|
1 <?php |
|
2 /** |
|
3 * Classes, which help reading streams of data from files. |
|
4 * Based on the classes from Danilo Segan <danilo@kvota.net> |
|
5 * |
|
6 * @version $Id: streams.php 138 2009-06-23 13:22:09Z nbachiyski $ |
|
7 * @package pomo |
|
8 * @subpackage streams |
|
9 */ |
|
10 |
|
11 |
|
12 /** |
|
13 * Provides file-like methods for manipulating a string instead |
|
14 * of a physical file. |
|
15 */ |
|
16 class POMO_StringReader { |
|
17 var $_pos; |
|
18 var $_str; |
|
19 |
|
20 function POMO_StringReader($str = '') { |
|
21 $this->_str = $str; |
|
22 $this->_pos = 0; |
|
23 $this->is_overloaded = ((ini_get("mbstring.func_overload") & 2) != 0) && function_exists('mb_substr'); |
|
24 } |
|
25 |
|
26 function _substr($string, $start, $length) { |
|
27 if ($this->is_overloaded) { |
|
28 return mb_substr($string,$start,$length,'ascii'); |
|
29 } else { |
|
30 return substr($string,$start,$length); |
|
31 } |
|
32 } |
|
33 |
|
34 function _strlen($string) { |
|
35 if ($this->is_overloaded) { |
|
36 return mb_strlen($string,'ascii'); |
|
37 } else { |
|
38 return strlen($string); |
|
39 } |
|
40 } |
|
41 |
|
42 function read($bytes) { |
|
43 $data = $this->_substr($this->_str, $this->_pos, $bytes); |
|
44 $this->_pos += $bytes; |
|
45 if ($this->_strlen($this->_str) < $this->_pos) $this->_pos = $this->_strlen($this->_str); |
|
46 return $data; |
|
47 } |
|
48 |
|
49 function seekto($pos) { |
|
50 $this->_pos = $pos; |
|
51 if ($this->_strlen($this->_str) < $this->_pos) $this->_pos = $this->_strlen($this->_str); |
|
52 return $this->_pos; |
|
53 } |
|
54 |
|
55 function pos() { |
|
56 return $this->_pos; |
|
57 } |
|
58 |
|
59 function length() { |
|
60 return $this->_strlen($this->_str); |
|
61 } |
|
62 |
|
63 } |
|
64 |
|
65 /** |
|
66 * Reads the contents of the file in the beginning. |
|
67 */ |
|
68 class POMO_CachedFileReader extends POMO_StringReader { |
|
69 function POMO_CachedFileReader($filename) { |
|
70 parent::POMO_StringReader(); |
|
71 $this->_str = file_get_contents($filename); |
|
72 if (false === $this->_str) |
|
73 return false; |
|
74 $this->_pos = 0; |
|
75 } |
|
76 } |
|
77 |
|
78 /** |
|
79 * Allows reading integers from a file. |
|
80 */ |
|
81 class POMO_CachedIntFileReader extends POMO_CachedFileReader { |
|
82 |
|
83 var $endian = 'little'; |
|
84 |
|
85 /** |
|
86 * Opens a file and caches it. |
|
87 * |
|
88 * @param $filename string name of the file to be opened |
|
89 * @param $endian string endianness of the words in the file, allowed |
|
90 * values are 'little' or 'big'. Default value is 'little' |
|
91 */ |
|
92 function POMO_CachedIntFileReader($filename, $endian = 'little') { |
|
93 $this->endian = $endian; |
|
94 parent::POMO_CachedFileReader($filename); |
|
95 } |
|
96 |
|
97 /** |
|
98 * Sets the endianness of the file. |
|
99 * |
|
100 * @param $endian string 'big' or 'little' |
|
101 */ |
|
102 function setEndian($endian) { |
|
103 $this->endian = $endian; |
|
104 } |
|
105 |
|
106 /** |
|
107 * Reads a 32bit Integer from the Stream |
|
108 * |
|
109 * @return mixed The integer, corresponding to the next 32 bits from |
|
110 * the stream of false if there are not enough bytes or on error |
|
111 */ |
|
112 function readint32() { |
|
113 $bytes = $this->read(4); |
|
114 if (4 != $this->_strlen($bytes)) |
|
115 return false; |
|
116 $endian_letter = ('big' == $this->endian)? 'N' : 'V'; |
|
117 $int = unpack($endian_letter, $bytes); |
|
118 return array_shift($int); |
|
119 } |
|
120 |
|
121 /** |
|
122 * Reads an array of 32-bit Integers from the Stream |
|
123 * |
|
124 * @param integer count How many elements should be read |
|
125 * @return mixed Array of integers or false if there isn't |
|
126 * enough data or on error |
|
127 */ |
|
128 function readint32array($count) { |
|
129 $bytes = $this->read(4 * $count); |
|
130 if (4*$count != $this->_strlen($bytes)) |
|
131 return false; |
|
132 $endian_letter = ('big' == $this->endian)? 'N' : 'V'; |
|
133 return unpack($endian_letter.$count, $bytes); |
|
134 } |
|
135 } |
|
136 |
|
137 ?> |