3 * A class for reading files
5 * @author Roland Haeder <webmaster@shipsimu.org>
7 * @copyright Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2017 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 $fileName The file name we shall pass to fopen()
41 * @throws FileIsEmptyException If the given file name is NULL or empty
42 * @throws FileReadProtectedException If PHP cannot read an existing file
43 * @throws FileWriteProtectedException If PHP cannot write an existing file
44 * @throws PathWriteProtectedException If PHP cannot write to an existing path
45 * @throws FileIoException If fopen() returns not a file resource
47 public static final function createFrameworkFileInputOutputPointer ($fileName) {
48 // Some pre-sanity checks...
49 if ((is_null($fileName)) || (empty($fileName))) {
51 throw new FileIsEmptyException(NULL, self::EXCEPTION_UNEXPECTED_EMPTY_STRING);
52 } elseif (!BaseFrameworkSystem::isReachableFilePath($fileName)) {
53 // File exists but cannot be read
54 throw new FileIoException($fileName, self::EXCEPTION_FILE_NOT_REACHABLE);
55 } elseif ((!BaseFrameworkSystem::isReadableFile($fileName)) && (file_exists($fileName))) {
56 // File exists but cannot be read
57 throw new FileReadProtectedException($fileName, self::EXCEPTION_FILE_CANNOT_BE_READ);
58 } elseif ((file_exists($fileName)) && (!is_writable($fileName))) {
59 // File exists but cannot be written
60 throw new FileWriteProtectedException($fileName, self::EXCEPTION_FILE_CANNOT_BE_WRITTEN);
61 } elseif (!is_writable(dirname($fileName))) {
62 // Path is not writable
63 throw new PathWriteProtectedException($fileName, self::EXCEPTION_PATH_CANNOT_BE_WRITTEN);
66 // Try to open a handler
67 $filePointer = fopen($fileName, 'c+b');
68 if ((is_null($filePointer)) || ($filePointer === FALSE)) {
69 // Something bad happend
70 throw new FileIoException($fileName, self::EXCEPTION_FILE_POINTER_INVALID);
73 // Create new instance
74 $pointerInstance = new FrameworkFileInputOutputPointer();
76 // Set file pointer and file name
77 $pointerInstance->setPointer($filePointer);
78 $pointerInstance->setFileName($fileName);
80 // Return the instance
81 return $pointerInstance;
85 * Validates file pointer and throws exceptions. This method does not return
86 * anything (not reliable) as this method checks the file pointer and on
87 * case of an error it throws an exception. If this method does not throw
88 * any exceptions, the file pointer seems to be fine.
91 * @throws NullPointerException If the file pointer instance
92 * is not set by setPointer()
93 * @throws InvalidResourceException If there is being set
95 private function validateFilePointer () {
96 if (is_null($this->getPointer())) {
97 // Pointer not initialized
98 throw new NullPointerException($this, self::EXCEPTION_IS_NULL_POINTER);
99 } elseif (!is_resource($this->getPointer())) {
100 // Pointer is not a valid resource!
101 throw new InvalidResourceException($this, self::EXCEPTION_INVALID_RESOURCE);
108 * Read 1024 bytes data from a file pointer
110 * @return mixed The result of fread()
112 public function readFromFile () {
113 // Validate the pointer
114 $this->validateFilePointer();
116 // Read data from the file pointer and return it
117 return $this->read(1024);
121 * Write data to a file pointer
123 * @param $dataStream The data stream we shall write to the file
124 * @return mixed Number of writes bytes or FALSE on error
126 public function writeToFile ($dataStream) {
127 // Validate the pointer
128 $this->validateFilePointer();
130 // Write data to the file pointer and return written bytes
131 return fwrite($this->getPointer(), $dataStream, strlen($dataStream));
135 * Writes at given position by seeking to it.
137 * @param $seekPosition Seek position in file
138 * @param $data Data to be written
139 * @return mixed Number of writes bytes or FALSE on error
141 public function writeAtPosition ($seekPosition, $data) {
143 $this->seek($seekPosition);
145 // Then write the data at that position
146 return $this->writeToFile($data);
150 * Rewinds to the beginning of the file
152 * @return $status Status of this operation
154 public function rewind () {
155 // Validate the pointer
156 $this->validateFilePointer();
158 // Rewind the pointer
159 return rewind($this->getPointer());
163 * Seeks to given position
165 * @param $seekPosition Seek position in file
166 * @param $whence "Seek mode" (see http://de.php.net/fseek)
167 * @return $status Status of this operation
169 public function seek ($seekPosition, $whence = SEEK_SET) {
170 // Validate the pointer
171 $this->validateFilePointer();
173 // Move the file pointer
174 return fseek($this->getPointer(), $seekPosition, $whence);
178 * Reads a line, maximum 4096 Bytes from current file pointer
180 * @return $data Read data from file
182 public function readLine () {
184 return $this->read();
188 * Reads given amount of bytes from file.
190 * @param $bytes Amount of bytes to read
191 * @return $data Data read from file
193 public function read ($bytes = NULL) {
194 // Validate the pointer
195 $this->validateFilePointer();
198 if (is_int($bytes)) {
199 // Try to read given characters
200 $data = fread($this->getPointer(), $bytes);
202 // Try to read whole line
203 $data = fread($this->getPointer());
211 * Analyzes entries in index file. This will count all found (and valid)
212 * entries, mark invalid as damaged and count gaps ("fragmentation"). If
213 * only gaps are found, the file is considered as "virgin" (no entries).
216 * @throws UnsupportedOperationException If this method is called
218 public function analyzeFile () {
219 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
223 * Advances to next "block" of bytes
226 * @throws UnsupportedOperationException If this method is called
228 public function next () {
229 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
233 * Checks wether the current entry is valid (not at the end of the file).
234 * This method will return TRUE if an emptied (nulled) entry has been found.
236 * @return $isValid Whether the next entry is valid
237 * @throws UnsupportedOperationException If this method is called
239 public function valid () {
240 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
244 * Gets current seek position ("key").
246 * @return $key Current key in iteration
247 * @throws UnsupportedOperationException If this method is called
249 public function key () {
250 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
254 * "Getter" for file size
256 * @return $fileSize Size of currently loaded file
258 public function getFileSize () {
259 // Check if the pointer is still valid
260 $this->validateFilePointer();
263 $fileData = fstat($this->getPointer());
265 // Make sure the required array key is there
266 assert(isset($fileData['size']));
269 return $fileData['size'];