inc/classes/main/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 - 2013 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       $fileName       The file name we shall pass to fopen()
  40          * @return      void
  41          * @throws      FileIsEmptyException            If the given file name is NULL or empty
  42          * @throws      FileReadProtectedException      If PHP cannot read an existing file
  43          * @throws      FileWriteProtectedException     If PHP cannot write an existing file
  44          * @throws      FileIoException                         If fopen() returns not a file resource
  45          */
  46         public static final function createFrameworkFileInputOutputPointer ($fileName) {
  47                 // Some pre-sanity checks...
  48                 if ((is_null($fileName)) || (empty($fileName))) {
  49                         // No filename given
  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);
  57                 }
  58
  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);
  64                 } // END - if
  65
  66                 // Create new instance
  67                 $pointerInstance = new FrameworkFileInputOutputPointer();
  68
  69                 // Set file pointer and file name
  70                 $pointerInstance->setPointer($filePointer);
  71                 $pointerInstance->setFileName($fileName);
  72
  73                 // Return the instance
  74                 return $pointerInstance;
  75         }
  76
  77         /**
  78          * Validates file pointer and throws exceptions. This method does not return
  79          * anything (not reliable) as this method checks the file pointer and on
  80          * case of an error it throws an exception. If this method does not throw
  81          * any exceptions, the file pointer seems to be fine.
  82          *
  83          * @return      void
  84          * @throws      NullPointerException    If the file pointer instance
  85          *                                                                      is not set by setPointer()
  86          * @throws      InvalidResourceException        If there is being set
  87          */
  88         private function validateFilePointer () {
  89                 if (is_null($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);
  95                 }
  96
  97                 // All fine here
  98         }
  99
 100         /**
 101          * Read 1024 bytes data from a file pointer
 102          *
 103          * @return      mixed   The result of fread()
 104          */
 105         public function readFromFile () {
 106                 // Validate the pointer
 107                 $this->validateFilePointer();
 108
 109                 // Read data from the file pointer and return it
 110                 return $this->read(1024);
 111         }
 112
 113         /**
 114          * Write data to a file pointer
 115          *
 116          * @param       $dataStream             The data stream we shall write to the file
 117          * @return      mixed                   Number of writes bytes or FALSE on error
 118          */
 119         public function writeToFile ($dataStream) {
 120                 // Validate the pointer
 121                 $this->validateFilePointer();
 122
 123                 // Write data to the file pointer and return written bytes
 124                 return fwrite($this->getPointer(), $dataStream, strlen($dataStream));
 125         }
 126
 127         /**
 128          * Rewinds to the beginning of the file
 129          *
 130          * @return      $status         Status of this operation
 131          */
 132         public function rewind () {
 133                 // Validate the pointer
 134                 $this->validateFilePointer();
 135
 136                 // Rewind the pointer
 137                 return rewind($this->getPointer());
 138         }
 139
 140         /**
 141          * Seeks to given position
 142          *
 143          * @param       $seekPosition   Seek position in file
 144          * @param       $whence                 "Seek mode" (see http://de.php.net/fseek)
 145          * @return      $status                 Status of this operation
 146          */
 147         public function seek ($seekPosition, $whence = SEEK_SET) {
 148                 // Validate the pointer
 149                 $this->validateFilePointer();
 150
 151                 // Move the file pointer
 152                 return fseek($this->getPointer(), $seekPosition, $whence);
 153         }
 154
 155         /**
 156          * Reads given amount of bytes from file.
 157          *
 158          * @param       $bytes  Amount of bytes to read
 159          * @return      $data   Data read from file
 160          */
 161         public function read ($bytes) {
 162                 // Validate the pointer
 163                 $this->validateFilePointer();
 164
 165                 // Try to read given characters
 166                 $data = fread($this->getPointer(), $bytes);
 167
 168                 // Was this successfull?
 169                 assert(is_string($data));
 170
 171                 // Then return it
 172                 return $data;
 173         }
 174 }
 175
 176 // [EOF]
 177 ?>