982a07cb873e78996dce387f53bda9973c4d524d
[core.git] / inc / classes / main / file_directories / input / class_FrameworkFileInputPointer.php
1 <?php
2 /**
3  * A class for reading files
4  *
5  * @author              Roland Haeder <webmaster@shipsimu.org>
6  * @version             0.0.0
7  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2014 Core Developer Team
8  * @license             GNU GPL 3.0 or any newer version
9  * @link                http://www.shipsimu.org
10  *
11  * This program is free software: you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation, either version 3 of the License, or
14  * (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program. If not, see <http://www.gnu.org/licenses/>.
23  */
24 class FrameworkFileInputPointer extends BaseFileIo implements InputPointer {
25         /**
26          * Protected constructor
27          *
28          * @return      void
29          */
30         protected function __construct () {
31                 // Call parent constructor
32                 parent::__construct(__CLASS__);
33         }
34
35         /**
36          * Create a file pointer based on the given file. The file will also
37          * be verified here.
38          *
39          * @param       $fileName       The file name we shall pass to fopen()
40          * @throws      FileIsEmptyException    If the provided file name is empty.
41          * @throws      FileIoException                 If fopen() returns not a file resource
42          * @return      void
43          */
44         public static final function createFrameworkFileInputPointer ($fileName) {
45                 // Some pre-sanity checks...
46                 if ((is_null($fileName)) || (empty($fileName))) {
47                         // No filename given
48                         throw new FileIsEmptyException(NULL, self::EXCEPTION_UNEXPECTED_EMPTY_STRING);
49                 } elseif (!file_exists($fileName)) {
50                         // File does not exist!
51                         throw new FileIoException($fileName, self::EXCEPTION_FILE_NOT_FOUND);
52                 } elseif (!is_readable($fileName)) {
53                         // File does not exist!
54                         throw new FileReadProtectedException($fileName, self::EXCEPTION_FILE_CANNOT_BE_READ);
55                 }
56
57                 // Try to open a handler
58                 $filePointer = fopen($fileName, 'rb');
59                 if ((is_null($filePointer)) || ($filePointer === FALSE)) {
60                         // Something bad happend
61                         throw new FileIoException($fileName, self::EXCEPTION_FILE_POINTER_INVALID);
62                 } // END - if
63
64                 // Create new instance
65                 $pointerInstance = new FrameworkFileInputPointer();
66
67                 // Set file pointer and file name
68                 $pointerInstance->setPointer($filePointer);
69                 $pointerInstance->setFileName($fileName);
70
71                 // Return the instance
72                 return $pointerInstance;
73         }
74
75         /**
76          * Read data a file pointer
77          *
78          * @return      mixed   The result of fread()
79          * @throws      NullPointerException    If the file pointer instance
80          *                                                                      is not set by setPointer()
81          * @throws      InvalidResourceException        If there is being set
82          */
83         public function readFromFile () {
84                 if (is_null($this->getPointer())) {
85                         // Pointer not initialized
86                         throw new NullPointerException($this, self::EXCEPTION_IS_NULL_POINTER);
87                 } elseif (!is_resource($this->getPointer())) {
88                         // Pointer is not a valid resource!
89                         throw new InvalidResourceException($this, self::EXCEPTION_INVALID_RESOURCE);
90                 }
91
92                 // Read data from the file pointer and return it
93                 return $this->read(1024);
94         }
95
96         /**
97          * Reads given amount of bytes from file.
98          *
99          * @param       $bytes  Amount of bytes to read
100          * @return      $data   Data read from file
101          */
102         public function read ($bytes) {
103                 // Try to read given characters
104                 $data = fread($this->getPointer(), $bytes);
105
106                 // Was this successfull?
107                 assert(is_string($data));
108
109                 // Then return it
110                 return $data;
111         }
112
113         /**
114          * Analyzes entries in index file. This will count all found (and valid)
115          * entries, mark invalid as damaged and count gaps ("fragmentation"). If
116          * only gaps are found, the file is considered as "virgin" (no entries).
117          *
118          * @return      void
119          * @throws      UnsupportedOperationException   If this method is called
120          */
121         public function analyzeFile () {
122                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
123         }
124
125         /**
126          * Advances to next "block" of bytes
127          *
128          * @return      void
129          * @throws      UnsupportedOperationException   If this method is called
130          */
131         public function next () {
132                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
133         }
134
135         /**
136          * Checks wether the current entry is valid (not at the end of the file).
137          * This method will return TRUE if an emptied (nulled) entry has been found.
138          *
139          * @return      $isValid        Whether the next entry is valid
140          * @throws      UnsupportedOperationException   If this method is called
141          */
142         public function valid () {
143                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
144         }
145
146         /**
147          * Gets current seek position ("key").
148          *
149          * @return      $key    Current key in iteration
150          * @throws      UnsupportedOperationException   If this method is called
151          */
152         public function key () {
153                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
154         }
155 }
156
157 // [EOF]
158 ?>