add ifs and utility services

aqua-examples/decentralized-blockchain-gateway/wasm-modules/utilities/src/main.rs

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2022 Fluence Labs Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+use marine_rs_sdk::{marine, module_manifest};
+use serde_json;
+
+module_manifest!();
+
+fn main() {}
+
+#[marine]
+fn kv_to_u64(kv_string: String, k: String) -> u64 {
+    let obj: serde_json::Value = serde_json::from_str(&kv_string).unwrap();
+    obj[&k].as_u64().unwrap()
+}