/*

 * Copyright 2000-2009 JetBrains s.r.o.

 *

 * Licensed 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.

 */



/*

 * @author max

 */

package com.intellij.psi.stubs;



import com.intellij.util.CompressionUtil;

import com.intellij.util.io.UnsyncByteArrayInputStream;

import org.jetbrains.annotations.Nullable;



import java.io.DataInput;

import java.io.DataOutput;

import java.io.IOException;



public class SerializedStubTree {

  private final byte[] myBytes;

  private final int myLength;

  private Stub myStubElement;



  public SerializedStubTree(final byte[] bytes, int length, @Nullable Stub stubElement) {

    myBytes = bytes;

    myLength = length;

    myStubElement = stubElement;

  }

  

  public SerializedStubTree(DataInput in) throws IOException {

    myBytes = CompressionUtil.readCompressed(in);

    myLength = myBytes.length;

  }



  public void write(DataOutput out) throws IOException {

    CompressionUtil.writeCompressed(out, myBytes, myLength);

  }



  // willIndexStub is one time optimization hint, once can safely pass false

  public Stub getStub(boolean willIndexStub) throws SerializerNotFoundException {

    Stub stubElement = myStubElement;

    if (stubElement != null) {

      // not null myStubElement means we just built SerializedStubTree for indexing,

      // if we request stub for indexing we can safely use it

      myStubElement = null;

      if (willIndexStub) return stubElement;

    }

    return SerializationManagerEx.getInstanceEx().deserialize(new UnsyncByteArrayInputStream(myBytes));

  }



  public boolean equals(final Object that) {

    if (this == that) {

      return true;

    }

    if (!(that instanceof SerializedStubTree)) {

      return false;

    }

    final SerializedStubTree thatTree = (SerializedStubTree)that;

    final int length = myLength;

    if (length != thatTree.myLength) {

      return false;

    }



    final byte[] thisBytes = myBytes;

    final byte[] thatBytes = thatTree.myBytes;

    for (int i=0; i< length; i++) {

      if (thisBytes[i] != thatBytes[i]) {

        return false;

      }

    }

    

    return true;

  }



  public int hashCode() {

    if (myBytes == null)

        return 0;



    int result = 1;

    for (int i = 0; i < myLength; i++) {

      result = 31 * result + myBytes[i];

    }



    return result;

  }



}