Add YAMLConfigManager support

modules/siddhi-core/pom.xml

@@ -94,6 +94,10 @@
             <groupId>org.osgi</groupId>
             <artifactId>org.osgi.core</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.yaml</groupId>
+            <artifactId>snakeyaml</artifactId>
+        </dependency>
     </dependencies>
 
     <build>

modules/siddhi-core/src/main/java/io/siddhi/core/exception/YAMLConfigManagerException.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2019, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
+ *
+ * WSO2 Inc. licenses this file to you 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 io.siddhi.core.exception;
+
+/**
+ * Exception class to be used when non-existence definition is requested.
+ */
+public class YAMLConfigManagerException extends RuntimeException {
+
+    public YAMLConfigManagerException() {
+        super();
+    }
+
+    public YAMLConfigManagerException(String message) {
+        super(message);
+    }
+
+    public YAMLConfigManagerException(String message, Throwable throwable) {
+        super(message, throwable);
+    }
+
+    public YAMLConfigManagerException(Throwable throwable) {
+        super(throwable);
+    }
+}

modules/siddhi-core/src/main/java/io/siddhi/core/util/FileReader.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2019, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
+ *
+ * WSO2 Inc. licenses this file to you 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 io.siddhi.core.util;
+
+import io.siddhi.core.exception.YAMLConfigManagerException;
+import org.apache.log4j.Logger;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+/**
+ * Util class to read file content
+ */
+public class FileReader {
+
+    private static final Logger LOG = Logger.getLogger(FileReader.class);
+
+    public static String readYAMLConfigFile(Path filePath) throws YAMLConfigManagerException {
+        if (!filePath.toFile().exists()) {
+            throw new YAMLConfigManagerException("Error while initializing YAML config manager, " +
+                    "YAML file does not exist with path '" + filePath.toAbsolutePath().toString() + "'.");
+        }
+        if (!filePath.toString().endsWith(".yaml")) {
+            throw new YAMLConfigManagerException("Error while initializing YAML config manager, file extension " +
+                    "'yaml' expected");
+        }
+
+        if (LOG.isDebugEnabled()) {
+            LOG.debug("Initialize config provider instance from configuration file: " + filePath.toString());
+        }
+        try {
+            return readContent(filePath);
+        } catch (IOException e) {
+            throw new YAMLConfigManagerException("Unable to read config file '" + filePath.toAbsolutePath().toString()
+                    + "'.", e);
+        }
+    }
+
+    private static String readContent(Path filePath) throws IOException {
+        byte[] contentBytes = Files.readAllBytes(filePath);
+        return new String(contentBytes, StandardCharsets.UTF_8);
+    }
+
+}

modules/siddhi-core/src/main/java/io/siddhi/core/util/config/ConfigManager.java

@@ -25,9 +25,28 @@
  */
 public interface ConfigManager {
 
+    /**
+     * Generates Config reader for extensions with specific namespace and name
+     *
+     * @param namespace Namespace of the extension
+     * @param name Name of the extension
+     * @return ConfigReader
+     */
     ConfigReader generateConfigReader(String namespace, String name);
 
+    /**
+     * Generates hash map of properties for siddhi annotation reference
+     *
+     * @param name Reference Name
+     * @return Hashmap of the properties
+     */
     Map<String, String> extractSystemConfigs(String name);
 
+    /**
+     * Extracts specific siddhi property in system properties
+     *
+     * @param name Name of the property
+     * @return Value of the property
+     */
     String extractProperty(String name);
 }

modules/siddhi-core/src/main/java/io/siddhi/core/util/config/ConfigReader.java

@@ -25,8 +25,19 @@
  */
 public interface ConfigReader {
 
+    /**
+     * Returns the value of the system property if set else the default value is returned
+     *
+     * @param name Name of the property
+     * @param defaultValue Default value for the property
+     * @return Value of the system property
+     */
     String readConfig(String name, String defaultValue);
 
+    /**
+     * Return all the configurations in the config reader
+     * @return Hashmap of properties and values
+     */
     Map<String, String> getAllConfigs();
 
 }

modules/siddhi-core/src/main/java/io/siddhi/core/util/config/YAMLConfigManager.java

@@ -0,0 +1,111 @@
+/*
+ * Copyright (c) 2019, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
+ *
+ * WSO2 Inc. licenses this file to you 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 io.siddhi.core.util.config;
+
+import io.siddhi.core.exception.YAMLConfigManagerException;
+import io.siddhi.core.util.SiddhiConstants;
+import io.siddhi.core.util.config.model.Extension;
+import io.siddhi.core.util.config.model.ExtensionChildConfiguration;
+import io.siddhi.core.util.config.model.Reference;
+import io.siddhi.core.util.config.model.ReferenceChildConfiguration;
+import io.siddhi.core.util.config.model.RootConfiguration;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.yaml.snakeyaml.Yaml;
+import org.yaml.snakeyaml.constructor.CustomClassLoaderConstructor;
+import org.yaml.snakeyaml.introspector.BeanAccess;
+import org.yaml.snakeyaml.introspector.PropertyUtils;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * YAML file based Config Manger
+ */
+public class YAMLConfigManager implements ConfigManager {
+
+    private static final Logger LOG = LoggerFactory.getLogger(YAMLConfigManager.class);
+    private RootConfiguration rootConfiguration;
+
+    public YAMLConfigManager(String yamlContent) {
+        init(yamlContent);
+    }
+
+    /**
+     * Initialises YAML Config Manager by parsing the YAML file
+     *
+     * @throws YAMLConfigManagerException Exception is thrown if there are issues in processing thr yaml file
+     */
+    private void init(String yamlContent) throws YAMLConfigManagerException {
+        try {
+            CustomClassLoaderConstructor constructor = new CustomClassLoaderConstructor(
+                    RootConfiguration.class, RootConfiguration.class.getClassLoader());
+            PropertyUtils propertyUtils = new PropertyUtils();
+            propertyUtils.setSkipMissingProperties(true);
+            constructor.setPropertyUtils(propertyUtils);
+
+            Yaml yaml = new Yaml(constructor);
+            yaml.setBeanAccess(BeanAccess.FIELD);
+            this.rootConfiguration = yaml.load(yamlContent);
+        } catch (Exception e) {
+            throw new YAMLConfigManagerException("Unable to parse YAML string, '" + yamlContent + "'.", e);
+        }
+    }
+
+    @Override
+    public ConfigReader generateConfigReader(String namespace, String name) {
+        for (Extension extension : this.rootConfiguration.getExtensions()) {
+            ExtensionChildConfiguration childConfiguration = extension.getExtension();
+            if (childConfiguration.getNamespace().equals(namespace) &&
+                    childConfiguration.getName().equals(name)) {
+                return new YAMLConfigReader(childConfiguration.getProperties());
+            }
+        }
+        if (LOG.isDebugEnabled()) {
+            LOG.debug("Could not find a matching configuration for name: " + name + "and namespace: " +
+                    namespace + "!");
+        }
+        return new YAMLConfigReader(new HashMap<>());
+    }
+
+    @Override
+    public Map<String, String> extractSystemConfigs(String name) {
+        for (Reference reference : this.rootConfiguration.getRefs()) {
+            ReferenceChildConfiguration childConf = reference.getReference();
+            if (childConf.getName().equals(name)) {
+                Map<String, String> referenceConfigs = new HashMap<>();
+                referenceConfigs.put(SiddhiConstants.ANNOTATION_ELEMENT_TYPE, childConf.getType());
+                referenceConfigs.putAll(childConf.getProperties());
+                return referenceConfigs;
+            }
+        }
+        if (LOG.isDebugEnabled()) {
+            LOG.debug("Could not find a matching reference for name: '" + name + "'!");
+        }
+        return new HashMap<>();
+    }
+
+    @Override
+    public String extractProperty(String name) {
+        String property = this.rootConfiguration.getProperties().get(name);
+        if (LOG.isDebugEnabled()) {
+            LOG.debug("Could not find a matching configuration for property name: " + name + "");
+        }
+        return property;
+    }
+}

modules/siddhi-core/src/main/java/io/siddhi/core/util/config/YAMLConfigReader.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2019, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
+ *
+ * WSO2 Inc. licenses this file to you 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 io.siddhi.core.util.config;
+
+import java.util.Map;
+
+/**
+ * Extension config readers
+ */
+public class YAMLConfigReader implements ConfigReader {
+    private final Map<String, String> configs;
+
+    public YAMLConfigReader(Map<String, String> configs) {
+        this.configs = configs;
+    }
+
+    @Override
+    public String readConfig(String name, String defaultValue) {
+        String value = configs.get(name);
+        if (value != null) {
+            return value;
+        } else {
+            return defaultValue;
+        }
+    }
+
+    @Override
+    public Map<String, String> getAllConfigs() {
+        return configs;
+    }
+}

modules/siddhi-core/src/main/java/io/siddhi/core/util/config/model/Extension.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c)  2019, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
+ *
+ * WSO2 Inc. licenses this file to you 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 io.siddhi.core.util.config.model;
+
+/**
+ * A third level configuration bean class for siddhi extension config.
+ */
+public class Extension {
+
+    private ExtensionChildConfiguration extension = new ExtensionChildConfiguration();
+
+    public ExtensionChildConfiguration getExtension() {
+        return extension;
+    }
+}
+