/*
    * Copyright 2012 The Netty Project
    *
    * The Netty Project 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.
   */
  package io.netty.handler.codec.serialization;
  
  import java.io.EOFException;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.ObjectInputStream;
  import java.io.ObjectStreamClass;
  import java.io.StreamCorruptedException;
  
  class CompactObjectInputStream extends ObjectInputStream {
  
      private final ClassResolver classResolver;
  
      CompactObjectInputStream(InputStream in, ClassResolver classResolver) throws IOException {
          super(in);
          this.classResolver = classResolver;
      }
  
      @Override
      protected void readStreamHeader() throws IOException {
          int version = readByte() & 0xFF;
          if (version != STREAM_VERSION) {
              throw new StreamCorruptedException(
                      "Unsupported version: " + version);
          }
      }
  
      @Override
      protected ObjectStreamClass readClassDescriptor()
              throws IOException, ClassNotFoundException {
          int type = read();
          if (type < 0) {
              throw new EOFException();
          }
          switch (type) {
          case CompactObjectOutputStream.TYPE_FAT_DESCRIPTOR:
              return super.readClassDescriptor();
          case CompactObjectOutputStream.TYPE_THIN_DESCRIPTOR:
              String className = readUTF();
              Class<?> clazz = classResolver.resolve(className);
              return ObjectStreamClass.lookupAny(clazz);
          default:
              throw new StreamCorruptedException(
                      "Unexpected class descriptor type: " + type);
          }
      }
  
      @Override
      protected Class<?> resolveClass(ObjectStreamClass desc) throws IOException, ClassNotFoundException {
          Class<?> clazz;
          try {
              clazz = classResolver.resolve(desc.getName());
          } catch (ClassNotFoundException ignored) {
              clazz = super.resolveClass(desc);
          }
  
          return clazz;
      }
  
  }