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\FileSystem\FileReadProtectedException;
   9 use CoreFramework\FileSystem\FileWriteProtectedException;
  10 use CoreFramework\Filesystem\PathWriteProtectedException;
  11 use CoreFramework\Generic\NullPointerException;
  12 use CoreFramework\Generic\UnsupportedOperationException;
  13 use CoreFramework\Object\BaseFrameworkSystem;
  14
  15 /**
  16  * A class for reading files
  17  *
  18  * @author              Roland Haeder <webmaster@shipsimu.org>
  19  * @version             0.0.0
  20  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2017 Core Developer Team
  21  * @license             GNU GPL 3.0 or any newer version
  22  * @link                http://www.shipsimu.org
  23  *
  24  * This program is free software: you can redistribute it and/or modify
  25  * it under the terms of the GNU General Public License as published by
  26  * the Free Software Foundation, either version 3 of the License, or
  27  * (at your option) any later version.
  28  *
  29  * This program is distributed in the hope that it will be useful,
  30  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  31  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  32  * GNU General Public License for more details.
  33  *
  34  * You should have received a copy of the GNU General Public License
  35  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  36  */
  37 class FrameworkFileInputOutputPointer extends BaseFileIo implements InputOutputPointer {
  38         /**
  39          * Protected constructor
  40          *
  41          * @return      void
  42          */
  43         protected function __construct () {
  44                 // Call parent constructor
  45                 parent::__construct(__CLASS__);
  46         }
  47
  48         /**
  49          * Create a file pointer based on the given file. The file will also
  50          * be verified here.
  51          *
  52          * @param       $fileName       The file name we shall pass to fopen()
  53          * @return      void
  54          * @throws      FileIsEmptyException            If the given file name is NULL or empty
  55          * @throws      FileReadProtectedException      If PHP cannot read an existing file
  56          * @throws      FileWriteProtectedException     If PHP cannot write an existing file
  57          * @throws      PathWriteProtectedException     If PHP cannot write to an existing path
  58          * @throws      FileIoException                         If fopen() returns not a file resource
  59          */
  60         public static final function createFrameworkFileInputOutputPointer ($fileName) {
  61                 // Some pre-sanity checks...
  62                 if ((is_null($fileName)) || (empty($fileName))) {
  63                         // No filename given
  64                         throw new FileIsEmptyException(NULL, self::EXCEPTION_UNEXPECTED_EMPTY_STRING);
  65                 } elseif (!FrameworkBootstrap::isReachableFilePath($fileName)) {
  66                         // File exists but cannot be read
  67                         throw new FileIoException($fileName, self::EXCEPTION_FILE_NOT_REACHABLE);
  68                 } elseif ((!FrameworkBootstrap::isReadableFile($fileName)) && (file_exists($fileName))) {
  69                         // File exists but cannot be read
  70                         throw new FileReadProtectedException($fileName, self::EXCEPTION_FILE_CANNOT_BE_READ);
  71                 } elseif ((file_exists($fileName)) && (!is_writable($fileName))) {
  72                         // File exists but cannot be written
  73                         throw new FileWriteProtectedException($fileName, self::EXCEPTION_FILE_CANNOT_BE_WRITTEN);
  74                 } elseif (!is_writable(dirname($fileName))) {
  75                         // Path is not writable
  76                         throw new PathWriteProtectedException($fileName, self::EXCEPTION_PATH_CANNOT_BE_WRITTEN);
  77                 }
  78
  79                 // Try to open a handler
  80                 $filePointer = fopen($fileName, 'c+b');
  81                 if ((is_null($filePointer)) || ($filePointer === false)) {
  82                         // Something bad happend
  83                         throw new FileIoException($fileName, self::EXCEPTION_FILE_POINTER_INVALID);
  84                 } // END - if
  85
  86                 // Create new instance
  87                 $pointerInstance = new FrameworkFileInputOutputPointer();
  88
  89                 // Set file pointer and file name
  90                 $pointerInstance->setPointer($filePointer);
  91                 $pointerInstance->setFileName($fileName);
  92
  93                 // Return the instance
  94                 return $pointerInstance;
  95         }
  96
  97         /**
  98          * Validates file pointer and throws exceptions. This method does not return
  99          * anything (not reliable) as this method checks the file pointer and on
 100          * case of an error it throws an exception. If this method does not throw
 101          * any exceptions, the file pointer seems to be fine.
 102          *
 103          * @return      void
 104          * @throws      NullPointerException    If the file pointer instance
 105          *                                                                      is not set by setPointer()
 106          * @throws      InvalidResourceException        If there is being set
 107          */
 108         private function validateFilePointer () {
 109                 if (is_null($this->getPointer())) {
 110                         // Pointer not initialized
 111                         throw new NullPointerException($this, self::EXCEPTION_IS_NULL_POINTER);
 112                 } elseif (!is_resource($this->getPointer())) {
 113                         // Pointer is not a valid resource!
 114                         throw new InvalidResourceException($this, self::EXCEPTION_INVALID_RESOURCE);
 115                 }
 116
 117                 // All fine here
 118         }
 119
 120         /**
 121          * Read 1024 bytes data from a file pointer
 122          *
 123          * @return      mixed   The result of fread()
 124          */
 125         public function readFromFile () {
 126                 // Validate the pointer
 127                 $this->validateFilePointer();
 128
 129                 // Read data from the file pointer and return it
 130                 return $this->read(1024);
 131         }
 132
 133         /**
 134          * Write data to a file pointer
 135          *
 136          * @param       $dataStream             The data stream we shall write to the file
 137          * @return      mixed                   Number of writes bytes or false on error
 138          */
 139         public function writeToFile ($dataStream) {
 140                 // Validate the pointer
 141                 $this->validateFilePointer();
 142
 143                 // Write data to the file pointer and return written bytes
 144                 return fwrite($this->getPointer(), $dataStream, strlen($dataStream));
 145         }
 146
 147         /**
 148          * Writes at given position by seeking to it.
 149          *
 150          * @param       $seekPosition   Seek position in file
 151          * @param       $data                   Data to be written
 152          * @return      mixed                   Number of writes bytes or false on error
 153          */
 154         public function writeAtPosition ($seekPosition, $data) {
 155                 // First seek to it
 156                 $this->seek($seekPosition);
 157
 158                 // Then write the data at that position
 159                 return $this->writeToFile($data);
 160         }
 161
 162         /**
 163          * Rewinds to the beginning of the file
 164          *
 165          * @return      $status         Status of this operation
 166          */
 167         public function rewind () {
 168                 // Validate the pointer
 169                 $this->validateFilePointer();
 170
 171                 // Rewind the pointer
 172                 return rewind($this->getPointer());
 173         }
 174
 175         /**
 176          * Seeks to given position
 177          *
 178          * @param       $seekPosition   Seek position in file
 179          * @param       $whence                 "Seek mode" (see http://de.php.net/fseek)
 180          * @return      $status                 Status of this operation
 181          */
 182         public function seek ($seekPosition, $whence = SEEK_SET) {
 183                 // Validate the pointer
 184                 $this->validateFilePointer();
 185
 186                 // Move the file pointer
 187                 return fseek($this->getPointer(), $seekPosition, $whence);
 188         }
 189
 190         /**
 191          * Reads a line, maximum 4096 Bytes from current file pointer
 192          *
 193          * @return      $data   Read data from file
 194          */
 195         public function readLine () {
 196                 // Read whole line
 197                 return $this->read();
 198         }
 199
 200         /**
 201          * Reads given amount of bytes from file.
 202          *
 203          * @param       $bytes  Amount of bytes to read
 204          * @return      $data   Data read from file
 205          */
 206         public function read ($bytes = NULL) {
 207                 // Validate the pointer
 208                 $this->validateFilePointer();
 209
 210                 // Is $bytes set?
 211                 if (is_int($bytes)) {
 212                         // Try to read given characters
 213                         $data = fread($this->getPointer(), $bytes);
 214                 } else {
 215                         // Try to read whole line
 216                         $data = fread($this->getPointer());
 217                 }
 218
 219                 // Then return it
 220                 return $data;
 221         }
 222
 223         /**
 224          * Analyzes entries in index file. This will count all found (and valid)
 225          * entries, mark invalid as damaged and count gaps ("fragmentation"). If
 226          * only gaps are found, the file is considered as "virgin" (no entries).
 227          *
 228          * @return      void
 229          * @throws      UnsupportedOperationException   If this method is called
 230          */
 231         public function analyzeFile () {
 232                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 233         }
 234
 235         /**
 236          * Advances to next "block" of bytes
 237          *
 238          * @return      void
 239          * @throws      UnsupportedOperationException   If this method is called
 240          */
 241         public function next () {
 242                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 243         }
 244
 245         /**
 246          * Checks wether the current entry is valid (not at the end of the file).
 247          * This method will return true if an emptied (nulled) entry has been found.
 248          *
 249          * @return      $isValid        Whether the next entry is valid
 250          * @throws      UnsupportedOperationException   If this method is called
 251          */
 252         public function valid () {
 253                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 254         }
 255
 256         /**
 257          * Gets current seek position ("key").
 258          *
 259          * @return      $key    Current key in iteration
 260          * @throws      UnsupportedOperationException   If this method is called
 261          */
 262         public function key () {
 263                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 264         }
 265
 266         /**
 267          * "Getter" for file size
 268          *
 269          * @return      $fileSize       Size of currently loaded file
 270          */
 271         public function getFileSize () {
 272                 // Check if the pointer is still valid
 273                 $this->validateFilePointer();
 274
 275                 // Get file's data
 276                 $fileData = fstat($this->getPointer());
 277
 278                 // Make sure the required array key is there
 279                 assert(isset($fileData['size']));
 280
 281                 // Return size
 282                 return $fileData['size'];
 283         }
 284
 285 }