<?php

/**

 * Classes, which help reading streams of data from files.

 * Based on the classes from Danilo Segan <danilo@kvota.net>

 *

 * @version $Id: streams.php 1157 2015-11-20 04:30:11Z dd32 $

 * @package pomo

 * @subpackage streams

 */

if ( ! class_exists( 'POMO_Reader', false ) ) :

	class POMO_Reader {

		var $endian = 'little';

		var $_post  = '';

		/**

		 * PHP5 constructor.

		 */

		function __construct() {

			$this->_pos          = 0;

		}

		/**

		 * PHP4 constructor.

		 */

		public function POMO_Reader() {

			self::__construct();

		}

		/**

		 * Sets the endianness of the file.

		 *

		 * @param string $endian Set the endianness of the file. Accepts 'big', or 'little'.

		 */

			$this->endian = $endian;

		}

		/**

		 * Reads a 32bit Integer from the Stream

		 *

		 * @return mixed The integer, corresponding to the next 32 bits from

		 *  the stream of false if there are not enough bytes or on error

		 */

		function readint32() {

			$bytes = $this->read( 4 );

			if ( 4 != $this->strlen( $bytes ) ) {

				return false;

			}

			$int           = unpack( $endian_letter, $bytes );

			return reset( $int );

		}

		/**

		 * Reads an array of 32-bit Integers from the Stream

		 *

		 * @param integer $count How many elements should be read

		 * @return mixed Array of integers or false if there isn't

		 *  enough data or on error

		 */

		function readint32array( $count ) {

			$bytes = $this->read( 4 * $count );

			if ( 4 * $count != $this->strlen( $bytes ) ) {

				return false;

			}

			return unpack( $endian_letter . $count, $bytes );

		}

		/**

		 * @param string $string

		 * @param int    $start

		 * @param int    $length

		 * @return string

		 */

		function substr( $string, $start, $length ) {

			if ( $this->is_overloaded ) {

				return mb_substr( $string, $start, $length, 'ascii' );

			} else {

				return substr( $string, $start, $length );

			}

		}

		/**

		 * @param string $string

		 * @return int

		 */

		function strlen( $string ) {

			if ( $this->is_overloaded ) {

				return mb_strlen( $string, 'ascii' );

			} else {

				return strlen( $string );

			}

		}

		/**

		 * @param string $string

		 * @param int    $chunk_size

		 * @return array

		 */

		function str_split( $string, $chunk_size ) {

			if ( ! function_exists( 'str_split' ) ) {

				$length = $this->strlen( $string );

				$out    = array();

				for ( $i = 0; $i < $length; $i += $chunk_size ) {

					$out[] = $this->substr( $string, $i, $chunk_size );

				}

				return $out;

			} else {

				return str_split( $string, $chunk_size );

			}

		}

		/**

		 * @return int

		 */

		function pos() {

			return $this->_pos;

		}

		/**

		 * @return true

		 */

		function is_resource() {

			return true;

		}

		/**

		 * @return true

		 */

		function close() {

			return true;

		}

	}

endif;

if ( ! class_exists( 'POMO_FileReader', false ) ) :

	class POMO_FileReader extends POMO_Reader {

		/**

		 * @param string $filename

		 */

		function __construct( $filename ) {

			$this->_f = fopen( $filename, 'rb' );

		}

		/**

		 * PHP4 constructor.

		 */

		public function POMO_FileReader( $filename ) {

			self::__construct( $filename );

		}

		/**

		 * @param int $bytes

		 * @return string|false Returns read string, otherwise false.

		 */

		function read( $bytes ) {

			return fread( $this->_f, $bytes );

		}

		/**

		 * @param int $pos

		 * @return boolean

		 */

		function seekto( $pos ) {

			if ( -1 == fseek( $this->_f, $pos, SEEK_SET ) ) {

				return false;

			}

			$this->_pos = $pos;

			return true;

		}

		/**

		 * @return bool

		 */

		function is_resource() {

			return is_resource( $this->_f );

		}

		/**

		 * @return bool

		 */

		function feof() {

			return feof( $this->_f );

		}

		/**

		 * @return bool

		 */

		function close() {

			return fclose( $this->_f );

		}

		/**

		 * @return string

		 */

		function read_all() {

			$all = '';

			while ( ! $this->feof() ) {

				$all .= $this->read( 4096 );

			}

			return $all;

		}

	}

endif;

if ( ! class_exists( 'POMO_StringReader', false ) ) :

	/**

	 * Provides file-like methods for manipulating a string instead

	 * of a physical file.

	 */

	class POMO_StringReader extends POMO_Reader {

		var $_str = '';

		/**

		 * PHP5 constructor.

		 */

		function __construct( $str = '' ) {

			$this->_str = $str;

			$this->_pos = 0;

		}

		/**

		 * PHP4 constructor.

		 */

		public function POMO_StringReader( $str = '' ) {

			self::__construct( $str );

		}

		/**

		 * @param string $bytes

		 * @return string

		 */

		function read( $bytes ) {

			$data        = $this->substr( $this->_str, $this->_pos, $bytes );

			$this->_pos += $bytes;

			if ( $this->strlen( $this->_str ) < $this->_pos ) {

				$this->_pos = $this->strlen( $this->_str );

			}

			return $data;

		}

		/**

		 * @param int $pos

		 * @return int

		 */

		function seekto( $pos ) {

			$this->_pos = $pos;

			if ( $this->strlen( $this->_str ) < $this->_pos ) {

				$this->_pos = $this->strlen( $this->_str );

			}

			return $this->_pos;

		}

		/**

		 * @return int

		 */

		function length() {

			return $this->strlen( $this->_str );

		}

		/**

		 * @return string

		 */

		function read_all() {

			return $this->substr( $this->_str, $this->_pos, $this->strlen( $this->_str ) );

		}

	}

endif;

if ( ! class_exists( 'POMO_CachedFileReader', false ) ) :

	/**

	 * Reads the contents of the file in the beginning.

	 */

	class POMO_CachedFileReader extends POMO_StringReader {

		/**

		 * PHP5 constructor.

		 */

		function __construct( $filename ) {

			$this->_str = file_get_contents( $filename );

			if ( false === $this->_str ) {

				return false;

			}

			$this->_pos = 0;

		}

		/**

		 * PHP4 constructor.

		 */

		public function POMO_CachedFileReader( $filename ) {

			self::__construct( $filename );

		}

	}

endif;

if ( ! class_exists( 'POMO_CachedIntFileReader', false ) ) :

	/**

	 * Reads the contents of the file in the beginning.

	 */

	class POMO_CachedIntFileReader extends POMO_CachedFileReader {

		/**

		 * PHP5 constructor.

		 */

		public function __construct( $filename ) {

		}

		/**

		 * PHP4 constructor.

		 */

		function POMO_CachedIntFileReader( $filename ) {

			self::__construct( $filename );

		}

	}

endif;