package org.apache.maven.repository.internal;
   
   /*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF 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.
   */
  
  import org.apache.maven.model.building.ModelCache;
  import org.sonatype.aether.RepositoryCache;
  import org.sonatype.aether.RepositorySystemSession;
  
  /**
   * A model builder cache backed by the repository system cache.
   * 
   * @author Benjamin Bentmann
   */
  class DefaultModelCache
      implements ModelCache
  {
  
      private final RepositorySystemSession session;
  
      private final RepositoryCache cache;
  
      public static ModelCache newInstance( RepositorySystemSession session )
      {
          if ( session.getCache() == null )
          {
              return null;
          }
          else
          {
              return new DefaultModelCache( session );
          }
      }
  
      private DefaultModelCache( RepositorySystemSession session )
      {
          this.session = session;
          this.cache = session.getCache();
      }
  
      public Object get( String groupId, String artifactId, String version, String tag )
      {
          return cache.get( session, new Key( groupId, artifactId, version, tag ) );
      }
  
      public void put( String groupId, String artifactId, String version, String tag, Object data )
      {
          cache.put( session, new Key( groupId, artifactId, version, tag ), data );
      }
  
      static class Key
      {
  
          private final String groupId;
  
          private final String artifactId;
  
          private final String version;
  
          private final String tag;
  
          private final int hash;
  
          public Key( String groupId, String artifactId, String version, String tag )
          {
              this.groupId = groupId;
              this.artifactId = artifactId;
              this.version = version;
              this.tag = tag;
  
              int h = 17;
              h = h * 31 + this.groupId.hashCode();
              h = h * 31 + this.artifactId.hashCode();
              h = h * 31 + this.version.hashCode();
              h = h * 31 + this.tag.hashCode();
              hash = h;
          }
  
          @Override
          public boolean equals( Object obj )
          {
              if ( this == obj )
              {
                 return true;
             }
             if ( null == obj || !getClass().equals( obj.getClass() ) )
             {
                 return false;
             }
 
             Key that = (Key) obj;
             return artifactId.equals( that.artifactId ) && groupId.equals( that.groupId )
                 && version.equals( that.version ) && tag.equals( that.tag );
         }
 
         @Override
         public int hashCode()
         {
             return hash;
         }
 
     }
 }