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 */
22class 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      $out = $this->wBuf_;
135
136      // Note that we clear the internal wBuf_ prior to the underlying write
137      // to ensure we're in a sane state (i.e. internal buffer cleaned)
138      // if the underlying write throws up an exception
139      $this->wBuf_ = '';
140      $this->transport_->write($out);
141    }
142  }
143
144  public function flush() {
145    if (strlen($this->wBuf_) > 0) {
146      $this->transport_->write($this->wBuf_);
147      $this->wBuf_ = '';
148    }
149    $this->transport_->flush();
150  }
151
152}
153
154?>
155