Merge "Removed unused dependency."

[yangtools.git] / yang / yang-common / src / main / java / org / opendaylight / yangtools / yang / common / QNameModule.java

diff --git a/yang/yang-common/src/main/java/org/opendaylight/yangtools/yang/common/QNameModule.java b/yang/yang-common/src/main/java/org/opendaylight/yangtools/yang/common/QNameModule.java
index 74844de8f7e242c2f2dfbcb92baf79c5b43d58bf..def8da86cbeeec77689b50f44c0493456a172b9f 100644 (file)
--- a/yang/yang-common/src/main/java/org/opendaylight/yangtools/yang/common/QNameModule.java
+++ b/yang/yang-common/src/main/java/org/opendaylight/yangtools/yang/common/QNameModule.java
@@ -7,17 +7,22 @@
  */
 package org.opendaylight.yangtools.yang.common;
 
+import com.google.common.base.MoreObjects;
 import java.io.Serializable;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.util.Date;
-
+import java.util.Objects;
 import org.opendaylight.yangtools.concepts.Immutable;
+import org.opendaylight.yangtools.objcache.ObjectCache;
+import org.opendaylight.yangtools.objcache.ObjectCacheFactory;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public final class QNameModule implements Immutable, Serializable {
+    private static final ObjectCache CACHE = ObjectCacheFactory.getObjectCache(QNameModule.class);
     private static final Logger LOG = LoggerFactory.getLogger(QNameModule.class);
+    private static final QNameModule NULL_INSTANCE = new QNameModule(null, null);
     private static final long serialVersionUID = 1L;
 
     //Nullable
@@ -27,14 +32,35 @@ public final class QNameModule implements Immutable, Serializable {
     private final Date revision;
 
     //Nullable
-    private String formattedRevision;
+    private volatile String formattedRevision;
 
     private QNameModule(final URI namespace, final Date revision) {
         this.namespace = namespace;
         this.revision = revision;
     }
 
+    /**
+     * Look up specified module in the global cache and return a shared reference.
+     *
+     * @param module Module instance
+     * @return Cached instance, according to {@link ObjectCache} policy.
+     */
+    public static QNameModule cachedReference(final QNameModule module) {
+        return CACHE.getReference(module);
+    }
+
+    /**
+     * Create a new QName module instance with specified namespace/revision.
+     *
+     * @param namespace Module namespace
+     * @param revision Module revision
+     * @return A new, potentially shared, QNameModule instance
+     */
     public static QNameModule create(final URI namespace, final Date revision) {
+        if (namespace == null && revision == null) {
+            return NULL_INSTANCE;
+        }
+
         return new QNameModule(namespace, revision);
     }
 
@@ -43,21 +69,31 @@ public final class QNameModule implements Immutable, Serializable {
             return null;
         }
 
-        if (formattedRevision == null) {
-            synchronized (this) {
-                if (formattedRevision == null) {
-                    formattedRevision = SimpleDateFormatUtil.getRevisionFormat().format(revision);
-                }
-            }
+        String ret = formattedRevision;
+        if (ret == null) {
+            ret = SimpleDateFormatUtil.getRevisionFormat().format(revision);
+            formattedRevision = ret;
         }
 
-        return formattedRevision;
+        return ret;
     }
 
+    /**
+     * Returns the namespace of the module which is specified as argument of
+     * YANG Module <b><font color="#00FF00">namespace</font></b> keyword.
+     *
+     * @return URI format of the namespace of the module
+     */
     public URI getNamespace() {
         return namespace;
     }
 
+    /**
+     * Returns the revision date for the module.
+     *
+     * @return date of the module revision which is specified as argument of
+     *         YANG Module <b><font color="#339900">revison</font></b> keyword
+     */
     public Date getRevision() {
         return revision;
     }
@@ -79,18 +115,10 @@ public final class QNameModule implements Immutable, Serializable {
             return false;
         }
         final QNameModule other = (QNameModule) obj;
-        if (namespace == null) {
-            if (other.namespace != null) {
-                return false;
-            }
-        } else if (!namespace.equals(other.namespace)) {
+        if (!Objects.equals(revision, other.revision)) {
             return false;
         }
-        if (revision == null) {
-            if (other.revision != null) {
-                return false;
-            }
-        } else if (!revision.equals(other.revision)) {
+        if (!Objects.equals(namespace, other.namespace)) {
             return false;
         }
         return true;
@@ -122,9 +150,14 @@ public final class QNameModule implements Immutable, Serializable {
         try {
             compositeURI = new URI(namespace.getScheme(), namespace.getUserInfo(), namespace.getHost(),
                     namespace.getPort(), namespace.getPath(), query, namespace.getFragment());
-        } catch (URISyntaxException e) {
+        } catch (final URISyntaxException e) {
             LOG.error("", e);
         }
         return compositeURI;
     }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(this).omitNullValues().add("ns", getNamespace()).add("rev", getFormattedRevision()).toString();
+    }
 }