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