lib/php/src/transport/TBufferedTransport.php

   1 <?php
   2
   3 /**
   4  * Copyright (c) 2006- Facebook
   5  * Distributed under the Thrift Software License
   6  *
   7  * See accompanying file LICENSE or visit the Thrift site at:
   8  * http://developers.facebook.com/thrift/
   9  *
  10  * @package thrift.transport
  11  * @author Mark Slee <mcslee@facebook.com>
  12  */
  13
  14 /**
  15  * Buffered transport. Stores data to an internal buffer that it doesn't
  16  * actually write out until flush is called. For reading, we do a greedy
  17  * read and then serve data out of the internal buffer.
  18  *
  19  * @package thrift.transport
  20  * @author Mark Slee <mcslee@facebook.com>
  21  */
  22 class TBufferedTransport extends TTransport {
  23
  24   /**
  25    * Constructor. Creates a buffered transport around an underlying transport
  26    */
  27   public function __construct($transport=null, $rBufSize=512, $wBufSize=512) {
  28     $this->transport_ = $transport;
  29     $this->rBufSize_ = $rBufSize;
  30     $this->wBufSize_ = $wBufSize;
  31   }
  32
  33   /**
  34    * The underlying transport
  35    *
  36    * @var TTransport
  37    */
  38   protected $transport_ = null;
  39
  40   /**
  41    * The receive buffer size
  42    *
  43    * @var int
  44    */
  45   protected $rBufSize_ = 512;
  46
  47   /**
  48    * The write buffer size
  49    *
  50    * @var int
  51    */
  52   protected $wBufSize_ = 512;
  53
  54   /**
  55    * The write buffer.
  56    *
  57    * @var string
  58    */
  59   protected $wBuf_ = '';
  60
  61   /**
  62    * The read buffer.
  63    *
  64    * @var string
  65    */
  66   protected $rBuf_ = '';
  67
  68   public function isOpen() {
  69     return $this->transport_->isOpen();
  70   }
  71
  72   public function open() {
  73     $this->transport_->open();
  74   }
  75
  76   public function close() {
  77     $this->transport_->close();
  78   }
  79
  80   public function putBack($data) {
  81     if (strlen($this->rBuf_) === 0) {
  82       $this->rBuf_ = $data;
  83     } else {
  84       $this->rBuf_ = ($data . $this->rBuf_);
  85     }
  86   }
  87
  88   /**
  89    * The reason that we customize readAll here is that the majority of PHP
  90    * streams are already internally buffered by PHP. The socket stream, for
  91    * example, buffers internally and blocks if you call read with $len greater
  92    * than the amount of data available, unlike recv() in C.
  93    *
  94    * Therefore, use the readAll method of the wrapped transport inside
  95    * the buffered readAll.
  96    */
  97   public function readAll($len) {
  98     $have = strlen($this->rBuf_);
  99     if ($have == 0) {
 100       $data = $this->transport_->readAll($len);
 101     } else if ($have < $len) {
 102       $data = $this->rBuf_;
 103       $this->rBuf_ = '';
 104       $data .= $this->transport_->readAll($len - $have);
 105     } else if ($have == $len) {
 106       $data = $this->rBuf_;
 107       $this->rBuf_ = '';
 108     } else if ($have > $len) {
 109       $data = substr($this->rBuf_, 0, $len);
 110       $this->rBuf_ = substr($this->rBuf_, $len);
 111     }
 112     return $data;
 113   }
 114
 115   public function read($len) {
 116     if (strlen($this->rBuf_) === 0) {
 117       $this->rBuf_ = $this->transport_->read($this->rBufSize_);
 118     }
 119
 120     if (strlen($this->rBuf_) <= $len) {
 121       $ret = $this->rBuf_;
 122       $this->rBuf_ = '';
 123       return $ret;
 124     }
 125
 126     $ret = substr($this->rBuf_, 0, $len);
 127     $this->rBuf_ = substr($this->rBuf_, $len);
 128     return $ret;
 129   }
 130
 131   public function write($buf) {
 132     $this->wBuf_ .= $buf;
 133     if (strlen($this->wBuf_) >= $this->wBufSize_) {
 134       $this->transport_->write($this->wBuf_);
 135       $this->wBuf_ = '';
 136     }
 137   }
 138
 139   public function flush() {
 140     if (strlen($this->wBuf_) > 0) {
 141       $this->transport_->write($this->wBuf_);
 142       $this->wBuf_ = '';
 143     }
 144     $this->transport_->flush();
 145   }
 146
 147 }
 148
 149 ?>