/*
    * 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.
   */
  package com.addthis.codec.binary;
  
  import java.io.ByteArrayInputStream;
  import java.io.IOException;
  
  import java.util.Stack;
  
  import com.addthis.basis.util.Bytes;
  
  final class BufferIn {
  
      ByteArrayInputStream        in;
      Stack<ByteArrayInputStream> stack;
  
      BufferIn(final byte[] data) throws IOException {
          stack = new Stack<>();
          in = new ByteArrayInputStream(data);
      }
  
      public void push() throws IOException {
          int len = (int) Bytes.readLength(in);
          byte[] ndat = Bytes.readBytes(in, len);
          stack.push(in);
          in = new ByteArrayInputStream(ndat);
      }
  
      public void pop() {
          in = stack.pop();
      }
  
      @Override
      public String toString() {
          return "BufferIn:" + (in != null ? in.available() : -1);
      }
  }