inc/main/classes/file_directories/io/class_FrameworkFileInputOutputPointer.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 - 2017 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 FrameworkFileInputOutputPointer extends BaseFileIo implements InputOutputPointer {
  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       $fileName       The file name we shall pass to fopen()
  40          * @return      void
  41          * @throws      FileIsEmptyException            If the given file name is NULL or empty
  42          * @throws      FileReadProtectedException      If PHP cannot read an existing file
  43          * @throws      FileWriteProtectedException     If PHP cannot write an existing file
  44          * @throws      PathWriteProtectedException     If PHP cannot write to an existing path
  45          * @throws      FileIoException                         If fopen() returns not a file resource
  46          */
  47         public static final function createFrameworkFileInputOutputPointer ($fileName) {
  48                 // Some pre-sanity checks...
  49                 if ((is_null($fileName)) || (empty($fileName))) {
  50                         // No filename given
  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);
  64                 }
  65
  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);
  71                 } // END - if
  72
  73                 // Create new instance
  74                 $pointerInstance = new FrameworkFileInputOutputPointer();
  75
  76                 // Set file pointer and file name
  77                 $pointerInstance->setPointer($filePointer);
  78                 $pointerInstance->setFileName($fileName);
  79
  80                 // Return the instance
  81                 return $pointerInstance;
  82         }
  83
  84         /**
  85          * Validates file pointer and throws exceptions. This method does not return
  86          * anything (not reliable) as this method checks the file pointer and on
  87          * case of an error it throws an exception. If this method does not throw
  88          * any exceptions, the file pointer seems to be fine.
  89          *
  90          * @return      void
  91          * @throws      NullPointerException    If the file pointer instance
  92          *                                                                      is not set by setPointer()
  93          * @throws      InvalidResourceException        If there is being set
  94          */
  95         private function validateFilePointer () {
  96                 if (is_null($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);
 102                 }
 103
 104                 // All fine here
 105         }
 106
 107         /**
 108          * Read 1024 bytes data from a file pointer
 109          *
 110          * @return      mixed   The result of fread()
 111          */
 112         public function readFromFile () {
 113                 // Validate the pointer
 114                 $this->validateFilePointer();
 115
 116                 // Read data from the file pointer and return it
 117                 return $this->read(1024);
 118         }
 119
 120         /**
 121          * Write data to a file pointer
 122          *
 123          * @param       $dataStream             The data stream we shall write to the file
 124          * @return      mixed                   Number of writes bytes or FALSE on error
 125          */
 126         public function writeToFile ($dataStream) {
 127                 // Validate the pointer
 128                 $this->validateFilePointer();
 129
 130                 // Write data to the file pointer and return written bytes
 131                 return fwrite($this->getPointer(), $dataStream, strlen($dataStream));
 132         }
 133
 134         /**
 135          * Writes at given position by seeking to it.
 136          *
 137          * @param       $seekPosition   Seek position in file
 138          * @param       $data                   Data to be written
 139          * @return      mixed                   Number of writes bytes or FALSE on error
 140          */
 141         public function writeAtPosition ($seekPosition, $data) {
 142                 // First seek to it
 143                 $this->seek($seekPosition);
 144
 145                 // Then write the data at that position
 146                 return $this->writeToFile($data);
 147         }
 148
 149         /**
 150          * Rewinds to the beginning of the file
 151          *
 152          * @return      $status         Status of this operation
 153          */
 154         public function rewind () {
 155                 // Validate the pointer
 156                 $this->validateFilePointer();
 157
 158                 // Rewind the pointer
 159                 return rewind($this->getPointer());
 160         }
 161
 162         /**
 163          * Seeks to given position
 164          *
 165          * @param       $seekPosition   Seek position in file
 166          * @param       $whence                 "Seek mode" (see http://de.php.net/fseek)
 167          * @return      $status                 Status of this operation
 168          */
 169         public function seek ($seekPosition, $whence = SEEK_SET) {
 170                 // Validate the pointer
 171                 $this->validateFilePointer();
 172
 173                 // Move the file pointer
 174                 return fseek($this->getPointer(), $seekPosition, $whence);
 175         }
 176
 177         /**
 178          * Reads a line, maximum 4096 Bytes from current file pointer
 179          *
 180          * @return      $data   Read data from file
 181          */
 182         public function readLine () {
 183                 // Read whole line
 184                 return $this->read();
 185         }
 186
 187         /**
 188          * Reads given amount of bytes from file.
 189          *
 190          * @param       $bytes  Amount of bytes to read
 191          * @return      $data   Data read from file
 192          */
 193         public function read ($bytes = NULL) {
 194                 // Validate the pointer
 195                 $this->validateFilePointer();
 196
 197                 // Is $bytes set?
 198                 if (is_int($bytes)) {
 199                         // Try to read given characters
 200                         $data = fread($this->getPointer(), $bytes);
 201                 } else {
 202                         // Try to read whole line
 203                         $data = fread($this->getPointer());
 204                 }
 205
 206                 // Then return it
 207                 return $data;
 208         }
 209
 210         /**
 211          * Analyzes entries in index file. This will count all found (and valid)
 212          * entries, mark invalid as damaged and count gaps ("fragmentation"). If
 213          * only gaps are found, the file is considered as "virgin" (no entries).
 214          *
 215          * @return      void
 216          * @throws      UnsupportedOperationException   If this method is called
 217          */
 218         public function analyzeFile () {
 219                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 220         }
 221
 222         /**
 223          * Advances to next "block" of bytes
 224          *
 225          * @return      void
 226          * @throws      UnsupportedOperationException   If this method is called
 227          */
 228         public function next () {
 229                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 230         }
 231
 232         /**
 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.
 235          *
 236          * @return      $isValid        Whether the next entry is valid
 237          * @throws      UnsupportedOperationException   If this method is called
 238          */
 239         public function valid () {
 240                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 241         }
 242
 243         /**
 244          * Gets current seek position ("key").
 245          *
 246          * @return      $key    Current key in iteration
 247          * @throws      UnsupportedOperationException   If this method is called
 248          */
 249         public function key () {
 250                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 251         }
 252
 253         /**
 254          * "Getter" for file size
 255          *
 256          * @return      $fileSize       Size of currently loaded file
 257          */
 258         public function getFileSize () {
 259                 // Check if the pointer is still valid
 260                 $this->validateFilePointer();
 261
 262                 // Get file's data
 263                 $fileData = fstat($this->getPointer());
 264
 265                 // Make sure the required array key is there
 266                 assert(isset($fileData['size']));
 267
 268                 // Return size
 269                 return $fileData['size'];
 270         }
 271 }
 272
 273 // [EOF]
 274 ?>