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 - 2015 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 (!BaseFrameworkSystem::isReachableFilePath($fileName)) {
  52                         // File exists but cannot be read
  53                         throw new FileIoException($fileName, self::EXCEPTION_FILE_NOT_REACHABLE);
  54                 } elseif (!BaseFrameworkSystem::isReadableFile($fileName)) {
  55                         // File exists but cannot be read
  56                         throw new FileReadProtectedException($fileName, self::EXCEPTION_FILE_CANNOT_BE_READ);
  57                 } elseif (!is_writable($fileName)) {
  58                         // File exists but cannot be written
  59                         throw new FileWriteProtectedException($fileName, self::EXCEPTION_FILE_CANNOT_BE_WRITTEN);
  60                 }
  61
  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);
  67                 } // END - if
  68
  69                 // Create new instance
  70                 $pointerInstance = new FrameworkFileInputOutputPointer();
  71
  72                 // Set file pointer and file name
  73                 $pointerInstance->setPointer($filePointer);
  74                 $pointerInstance->setFileName($fileName);
  75
  76                 // Return the instance
  77                 return $pointerInstance;
  78         }
  79
  80         /**
  81          * Validates file pointer and throws exceptions. This method does not return
  82          * anything (not reliable) as this method checks the file pointer and on
  83          * case of an error it throws an exception. If this method does not throw
  84          * any exceptions, the file pointer seems to be fine.
  85          *
  86          * @return      void
  87          * @throws      NullPointerException    If the file pointer instance
  88          *                                                                      is not set by setPointer()
  89          * @throws      InvalidResourceException        If there is being set
  90          */
  91         private function validateFilePointer () {
  92                 if (is_null($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);
  98                 }
  99
 100                 // All fine here
 101         }
 102
 103         /**
 104          * Read 1024 bytes data from a file pointer
 105          *
 106          * @return      mixed   The result of fread()
 107          */
 108         public function readFromFile () {
 109                 // Validate the pointer
 110                 $this->validateFilePointer();
 111
 112                 // Read data from the file pointer and return it
 113                 return $this->read(1024);
 114         }
 115
 116         /**
 117          * Write data to a file pointer
 118          *
 119          * @param       $dataStream             The data stream we shall write to the file
 120          * @return      mixed                   Number of writes bytes or FALSE on error
 121          */
 122         public function writeToFile ($dataStream) {
 123                 // Validate the pointer
 124                 $this->validateFilePointer();
 125
 126                 // Write data to the file pointer and return written bytes
 127                 return fwrite($this->getPointer(), $dataStream, strlen($dataStream));
 128         }
 129
 130         /**
 131          * Writes at given position by seeking to it.
 132          *
 133          * @param       $seekPosition   Seek position in file
 134          * @param       $data                   Data to be written
 135          * @return      mixed                   Number of writes bytes or FALSE on error
 136          */
 137         public function writeAtPosition ($seekPosition, $data) {
 138                 // First seek to it
 139                 $this->seek($seekPosition);
 140
 141                 // Then write the data at that position
 142                 return $this->writeToFile($data);
 143         }
 144
 145         /**
 146          * Rewinds to the beginning of the file
 147          *
 148          * @return      $status         Status of this operation
 149          */
 150         public function rewind () {
 151                 // Validate the pointer
 152                 $this->validateFilePointer();
 153
 154                 // Rewind the pointer
 155                 return rewind($this->getPointer());
 156         }
 157
 158         /**
 159          * Seeks to given position
 160          *
 161          * @param       $seekPosition   Seek position in file
 162          * @param       $whence                 "Seek mode" (see http://de.php.net/fseek)
 163          * @return      $status                 Status of this operation
 164          */
 165         public function seek ($seekPosition, $whence = SEEK_SET) {
 166                 // Validate the pointer
 167                 $this->validateFilePointer();
 168
 169                 // Move the file pointer
 170                 return fseek($this->getPointer(), $seekPosition, $whence);
 171         }
 172
 173         /**
 174          * Reads a line, maximum 4096 Bytes from current file pointer
 175          *
 176          * @return      $data   Read data from file
 177          */
 178         public function readLine () {
 179                 // Read whole line
 180                 return $this->read();
 181         }
 182
 183         /**
 184          * Reads given amount of bytes from file.
 185          *
 186          * @param       $bytes  Amount of bytes to read
 187          * @return      $data   Data read from file
 188          */
 189         public function read ($bytes = NULL) {
 190                 // Validate the pointer
 191                 $this->validateFilePointer();
 192
 193                 // Is $bytes set?
 194                 if (is_int($bytes)) {
 195                         // Try to read given characters
 196                         $data = fread($this->getPointer(), $bytes);
 197                 } else {
 198                         // Try to read whole line
 199                         $data = fread($this->getPointer());
 200                 }
 201
 202                 // Then return it
 203                 return $data;
 204         }
 205
 206         /**
 207          * Analyzes entries in index file. This will count all found (and valid)
 208          * entries, mark invalid as damaged and count gaps ("fragmentation"). If
 209          * only gaps are found, the file is considered as "virgin" (no entries).
 210          *
 211          * @return      void
 212          * @throws      UnsupportedOperationException   If this method is called
 213          */
 214         public function analyzeFile () {
 215                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 216         }
 217
 218         /**
 219          * Advances to next "block" of bytes
 220          *
 221          * @return      void
 222          * @throws      UnsupportedOperationException   If this method is called
 223          */
 224         public function next () {
 225                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 226         }
 227
 228         /**
 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.
 231          *
 232          * @return      $isValid        Whether the next entry is valid
 233          * @throws      UnsupportedOperationException   If this method is called
 234          */
 235         public function valid () {
 236                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 237         }
 238
 239         /**
 240          * Gets current seek position ("key").
 241          *
 242          * @return      $key    Current key in iteration
 243          * @throws      UnsupportedOperationException   If this method is called
 244          */
 245         public function key () {
 246                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 247         }
 248
 249         /**
 250          * "Getter" for file size
 251          *
 252          * @return      $fileSize       Size of currently loaded file
 253          */
 254         public function getFileSize () {
 255                 // Check if the pointer is still valid
 256                 $this->validateFilePointer();
 257
 258                 // Get file's data
 259                 $fileData = fstat($this->getPointer());
 260
 261                 // Make sure the required array key is there
 262                 assert(isset($fileData['size']));
 263
 264                 // Return size
 265                 return $fileData['size'];
 266         }
 267 }
 268
 269 // [EOF]
 270 ?>