3 * A class for reading files
5 * @author Roland Haeder <webmaster@shipsimu.org>
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
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.
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.
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/>.
24 class FrameworkFileInputOutputPointer extends BaseFileIo implements InputOutputPointer {
26 * Protected constructor
30 protected function __construct () {
31 // Call parent constructor
32 parent::__construct(__CLASS__);
36 * Create a file pointer based on the given file. The file will also
39 * @param $fileName The file name we shall pass to fopen()
41 * @throws FileIsEmptyException If the given file name is NULL or empty
42 * @throws FileReadProtectedException If PHP cannot read an existing file
43 * @throws FileWriteProtectedException If PHP cannot write an existing file
44 * @throws FileIoException If fopen() returns not a file resource
46 public static final function createFrameworkFileInputOutputPointer ($fileName) {
47 // Some pre-sanity checks...
48 if ((is_null($fileName)) || (empty($fileName))) {
50 throw new FileIsEmptyException(NULL, self::EXCEPTION_UNEXPECTED_EMPTY_STRING);
51 } elseif ((file_exists($fileName)) && (!is_readable($fileName))) {
52 // File exists but cannot be read
53 throw new FileReadProtectedException($fileName, self::EXCEPTION_FILE_CANNOT_BE_READ);
54 } elseif ((file_exists($fileName)) && (!is_writable($fileName))) {
55 // File exists but cannot be written
56 throw new FileWriteProtectedException($fileName, self::EXCEPTION_FILE_CANNOT_BE_READ);
59 // Try to open a handler
60 $filePointer = fopen($fileName, 'c+b');
61 if ((is_null($filePointer)) || ($filePointer === FALSE)) {
62 // Something bad happend
63 throw new FileIoException($fileName, self::EXCEPTION_FILE_POINTER_INVALID);
66 // Create new instance
67 $pointerInstance = new FrameworkFileInputOutputPointer();
69 // Set file pointer and file name
70 $pointerInstance->setPointer($filePointer);
71 $pointerInstance->setFileName($fileName);
73 // Return the instance
74 return $pointerInstance;
78 * Validates file pointer and throws exceptions. This method does not return
79 * anything (not reliable) as this method checks the file pointer and on
80 * case of an error it throws an exception. If this method does not throw
81 * any exceptions, the file pointer seems to be fine.
84 * @throws NullPointerException If the file pointer instance
85 * is not set by setPointer()
86 * @throws InvalidResourceException If there is being set
88 private function validateFilePointer () {
89 if (is_null($this->getPointer())) {
90 // Pointer not initialized
91 throw new NullPointerException($this, self::EXCEPTION_IS_NULL_POINTER);
92 } elseif (!is_resource($this->getPointer())) {
93 // Pointer is not a valid resource!
94 throw new InvalidResourceException($this, self::EXCEPTION_INVALID_RESOURCE);
101 * Read 1024 bytes data from a file pointer
103 * @return mixed The result of fread()
105 public function readFromFile () {
106 // Validate the pointer
107 $this->validateFilePointer();
109 // Read data from the file pointer and return it
110 return $this->read(1024);
114 * Write data to a file pointer
116 * @param $dataStream The data stream we shall write to the file
117 * @return mixed Number of writes bytes or FALSE on error
119 public function writeToFile ($dataStream) {
120 // Validate the pointer
121 $this->validateFilePointer();
123 // Write data to the file pointer and return written bytes
124 return fwrite($this->getPointer(), $dataStream, strlen($dataStream));
128 * Writes at given position by seeking to it.
130 * @param $seekPosition Seek position in file
131 * @param $data Data to be written
132 * @return mixed Number of writes bytes or FALSE on error
134 public function writeAtPosition ($seekPosition, $data) {
136 $this->seek($seekPosition);
138 // Then write the data at that position
139 return $this->writeToFile($data);
143 * Rewinds to the beginning of the file
145 * @return $status Status of this operation
147 public function rewind () {
148 // Validate the pointer
149 $this->validateFilePointer();
151 // Rewind the pointer
152 return rewind($this->getPointer());
156 * Seeks to given position
158 * @param $seekPosition Seek position in file
159 * @param $whence "Seek mode" (see http://de.php.net/fseek)
160 * @return $status Status of this operation
162 public function seek ($seekPosition, $whence = SEEK_SET) {
163 // Validate the pointer
164 $this->validateFilePointer();
166 // Move the file pointer
167 return fseek($this->getPointer(), $seekPosition, $whence);
171 * Reads given amount of bytes from file.
173 * @param $bytes Amount of bytes to read
174 * @return $data Data read from file
176 public function read ($bytes) {
177 // Validate the pointer
178 $this->validateFilePointer();
180 // Try to read given characters
181 $data = fread($this->getPointer(), $bytes);
183 // Was this successfull?
184 assert(is_string($data));
191 * Analyzes entries in index file. This will count all found (and valid)
192 * entries, mark invalid as damaged and count gaps ("fragmentation"). If
193 * only gaps are found, the file is considered as "virgin" (no entries).
196 * @throws UnsupportedOperationException If this method is called
198 public function analyzeFile () {
199 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
203 * Advances to next "block" of bytes
206 * @throws UnsupportedOperationException If this method is called
208 public function next () {
209 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
213 * Checks wether the current entry is valid (not at the end of the file).
214 * This method will return TRUE if an emptied (nulled) entry has been found.
216 * @return $isValid Whether the next entry is valid
217 * @throws UnsupportedOperationException If this method is called
219 public function valid () {
220 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
224 * Gets current seek position ("key").
226 * @return $key Current key in iteration
227 * @throws UnsupportedOperationException If this method is called
229 public function key () {
230 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
234 * "Getter" for file size
236 * @return $fileSize Size of currently loaded file
238 public function getFileSize () {
239 // Check if the pointer is still valid
240 $this->validateFilePointer();
243 $fileData = fstat($this->getPointer());
245 // Make sure the required array key is there
246 assert(isset($fileData['size']));
249 return $fileData['size'];