src/com/hughes/android/dictionary/engine/ReadAheadBuffer.java

   1 // Copyright 2017 Reimar Döffinger
   2 //
   3 // Licensed under the Apache License, Version 2.0 (the "License");
   4 // you may not use this file except in compliance with the License.
   5 // You may obtain a copy of the License at
   6 //
   7 //     http://www.apache.org/licenses/LICENSE-2.0
   8 //
   9 // Unless required by applicable law or agreed to in writing, software
  10 // distributed under the License is distributed on an "AS IS" BASIS,
  11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 // See the License for the specific language governing permissions and
  13 // limitations under the License.
  14
  15 package com.hughes.android.dictionary.engine;
  16
  17 import java.io.InputStream;
  18 import java.io.IOException;
  19 import java.io.PipedInputStream;
  20 import java.io.PipedOutputStream;
  21
  22 public class ReadAheadBuffer extends PipedInputStream {
  23     static int BLOCK_SIZE = 1024 * 1024;
  24     public ReadAheadBuffer(InputStream in, int size) {
  25         super(size);
  26         assert size >= 2 * BLOCK_SIZE;
  27         this.in = in;
  28         try {
  29             pipe = new PipedOutputStream(this);
  30             buffer = new byte[BLOCK_SIZE];
  31             new Thread(new Runnable() {
  32                 public void run() {
  33                     int read;
  34                     try {
  35                         while ((read = in.read(buffer)) > 0)
  36                         {
  37                             pipe.write(buffer, 0, read);
  38                             pipe.flush();
  39                         }
  40                     } catch (IOException e) {}
  41                     try {
  42                         pipe.close();
  43                     } catch (IOException e) {}
  44                 }
  45             }).start();
  46         } catch (IOException e) {}
  47     }
  48
  49     InputStream in;
  50     PipedOutputStream pipe;
  51     byte buffer[];
  52 }