Ticket #14207: streams.php

<?php
/**
 * Classes, which help reading streams of data from files.
 * Based on the classes from Danilo Segan <danilo@kvota.net>
 *
 * @version $Id: streams.php 406 2010-02-07 11:10:24Z nbachiyski $
 * @package pomo
 * @subpackage streams
 */

if ( !class_exists( 'POMO_Reader' ) ):
class POMO_Reader {

        var $endian = 'little';
        var $_post = '';

        function POMO_Reader() {
                $this->is_overloaded = ((ini_get("mbstring.func_overload") & 2) != 0) && function_exists('mb_substr');
                $this->_pos = 0;
        }

        /**
         * Sets the endianness of the file.
         *
         * @param $endian string 'big' or 'little'
         */
        function setEndian($endian) {
                $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;
                $endian_letter = ('big' == $this->endian)? 'N' : 'V';
                $int = unpack($endian_letter, $bytes);
                return array_shift($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;
                $endian_letter = ('big' == $this->endian)? 'N' : 'V';
                return unpack($endian_letter.$count, $bytes);
        }


        function substr($string, $start, $length) {
                if ($this->is_overloaded) {
                        return mb_substr($string, $start, $length, 'ascii');
                } else {
                        return substr($string, $start, $length);
                }
        }

        function strlen($string) {
                if ($this->is_overloaded) {
                        return mb_strlen($string, 'ascii');
                } else {
                        return strlen($string);
                }
        }

        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 );
                }
        }


        function pos() {
                return $this->_pos;
        }

        function is_resource() {
                return true;
        }

        function close() {
                return true;
        }
}
endif;

if ( !class_exists( 'POMO_FileReader' ) ):
class POMO_FileReader extends POMO_Reader {
        function POMO_FileReader($filename) {
                parent::POMO_Reader();
                $this->_f = fopen($filename, 'r');
        }

        function read($bytes) {
                if ( empty($bytes) )
                        return fread($this->_f, $bytes);
                else
                        return;
        }

        function seekto($pos) {
                if ( -1 == fseek($this->_f, $pos, SEEK_SET)) {
                        return false;
                }
                $this->_pos = $pos;
                return true;
        }

        function is_resource() {
                return is_resource($this->_f);
        }

        function feof() {
                return feof($this->_f);
        }

        function close() {
                return fclose($this->_f);
        }

        function read_all() {
                $all = '';
                while ( !$this->feof() )
                        $all .= $this->read(4096);
                return $all;
        }
}
endif;

if ( !class_exists( 'POMO_StringReader' ) ):
/**
 * Provides file-like methods for manipulating a string instead
 * of a physical file.
 */
class POMO_StringReader extends POMO_Reader {

        var $_str = '';

        function POMO_StringReader($str = '') {
                parent::POMO_Reader();
                $this->_str = $str;
                $this->_pos = 0;
        }


        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;
        }

        function seekto($pos) {
                $this->_pos = $pos;
                if ($this->strlen($this->_str) < $this->_pos) $this->_pos = $this->strlen($this->_str);
                return $this->_pos;
        }

        function length() {
                return $this->strlen($this->_str);
        }

        function read_all() {
                return $this->substr($this->_str, $this->_pos, $this->strlen($this->_str));
        }

}
endif;

if ( !class_exists( 'POMO_CachedFileReader' ) ):
/**
 * Reads the contents of the file in the beginning.
 */
class POMO_CachedFileReader extends POMO_StringReader {
        function POMO_CachedFileReader($filename) {
                parent::POMO_StringReader();
                $this->_str = file_get_contents($filename);
                if (false === $this->_str)
                        return false;
                $this->_pos = 0;
        }
}
endif;

if ( !class_exists( 'POMO_CachedIntFileReader' ) ):
/**
 * Reads the contents of the file in the beginning.
 */
class POMO_CachedIntFileReader extends POMO_CachedFileReader {
        function POMO_CachedIntFileReader($filename) {
                parent::POMO_CachedFileReader($filename);
        }
}
endif;