feat(proxyd): avoid caching debug_getRawReceipts responses with 0 receipts

proxyd/proxyd/cache.go

@@ -128,7 +128,7 @@ type rpcCache struct {
 func newRPCCache(cache Cache) RPCCache {
 	staticHandler := &StaticMethodHandler{cache: cache}
 	debugGetRawReceiptsHandler := &StaticMethodHandler{cache: cache,
-		filter: func(req *RPCReq) bool {
+		filterGet: func(req *RPCReq) bool {
 			// cache only if the request is for a block hash
 
 			var p []rpc.BlockNumberOrHash
@@ -141,6 +141,14 @@ func newRPCCache(cache Cache) RPCCache {
 			}
 			return p[0].BlockHash != nil
 		},
+		filterPut: func(req *RPCReq, res *RPCRes) bool {
+			// don't cache if response contains 0 receipts
+			rawReceipts, ok := res.Result.([]interface{})
+			if !ok {
+				return false
+			}
+			return len(rawReceipts) > 0
+		},
 	}
 	handlers := map[string]RPCMethodHandler{
 		"eth_chainId":                           staticHandler,

proxyd/proxyd/methods.go

@@ -17,9 +17,10 @@ type RPCMethodHandler interface {
 }
 
 type StaticMethodHandler struct {
-	cache  Cache
-	m      sync.RWMutex
-	filter func(*RPCReq) bool
+	cache     Cache
+	m         sync.RWMutex
+	filterGet func(*RPCReq) bool
+	filterPut func(*RPCReq, *RPCRes) bool
 }
 
 func (e *StaticMethodHandler) key(req *RPCReq) string {
@@ -34,7 +35,7 @@ func (e *StaticMethodHandler) GetRPCMethod(ctx context.Context, req *RPCReq) (*R
 	if e.cache == nil {
 		return nil, nil
 	}
-	if e.filter != nil && !e.filter(req) {
+	if e.filterGet != nil && !e.filterGet(req) {
 		return nil, nil
 	}
 
@@ -67,7 +68,12 @@ func (e *StaticMethodHandler) PutRPCMethod(ctx context.Context, req *RPCReq, res
 	if e.cache == nil {
 		return nil
 	}
-	if e.filter != nil && !e.filter(req) {
+	// if there is a filter on get, we don't want to cache it because its irretrievable
+	if e.filterGet != nil && !e.filterGet(req) {
+		return nil
+	}
+	// response filter
+	if e.filterPut != nil && !e.filterPut(req, res) {
 		return nil
 	}
 

proxyd/proxyd/tools/mockserver/handler/handler.go

@@ -77,7 +77,7 @@ func (mh *MockedHandler) Handler(w http.ResponseWriter, req *http.Request) {
 	for _, r := range requests {
 		method := r["method"]
 		block := ""
-		if method == "eth_getBlockByNumber" {
+		if method == "eth_getBlockByNumber" || method == "debug_getRawReceipts" {
 			block = (r["params"].([]interface{})[0]).(string)
 		}