Change node naming (#4)

* Fix node descriptor class

* Remove unused config options

* Add more clear node names behaviour

* Fix tick-tock handler

* Fix config bug

* Expand docs

Author: xxlabaza

.codestyle/pmd.xml

@@ -38,6 +38,7 @@ limitations under the License.
     <exclude name="LongVariable" />
     <exclude name="MethodArgumentCouldBeFinal" />
     <exclude name="OnlyOneReturn" />
+    <exclude name="PrematureDeclaration" />
     <exclude name="ShortClassName" />
     <exclude name="ShortMethodName" />
     <exclude name="ShortVariable" />

CHANGELOG.md

@@ -17,6 +17,16 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Rething caches in terms and modules.
 - Add lazy deserialization for terms.
 
+## [1.3.0](https://github.com/appulse-projects/encon-java/releases/tag/1.3.0) - 2018-06-28
+
+Add correct node naming.
+
+### Changed
+
+- Configs from `encon-config` are now cloneable via constructor.
+- `NodeDescriptor` works as in Erlang's docs said.
+- Several minor fixes.
+
 ## [1.2.0](https://github.com/appulse-projects/encon-java/releases/tag/1.2.0) - 2018-06-25
 
 Refactoring and cleaning.

encon-common/pom.xml

@@ -25,7 +25,7 @@ limitations under the License.
   <parent>
     <groupId>io.appulse.encon</groupId>
     <artifactId>encon-parent</artifactId>
-    <version>1.2.0</version>
+    <version>1.3.0</version>
   </parent>
 
   <artifactId>encon-common</artifactId>

encon-common/src/main/java/io/appulse/encon/common/NodeDescriptor.java

@@ -24,8 +24,8 @@
 import java.net.UnknownHostException;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
-import java.util.function.Function;
 
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import lombok.AllArgsConstructor;
 import lombok.EqualsAndHashCode;
 import lombok.NonNull;
@@ -50,72 +50,214 @@
 @Value
 @EqualsAndHashCode(of = "fullName")
 @AllArgsConstructor(access = PRIVATE)
+@SuppressWarnings({
+    "PMD.AvoidThrowingRawExceptionTypes",
+    "PMD.AvoidLiteralsInIfCondition"
+})
+@SuppressFBWarnings("RV_RETURN_VALUE_OF_PUTIFABSENT_IGNORED")
 public class NodeDescriptor implements Serializable {
 
   private static final long serialVersionUID = 7324588959922091097L;
 
   private static final Map<String, NodeDescriptor> NODE_DESCRIPTOR_CACHE;
 
-  private static final Function<String, NodeDescriptor> COMPUTE_NODE_DESCRIPTOR;
+  private static final InetAddress LOCALHOST;
+
+  private static final InetAddress LOOPBACK;
+
+  private static final String HOST_NAME;
 
   static {
-    val loopback = InetAddress.getLoopbackAddress();
+    try {
+      LOCALHOST = InetAddress.getLocalHost();
+    } catch (UnknownHostException ex) {
+      throw new RuntimeException(ex);
+    }
+    LOOPBACK = InetAddress.getLoopbackAddress();
+    HOST_NAME = LOCALHOST.getHostName();
     NODE_DESCRIPTOR_CACHE = new ConcurrentHashMap<>();
-    COMPUTE_NODE_DESCRIPTOR = str -> {
-      val tokens = str.split("@", 2);
-      val shortName = tokens[0];
-      val fullName = tokens.length == 2
-                     ? str
-                     : shortName + '@' + loopback.getHostName();
-
-      val address = tokens.length == 2
-                    ? getByName(tokens[1])
-                    : loopback;
-
-      return new NodeDescriptor(shortName, fullName, address);
-    };
   }
 
   /**
    * Parses node descriptor from string.
    * <p>
-   * A string could be short like <b>popa_node</b> and full, like <b>[email protected]</b>.
+   * A string could be short like <b>popa_node</b> and long, like <b>[email protected]</b>.
    * <p>
    * Node descriptors are caching.
    *
    * @param node node name
    *
    * @return parsed {@link NodeDescriptor} instance
    */
-  @SneakyThrows
   public static NodeDescriptor from (@NonNull String node) {
     val cached = NODE_DESCRIPTOR_CACHE.get(node);
     if (cached != null) {
       return cached;
     }
-    return of(node)
+    val descriptor = getFromCacheOrCreateNew(node);
+    NODE_DESCRIPTOR_CACHE.putIfAbsent(node, descriptor);
+    NODE_DESCRIPTOR_CACHE.putIfAbsent(descriptor.getFullName(), descriptor);
+    NODE_DESCRIPTOR_CACHE.putIfAbsent(descriptor.getNodeName(), descriptor);
+    return descriptor;
+  }
+
+  /**
+   * Parses node descriptor from string.
+   * <p>
+   * A string could be short like <b>popa_node</b> and long, like <b>[email protected]</b>.
+   * <p>
+   * Node descriptors are caching.
+   *
+   * @param node        node name
+   *
+   * @param isShortName indicates is this node name short or long
+   *
+   * @return parsed {@link NodeDescriptor} instance
+   */
+
+  public static NodeDescriptor from (@NonNull String node, boolean isShortName) {
+    val cached = NODE_DESCRIPTOR_CACHE.get(node);
+    if (cached != null) {
+      return cached;
+    }
+    val descriptor = getFromCacheOrCreateNew(node, isShortName);
+    NODE_DESCRIPTOR_CACHE.putIfAbsent(node, descriptor);
+    NODE_DESCRIPTOR_CACHE.putIfAbsent(descriptor.getFullName(), descriptor);
+    NODE_DESCRIPTOR_CACHE.putIfAbsent(descriptor.getNodeName(), descriptor);
+    return descriptor;
+  }
+
+  /**
+   * Checks, if this node cached or not.
+   *
+   * @param node node name
+   *
+   * @return {@code true}, if node descriptor was cached, or
+   *         {@code false} if there was no such node
+   */
+  public static boolean wasCached (@NonNull String node) {
+    val descriptor = getFromCacheOrCreateNew(node);
+    return wasCached(descriptor);
+  }
+
+  /**
+   * Checks, if this node cached or not.
+   *
+   * @param descriptor node descriptor
+   *
+   * @return {@code true}, if node descriptor was cached, or
+   *         {@code false} if there was no such node
+   */
+  public static boolean wasCached (@NonNull NodeDescriptor descriptor) {
+    return NODE_DESCRIPTOR_CACHE.containsKey(descriptor.getNodeName()) ||
+           NODE_DESCRIPTOR_CACHE.containsKey(descriptor.getFullName());
+  }
+
+  /**
+   * Removes a node from cached values.
+   *
+   * @param node node name
+   *
+   * @return {@code true}, if node descriptor was removed, or
+   *         {@code false} if there was no such node
+   */
+  public static boolean removeFromCache (@NonNull String node) {
+    val descriptor = getFromCacheOrCreateNew(node);
+    return removeFromCache(descriptor);
+  }
+
+  /**
+   * Removes a node from cached values.
+   *
+   * @param descriptor node descriptor
+   *
+   * @return {@code true}, if node descriptor was removed, or
+   *         {@code false} if there was no such node
+   */
+  public static boolean removeFromCache (@NonNull NodeDescriptor descriptor) {
+    val wasRemoved = NODE_DESCRIPTOR_CACHE.remove(descriptor.getNodeName()) != null;
+    return NODE_DESCRIPTOR_CACHE.remove(descriptor.getFullName()) != null || wasRemoved;
+  }
+
+  private static NodeDescriptor getFromCacheOrCreateNew (@NonNull String node) {
+    val atIndex = node.indexOf('@');
+    val isShortName = atIndex < 0 || node.indexOf('.', atIndex) < 0;
+    return getFromCacheOrCreateNew(node, isShortName);
+  }
+
+  private static NodeDescriptor getFromCacheOrCreateNew (@NonNull String node, boolean isShortName) {
+    String trimmedNode = of(node)
         .map(String::trim)
         .filter(it -> !it.isEmpty())
-        .map(it -> NODE_DESCRIPTOR_CACHE.computeIfAbsent(it, COMPUTE_NODE_DESCRIPTOR))
-        .orElseThrow(() -> new IllegalArgumentException("Invalid node descriptor string"));
+        .orElseThrow(() -> new IllegalArgumentException("Invalid node descriptor string '" + node + "'"));
+
+    val cached = NODE_DESCRIPTOR_CACHE.get(trimmedNode);
+    return cached == null
+           ? parse(trimmedNode, isShortName)
+           : cached;
   }
 
-  @SuppressWarnings("PMD.PreserveStackTrace")
-  private static InetAddress getByName (@NonNull String hostname) {
-    try {
-      return InetAddress.getByName(hostname);
-    } catch (UnknownHostException ex) {
-      try {
-        return InetAddress.getByName(hostname + ".local");
-      } catch (UnknownHostException ex1) {
-        throw new IllegalArgumentException("Wrapped", ex);
+  @SneakyThrows
+  private static NodeDescriptor parse (@NonNull String node, boolean isShortName) {
+    val tokens = node.split("@", 2);
+
+    val nodeName = tokens[0];
+    if (nodeName.isEmpty()) {
+      throw new IllegalArgumentException();
+    }
+
+    String hostName;
+    InetAddress address;
+    if (tokens.length == 2) {
+      hostName = tokens[1];
+      if (isShortName && hostName.contains(".")) {
+        val message = String.format("Using host name '%s' in short node name is illegal, " +
+                                    "because it contains dots ('.') and suits only for long name nodes",
+                                    hostName);
+        throw new IllegalArgumentException(message);
       }
+      address = InetAddress.getByName(hostName);
+    } else if (isShortName) {
+      val dotIndex = HOST_NAME.indexOf('.');
+      hostName = dotIndex > 0
+                  ? HOST_NAME.substring(dotIndex)
+                  : HOST_NAME;
+
+      address = LOOPBACK;
+    } else {
+      hostName = HOST_NAME;
+      address = LOCALHOST;
     }
+
+    val fullName = nodeName + '@' + hostName;
+    return new NodeDescriptor(nodeName, hostName, fullName, address, isShortName);
   }
 
-  String shortName;
+  String nodeName;
+
+  String hostName;
 
   String fullName;
 
   InetAddress address;
+
+  boolean shortName;
+
+  /**
+   * Tells is this {@link NodeDescriptor} instance for short-named node or not.
+   *
+   * @return {@code true} if node name is short, {@code false} otherwise
+   */
+  public boolean isShortName () {
+    return shortName;
+  }
+
+  /**
+   * Tells is this {@link NodeDescriptor} instance for long-named node or not.
+   *
+   * @return {@code true} if node name is long, {@code false} otherwise
+   */
+  public boolean isLongName () {
+    return !shortName;
+  }
 }