lib/java/src/transport/TFramedTransport.java

   1 // Copyright (c) 2006- Facebook
   2 // Distributed under the Thrift Software License
   3 //
   4 // See accompanying file LICENSE or visit the Thrift site at:
   5 // http://developers.facebook.com/thrift/
   6
   7 package com.facebook.thrift.transport;
   8
   9 import java.io.ByteArrayInputStream;
  10 import java.io.ByteArrayOutputStream;
  11
  12 import com.facebook.thrift.TByteArrayOutputStream;
  13
  14 /**
  15  * Socket implementation of the TTransport interface. To be commented soon!
  16  *
  17  * @author Mark Slee <mcslee@facebook.com>
  18  */
  19 public class TFramedTransport extends TTransport {
  20
  21   /**
  22    * Underlying transport
  23    */
  24   private TTransport transport_ = null;
  25
  26   /**
  27    * Buffer for output
  28    */
  29   private final TByteArrayOutputStream writeBuffer_ =
  30     new TByteArrayOutputStream(1024);
  31
  32   /**
  33    * Buffer for input
  34    */
  35   private ByteArrayInputStream readBuffer_ = null;
  36
  37   /**
  38    * Whether to frame input
  39    */
  40   private boolean frameRead_ = true;
  41
  42   /**
  43    * Whether to frame output
  44    */
  45   private boolean frameWrite_ = true;
  46
  47   /**
  48    * Constructor wraps around another tranpsort
  49    */
  50   public TFramedTransport(TTransport transport) {
  51     this(transport, true, true);
  52   }
  53
  54   /**
  55    * Constructor wraps around another tranpsort
  56    */
  57   public TFramedTransport(TTransport transport, boolean in, boolean out) {
  58     transport_ = transport;
  59     frameRead_ = in;
  60     frameWrite_ = out;
  61   }
  62
  63   public void setFrameRead(boolean frameRead) {
  64     frameRead_ = frameRead;
  65   }
  66
  67   public void setFrameWrite(boolean frameWrite) {
  68     frameWrite_ = frameWrite;
  69   }
  70
  71   public void open() throws TTransportException {
  72     transport_.open();
  73   }
  74
  75   public boolean isOpen() {
  76     return transport_.isOpen();
  77   }
  78
  79   public void close() {
  80     transport_.close();
  81   }
  82
  83   public int read(byte[] buf, int off, int len) throws TTransportException {
  84     if (!frameRead_) {
  85       return transport_.read(buf, off, len);
  86     }
  87
  88     if (readBuffer_ != null) {
  89       int got = readBuffer_.read(buf, off, len);
  90       if (got > 0) {
  91         return got;
  92       }
  93     }
  94
  95     // Read another frame of data
  96     readFrame();
  97
  98     return readBuffer_.read(buf, off, len);
  99   }
 100
 101   private void readFrame() throws TTransportException {
 102     byte[] i32rd = new byte[4];
 103     transport_.readAll(i32rd, 0, 4);
 104     int size =
 105       ((i32rd[0] & 0xff) << 24) |
 106       ((i32rd[1] & 0xff) << 16) |
 107       ((i32rd[2] & 0xff) <<  8) |
 108       ((i32rd[3] & 0xff));
 109
 110     byte[] buff = new byte[size];
 111     transport_.readAll(buff, 0, size);
 112     readBuffer_ = new ByteArrayInputStream(buff);
 113   }
 114
 115   public void write(byte[] buf, int off, int len) throws TTransportException {
 116     if (!frameWrite_) {
 117       transport_.write(buf, off, len);
 118       return;
 119     }
 120     writeBuffer_.write(buf, off, len);
 121   }
 122
 123   public void flush() throws TTransportException {
 124     if (!frameWrite_) {
 125       transport_.flush();
 126       return;
 127     }
 128
 129     byte[] buf = writeBuffer_.get();
 130     int len = writeBuffer_.len();
 131     writeBuffer_.reset();
 132
 133     byte[] i32out = new byte[4];
 134     i32out[0] = (byte)(0xff & (len >> 24));
 135     i32out[1] = (byte)(0xff & (len >> 16));
 136     i32out[2] = (byte)(0xff & (len >> 8));
 137     i32out[3] = (byte)(0xff & (len));
 138     transport_.write(i32out, 0, 4);
 139     transport_.write(buf, 0, len);
 140     transport_.flush();
 141   }
 142 }