streams.php

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<?php
/*
    Copyright (c) 2003, 2005 Danilo Segan <[e-mail]>.

    This file is part of PHP-gettext.

    PHP-gettext is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    PHP-gettext is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with PHP-gettext; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/


# Simple class to wrap file streams, string streams, etc.
# seek is essential, and it should be byte stream
class StreamReader {
    function read($bytes) {
        return false;
    }
    # should return new position
    function seekto($position) {
        return false;
    }
    # returns current position
    function currentpos() {
        return false;
    }
    # returns length of entire stream (limit for seekto()s)
    function length() {
        return false;
    }
}

class StringReader {
    var $_pos;
    var $_str;
    function StringReader($str='') {
        $this->_str = $str;
        $this->_pos = 0;
    }
    function read($bytes) {
        $data = substr($this->_str, $this->_pos, $bytes);
        $this->_pos += $bytes;
        if (strlen($this->_str)<$this->_pos)
            $this->_pos = strlen($this->_str);
        return $data;
    }
    function seekto($pos) {
        $this->_pos = $pos;
        if (strlen($this->_str)<$this->_pos)
            $this->_pos = strlen($this->_str);
        return $this->_pos;
    }
    function currentpos() {
        return $this->_pos;
    }
    function length() {
        return strlen($this->_str);
    }
}

class FileReader {
    var $_pos;
    var $_fd;
    var $_length;
    function FileReader($filename) {
        if (file_exists($filename)) {
            $this->_length=filesize($filename);
            $this->_pos = 0;
            $this->_fd = fopen($filename,'rb');
            if (!$this->_fd) {
                $this->error = 3; # Cannot read file, probably permissions
                return false;
            }
        } else {
            $this->error = 2; # File doesn't exist
            return false;
        }
    }
    function read($bytes) {
        if ($bytes) {
            fseek($this->_fd, $this->_pos);
            # PHP 5.1.1 does not read more than 8192 bytes in one fread()
            # the discussions at PHP Bugs suggest it's the intended behaviour
            while ($bytes > 0) {
                $data = (empty($data)) ? '' : $data ;
                $chunk  = fread($this->_fd, $bytes);
                $data  .= $chunk;
                $bytes -= strlen($chunk);
            }
            $this->_pos = ftell($this->_fd);
            return $data;
        } else return '';
    }
    function seekto($pos) {
        fseek($this->_fd, $pos);
        $this->_pos = ftell($this->_fd);
        return $this->_pos;
    }
    function currentpos() {
        return $this->_pos;
    }
    function length() {
        return $this->_length;
    }
    function close() {
        fclose($this->_fd);
    }
}

# Preloads entire file in memory first, then creates a StringReader
# over it (it assumes knowledge of StringReader internals)
class CachedFileReader extends StringReader {
    function CachedFileReader($filename) {
        if (file_exists($filename)) {
            $length=filesize($filename);
            $fd = fopen($filename,'rb');

            if (!$fd) {
                $this->error = 3; # Cannot read file, probably permissions
                return false;
            }
            $this->_str = fread($fd, $length);
            fclose($fd);
        } else {
            $this->error = 2; # File doesn't exist
            return false;
        }
    }
}
?>