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

   1 <?php
   2 // Own namespace
   3 namespace Org\Mxchange\CoreFramework\Filesystem\Pointer;
   4
   5 // Import framework stuff
   6 use Org\Mxchange\CoreFramework\Bootstrap\FrameworkBootstrap;
   7 use Org\Mxchange\CoreFramework\FileSystem\BaseFileIo;
   8 use Org\Mxchange\CoreFramework\FileSystem\FileReadProtectedException;
   9 use Org\Mxchange\CoreFramework\FileSystem\FileWriteProtectedException;
  10 use Org\Mxchange\CoreFramework\Filesystem\PathWriteProtectedException;
  11 use Org\Mxchange\CoreFramework\Generic\NullPointerException;
  12 use Org\Mxchange\CoreFramework\Generic\UnsupportedOperationException;
  13 use Org\Mxchange\CoreFramework\Object\BaseFrameworkSystem;
  14
  15 // Import SPL stuff
  16 use \SplFileInfo;
  17
  18 /**
  19  * A class for reading files
  20  *
  21  * @author              Roland Haeder <webmaster@shipsimu.org>
  22  * @version             0.0.0
  23  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2017 Core Developer Team
  24  * @license             GNU GPL 3.0 or any newer version
  25  * @link                http://www.shipsimu.org
  26  *
  27  * This program is free software: you can redistribute it and/or modify
  28  * it under the terms of the GNU General Public License as published by
  29  * the Free Software Foundation, either version 3 of the License, or
  30  * (at your option) any later version.
  31  *
  32  * This program is distributed in the hope that it will be useful,
  33  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  34  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  35  * GNU General Public License for more details.
  36  *
  37  * You should have received a copy of the GNU General Public License
  38  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  39  */
  40 class FrameworkFileInputOutputPointer extends BaseFileIo implements InputOutputPointer {
  41         /**
  42          * Protected constructor
  43          *
  44          * @return      void
  45          */
  46         protected function __construct () {
  47                 // Call parent constructor
  48                 parent::__construct(__CLASS__);
  49         }
  50
  51         /**
  52          * Create a file pointer based on the given file. The file will also
  53          * be verified here.
  54          *
  55          * @param       $fileInstance   An instance of a SplFileInfo class
  56          * @return      void
  57          * @throws      FileReadProtectedException      If PHP cannot read an existing file
  58          * @throws      FileWriteProtectedException     If PHP cannot write an existing file
  59          * @throws      PathWriteProtectedException     If PHP cannot write to an existing path
  60          * @throws      FileIoException                         If fopen() returns not a file resource
  61          */
  62         public static final function createFrameworkFileInputOutputPointer (SplFileInfo $fileInstance) {
  63                 // Some pre-sanity checks...
  64                 if (!FrameworkBootstrap::isReachableFilePath($fileInstance)) {
  65                         // File exists but cannot be read
  66                         throw new FileIoException($fileInstance, self::EXCEPTION_FILE_NOT_REACHABLE);
  67                 } elseif ((!FrameworkBootstrap::isReadableFile($fileInstance)) && (file_exists($fileInstance))) {
  68                         // File exists but cannot be read
  69                         throw new FileReadProtectedException($fileInstance, self::EXCEPTION_FILE_CANNOT_BE_READ);
  70                 } elseif (!is_writable($fileInstance->getPath())) {
  71                         // Path is not writable
  72                         throw new PathWriteProtectedException($fileInstance, self::EXCEPTION_PATH_CANNOT_BE_WRITTEN);
  73                 } elseif (($fileInstance->isFile()) && (!$fileInstance->isWritable())) {
  74                         // File exists but cannot be written
  75                         throw new FileWriteProtectedException($fileInstance, self::EXCEPTION_FILE_CANNOT_BE_WRITTEN);
  76                 }
  77
  78                 // Try to open a handler
  79                 $fileObject = $fileInstance->openFile('c+b');
  80
  81                 // Is it valid?
  82                 if ((is_null($fileObject)) || ($fileObject === false)) {
  83                         // Something bad happend
  84                         throw new FileIoException($fileInstance->getPathname(), self::EXCEPTION_FILE_POINTER_INVALID);
  85                 } // END - if
  86
  87                 // Create new instance
  88                 $pointerInstance = new FrameworkFileInputOutputPointer();
  89
  90                 // Set file object and file name
  91                 $pointerInstance->setFileObject($fileObject);
  92
  93                 // Return the instance
  94                 return $pointerInstance;
  95         }
  96
  97         /**
  98          * Validates file pointer and throws exceptions. This method does not return
  99          * anything (not reliable) as this method checks the file pointer and on
 100          * case of an error it throws an exception. If this method does not throw
 101          * any exceptions, the file pointer seems to be fine.
 102          *
 103          * @return      void
 104          * @throws      NullPointerException    If the file pointer instance
 105          *                                                                      is not set by setPointer()
 106          * @todo Add more checks
 107          */
 108         private function validateFilePointer () {
 109                 if (is_null($this->getFileObject())) {
 110                         // Pointer not initialized
 111                         throw new NullPointerException($this, self::EXCEPTION_IS_NULL_POINTER);
 112                 } // END - if
 113
 114                 // All fine here
 115         }
 116
 117         /**
 118          * Read 1024 bytes data from a file pointer
 119          *
 120          * @return      mixed   The result of fread()
 121          */
 122         public function readFromFile () {
 123                 // Validate the pointer
 124                 $this->validateFilePointer();
 125
 126                 // Read data from the file pointer and return it
 127                 return $this->read(1024);
 128         }
 129
 130         /**
 131          * Write data to a file pointer
 132          *
 133          * @param       $dataStream             The data stream we shall write to the file
 134          * @return      mixed                   Number of writes bytes or false on error
 135          */
 136         public function writeToFile ($dataStream) {
 137                 // Validate the pointer
 138                 $this->validateFilePointer();
 139
 140                 // Write data to the file pointer and return written bytes
 141                 return $this->getFileObject()->fwrite($dataStream, strlen($dataStream));
 142         }
 143
 144         /**
 145          * Writes at given position by seeking to it.
 146          *
 147          * @param       $seekPosition   Seek position in file
 148          * @param       $data                   Data to be written
 149          * @return      mixed                   Number of writes bytes or false on error
 150          */
 151         public function writeAtPosition ($seekPosition, $data) {
 152                 // First seek to it
 153                 $this->seek($seekPosition);
 154
 155                 // Then write the data at that position
 156                 return $this->writeToFile($data);
 157         }
 158
 159         /**
 160          * Rewinds to the beginning of the file
 161          *
 162          * @return      $status         Status of this operation
 163          */
 164         public function rewind () {
 165                 // Validate the pointer
 166                 $this->validateFilePointer();
 167
 168                 // Rewind the pointer
 169                 return $this->getFileObject()->rewind();
 170         }
 171
 172         /**
 173          * Seeks to given position
 174          *
 175          * @param       $seekPosition   Seek position in file
 176          * @param       $whence                 "Seek mode" (see http://de.php.net/fseek)
 177          * @return      $status                 Status of this operation
 178          */
 179         public function seek ($seekPosition, $whence = SEEK_SET) {
 180                 // Validate the pointer
 181                 $this->validateFilePointer();
 182
 183                 // Move the file pointer
 184                 return $this->getFileObject()->fseek($seekPosition, $whence);
 185         }
 186
 187         /**
 188          * Reads a line, maximum 4096 Bytes from current file pointer
 189          *
 190          * @return      $data   Read data from file
 191          */
 192         public function readLine () {
 193                 // Read whole line
 194                 return $this->read();
 195         }
 196
 197         /**
 198          * Reads given amount of bytes from file.
 199          *
 200          * @param       $bytes  Amount of bytes to read
 201          * @return      $data   Data read from file
 202          */
 203         public function read ($bytes = NULL) {
 204                 // Validate the pointer
 205                 $this->validateFilePointer();
 206
 207                 // Is $bytes set?
 208                 if (is_int($bytes)) {
 209                         // Try to read given characters
 210                         $data = $this->getFileObject()->fread($bytes);
 211                 } else {
 212                         // Try to read whole line
 213                         $data = $this->getFileObject()->fgets();
 214                 }
 215
 216                 // Then return it
 217                 return $data;
 218         }
 219
 220         /**
 221          * Analyzes entries in index file. This will count all found (and valid)
 222          * entries, mark invalid as damaged and count gaps ("fragmentation"). If
 223          * only gaps are found, the file is considered as "virgin" (no entries).
 224          *
 225          * @return      void
 226          * @throws      UnsupportedOperationException   If this method is called
 227          */
 228         public function analyzeFile () {
 229                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 230         }
 231
 232         /**
 233          * Advances to next "block" of bytes
 234          *
 235          * @return      void
 236          * @throws      UnsupportedOperationException   If this method is called
 237          */
 238         public function next () {
 239                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 240         }
 241
 242         /**
 243          * Checks wether the current entry is valid (not at the end of the file).
 244          * This method will return true if an emptied (nulled) entry has been found.
 245          *
 246          * @return      $isValid        Whether the next entry is valid
 247          * @throws      UnsupportedOperationException   If this method is called
 248          */
 249         public function valid () {
 250                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 251         }
 252
 253         /**
 254          * Gets current seek position ("key").
 255          *
 256          * @return      $key    Current key in iteration
 257          * @throws      UnsupportedOperationException   If this method is called
 258          */
 259         public function key () {
 260                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 261         }
 262
 263         /**
 264          * "Getter" for file size
 265          *
 266          * @return      $fileSize       Size of currently loaded file
 267          */
 268         public function getFileSize () {
 269                 // Check if the pointer is still valid
 270                 $this->validateFilePointer();
 271
 272                 // Get file's data
 273                 $fileData = $this->getFileObject()->fstat();
 274
 275                 // Make sure the required array key is there
 276                 assert(isset($fileData['size']));
 277
 278                 // Return size
 279                 return $fileData['size'];
 280         }
 281
 282 }