X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?a=blobdiff_plain;f=yang%2Fyang-common%2Fsrc%2Fmain%2Fjava%2Forg%2Fopendaylight%2Fyangtools%2Fyang%2Fcommon%2FQNameModule.java;h=628af0c4ebfe964116ae6130ed4b0dcc57bff75e;hb=1a82a083eee3d050fea52250e88ccf4b38b21811;hp=22428e36d4b1afbef8e76ef22c090ca8a5d44f9b;hpb=f9cca8e6d90812f6fe7fc7914699daca77bab846;p=yangtools.git

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 22428e36d4..628af0c4eb 100644
--- 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
@@ -7,18 +7,22 @@
  */
 package org.opendaylight.yangtools.yang.common;
 
+import com.google.common.base.Objects;
 import java.io.Serializable;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.util.Date;
-
 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;
 
-final class QNameModule implements Immutable, Serializable {
-	private static final Logger LOG = LoggerFactory.getLogger(QNameModule.class);
-	private static final long serialVersionUID = 1L;
+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
     private final URI namespace;
@@ -27,39 +31,77 @@ final class QNameModule implements Immutable, Serializable {
     private final Date revision;
 
     //Nullable
-    private final String formattedRevision;
+    private volatile String formattedRevision;
 
     private QNameModule(final URI namespace, final Date revision) {
         this.namespace = namespace;
         this.revision = revision;
-        if(revision != null) {
-            this.formattedRevision = SimpleDateFormatUtil.getRevisionFormat().format(revision);
-        } else {
-            this.formattedRevision = null;
+    }
+
+    /**
+     * 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);
     }
 
-	public static QNameModule create(final URI namespace, final Date revision) {
-		return new QNameModule(namespace, revision);
-	}
+    public String getFormattedRevision() {
+        if (revision == null) {
+            return null;
+        }
 
-	public String getFormattedRevision() {
-		return formattedRevision;
-	}
+        String ret = formattedRevision;
+        if (ret == null) {
+            ret = SimpleDateFormatUtil.getRevisionFormat().format(revision);
+            formattedRevision = ret;
+        }
+
+        return ret;
+    }
 
-	public URI getNamespace() {
-		return namespace;
-	}
+    /**
+     * 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;
+    }
 
-	public Date getRevision() {
-		return revision;
-	}
+    /**
+     * 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;
+    }
 
     @Override
     public int hashCode() {
         final int prime = 31;
         int result = (namespace == null) ? 0 : namespace.hashCode();
-        result = prime * result + ((formattedRevision == null) ? 0 : formattedRevision.hashCode());
+        result = prime * result + ((revision == null) ? 0 : revision.hashCode());
         return result;
     }
 
@@ -72,18 +114,18 @@ final class QNameModule implements Immutable, Serializable {
             return false;
         }
         final QNameModule other = (QNameModule) obj;
-        if (namespace == null) {
-            if (other.namespace != null) {
+        if (revision == null) {
+            if (other.revision != null) {
                 return false;
             }
-        } else if (!namespace.equals(other.namespace)) {
+        } else if (!revision.equals(other.revision)) {
             return false;
         }
-        if (formattedRevision == null) {
-            if (other.formattedRevision != null) {
+        if (namespace == null) {
+            if (other.namespace != null) {
                 return false;
             }
-        } else if (!revision.equals(other.revision)) {
+        } else if (!namespace.equals(other.namespace)) {
             return false;
         }
         return true;
@@ -108,7 +150,7 @@ final class QNameModule implements Immutable, Serializable {
 
         String query = "";
         if (revision != null) {
-            query = "revision=" + formattedRevision;
+            query = "revision=" + getFormattedRevision();
         }
 
         URI compositeURI = null;
@@ -120,4 +162,9 @@ final class QNameModule implements Immutable, Serializable {
         }
         return compositeURI;
     }
+
+    @Override
+    public String toString() {
+        return Objects.toStringHelper(this).omitNullValues().add("ns", getNamespace()).add("rev", getFormattedRevision()).toString();
+    }
 }