3 * A class for reading files
5 * @author Roland Haeder <webmaster@shipsimu.org>
7 * @copyright Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2015 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 (!BaseFrameworkSystem::isReachableFilePath($fileName)) {
52 // File exists but cannot be read
53 throw new FileIoException($fileName, self::EXCEPTION_FILE_NOT_REACHABLE);
54 } elseif ((!BaseFrameworkSystem::isReadableFile($fileName)) && (file_exists($fileName))) {
55 // File exists but cannot be read
56 throw new FileReadProtectedException($fileName, self::EXCEPTION_FILE_CANNOT_BE_READ);
57 } elseif ((file_exists($fileName)) && (!is_writable($fileName))) {
58 // File exists but cannot be written
59 throw new FileWriteProtectedException($fileName, self::EXCEPTION_FILE_CANNOT_BE_WRITTEN);
62 // Try to open a handler
63 $filePointer = fopen($fileName, 'c+b');
64 if ((is_null($filePointer)) || ($filePointer === FALSE)) {
65 // Something bad happend
66 throw new FileIoException($fileName, self::EXCEPTION_FILE_POINTER_INVALID);
69 // Create new instance
70 $pointerInstance = new FrameworkFileInputOutputPointer();
72 // Set file pointer and file name
73 $pointerInstance->setPointer($filePointer);
74 $pointerInstance->setFileName($fileName);
76 // Return the instance
77 return $pointerInstance;
81 * Validates file pointer and throws exceptions. This method does not return
82 * anything (not reliable) as this method checks the file pointer and on
83 * case of an error it throws an exception. If this method does not throw
84 * any exceptions, the file pointer seems to be fine.
87 * @throws NullPointerException If the file pointer instance
88 * is not set by setPointer()
89 * @throws InvalidResourceException If there is being set
91 private function validateFilePointer () {
92 if (is_null($this->getPointer())) {
93 // Pointer not initialized
94 throw new NullPointerException($this, self::EXCEPTION_IS_NULL_POINTER);
95 } elseif (!is_resource($this->getPointer())) {
96 // Pointer is not a valid resource!
97 throw new InvalidResourceException($this, self::EXCEPTION_INVALID_RESOURCE);
104 * Read 1024 bytes data from a file pointer
106 * @return mixed The result of fread()
108 public function readFromFile () {
109 // Validate the pointer
110 $this->validateFilePointer();
112 // Read data from the file pointer and return it
113 return $this->read(1024);
117 * Write data to a file pointer
119 * @param $dataStream The data stream we shall write to the file
120 * @return mixed Number of writes bytes or FALSE on error
122 public function writeToFile ($dataStream) {
123 // Validate the pointer
124 $this->validateFilePointer();
126 // Write data to the file pointer and return written bytes
127 return fwrite($this->getPointer(), $dataStream, strlen($dataStream));
131 * Writes at given position by seeking to it.
133 * @param $seekPosition Seek position in file
134 * @param $data Data to be written
135 * @return mixed Number of writes bytes or FALSE on error
137 public function writeAtPosition ($seekPosition, $data) {
139 $this->seek($seekPosition);
141 // Then write the data at that position
142 return $this->writeToFile($data);
146 * Rewinds to the beginning of the file
148 * @return $status Status of this operation
150 public function rewind () {
151 // Validate the pointer
152 $this->validateFilePointer();
154 // Rewind the pointer
155 return rewind($this->getPointer());
159 * Seeks to given position
161 * @param $seekPosition Seek position in file
162 * @param $whence "Seek mode" (see http://de.php.net/fseek)
163 * @return $status Status of this operation
165 public function seek ($seekPosition, $whence = SEEK_SET) {
166 // Validate the pointer
167 $this->validateFilePointer();
169 // Move the file pointer
170 return fseek($this->getPointer(), $seekPosition, $whence);
174 * Reads a line, maximum 4096 Bytes from current file pointer
176 * @return $data Read data from file
178 public function readLine () {
180 return $this->read();
184 * Reads given amount of bytes from file.
186 * @param $bytes Amount of bytes to read
187 * @return $data Data read from file
189 public function read ($bytes = NULL) {
190 // Validate the pointer
191 $this->validateFilePointer();
194 if (is_int($bytes)) {
195 // Try to read given characters
196 $data = fread($this->getPointer(), $bytes);
198 // Try to read whole line
199 $data = fread($this->getPointer());
207 * Analyzes entries in index file. This will count all found (and valid)
208 * entries, mark invalid as damaged and count gaps ("fragmentation"). If
209 * only gaps are found, the file is considered as "virgin" (no entries).
212 * @throws UnsupportedOperationException If this method is called
214 public function analyzeFile () {
215 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
219 * Advances to next "block" of bytes
222 * @throws UnsupportedOperationException If this method is called
224 public function next () {
225 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
229 * Checks wether the current entry is valid (not at the end of the file).
230 * This method will return TRUE if an emptied (nulled) entry has been found.
232 * @return $isValid Whether the next entry is valid
233 * @throws UnsupportedOperationException If this method is called
235 public function valid () {
236 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
240 * Gets current seek position ("key").
242 * @return $key Current key in iteration
243 * @throws UnsupportedOperationException If this method is called
245 public function key () {
246 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
250 * "Getter" for file size
252 * @return $fileSize Size of currently loaded file
254 public function getFileSize () {
255 // Check if the pointer is still valid
256 $this->validateFilePointer();
259 $fileData = fstat($this->getPointer());
261 // Make sure the required array key is there
262 assert(isset($fileData['size']));
265 return $fileData['size'];