<?php
/**
 * Classes, which help reading streams of data from files.
 * Based on the classes from Danilo Segan <[email protected]>
 *
 * @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->is_overloaded = ((ini_get("mbstring.func_overload") & 2) != 0) && function_exists('mb_substr');
        $this->_pos = 0;
    }

    /**
     * PHP4 constructor.
     */
    public function POMO_Reader() {
        self::__construct();
    }

    /**
     * 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 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;
        $endian_letter = ('big' == $this->endian)? 'N' : 'V';
        return unpack($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 ) {
        parent::POMO_Reader();
        $this->_f = fopen($filename, 'rb');
    }

    /**
     * PHP4 constructor.
     */
    public function POMO_FileReader( $filename ) {
        self::__construct( $filename );
    }

    /**
     * @param int $bytes
     */
    function read($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 = '' ) {
        parent::POMO_Reader();
        $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 ) {
        parent::POMO_StringReader();
        $this->_str = file_get_contents($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( $filename ) {
        parent::POMO_CachedFileReader($filename);
    }

    /**
     * PHP4 constructor.
     */
    function POMO_CachedIntFileReader( $filename ) {
        self::__construct( $filename );
    }
}
endif;