<?php

class Fifo
{
  private $buffer_;
  private $len_;

  function __construct()
  {
    $this->buffer_ = '';
    $this->len_ = 0;
  }

  function __destruct()
  {
    if (0 < $this->len_) {
      fprintf(STDERR, "%s: %d bytes unused\n", __METHOD__, $this->len_);
    }
  }

  function len()
  {
    return $this->len_;
  }

  function strpos($str)
  {
    return strpos($this->buffer_, $str);
  }


  function append($str)
  {
    $this->buffer_ .= $str;
    $this->len_ += strlen($str);
  }

  function get($n = NULL)
  {
    if (is_null($n)) {
      $n = $this->len_;
    }

    if ($this->len_ < $n) {
      fprintf(STDERR, "%s:%s: short buffer: requested=%d available=%d\n",
	      __CLASS__, __FUNCTION__,
	      $n, $this->len_);
      $n = $this->len_;
    }

    $rtn = substr($this->buffer_, 0, $n);

    $this->buffer_ = substr($this->buffer_, $n);
    $this->len_ = strlen($this->buffer_);

    return $rtn;
  }

}

// End of file