Refactor data source hierarchy: spilt into readable and writable data source

sentinel-demo/sentinel-demo-apollo-datasource/src/main/java/com/alibaba/csp/sentinel/demo/datasource/apollo/ApolloDataSourceDemo.java

@@ -1,11 +1,12 @@
 package com.alibaba.csp.sentinel.demo.datasource.apollo;
 
-import com.alibaba.csp.sentinel.datasource.DataSource;
+import com.alibaba.csp.sentinel.datasource.ReadableDataSource;
 import com.alibaba.csp.sentinel.datasource.apollo.ApolloDataSource;
 import com.alibaba.csp.sentinel.slots.block.flow.FlowRule;
 import com.alibaba.csp.sentinel.slots.block.flow.FlowRuleManager;
 import com.alibaba.fastjson.JSON;
 import com.alibaba.fastjson.TypeReference;
+
 import java.util.List;
 
 /**
@@ -37,34 +38,33 @@
  * @author Jason Song
  */
 public class ApolloDataSourceDemo {
-  private static final String KEY = "TestResource";
 
-  public static void main(String[] args) {
-    loadRules();
-    // Assume we config: resource is `TestResource`, initial QPS threshold is 5.
-    FlowQpsRunner runner = new FlowQpsRunner(KEY, 1, 100);
-    runner.simulateTraffic();
-    runner.tick();
-  }
+    private static final String KEY = "TestResource";
+
+    public static void main(String[] args) {
+        loadRules();
+        // Assume we config: resource is `TestResource`, initial QPS threshold is 5.
+        FlowQpsRunner runner = new FlowQpsRunner(KEY, 1, 100);
+        runner.simulateTraffic();
+        runner.tick();
+    }
 
-  private static void loadRules() {
-    /**
-     * Set up basic information, only for demo purpose. You may adjust them based on your actual environment.
-     * <br />
-     * For more information, please refer https://github.com/ctripcorp/apollo
-     */
-    String appId = "sentinel-demo";
-    String apolloMetaServerAddress = "http://localhost:8080";
-    System.setProperty("app.id", appId);
-    System.setProperty("apollo.meta", apolloMetaServerAddress);
+    private static void loadRules() {
+        // Set up basic information, only for demo purpose. You may adjust them based on your actual environment.
+        // For more information, please refer https://github.com/ctripcorp/apollo
+        String appId = "sentinel-demo";
+        String apolloMetaServerAddress = "http://localhost:8080";
+        System.setProperty("app.id", appId);
+        System.setProperty("apollo.meta", apolloMetaServerAddress);
 
-    String namespaceName = "application";
-    String flowRuleKey = "flowRules";
-    String defaultFlowRules = "[]"; //it's better to provide a meaningful default value
+        String namespaceName = "application";
+        String flowRuleKey = "flowRules";
+        // It's better to provide a meaningful default value.
+        String defaultFlowRules = "[]";
 
-    DataSource<String, List<FlowRule>> flowRuleDataSource = new ApolloDataSource<>(namespaceName, flowRuleKey,
-        defaultFlowRules, source -> JSON.parseObject(source, new TypeReference<List<FlowRule>>() {
-    }));
-    FlowRuleManager.register2Property(flowRuleDataSource.getProperty());
-  }
+        ReadableDataSource<String, List<FlowRule>> flowRuleDataSource = new ApolloDataSource<>(namespaceName,
+            flowRuleKey, defaultFlowRules, source -> JSON.parseObject(source, new TypeReference<List<FlowRule>>() {
+        }));
+        FlowRuleManager.register2Property(flowRuleDataSource.getProperty());
+    }
 }

sentinel-demo/sentinel-demo-dynamic-file-rule/pom.xml

@@ -19,11 +19,29 @@
             <groupId>com.alibaba.csp</groupId>
             <artifactId>sentinel-datasource-extension</artifactId>
         </dependency>
+        <dependency>
+            <groupId>com.alibaba.csp</groupId>
+            <artifactId>sentinel-transport-simple-http</artifactId>
+        </dependency>
 
         <dependency>
             <groupId>com.alibaba</groupId>
             <artifactId>fastjson</artifactId>
         </dependency>
     </dependencies>
 
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>${maven.compiler.version}</version>
+                <configuration>
+                    <source>1.8</source>
+                    <target>1.8</target>
+                    <encoding>${java.encoding}</encoding>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
 </project>

sentinel-demo/sentinel-demo-dynamic-file-rule/src/main/java/com/alibaba/csp/sentinel/demo/file/rule/FileDataSourceDemo.java

@@ -15,14 +15,12 @@
  */
 package com.alibaba.csp.sentinel.demo.file.rule;
 
+import java.net.URLDecoder;
 import java.util.List;
 
-import com.alibaba.csp.sentinel.datasource.ConfigParser;
-import com.alibaba.csp.sentinel.datasource.DataSource;
+import com.alibaba.csp.sentinel.datasource.Converter;
+import com.alibaba.csp.sentinel.datasource.ReadableDataSource;
 import com.alibaba.csp.sentinel.datasource.FileRefreshableDataSource;
-import com.alibaba.csp.sentinel.demo.file.rule.parser.JsonDegradeRuleListParser;
-import com.alibaba.csp.sentinel.demo.file.rule.parser.JsonFlowRuleListParser;
-import com.alibaba.csp.sentinel.demo.file.rule.parser.JsonSystemRuleListParser;
 import com.alibaba.csp.sentinel.property.PropertyListener;
 import com.alibaba.csp.sentinel.property.SentinelProperty;
 import com.alibaba.csp.sentinel.slots.block.Rule;
@@ -32,6 +30,8 @@
 import com.alibaba.csp.sentinel.slots.block.flow.FlowRuleManager;
 import com.alibaba.csp.sentinel.slots.system.SystemRule;
 import com.alibaba.csp.sentinel.slots.system.SystemRuleManager;
+import com.alibaba.fastjson.JSON;
+import com.alibaba.fastjson.TypeReference;
 
 /**
  * <p>
@@ -40,9 +40,9 @@
  * inform the listener if the file is updated.
  * </p>
  * <p>
- * Each {@link DataSource} has a {@link SentinelProperty} to hold the deserialized config data.
+ * Each {@link ReadableDataSource} has a {@link SentinelProperty} to hold the deserialized config data.
  * {@link PropertyListener} will listen to the {@link SentinelProperty} instead of the datasource.
- * {@link ConfigParser} is used for telling how to deserialize the data.
+ * {@link Converter} is used for telling how to deserialize the data.
  * </p>
  * <p>
  * {@link FlowRuleManager#register2Property(SentinelProperty)},
@@ -52,45 +52,55 @@
  * </p>
  * <p>
  * For other kinds of data source, such as <a href="https://github.com/alibaba/nacos">Nacos</a>,
- * Zookeeper, Git, or even CSV file, We could implement {@link DataSource} interface to read these
+ * Zookeeper, Git, or even CSV file, We could implement {@link ReadableDataSource} interface to read these
  * configs.
  * </p>
  *
  * @author Carpenter Lee
+ * @author Eric Zhao
  */
 public class FileDataSourceDemo {
 
     public static void main(String[] args) throws Exception {
         FileDataSourceDemo demo = new FileDataSourceDemo();
         demo.listenRules();
 
-        /**
+        /*
          * Start to require tokens, rate will be limited by rule in FlowRule.json
          */
         FlowQpsRunner runner = new FlowQpsRunner();
         runner.simulateTraffic();
         runner.tick();
     }
 
-    public void listenRules() throws Exception {
+    private void listenRules() throws Exception {
         ClassLoader classLoader = getClass().getClassLoader();
-        String flowRulePath = classLoader.getResource("FlowRule.json").getFile();
-        String degradeRulePath = classLoader.getResource("DegradeRule.json").getFile();
-        String systemRulePath = classLoader.getResource("SystemRule.json").getFile();
+        String flowRulePath = URLDecoder.decode(classLoader.getResource("FlowRule.json").getFile(), "UTF-8");
+        String degradeRulePath = URLDecoder.decode(classLoader.getResource("DegradeRule.json").getFile(), "UTF-8");
+        String systemRulePath = URLDecoder.decode(classLoader.getResource("SystemRule.json").getFile(), "UTF-8");
 
-        // data source for FlowRule
-        DataSource<String, List<FlowRule>> flowRuleDataSource = new FileRefreshableDataSource<List<FlowRule>>(
-            flowRulePath, new JsonFlowRuleListParser());
+        // Data source for FlowRule
+        FileRefreshableDataSource<List<FlowRule>> flowRuleDataSource = new FileRefreshableDataSource<>(
+            flowRulePath, flowRuleListParser);
         FlowRuleManager.register2Property(flowRuleDataSource.getProperty());
 
-        // data source for DegradeRule
-        DataSource<String, List<DegradeRule>> degradeRuleDataSource = new FileRefreshableDataSource<List<DegradeRule>>(
-            degradeRulePath, new JsonDegradeRuleListParser());
+        // Data source for DegradeRule
+        FileRefreshableDataSource<List<DegradeRule>> degradeRuleDataSource
+            = new FileRefreshableDataSource<>(
+            degradeRulePath, degradeRuleListParser);
         DegradeRuleManager.register2Property(degradeRuleDataSource.getProperty());
 
-        // data source for SystemRule
-        DataSource<String, List<SystemRule>> systemRuleDataSource = new FileRefreshableDataSource<List<SystemRule>>(
-            systemRulePath, new JsonSystemRuleListParser());
+        // Data source for SystemRule
+        FileRefreshableDataSource<List<SystemRule>> systemRuleDataSource
+            = new FileRefreshableDataSource<>(
+            systemRulePath, systemRuleListParser);
         SystemRuleManager.register2Property(systemRuleDataSource.getProperty());
     }
+
+    private Converter<String, List<FlowRule>> flowRuleListParser = source -> JSON.parseObject(source,
+        new TypeReference<List<FlowRule>>() {});
+    private Converter<String, List<DegradeRule>> degradeRuleListParser = source -> JSON.parseObject(source,
+        new TypeReference<List<DegradeRule>>() {});
+    private Converter<String, List<SystemRule>> systemRuleListParser = source -> JSON.parseObject(source,
+        new TypeReference<List<SystemRule>>() {});
 }

sentinel-demo/sentinel-demo-dynamic-file-rule/src/main/java/com/alibaba/csp/sentinel/demo/file/rule/FileDataSourceInit.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright 1999-2018 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.
+ */
+package com.alibaba.csp.sentinel.demo.file.rule;
+
+import java.util.List;
+
+import com.alibaba.csp.sentinel.datasource.FileRefreshableDataSource;
+import com.alibaba.csp.sentinel.datasource.FileWritableDataSource;
+import com.alibaba.csp.sentinel.datasource.ReadableDataSource;
+import com.alibaba.csp.sentinel.datasource.WritableDataSource;
+import com.alibaba.csp.sentinel.init.InitFunc;
+import com.alibaba.csp.sentinel.slots.block.flow.FlowRule;
+import com.alibaba.csp.sentinel.slots.block.flow.FlowRuleManager;
+import com.alibaba.csp.sentinel.transport.util.WritableDataSourceRegistry;
+import com.alibaba.fastjson.JSON;
+import com.alibaba.fastjson.TypeReference;
+
+/**
+ * <p>
+ * A sample showing how to register readable and writable data source via Sentinel init SPI mechanism.
+ * </p>
+ * <p>
+ * To activate this, you can add the class name to `com.alibaba.csp.sentinel.init.InitFunc` file
+ * in `META-INF/services/` directory of the resource directory. Then the data source will be automatically
+ * registered during the initialization of Sentinel.
+ * </p>
+ *
+ * @author Eric Zhao
+ */
+public class FileDataSourceInit implements InitFunc {
+
+    @Override
+    public void init() throws Exception {
+        // A fake path.
+        String flowRuleDir = System.getProperty("user.home") + "/sentinel/rules";
+        String flowRuleFile = "flowRule.json";
+        String flowRulePath = flowRuleDir + "/" + flowRuleFile;
+
+        ReadableDataSource<String, List<FlowRule>> ds = new FileRefreshableDataSource<>(
+            flowRulePath, source -> JSON.parseObject(source, new TypeReference<List<FlowRule>>() {})
+        );
+        // Register to flow rule manager.
+        FlowRuleManager.register2Property(ds.getProperty());
+
+        WritableDataSource<List<FlowRule>> wds = new FileWritableDataSource<>(flowRulePath, this::encodeJson);
+        // Register to writable data source registry so that rules can be updated to file
+        // when there are rules pushed from the Sentinel Dashboard.
+        WritableDataSourceRegistry.registerFlowDataSource(wds);
+    }
+
+    private <T> String encodeJson(T t) {
+        return JSON.toJSONString(t);
+    }
+}

sentinel-demo/sentinel-demo-nacos-datasource/src/main/java/com/alibaba/csp/sentinel/demo/datasource/nacos/NacosDataSourceDemo.java

@@ -17,7 +17,7 @@
 
 import java.util.List;
 
-import com.alibaba.csp.sentinel.datasource.DataSource;
+import com.alibaba.csp.sentinel.datasource.ReadableDataSource;
 import com.alibaba.csp.sentinel.datasource.nacos.NacosDataSource;
 import com.alibaba.csp.sentinel.slots.block.flow.FlowRule;
 import com.alibaba.csp.sentinel.slots.block.flow.FlowRuleManager;
@@ -49,7 +49,7 @@ private static void loadRules() {
         final String groupId = "Sentinel:Demo";
         final String dataId = "com.alibaba.csp.sentinel.demo.flow.rule";
 
-        DataSource<String, List<FlowRule>> flowRuleDataSource = new NacosDataSource<>(remoteAddress, groupId, dataId,
+        ReadableDataSource<String, List<FlowRule>> flowRuleDataSource = new NacosDataSource<>(remoteAddress, groupId, dataId,
             source -> JSON.parseObject(source, new TypeReference<List<FlowRule>>() {}));
         FlowRuleManager.register2Property(flowRuleDataSource.getProperty());
     }