1. Added a ranger-client module to contain the client creation abstra…

…ctions and added http and zk clients respectively with required test cases. This will help end-clients not replicate the same boiler plate code again and again

pom.xml

@@ -12,7 +12,9 @@
         <module>ranger-core</module>
         <module>ranger-zookeeper</module>
         <module>ranger-http</module>
-        <module>ranger-server</module>
+        <module>ranger-client</module>
+        <module>ranger-zk-client</module>
+        <module>ranger-http-client</module>
     </modules>
 
     <distributionManagement>

ranger-server/pom.xml → ranger-client/pom.xml

@@ -9,14 +9,24 @@
     </parent>
     <modelVersion>4.0.0</modelVersion>
 
-    <artifactId>ranger-server</artifactId>
+    <artifactId>ranger-client</artifactId>
 
     <dependencies>
         <dependency>
             <groupId>com.flipkart.ranger</groupId>
-            <artifactId>ranger-zookeeper</artifactId>
+            <artifactId>ranger-core</artifactId>
             <version>${project.version}</version>
         </dependency>
+        <dependency>
+            <groupId>com.flipkart.ranger</groupId>
+            <artifactId>ranger-core</artifactId>
+            <version>${project.version}</version>
+            <type>test-jar</type>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>${jackson.version}</version>
+        </dependency>
     </dependencies>
-
 </project>

ranger-client/src/main/java/com/flipkart/ranger/client/AbstractRangerHubClient.java

@@ -0,0 +1,111 @@
+/*
+ * Copyright 2015 Flipkart Internet Pvt. 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.flipkart.ranger.client;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.flipkart.ranger.core.finderhub.ServiceDataSource;
+import com.flipkart.ranger.core.finderhub.ServiceFinderFactory;
+import com.flipkart.ranger.core.finderhub.ServiceFinderHub;
+import com.flipkart.ranger.core.model.*;
+import com.google.common.base.Preconditions;
+import lombok.Getter;
+import lombok.extern.slf4j.Slf4j;
+import lombok.val;
+
+import java.util.List;
+import java.util.Optional;
+
+@Slf4j
+@Getter
+public abstract class AbstractRangerHubClient<T, C extends Criteria<T>, R extends ServiceRegistry<T>, D extends Deserializer<T>> implements RangerHubClient<T, C> {
+
+    private final String namespace;
+    private final ObjectMapper mapper;
+    private final C criteria;
+    private final D deserializer;
+
+    private int nodeRefreshTimeMs;
+    private ServiceFinderHub<T, C, R> hub;
+
+    public AbstractRangerHubClient(
+            String namespace,
+            ObjectMapper mapper,
+            int nodeRefreshTimeMs,
+            C criteria,
+            D deserializer
+    ){
+        this.namespace = namespace;
+        this.mapper = mapper;
+        this.nodeRefreshTimeMs = nodeRefreshTimeMs;
+        this.criteria = criteria;
+        this.deserializer = deserializer;
+    }
+
+    public void start(){
+        Preconditions.checkNotNull(mapper, "Mapper can't be null");
+        Preconditions.checkNotNull(namespace, "namespace can't be null");
+        Preconditions.checkNotNull(deserializer, "deserializer can't be null");
+
+        if (this.nodeRefreshTimeMs < RangerClientConstants.MINIMUM_REFRESH_TIME) {
+            log.warn("Node info update interval too low: {} ms. Has been upgraded to {} ms ",
+                    this.nodeRefreshTimeMs,
+                    RangerClientConstants.MINIMUM_REFRESH_TIME);
+        }
+        this.nodeRefreshTimeMs = Math.max(RangerClientConstants.MINIMUM_REFRESH_TIME, this.nodeRefreshTimeMs);
+        this.hub = buildHub();
+        this.hub.start();
+    }
+
+    public void stop(){
+        hub.stop();
+    }
+
+    public Optional<ServiceNode<T>> getNode(
+            final Service service
+    ){
+        return getNode(service, criteria);
+    }
+
+    public Optional<List<ServiceNode<T>>> getAllNodes(
+            final Service service
+    ){
+        return getAllNodes(service, criteria);
+    }
+
+    public Optional<ServiceNode<T>> getNode(
+            final Service service,
+            final C criteria
+    ){
+        val optionalFinder = this.getHub().finder(service);
+        return optionalFinder.map(trcServiceFinder -> trcServiceFinder.get(criteria));
+    }
+
+    public Optional<List<ServiceNode<T>>> getAllNodes(
+            final Service service,
+            final C criteria
+    ){
+        val optionalFinder = this.getHub().finder(service);
+        return optionalFinder.map(trcServiceFinder -> trcServiceFinder.getAll(criteria));
+    }
+
+    protected abstract ServiceFinderHub<T, C, R> buildHub();
+
+    protected abstract ServiceDataSource buildServiceDataSource();
+
+    protected abstract ServiceFinderFactory<T,C, R> buildFinderFactory();
+
+}
+

ranger-client/src/main/java/com/flipkart/ranger/client/RangerClient.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2015 Flipkart Internet Pvt. Ltd.
+ * <p>
+ * 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
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * 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.flipkart.ranger.client;
+
+import com.flipkart.ranger.core.model.Criteria;
+import com.flipkart.ranger.core.model.Deserializer;
+import com.flipkart.ranger.core.model.ServiceNode;
+
+import java.util.List;
+import java.util.Optional;
+
+public interface RangerClient<T, C extends Criteria<T>> {
+
+    void start();
+
+    void stop();
+
+    Optional<ServiceNode<T>> getNode();
+
+    Optional<ServiceNode<T>> getNode(final C criteria);
+
+    Optional<List<ServiceNode<T>>> getAllNodes();
+
+    Optional<List<ServiceNode<T>>> getAllNodes(final C criteria);
+}

ranger-client/src/main/java/com/flipkart/ranger/client/RangerClientConstants.java

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2015 Flipkart Internet Pvt. 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.flipkart.ranger.client;
+
+public class RangerClientConstants {
+
+    private RangerClientConstants(){}
+
+    public static final int CONNECTION_RETRY_TIME = 5000;
+    public static final int MINIMUM_REFRESH_TIME = 5000;
+}

ranger-client/src/main/java/com/flipkart/ranger/client/RangerHubClient.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2015 Flipkart Internet Pvt. 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.flipkart.ranger.client;
+
+import com.flipkart.ranger.core.model.Criteria;
+import com.flipkart.ranger.core.model.Service;
+import com.flipkart.ranger.core.model.ServiceNode;
+
+import java.util.List;
+import java.util.Optional;
+
+public interface RangerHubClient<T, C extends Criteria<T>> {
+
+        void start();
+
+        void stop();
+
+        Optional<ServiceNode<T>> getNode(final Service service);
+
+        Optional<ServiceNode<T>> getNode(final Service service, final C criteria);
+
+        Optional<List<ServiceNode<T>>> getAllNodes(final Service service);
+
+        Optional<List<ServiceNode<T>>> getAllNodes(final Service service, final C criteria);
+
+}