content: /*
   * Copyright (C) 2010 The Android Open Source Project
   *
   * 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 android.framework.langlang;
  
  import java.nio.charset.Charset;
  
  /**
   * A cheaper ByteArrayOutputStream for internal use. This class is unsynchronized,
   * and returns its internal array if it's the right size. This makes String.getBytes("UTF-8")
   * 10x faster than the baseline non-fast-path implementation instead of 8x faster when using
   * ByteArrayOutputStream. When GC and uncontended synchronization become cheap, we should be
   * able to get rid of this class. In the meantime, if you need to add further API, please try
   * to keep it plug-compatible with ByteArrayOutputStream with an eye to future obsolescence.
   *
   * @hide
   */
  public class UnsafeByteSequence {
      private byte[] bytes;
      private int count;
  
      public UnsafeByteSequence(int initialCapacity) {
          this.bytes = new byte[initialCapacity];
      }
  
      public int size() {
          return count;
      }
  
      /**
       * Moves the write pointer back to the beginning of the sequence,
       * but without resizing or reallocating the buffer.
       */
      public void rewind() {
          count = 0;
      }
  
      public void write(byte[] buffer, int offset, int length) {
          if (count + length >= bytes.length) {
              byte[] newBytes = new byte[(count + length) * 2];
              System.arraycopy(bytes, 0, newBytes, 0, count);
              bytes = newBytes;
          }
          System.arraycopy(buffer, offset, bytes, count, length);
          count += length;
      }
  
      public void write(int b) {
          if (count == bytes.length) {
              byte[] newBytes = new byte[count * 2];
              System.arraycopy(bytes, 0, newBytes, 0, count);
              bytes = newBytes;
          }
          bytes[count++] = (byte) b;
      }
  
      public byte[] toByteArray() {
          if (count == bytes.length) {
              return bytes;
          }
          byte[] result = new byte[count];
          System.arraycopy(bytes, 0, result, 0, count);
          return result;
      }
  
      public String toString(Charset cs) {
          return new String(bytes, 0, count, cs);
      }
  }
  