inc/main/classes/file_directories/io/class_FrameworkFileInputOutputPointer.php

   1 <?php
   2 // Own namespace
   3 namespace CoreFramework\Filesystem\Pointer;
   4
   5 // Import framework stuff
   6 use CoreFramework\Generic\NullPointerException;
   7 use CoreFramework\Object\BaseFrameworkSystem;
   8
   9 /**
  10  * A class for reading files
  11  *
  12  * @author              Roland Haeder <webmaster@shipsimu.org>
  13  * @version             0.0.0
  14  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2017 Core Developer Team
  15  * @license             GNU GPL 3.0 or any newer version
  16  * @link                http://www.shipsimu.org
  17  *
  18  * This program is free software: you can redistribute it and/or modify
  19  * it under the terms of the GNU General Public License as published by
  20  * the Free Software Foundation, either version 3 of the License, or
  21  * (at your option) any later version.
  22  *
  23  * This program is distributed in the hope that it will be useful,
  24  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  25  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  26  * GNU General Public License for more details.
  27  *
  28  * You should have received a copy of the GNU General Public License
  29  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  30  */
  31 class FrameworkFileInputOutputPointer extends BaseFileIo implements InputOutputPointer {
  32         /**
  33          * Protected constructor
  34          *
  35          * @return      void
  36          */
  37         protected function __construct () {
  38                 // Call parent constructor
  39                 parent::__construct(__CLASS__);
  40         }
  41
  42         /**
  43          * Create a file pointer based on the given file. The file will also
  44          * be verified here.
  45          *
  46          * @param       $fileName       The file name we shall pass to fopen()
  47          * @return      void
  48          * @throws      FileIsEmptyException            If the given file name is NULL or empty
  49          * @throws      FileReadProtectedException      If PHP cannot read an existing file
  50          * @throws      FileWriteProtectedException     If PHP cannot write an existing file
  51          * @throws      PathWriteProtectedException     If PHP cannot write to an existing path
  52          * @throws      FileIoException                         If fopen() returns not a file resource
  53          */
  54         public static final function createFrameworkFileInputOutputPointer ($fileName) {
  55                 // Some pre-sanity checks...
  56                 if ((is_null($fileName)) || (empty($fileName))) {
  57                         // No filename given
  58                         throw new FileIsEmptyException(NULL, self::EXCEPTION_UNEXPECTED_EMPTY_STRING);
  59                 } elseif (!BaseFrameworkSystem::isReachableFilePath($fileName)) {
  60                         // File exists but cannot be read
  61                         throw new FileIoException($fileName, self::EXCEPTION_FILE_NOT_REACHABLE);
  62                 } elseif ((!BaseFrameworkSystem::isReadableFile($fileName)) && (file_exists($fileName))) {
  63                         // File exists but cannot be read
  64                         throw new FileReadProtectedException($fileName, self::EXCEPTION_FILE_CANNOT_BE_READ);
  65                 } elseif ((file_exists($fileName)) && (!is_writable($fileName))) {
  66                         // File exists but cannot be written
  67                         throw new FileWriteProtectedException($fileName, self::EXCEPTION_FILE_CANNOT_BE_WRITTEN);
  68                 } elseif (!is_writable(dirname($fileName))) {
  69                         // Path is not writable
  70                         throw new PathWriteProtectedException($fileName, self::EXCEPTION_PATH_CANNOT_BE_WRITTEN);
  71                 }
  72
  73                 // Try to open a handler
  74                 $filePointer = fopen($fileName, 'c+b');
  75                 if ((is_null($filePointer)) || ($filePointer === FALSE)) {
  76                         // Something bad happend
  77                         throw new FileIoException($fileName, self::EXCEPTION_FILE_POINTER_INVALID);
  78                 } // END - if
  79
  80                 // Create new instance
  81                 $pointerInstance = new FrameworkFileInputOutputPointer();
  82
  83                 // Set file pointer and file name
  84                 $pointerInstance->setPointer($filePointer);
  85                 $pointerInstance->setFileName($fileName);
  86
  87                 // Return the instance
  88                 return $pointerInstance;
  89         }
  90
  91         /**
  92          * Validates file pointer and throws exceptions. This method does not return
  93          * anything (not reliable) as this method checks the file pointer and on
  94          * case of an error it throws an exception. If this method does not throw
  95          * any exceptions, the file pointer seems to be fine.
  96          *
  97          * @return      void
  98          * @throws      NullPointerException    If the file pointer instance
  99          *                                                                      is not set by setPointer()
 100          * @throws      InvalidResourceException        If there is being set
 101          */
 102         private function validateFilePointer () {
 103                 if (is_null($this->getPointer())) {
 104                         // Pointer not initialized
 105                         throw new NullPointerException($this, self::EXCEPTION_IS_NULL_POINTER);
 106                 } elseif (!is_resource($this->getPointer())) {
 107                         // Pointer is not a valid resource!
 108                         throw new InvalidResourceException($this, self::EXCEPTION_INVALID_RESOURCE);
 109                 }
 110
 111                 // All fine here
 112         }
 113
 114         /**
 115          * Read 1024 bytes data from a file pointer
 116          *
 117          * @return      mixed   The result of fread()
 118          */
 119         public function readFromFile () {
 120                 // Validate the pointer
 121                 $this->validateFilePointer();
 122
 123                 // Read data from the file pointer and return it
 124                 return $this->read(1024);
 125         }
 126
 127         /**
 128          * Write data to a file pointer
 129          *
 130          * @param       $dataStream             The data stream we shall write to the file
 131          * @return      mixed                   Number of writes bytes or FALSE on error
 132          */
 133         public function writeToFile ($dataStream) {
 134                 // Validate the pointer
 135                 $this->validateFilePointer();
 136
 137                 // Write data to the file pointer and return written bytes
 138                 return fwrite($this->getPointer(), $dataStream, strlen($dataStream));
 139         }
 140
 141         /**
 142          * Writes at given position by seeking to it.
 143          *
 144          * @param       $seekPosition   Seek position in file
 145          * @param       $data                   Data to be written
 146          * @return      mixed                   Number of writes bytes or FALSE on error
 147          */
 148         public function writeAtPosition ($seekPosition, $data) {
 149                 // First seek to it
 150                 $this->seek($seekPosition);
 151
 152                 // Then write the data at that position
 153                 return $this->writeToFile($data);
 154         }
 155
 156         /**
 157          * Rewinds to the beginning of the file
 158          *
 159          * @return      $status         Status of this operation
 160          */
 161         public function rewind () {
 162                 // Validate the pointer
 163                 $this->validateFilePointer();
 164
 165                 // Rewind the pointer
 166                 return rewind($this->getPointer());
 167         }
 168
 169         /**
 170          * Seeks to given position
 171          *
 172          * @param       $seekPosition   Seek position in file
 173          * @param       $whence                 "Seek mode" (see http://de.php.net/fseek)
 174          * @return      $status                 Status of this operation
 175          */
 176         public function seek ($seekPosition, $whence = SEEK_SET) {
 177                 // Validate the pointer
 178                 $this->validateFilePointer();
 179
 180                 // Move the file pointer
 181                 return fseek($this->getPointer(), $seekPosition, $whence);
 182         }
 183
 184         /**
 185          * Reads a line, maximum 4096 Bytes from current file pointer
 186          *
 187          * @return      $data   Read data from file
 188          */
 189         public function readLine () {
 190                 // Read whole line
 191                 return $this->read();
 192         }
 193
 194         /**
 195          * Reads given amount of bytes from file.
 196          *
 197          * @param       $bytes  Amount of bytes to read
 198          * @return      $data   Data read from file
 199          */
 200         public function read ($bytes = NULL) {
 201                 // Validate the pointer
 202                 $this->validateFilePointer();
 203
 204                 // Is $bytes set?
 205                 if (is_int($bytes)) {
 206                         // Try to read given characters
 207                         $data = fread($this->getPointer(), $bytes);
 208                 } else {
 209                         // Try to read whole line
 210                         $data = fread($this->getPointer());
 211                 }
 212
 213                 // Then return it
 214                 return $data;
 215         }
 216
 217         /**
 218          * Analyzes entries in index file. This will count all found (and valid)
 219          * entries, mark invalid as damaged and count gaps ("fragmentation"). If
 220          * only gaps are found, the file is considered as "virgin" (no entries).
 221          *
 222          * @return      void
 223          * @throws      UnsupportedOperationException   If this method is called
 224          */
 225         public function analyzeFile () {
 226                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 227         }
 228
 229         /**
 230          * Advances to next "block" of bytes
 231          *
 232          * @return      void
 233          * @throws      UnsupportedOperationException   If this method is called
 234          */
 235         public function next () {
 236                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 237         }
 238
 239         /**
 240          * Checks wether the current entry is valid (not at the end of the file).
 241          * This method will return TRUE if an emptied (nulled) entry has been found.
 242          *
 243          * @return      $isValid        Whether the next entry is valid
 244          * @throws      UnsupportedOperationException   If this method is called
 245          */
 246         public function valid () {
 247                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 248         }
 249
 250         /**
 251          * Gets current seek position ("key").
 252          *
 253          * @return      $key    Current key in iteration
 254          * @throws      UnsupportedOperationException   If this method is called
 255          */
 256         public function key () {
 257                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 258         }
 259
 260         /**
 261          * "Getter" for file size
 262          *
 263          * @return      $fileSize       Size of currently loaded file
 264          */
 265         public function getFileSize () {
 266                 // Check if the pointer is still valid
 267                 $this->validateFilePointer();
 268
 269                 // Get file's data
 270                 $fileData = fstat($this->getPointer());
 271
 272                 // Make sure the required array key is there
 273                 assert(isset($fileData['size']));
 274
 275                 // Return size
 276                 return $fileData['size'];
 277         }
 278
 279 }