src/com/hughes/android/dictionary/engine/WriteBuffer.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.IOException;
  18 import java.io.OutputStream;
  19 import java.io.PipedInputStream;
  20 import java.io.PipedOutputStream;
  21
  22 public class WriteBuffer extends PipedOutputStream {
  23     static int BLOCK_SIZE = 1024 * 1024;
  24     public WriteBuffer(OutputStream out, int size) {
  25         assert size >= 2 * BLOCK_SIZE;
  26         this.out = out;
  27         try {
  28             pipe = new PipedInputStream(this, size);
  29             buffer = new byte[BLOCK_SIZE];
  30             writeThread = new Thread(new Runnable() {
  31                 public void run() {
  32                     int read;
  33                     try {
  34                         while ((read = pipe.read(buffer)) > 0)
  35                         {
  36                             out.write(buffer, 0, read);
  37                             out.flush();
  38                         }
  39                     } catch (IOException e) {
  40                         System.out.println("Error writing to file " + e);
  41                     }
  42                     try {
  43                         out.close();
  44                     } catch (IOException e) {}
  45                 }
  46             });
  47             writeThread.start();
  48         } catch (IOException e) {}
  49     }
  50
  51     public void close() throws IOException
  52     {
  53         super.close();
  54         try {
  55             writeThread.join();
  56         } catch (InterruptedException e) {
  57             System.out.println("Failed waiting for WriteBuffer thread " + e);
  58         }
  59     }
  60
  61     Thread writeThread;
  62     OutputStream out;
  63     PipedInputStream pipe;
  64     byte buffer[];
  65 }