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(() -> {
  31                 int read;
  32                 try {
  33                     while ((read = pipe.read(buffer)) > 0)
  34                     {
  35                         out.write(buffer, 0, read);
  36                         out.flush();
  37                     }
  38                 } catch (IOException e) {
  39                     System.out.println("Error writing to file " + e);
  40                 }
  41                 try {
  42                     out.close();
  43                 } catch (IOException e) {}
  44             });
  45             writeThread.start();
  46         } catch (IOException e) {}
  47     }
  48
  49     public void close() throws IOException
  50     {
  51         super.close();
  52         try {
  53             writeThread.join();
  54         } catch (InterruptedException e) {
  55             System.out.println("Failed waiting for WriteBuffer thread " + e);
  56         }
  57     }
  58
  59     Thread writeThread;
  60     OutputStream out;
  61     PipedInputStream pipe;
  62     byte[] buffer;
  63 }