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
   *
   *      https://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.loopj.android.http;
  
  import java.io.FilterOutputStream;
  import java.io.IOException;
  import java.io.OutputStream;
  
  public class Base64OutputStream extends FilterOutputStream {
      private static final byte[] EMPTY = new byte[0];
      private final Base64.Coder coder;
      private final int flags;
      private byte[] buffer = null;
      private int bpos = 0;
  
      /**
       * Performs Base64 encoding on the data written to the stream, writing the encoded data to
       * another OutputStream.
       *
       * @param out   the OutputStream to write the encoded data to
       * @param flags bit flags for controlling the encoder; see the constants in {@link Base64}
       */
      public Base64OutputStream(OutputStream out, int flags) {
          this(out, flags, true);
      }
  
      /**
       * Performs Base64 encoding or decoding on the data written to the stream, writing the
       * encoded/decoded data to another OutputStream.
       *
       * @param out    the OutputStream to write the encoded data to
       * @param flags  bit flags for controlling the encoder; see the constants in {@link Base64}
       * @param encode true to encode, false to decode
       */
      public Base64OutputStream(OutputStream out, int flags, boolean encode) {
          super(out);
          this.flags = flags;
          if (encode) {
              coder = new Base64.Encoder(flags, null);
          } else {
              coder = new Base64.Decoder(flags, null);
          }
      }
  
      @Override
      public void write(int b) throws IOException {
          // To avoid invoking the encoder/decoder routines for single
          // bytes, we buffer up calls to write(int) in an internal
          // byte array to transform them into writes of decently-sized
          // arrays.
  
          if (buffer == null) {
              buffer = new byte[1024];
          }
          if (bpos >= buffer.length) {
              // internal buffer full; write it out.
              internalWrite(buffer, 0, bpos, false);
              bpos = 0;
          }
          buffer[bpos++] = (byte) b;
      }
  
      /**
       * Flush any buffered data from calls to write(int).  Needed before doing a write(byte[], int,
       * int) or a close().
       */
      private void flushBuffer() throws IOException {
          if (bpos > 0) {
              internalWrite(buffer, 0, bpos, false);
              bpos = 0;
          }
      }
  
      @Override
      public void write(byte[] b, int off, int len) throws IOException {
          if (len <= 0) return;
          flushBuffer();
          internalWrite(b, off, len, false);
      }
  
      @Override
      public void close() throws IOException {
          IOException thrown = null;
          try {
              flushBuffer();
              internalWrite(EMPTY, 0, 0, true);
          } catch (IOException e) {
              thrown = e;
          }
  
          try {
              if ((flags & Base64.NO_CLOSE) == 0) {
                  out.close();
              } else {
                  out.flush();
              }
          } catch (IOException e) {
              if (thrown != null) {
                  thrown = e;
              }
          }
  
          if (thrown != null) {
              throw thrown;
          }
      }
  
      /**
       * Write the given bytes to the encoder/decoder.
       *
       * @param finish true if this is the last batch of input, to cause encoder/decoder state to be
       *               finalized.
       */
      private void internalWrite(byte[] b, int off, int len, boolean finish) throws IOException {
          coder.output = embiggen(coder.output, coder.maxOutputSize(len));
          if (!coder.process(b, off, len, finish)) {
              throw new Base64DataException("bad base-64");
          }
          out.write(coder.output, 0, coder.op);
      }
  
      /**
       * If b.length is at least len, return b.  Otherwise return a new byte array of length len.
       */
      private byte[] embiggen(byte[] b, int len) {
          if (b == null || b.length < len) {
              return new byte[len];
          } else {
              return b;
          }
      }
  }