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\Bootstrap\FrameworkBootstrap;
   7 use CoreFramework\FileSystem\BaseFileIo;
   8 use CoreFramework\Generic\NullPointerException;
   9 use CoreFramework\Object\BaseFrameworkSystem;
  10
  11 /**
  12  * A class for reading files
  13  *
  14  * @author              Roland Haeder <webmaster@shipsimu.org>
  15  * @version             0.0.0
  16  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2017 Core Developer Team
  17  * @license             GNU GPL 3.0 or any newer version
  18  * @link                http://www.shipsimu.org
  19  *
  20  * This program is free software: you can redistribute it and/or modify
  21  * it under the terms of the GNU General Public License as published by
  22  * the Free Software Foundation, either version 3 of the License, or
  23  * (at your option) any later version.
  24  *
  25  * This program is distributed in the hope that it will be useful,
  26  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  27  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  28  * GNU General Public License for more details.
  29  *
  30  * You should have received a copy of the GNU General Public License
  31  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  32  */
  33 class FrameworkFileInputOutputPointer extends BaseFileIo implements InputOutputPointer {
  34         /**
  35          * Protected constructor
  36          *
  37          * @return      void
  38          */
  39         protected function __construct () {
  40                 // Call parent constructor
  41                 parent::__construct(__CLASS__);
  42         }
  43
  44         /**
  45          * Create a file pointer based on the given file. The file will also
  46          * be verified here.
  47          *
  48          * @param       $fileName       The file name we shall pass to fopen()
  49          * @return      void
  50          * @throws      FileIsEmptyException            If the given file name is NULL or empty
  51          * @throws      FileReadProtectedException      If PHP cannot read an existing file
  52          * @throws      FileWriteProtectedException     If PHP cannot write an existing file
  53          * @throws      PathWriteProtectedException     If PHP cannot write to an existing path
  54          * @throws      FileIoException                         If fopen() returns not a file resource
  55          */
  56         public static final function createFrameworkFileInputOutputPointer ($fileName) {
  57                 // Some pre-sanity checks...
  58                 if ((is_null($fileName)) || (empty($fileName))) {
  59                         // No filename given
  60                         throw new FileIsEmptyException(NULL, self::EXCEPTION_UNEXPECTED_EMPTY_STRING);
  61                 } elseif (!FrameworkBootstrap::isReachableFilePath($fileName)) {
  62                         // File exists but cannot be read
  63                         throw new FileIoException($fileName, self::EXCEPTION_FILE_NOT_REACHABLE);
  64                 } elseif ((!FrameworkBootstrap::isReadableFile($fileName)) && (file_exists($fileName))) {
  65                         // File exists but cannot be read
  66                         throw new FileReadProtectedException($fileName, self::EXCEPTION_FILE_CANNOT_BE_READ);
  67                 } elseif ((file_exists($fileName)) && (!is_writable($fileName))) {
  68                         // File exists but cannot be written
  69                         throw new FileWriteProtectedException($fileName, self::EXCEPTION_FILE_CANNOT_BE_WRITTEN);
  70                 } elseif (!is_writable(dirname($fileName))) {
  71                         // Path is not writable
  72                         throw new PathWriteProtectedException($fileName, self::EXCEPTION_PATH_CANNOT_BE_WRITTEN);
  73                 }
  74
  75                 // Try to open a handler
  76                 $filePointer = fopen($fileName, 'c+b');
  77                 if ((is_null($filePointer)) || ($filePointer === false)) {
  78                         // Something bad happend
  79                         throw new FileIoException($fileName, self::EXCEPTION_FILE_POINTER_INVALID);
  80                 } // END - if
  81
  82                 // Create new instance
  83                 $pointerInstance = new FrameworkFileInputOutputPointer();
  84
  85                 // Set file pointer and file name
  86                 $pointerInstance->setPointer($filePointer);
  87                 $pointerInstance->setFileName($fileName);
  88
  89                 // Return the instance
  90                 return $pointerInstance;
  91         }
  92
  93         /**
  94          * Validates file pointer and throws exceptions. This method does not return
  95          * anything (not reliable) as this method checks the file pointer and on
  96          * case of an error it throws an exception. If this method does not throw
  97          * any exceptions, the file pointer seems to be fine.
  98          *
  99          * @return      void
 100          * @throws      NullPointerException    If the file pointer instance
 101          *                                                                      is not set by setPointer()
 102          * @throws      InvalidResourceException        If there is being set
 103          */
 104         private function validateFilePointer () {
 105                 if (is_null($this->getPointer())) {
 106                         // Pointer not initialized
 107                         throw new NullPointerException($this, self::EXCEPTION_IS_NULL_POINTER);
 108                 } elseif (!is_resource($this->getPointer())) {
 109                         // Pointer is not a valid resource!
 110                         throw new InvalidResourceException($this, self::EXCEPTION_INVALID_RESOURCE);
 111                 }
 112
 113                 // All fine here
 114         }
 115
 116         /**
 117          * Read 1024 bytes data from a file pointer
 118          *
 119          * @return      mixed   The result of fread()
 120          */
 121         public function readFromFile () {
 122                 // Validate the pointer
 123                 $this->validateFilePointer();
 124
 125                 // Read data from the file pointer and return it
 126                 return $this->read(1024);
 127         }
 128
 129         /**
 130          * Write data to a file pointer
 131          *
 132          * @param       $dataStream             The data stream we shall write to the file
 133          * @return      mixed                   Number of writes bytes or false on error
 134          */
 135         public function writeToFile ($dataStream) {
 136                 // Validate the pointer
 137                 $this->validateFilePointer();
 138
 139                 // Write data to the file pointer and return written bytes
 140                 return fwrite($this->getPointer(), $dataStream, strlen($dataStream));
 141         }
 142
 143         /**
 144          * Writes at given position by seeking to it.
 145          *
 146          * @param       $seekPosition   Seek position in file
 147          * @param       $data                   Data to be written
 148          * @return      mixed                   Number of writes bytes or false on error
 149          */
 150         public function writeAtPosition ($seekPosition, $data) {
 151                 // First seek to it
 152                 $this->seek($seekPosition);
 153
 154                 // Then write the data at that position
 155                 return $this->writeToFile($data);
 156         }
 157
 158         /**
 159          * Rewinds to the beginning of the file
 160          *
 161          * @return      $status         Status of this operation
 162          */
 163         public function rewind () {
 164                 // Validate the pointer
 165                 $this->validateFilePointer();
 166
 167                 // Rewind the pointer
 168                 return rewind($this->getPointer());
 169         }
 170
 171         /**
 172          * Seeks to given position
 173          *
 174          * @param       $seekPosition   Seek position in file
 175          * @param       $whence                 "Seek mode" (see http://de.php.net/fseek)
 176          * @return      $status                 Status of this operation
 177          */
 178         public function seek ($seekPosition, $whence = SEEK_SET) {
 179                 // Validate the pointer
 180                 $this->validateFilePointer();
 181
 182                 // Move the file pointer
 183                 return fseek($this->getPointer(), $seekPosition, $whence);
 184         }
 185
 186         /**
 187          * Reads a line, maximum 4096 Bytes from current file pointer
 188          *
 189          * @return      $data   Read data from file
 190          */
 191         public function readLine () {
 192                 // Read whole line
 193                 return $this->read();
 194         }
 195
 196         /**
 197          * Reads given amount of bytes from file.
 198          *
 199          * @param       $bytes  Amount of bytes to read
 200          * @return      $data   Data read from file
 201          */
 202         public function read ($bytes = NULL) {
 203                 // Validate the pointer
 204                 $this->validateFilePointer();
 205
 206                 // Is $bytes set?
 207                 if (is_int($bytes)) {
 208                         // Try to read given characters
 209                         $data = fread($this->getPointer(), $bytes);
 210                 } else {
 211                         // Try to read whole line
 212                         $data = fread($this->getPointer());
 213                 }
 214
 215                 // Then return it
 216                 return $data;
 217         }
 218
 219         /**
 220          * Analyzes entries in index file. This will count all found (and valid)
 221          * entries, mark invalid as damaged and count gaps ("fragmentation"). If
 222          * only gaps are found, the file is considered as "virgin" (no entries).
 223          *
 224          * @return      void
 225          * @throws      UnsupportedOperationException   If this method is called
 226          */
 227         public function analyzeFile () {
 228                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 229         }
 230
 231         /**
 232          * Advances to next "block" of bytes
 233          *
 234          * @return      void
 235          * @throws      UnsupportedOperationException   If this method is called
 236          */
 237         public function next () {
 238                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 239         }
 240
 241         /**
 242          * Checks wether the current entry is valid (not at the end of the file).
 243          * This method will return true if an emptied (nulled) entry has been found.
 244          *
 245          * @return      $isValid        Whether the next entry is valid
 246          * @throws      UnsupportedOperationException   If this method is called
 247          */
 248         public function valid () {
 249                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 250         }
 251
 252         /**
 253          * Gets current seek position ("key").
 254          *
 255          * @return      $key    Current key in iteration
 256          * @throws      UnsupportedOperationException   If this method is called
 257          */
 258         public function key () {
 259                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 260         }
 261
 262         /**
 263          * "Getter" for file size
 264          *
 265          * @return      $fileSize       Size of currently loaded file
 266          */
 267         public function getFileSize () {
 268                 // Check if the pointer is still valid
 269                 $this->validateFilePointer();
 270
 271                 // Get file's data
 272                 $fileData = fstat($this->getPointer());
 273
 274                 // Make sure the required array key is there
 275                 assert(isset($fileData['size']));
 276
 277                 // Return size
 278                 return $fileData['size'];
 279         }
 280
 281 }