feat: add wasm-rust sdk with say-hello simple extension (#350)

plugins/wasm-rust/src/log.rs

@@ -0,0 +1,71 @@
+// Copyright (c) 2023 Alibaba Group Holding Ltd.
+//
+// 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 proxy_wasm::hostcalls;
+
+pub enum LogLevel {
+    Trace,
+    Debug,
+    Info,
+    Warn,
+    Error,
+    Critical,
+}
+
+pub struct Log {
+    plugin_name: String,
+}
+
+impl Log {
+    pub fn new(plugin_name: String) -> Log {
+        Log { plugin_name }
+    }
+
+    fn log(&self, level: LogLevel, msg: &str) {
+        let msg = format!("[{}] {}", self.plugin_name, msg);
+        let level = match level {
+            LogLevel::Trace => proxy_wasm::types::LogLevel::Trace,
+            LogLevel::Debug => proxy_wasm::types::LogLevel::Debug,
+            LogLevel::Info => proxy_wasm::types::LogLevel::Info,
+            LogLevel::Warn => proxy_wasm::types::LogLevel::Warn,
+            LogLevel::Error => proxy_wasm::types::LogLevel::Error,
+            LogLevel::Critical => proxy_wasm::types::LogLevel::Critical,
+        };
+        hostcalls::log(level, msg.as_str()).unwrap();
+    }
+
+    pub fn trace(&self, msg: &str) {
+        self.log(LogLevel::Trace, msg)
+    }
+
+    pub fn debug(&self, msg: &str) {
+        self.log(LogLevel::Debug, msg)
+    }
+
+    pub fn info(&self, msg: &str) {
+        self.log(LogLevel::Info, msg)
+    }
+
+    pub fn warn(&self, msg: &str) {
+        self.log(LogLevel::Warn, msg)
+    }
+
+    pub fn error(&self, msg: &str) {
+        self.log(LogLevel::Error, msg)
+    }
+
+    pub fn critical(&self, msg: &str) {
+        self.log(LogLevel::Critical, msg)
+    }
+}