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