<?php
class Buffer
{
    public $data = ""; //  buffer data
    public $seek = 0; // current position

    // initialize buffer
    public function __construct($data = '', $seek = 0)
    {
        $this->data = $data;
        $this->seek = $seek;
    }

    public function read(&$fp)
    {
        $this->seek = 0;
        $this->data = '';
        while($str = fread($fp, 1024))
        {
            $this->data .= $str;
        }
        return $this->data;
    }

    public function write(&$fp)
    {
        $write = fwrite($fp, $this->data);
        $this->data = '';
        $this->seek = 0;
        return $write;
    }

    public function get()
    {
        return $this->data[$this->seek++];
    }

    public function put($n)
    {
        $this->data .= chr($n);
        return $this->seek = strlen($this->data) - 1;
    }

    // read a string
    public function getstring($seek = -1)
    {
        $this->seek = $seek < 0 ? $this->seek : $seek;
        $str = '';
        for(;$this->seek<strlen($this->data);)
        {
            $chr = $this->get();
            if(ord($chr) == 0) break;
            $str .= $chr;
        }
        return $str;
    }

    public function getbin($len = NULL)
    {
        $out = substr($this->data, $this->seek, $len);
        $this->seek += $len;
        return $out;
    }

    // get an integer
    public function getint($seek = -1)
    {
        $this->seek = $seek < 0 ? $this->seek : $seek;
        if(!$this->remaining()) return false;
        $c = ord($this->get());
        if($c == 128)
        {
            $n = ord($this->get());
            $n |= ord($this->get())<<8;
            return $n > ((1<<15)-1) ? $n - 1<<16 : $n;
        }
        if($c == 129)
        {
            $n = ord($this->get());
            $n |= (ord($this->get()))<<8;
            $n |= (ord($this->get()))<<16;
            $n |= (ord($this->get()))<<24;
            return  $n > ((1<<31)-1) ? $n - 1<<32 : $n;
        }
        return $c > ((1<<7)-1) ? $c - (1<<8) : $c;
    }

    public function getuint($seek = -1)
    {
        $this->seek = $seek < 0 ? $this->seek : $seek;
        if(!$this->remaining()) return false;
        $c = ord($this->get());
        if($c == 128)
        {
            $n = ord($this->get());
            $n |= ord($this->get())<<8;
            return $n;
        }
        if($c == 129)
        {
            $n = ord($this->get());
            $n |= (ord($this->get()))<<8;
            $n |= (ord($this->get()))<<16;
            $n |= (ord($this->get()))<<24;
            return $n;
        }
        return $c;
    }

    public function getbyte($seek = -1)
    {
        $this->seek = $seek < 0 ? $this->seek : $seek;
        if(!$this->remaining()) return false;
        $c = ord($this->get());
        return $c;
    }

    // send a string
    public function putstring($str)
    {
        for($i = 0; $i<strlen($str); $i++)
        {
            $this->data .= $str{$i};
        }
        $this->put(0);
    }

    public function putbin($bin)
    {
        $this->data .= $bin;
        $this->seek = strlen($this->data) - 1;
    }

    // send an integer
    public function putint($n)
    {
        if($n<128 && $n>-127) $this->put($n);
        else if($n<0x8000 && $n>=-0x8000) { $this->put(0x80); $this->put($n); $this->put($n>>8); }
        else { $this->put(0x81); $this->put($n); $this->put($n>>8); $this->put($n>>16); $this->put($n>>24); }
    }

    public function remaining()
    {
        return max(0, strlen($this->data) - $this->seek);
    }
}
?>