if err != nil {
+		log.Errorf("Error listing keys in cache %s", err)
+		return errors.InternalServerError("cache.listkeys", "Error listing keys in cache")
+	}
+
+	rsp.Keys = keys
+
+	return nil
+}

cache/proto/cache.pb.go

@@ -1,6 +1,6 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
-// 	protoc-gen-go v1.26.0
+// 	protoc-gen-go v1.27.1
 // 	protoc        v3.15.6
 // source: proto/cache.proto
 
@@ -20,7 +20,7 @@ const (
 	_ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
 )
 
-// Get an item from the cache by key
+// Get an item from the cache by key. If key is not found, an empty response is returned.
 type GetRequest struct {
 	state         protoimpl.MessageState
 	sizeCache     protoimpl.SizeCache
@@ -135,7 +135,7 @@ func (x *GetResponse) GetTtl() int64 {
 	return 0
 }
 
-// Set an item in the cache
+// Set an item in the cache. Overwrites any existing value already set.
 type SetRequest struct {
 	state         protoimpl.MessageState
 	sizeCache     protoimpl.SizeCache
@@ -250,7 +250,7 @@ func (x *SetResponse) GetStatus() string {
 	return ""
 }
 
-// Delete a value from the cache
+// Delete a value from the cache. If key not found a success response is returned.
 type DeleteRequest struct {
 	state         protoimpl.MessageState
 	sizeCache     protoimpl.SizeCache
@@ -347,7 +347,7 @@ func (x *DeleteResponse) GetStatus() string {
 	return ""
 }
 
-// Increment a value (if its a number)
+// Increment a value (if it's a number). If key not found it is equivalent to set.
 type IncrementRequest struct {
 	state         protoimpl.MessageState
 	sizeCache     protoimpl.SizeCache
@@ -355,7 +355,7 @@ type IncrementRequest struct {
 
 	// The key to increment
 	Key string `protobuf:"bytes,1,opt,name=key,proto3" json:"key,omitempty"`
-	// The value to add
+	// The amount to increment the value by
 	Value int64 `protobuf:"varint,2,opt,name=value,proto3" json:"value,omitempty"`
 }
 
@@ -412,7 +412,7 @@ type IncrementResponse struct {
 
 	// The key incremented
 	Key string `protobuf:"bytes,1,opt,name=key,proto3" json:"key,omitempty"`
-	// The result value
+	// The new value
 	Value int64 `protobuf:"varint,2,opt,name=value,proto3" json:"value,omitempty"`
 }
 
@@ -462,7 +462,7 @@ func (x *IncrementResponse) GetValue() int64 {
 	return 0
 }
 
-// Decrement a value (if its a number)
+// Decrement a value (if it's a number). If key not found it is equivalent to set.
 type DecrementRequest struct {
 	state         protoimpl.MessageState
 	sizeCache     protoimpl.SizeCache
@@ -470,7 +470,7 @@ type DecrementRequest struct {
 
 	// The key to decrement
 	Key string `protobuf:"bytes,1,opt,name=key,proto3" json:"key,omitempty"`
-	// The delta value to decrement
+	// The amount to decrement the value by
 	Value int64 `protobuf:"varint,2,opt,name=value,proto3" json:"value,omitempty"`
 }
 
@@ -525,9 +525,9 @@ type DecrementResponse struct {
 	sizeCache     protoimpl.SizeCache
 	unknownFields protoimpl.UnknownFields
 
-	// The key of the item
+	// The key decremented
 	Key string `protobuf:"bytes,1,opt,name=key,proto3" json:"key,omitempty"`
-	// The result value of the item
+	// The new value
 	Value int64 `protobuf:"varint,2,opt,name=value,proto3" json:"value,omitempty"`
 }
 
@@ -577,6 +577,92 @@ func (x *DecrementResponse) GetValue() int64 {
 	return 0
 }
 
+// List all the available keys
+type ListKeysRequest struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+}
+
+func (x *ListKeysRequest) Reset() {
+	*x = ListKeysRequest{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_proto_cache_proto_msgTypes[10]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *ListKeysRequest) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*ListKeysRequest) ProtoMessage() {}
+
+func (x *ListKeysRequest) ProtoReflect() protoreflect.Message {
+	mi := &file_proto_cache_proto_msgTypes[10]
+	if protoimpl.UnsafeEnabled && x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use ListKeysRequest.ProtoReflect.Descriptor instead.
+func (*ListKeysRequest) Descriptor() ([]byte, []int) {
+	return file_proto_cache_proto_rawDescGZIP(), []int{10}
+}
+
+type ListKeysResponse struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+
+	Keys []string `protobuf:"bytes,1,rep,name=keys,proto3" json:"keys,omitempty"`
+}
+
+func (x *ListKeysResponse) Reset() {
+	*x = ListKeysResponse{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_proto_cache_proto_msgTypes[11]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *ListKeysResponse) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*ListKeysResponse) ProtoMessage() {}
+
+func (x *ListKeysResponse) ProtoReflect() protoreflect.Message {
+	mi := &file_proto_cache_proto_msgTypes[11]
+	if protoimpl.UnsafeEnabled && x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use ListKeysResponse.ProtoReflect.Descriptor instead.
+func (*ListKeysResponse) Descriptor() ([]byte, []int) {
+	return file_proto_cache_proto_rawDescGZIP(), []int{11}
+}
+
+func (x *ListKeysResponse) GetKeys() []string {
+	if x != nil {
+		return x.Keys
+	}
+	return nil
+}
+
 var File_proto_cache_proto protoreflect.FileDescriptor
 
 var file_proto_cache_proto_rawDesc = []byte{
@@ -615,27 +701,34 @@ var file_proto_cache_proto_rawDesc = []byte{
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+	0x63, 0x68, 0x65, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
 }
 
 var (
@@ -650,7 +743,7 @@ func file_proto_cache_proto_rawDescGZIP() []byte {
 	return file_proto_cache_proto_rawDescData
 }
 
-var file_proto_cache_proto_msgTypes = make([]protoimpl.MessageInfo, 10)
+var file_proto_cache_proto_msgTypes = make([]protoimpl.MessageInfo, 12)
 var file_proto_cache_proto_goTypes = []interface{}{
 	(*GetRequest)(nil),        // 0: cache.GetRequest
 	(*GetResponse)(nil),       // 1: cache.GetResponse
@@ -662,23 +755,27 @@ var file_proto_cache_proto_goTypes = []interface{}{
 	(*IncrementResponse)(nil), // 7: cache.IncrementResponse
 	(*DecrementRequest)(nil),  // 8: cache.DecrementRequest
 	(*DecrementResponse)(nil), // 9: cache.DecrementResponse
+	(*ListKeysRequest)(nil),   // 10: cache.ListKeysRequest
+	(*ListKeysResponse)(nil),  // 11: cache.ListKeysResponse
 }
 var file_proto_cache_proto_depIdxs = []int32{
-	0, // 0: cache.Cache.Get:input_type -> cache.GetRequest
+	0,  // 0: cache.Cache.Get:input_type -> cache.GetRequest
-	2, // 1: cache.Cache.Set:input_type -> cache.SetRequest
+	2,  // 1: cache.Cache.Set:input_type -> cache.SetRequest
-	4, // 2: cache.Cache.Delete:input_type -> cache.DeleteRequest
+	4,  // 2: cache.Cache.Delete:input_type -> cache.DeleteRequest
-	6, // 3: cache.Cache.Increment:input_type -> cache.IncrementRequest
+	6,  // 3: cache.Cache.Increment:input_type -> cache.IncrementRequest
-	8, // 4: cache.Cache.Decrement:input_type -> cache.DecrementRequest
+	8,  // 4: cache.Cache.Decrement:input_type -> cache.DecrementRequest
-	1, // 5: cache.Cache.Get:output_type -> cache.GetResponse
+	10, // 5: cache.Cache.ListKeys:input_type -> cache.ListKeysRequest
-	3, // 6: cache.Cache.Set:output_type -> cache.SetResponse
+	1,  // 6: cache.Cache.Get:output_type -> cache.GetResponse
-	5, // 7: cache.Cache.Delete:output_type -> cache.DeleteResponse
+	3,  // 7: cache.Cache.Set:output_type -> cache.SetResponse
-	7, // 8: cache.Cache.Increment:output_type -> cache.IncrementResponse
+	5,  // 8: cache.Cache.Delete:output_type -> cache.DeleteResponse
-	9, // 9: cache.Cache.Decrement:output_type -> cache.DecrementResponse
+	7,  // 9: cache.Cache.Increment:output_type -> cache.IncrementResponse
-	5, // [5:10] is the sub-list for method output_type
+	9,  // 10: cache.Cache.Decrement:output_type -> cache.DecrementResponse
-	0, // [0:5] is the sub-list for method input_type
+	11, // 11: cache.Cache.ListKeys:output_type -> cache.ListKeysResponse
-	0, // [0:0] is the sub-list for extension type_name
+	6,  // [6:12] is the sub-list for method output_type
-	0, // [0:0] is the sub-list for extension extendee
+	0,  // [0:6] is the sub-list for method input_type
-	0, // [0:0] is the sub-list for field type_name
+	0,  // [0:0] is the sub-list for extension type_name
+	0,  // [0:0] is the sub-list for extension extendee
+	0,  // [0:0] is the sub-list for field type_name
 }
 
 func init() { file_proto_cache_proto_init() }
@@ -807,6 +904,30 @@ func file_proto_cache_proto_init() {
 				return nil
 			}
 		}
+		file_proto_cache_proto_msgTypes[10].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*ListKeysRequest); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
+		file_proto_cache_proto_msgTypes[11].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*ListKeysResponse); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
 	}
 	type x struct{}
 	out := protoimpl.TypeBuilder{
@@ -814,7 +935,7 @@ func file_proto_cache_proto_init() {
 			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
 			RawDescriptor: file_proto_cache_proto_rawDesc,
 			NumEnums:      0,
-			NumMessages:   10,
+			NumMessages:   12,
 			NumExtensions: 0,
 			NumServices:   1,
 		},

cache/proto/cache.pb.micro.go

@@ -47,6 +47,7 @@ type CacheService interface {
 	Delete(ctx context.Context, in *DeleteRequest, opts ...client.CallOption) (*DeleteResponse, error)
 	Increment(ctx context.Context, in *IncrementRequest, opts ...client.CallOption) (*IncrementResponse, error)
 	Decrement(ctx context.Context, in *DecrementRequest, opts ...client.CallOption) (*DecrementResponse, error)
+	ListKeys(ctx context.Context, in *ListKeysRequest, opts ...client.CallOption) (*ListKeysResponse, error)
 }
 
 type cacheService struct {
@@ -111,6 +112,16 @@ func (c *cacheService) Decrement(ctx context.Context, in *DecrementRequest, opts
 	return out, nil
 }
 
+func (c *cacheService) ListKeys(ctx context.Context, in *ListKeysRequest, opts ...client.CallOption) (*ListKeysResponse, error) {
+	req := c.c.NewRequest(c.name, "Cache.ListKeys", in)
+	out := new(ListKeysResponse)
+	err := c.c.Call(ctx, req, out, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
 // Server API for Cache service
 
 type CacheHandler interface {
@@ -119,6 +130,7 @@ type CacheHandler interface {
 	Delete(context.Context, *DeleteRequest, *DeleteResponse) error
 	Increment(context.Context, *IncrementRequest, *IncrementResponse) error
 	Decrement(context.Context, *DecrementRequest, *DecrementResponse) error
+	ListKeys(context.Context, *ListKeysRequest, *ListKeysResponse) error
 }
 
 func RegisterCacheHandler(s server.Server, hdlr CacheHandler, opts ...server.HandlerOption) error {
@@ -128,6 +140,7 @@ func RegisterCacheHandler(s server.Server, hdlr CacheHandler, opts ...server.Han
 		Delete(ctx context.Context, in *DeleteRequest, out *DeleteResponse) error
 		Increment(ctx context.Context, in *IncrementRequest, out *IncrementResponse) error
 		Decrement(ctx context.Context, in *DecrementRequest, out *DecrementResponse) error
+		ListKeys(ctx context.Context, in *ListKeysRequest, out *ListKeysResponse) error
 	}
 	type Cache struct {
 		cache
@@ -159,3 +172,7 @@ func (h *cacheHandler) Increment(ctx context.Context, in *IncrementRequest, out
 func (h *cacheHandler) Decrement(ctx context.Context, in *DecrementRequest, out *DecrementResponse) error {
 	return h.CacheHandler.Decrement(ctx, in, out)
 }
+
+func (h *cacheHandler) ListKeys(ctx context.Context, in *ListKeysRequest, out *ListKeysResponse) error {
+	return h.CacheHandler.ListKeys(ctx, in, out)
+}

cache/proto/cache.proto

@@ -10,6 +10,7 @@ service Cache {
 	rpc Delete(DeleteRequest) returns (DeleteResponse) {}
 	rpc Increment(IncrementRequest) returns (IncrementResponse) {}
 	rpc Decrement(DecrementRequest) returns (DecrementResponse) {}
+	rpc ListKeys(ListKeysRequest) returns (ListKeysResponse) {}
 }
 
 // Get an item from the cache by key. If key is not found, an empty response is returned.
@@ -82,3 +83,12 @@ message DecrementResponse {
 	// The new value
 	int64 value = 2;
 }
+
+// List all the available keys
+message ListKeysRequest {
+
+}
+
+message ListKeysResponse {
+	repeated string keys = 1;
+}

pkg/cache/cache.go

@@ -6,6 +6,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"strings"
 	"sync"
 	"time"
 
@@ -24,11 +25,12 @@ type Cache interface {
 	Delete(key string) error
 	Increment(key string, val int64) (int64, error)
 	Decrement(key string, val int64) (int64, error)
+	ListKeys() ([]string, error)
 	Close() error
 }
 
 type cache struct {
-	sync.Mutex
+	sync.RWMutex
 	closed chan bool
 	LRU    *lru.Cache
 	Disk   *diskv.Diskv
@@ -259,6 +261,30 @@ func (c *cache) Decrement(key string, value int64) (int64, error) {
 	return val, nil
 }
 
+func (c *cache) ListKeys() ([]string, error) {
+	c.RLock()
+	defer c.RUnlock()
+
+	if c.Store == nil {
+		c.Store = store.DefaultStore
+	}
+
+	prefix := c.Key("")
+
+	recKeys, err := c.Store.List(store.ListPrefix(prefix))
+	if err != nil {
+		return nil, err
+	}
+
+	var keys []string
+
+	for _, key := range recKeys {
+		keys = append(keys, strings.TrimPrefix(key, prefix))
+	}
+
+	return keys, nil
+}
+
 func Context(ctx context.Context) Cache {
 	return DefaultCache.Context(ctx)
 }
@@ -282,3 +308,7 @@ func Increment(key string, val int64) (int64, error) {
 func Decrement(key string, val int64) (int64, error) {
 	return DefaultCache.Decrement(key, val)
 }
+
+func ListKeys() ([]string, error) {
+	return DefaultCache.ListKeys()
+}