framework/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\FileSystem\BaseFileIo;
   7 use CoreFramework\Generic\NullPointerException;
   8 use CoreFramework\Object\BaseFrameworkSystem;
   9
  10 /**
  11  * A class for reading files
  12  *
  13  * @author              Roland Haeder <webmaster@shipsimu.org>
  14  * @version             0.0.0
  15  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2017 Core Developer Team
  16  * @license             GNU GPL 3.0 or any newer version
  17  * @link                http://www.shipsimu.org
  18  *
  19  * This program is free software: you can redistribute it and/or modify
  20  * it under the terms of the GNU General Public License as published by
  21  * the Free Software Foundation, either version 3 of the License, or
  22  * (at your option) any later version.
  23  *
  24  * This program is distributed in the hope that it will be useful,
  25  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  26  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  27  * GNU General Public License for more details.
  28  *
  29  * You should have received a copy of the GNU General Public License
  30  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  31  */
  32 class FrameworkFileInputOutputPointer extends BaseFileIo implements InputOutputPointer {
  33         /**
  34          * Protected constructor
  35          *
  36          * @return      void
  37          */
  38         protected function __construct () {
  39                 // Call parent constructor
  40                 parent::__construct(__CLASS__);
  41         }
  42
  43         /**
  44          * Create a file pointer based on the given file. The file will also
  45          * be verified here.
  46          *
  47          * @param       $fileName       The file name we shall pass to fopen()
  48          * @return      void
  49          * @throws      FileIsEmptyException            If the given file name is NULL or empty
  50          * @throws      FileReadProtectedException      If PHP cannot read an existing file
  51          * @throws      FileWriteProtectedException     If PHP cannot write an existing file
  52          * @throws      PathWriteProtectedException     If PHP cannot write to an existing path
  53          * @throws      FileIoException                         If fopen() returns not a file resource
  54          */
  55         public static final function createFrameworkFileInputOutputPointer ($fileName) {
  56                 // Some pre-sanity checks...
  57                 if ((is_null($fileName)) || (empty($fileName))) {
  58                         // No filename given
  59                         throw new FileIsEmptyException(NULL, self::EXCEPTION_UNEXPECTED_EMPTY_STRING);
  60                 } elseif (!BaseFrameworkSystem::isReachableFilePath($fileName)) {
  61                         // File exists but cannot be read
  62                         throw new FileIoException($fileName, self::EXCEPTION_FILE_NOT_REACHABLE);
  63                 } elseif ((!BaseFrameworkSystem::isReadableFile($fileName)) && (file_exists($fileName))) {
  64                         // File exists but cannot be read
  65                         throw new FileReadProtectedException($fileName, self::EXCEPTION_FILE_CANNOT_BE_READ);
  66                 } elseif ((file_exists($fileName)) && (!is_writable($fileName))) {
  67                         // File exists but cannot be written
  68                         throw new FileWriteProtectedException($fileName, self::EXCEPTION_FILE_CANNOT_BE_WRITTEN);
  69                 } elseif (!is_writable(dirname($fileName))) {
  70                         // Path is not writable
  71                         throw new PathWriteProtectedException($fileName, self::EXCEPTION_PATH_CANNOT_BE_WRITTEN);
  72                 }
  73
  74                 // Try to open a handler
  75                 $filePointer = fopen($fileName, 'c+b');
  76                 if ((is_null($filePointer)) || ($filePointer === FALSE)) {
  77                         // Something bad happend
  78                         throw new FileIoException($fileName, self::EXCEPTION_FILE_POINTER_INVALID);
  79                 } // END - if
  80
  81                 // Create new instance
  82                 $pointerInstance = new FrameworkFileInputOutputPointer();
  83
  84                 // Set file pointer and file name
  85                 $pointerInstance->setPointer($filePointer);
  86                 $pointerInstance->setFileName($fileName);
  87
  88                 // Return the instance
  89                 return $pointerInstance;
  90         }
  91
  92         /**
  93          * Validates file pointer and throws exceptions. This method does not return
  94          * anything (not reliable) as this method checks the file pointer and on
  95          * case of an error it throws an exception. If this method does not throw
  96          * any exceptions, the file pointer seems to be fine.
  97          *
  98          * @return      void
  99          * @throws      NullPointerException    If the file pointer instance
 100          *                                                                      is not set by setPointer()
 101          * @throws      InvalidResourceException        If there is being set
 102          */
 103         private function validateFilePointer () {
 104                 if (is_null($this->getPointer())) {
 105                         // Pointer not initialized
 106                         throw new NullPointerException($this, self::EXCEPTION_IS_NULL_POINTER);
 107                 } elseif (!is_resource($this->getPointer())) {
 108                         // Pointer is not a valid resource!
 109                         throw new InvalidResourceException($this, self::EXCEPTION_INVALID_RESOURCE);
 110                 }
 111
 112                 // All fine here
 113         }
 114
 115         /**
 116          * Read 1024 bytes data from a file pointer
 117          *
 118          * @return      mixed   The result of fread()
 119          */
 120         public function readFromFile () {
 121                 // Validate the pointer
 122                 $this->validateFilePointer();
 123
 124                 // Read data from the file pointer and return it
 125                 return $this->read(1024);
 126         }
 127
 128         /**
 129          * Write data to a file pointer
 130          *
 131          * @param       $dataStream             The data stream we shall write to the file
 132          * @return      mixed                   Number of writes bytes or FALSE on error
 133          */
 134         public function writeToFile ($dataStream) {
 135                 // Validate the pointer
 136                 $this->validateFilePointer();
 137
 138                 // Write data to the file pointer and return written bytes
 139                 return fwrite($this->getPointer(), $dataStream, strlen($dataStream));
 140         }
 141
 142         /**
 143          * Writes at given position by seeking to it.
 144          *
 145          * @param       $seekPosition   Seek position in file
 146          * @param       $data                   Data to be written
 147          * @return      mixed                   Number of writes bytes or FALSE on error
 148          */
 149         public function writeAtPosition ($seekPosition, $data) {
 150                 // First seek to it
 151                 $this->seek($seekPosition);
 152
 153                 // Then write the data at that position
 154                 return $this->writeToFile($data);
 155         }
 156
 157         /**
 158          * Rewinds to the beginning of the file
 159          *
 160          * @return      $status         Status of this operation
 161          */
 162         public function rewind () {
 163                 // Validate the pointer
 164                 $this->validateFilePointer();
 165
 166                 // Rewind the pointer
 167                 return rewind($this->getPointer());
 168         }
 169
 170         /**
 171          * Seeks to given position
 172          *
 173          * @param       $seekPosition   Seek position in file
 174          * @param       $whence                 "Seek mode" (see http://de.php.net/fseek)
 175          * @return      $status                 Status of this operation
 176          */
 177         public function seek ($seekPosition, $whence = SEEK_SET) {
 178                 // Validate the pointer
 179                 $this->validateFilePointer();
 180
 181                 // Move the file pointer
 182                 return fseek($this->getPointer(), $seekPosition, $whence);
 183         }
 184
 185         /**
 186          * Reads a line, maximum 4096 Bytes from current file pointer
 187          *
 188          * @return      $data   Read data from file
 189          */
 190         public function readLine () {
 191                 // Read whole line
 192                 return $this->read();
 193         }
 194
 195         /**
 196          * Reads given amount of bytes from file.
 197          *
 198          * @param       $bytes  Amount of bytes to read
 199          * @return      $data   Data read from file
 200          */
 201         public function read ($bytes = NULL) {
 202                 // Validate the pointer
 203                 $this->validateFilePointer();
 204
 205                 // Is $bytes set?
 206                 if (is_int($bytes)) {
 207                         // Try to read given characters
 208                         $data = fread($this->getPointer(), $bytes);
 209                 } else {
 210                         // Try to read whole line
 211                         $data = fread($this->getPointer());
 212                 }
 213
 214                 // Then return it
 215                 return $data;
 216         }
 217
 218         /**
 219          * Analyzes entries in index file. This will count all found (and valid)
 220          * entries, mark invalid as damaged and count gaps ("fragmentation"). If
 221          * only gaps are found, the file is considered as "virgin" (no entries).
 222          *
 223          * @return      void
 224          * @throws      UnsupportedOperationException   If this method is called
 225          */
 226         public function analyzeFile () {
 227                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 228         }
 229
 230         /**
 231          * Advances to next "block" of bytes
 232          *
 233          * @return      void
 234          * @throws      UnsupportedOperationException   If this method is called
 235          */
 236         public function next () {
 237                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 238         }
 239
 240         /**
 241          * Checks wether the current entry is valid (not at the end of the file).
 242          * This method will return TRUE if an emptied (nulled) entry has been found.
 243          *
 244          * @return      $isValid        Whether the next entry is valid
 245          * @throws      UnsupportedOperationException   If this method is called
 246          */
 247         public function valid () {
 248                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 249         }
 250
 251         /**
 252          * Gets current seek position ("key").
 253          *
 254          * @return      $key    Current key in iteration
 255          * @throws      UnsupportedOperationException   If this method is called
 256          */
 257         public function key () {
 258                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 259         }
 260
 261         /**
 262          * "Getter" for file size
 263          *
 264          * @return      $fileSize       Size of currently loaded file
 265          */
 266         public function getFileSize () {
 267                 // Check if the pointer is still valid
 268                 $this->validateFilePointer();
 269
 270                 // Get file's data
 271                 $fileData = fstat($this->getPointer());
 272
 273                 // Make sure the required array key is there
 274                 assert(isset($fileData['size']));
 275
 276                 // Return size
 277                 return $fileData['size'];
 278         }
 279
 280 }