optimise default getBlockByNumber - skip processing requests of tx bodies

src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/LocalCallRouter.kt

@@ -136,6 +136,11 @@ class LocalCallRouter(
             throw RpcException(RpcResponseError.CODE_INVALID_METHOD_PARAMS, "Must provide 2 parameters")
         }
         val number: Long
+        val withTx = params[1].toString().toBoolean()
+        if (withTx) {
+            // with Tx request much more efficient in remote call
+            return null
+        }
         try {
             val blockRef = params[0].toString()
             when {
@@ -165,16 +170,8 @@ class LocalCallRouter(
         } catch (e: IllegalArgumentException) {
             throw RpcException(RpcResponseError.CODE_INVALID_METHOD_PARAMS, "[0] must be a block number")
         }
-        val withTx = params[1].toString().toBoolean()
-        var block = reader.blocksByHeightAsCont()
-            .read(number)
-        block = if (withTx) {
-            block.flatMap {
-                fullBlocksReader.read(it.hash)
-            }
-        } else {
-            block
-        }
-        return block.map { it.json!! }
+
+        return reader.blocksByHeightAsCont()
+            .read(number).map { it.json!! }
     }
 }

src/test/groovy/io/emeraldpay/dshackle/upstream/ethereum/LocalCallRouterSpec.groovy

@@ -138,4 +138,22 @@ class LocalCallRouterSpec extends Specification {
             }
         }
     }
+
+    def "getBlockByNumber skips requests with tx bodies"() {
+        setup:
+        def head = Mock(Head)
+        def reader = Mock(EthereumCachingReader) {
+            _ * blocksByIdAsCont() >> new EmptyReader<>()
+            _ * txByHashAsCont() >> new EmptyReader<>()
+            _ * blocksByHeightAsCont() >> new EmptyReader<>()
+        }
+        def methods = new DefaultEthereumMethods(Chain.ETHEREUM)
+        def router = new LocalCallRouter(reader, methods, head, true)
+
+        when:
+        def act = router.getBlockByNumber(["0x0", true])
+
+        then:
+        act == null
+    }
 }