/v1/mod_semanticweb/arc/ARC2_Reader.php

<?php

/*

homepage: http://arc.semsol.org/

license:  http://arc.semsol.org/license



class:    ARC2 Web Reader

author:   Benjamin Nowack

version:  2009-02-18 (Tweak: Improved error message on empty file:// base)

*/



ARC2::inc('Class');



class ARC2_Reader extends ARC2_Class {



  function __construct($a = '', &$caller) {

    parent::__construct($a, $caller);

  }

  

  function ARC2_Reader($a = '', &$caller) {

    $this->__construct($a, $caller);

  }



  function __init() {/* inc_path, proxy_host, proxy_port, proxy_skip, http_accept_header, http_user_agent_header, max_redirects */

    parent::__init();

    $this->http_method = $this->v('http_method', 'GET', $this->a);

    $this->message_body = $this->v('message_body', '', $this->a);;

    $this->http_accept_header = $this->v('http_accept_header', 'Accept: application/rdf+xml; q=0.9, */*; q=0.1', $this->a);

    $this->http_user_agent_header = $this->v('http_user_agent_header', 'User-Agent: ARC Reader (http://arc.semsol.org/)', $this->a);

    $this->http_custom_headers = $this->v('http_custom_headers', '', $this->a);

    $this->max_redirects = $this->v('max_redirects', 3, $this->a);

    $this->format = $this->v('format', false, $this->a);

    $this->redirects = array();

    $this->stream_id = '';

    $this->timeout = $this->v('reader_timeout', 0, $this->a);;



  }



  /*  */

  

  function setHTTPMethod($v) {

    $this->http_method = $v;

  }



  function setMessageBody($v) {

    $this->message_body = $v;

  }



  function setAcceptHeader($v) {

    $this->http_accept_header = $v;

  }



  function setCustomHeaders($v) {

    $this->http_custom_headers = $v;

  }



  function addCustomHeaders($v) {

    if ($this->http_custom_headers) $this->http_custom_headers .= "\r\n";

    $this->http_custom_headers .= $v;

  }



  /*  */



  function activate($path, $data = '', $ping_only = 0, $timeout = 0) {

    $this->setCredentials($path);

    $this->ping_only = $ping_only;

    if ($timeout) $this->timeout = $timeout;

    $id = md5($path . ' ' . $data);

    if ($this->stream_id != $id) {

      $this->stream_id = $id;

      $this->base = $this->calcBase($path);

      $this->uri = $this->calcURI($path, $this->base);

      $this->stream = ($data) ? $this->getDataStream($data) : $this->getSocketStream($this->base, $ping_only);

      if ($this->stream && !$this->ping_only) {

        $this->getFormat();

      }

    }

  }



  function setCredentials($path) {

    if ($creds = $this->v('arc_reader_credentials', array(), $this->a)) {

      foreach ($creds as $pattern => $cred) {

        $regex = '/' . preg_replace('/([\:\/\.\?])/', '\\\\\1', $pattern) . '/';

        if (preg_match($regex, $path)) {

          $this->setCustomHeaders('Authorization: Basic ' . base64_encode($cred));

        }

      }

    }

  }



  /*  */



  function useProxy($url) {

    if (!$this->v1('proxy_host', 0, $this->a)) {

      return false;

    }

    $skips = $this->v1('proxy_skip', array(), $this->a);

    foreach ($skips as $skip) {

      if (strpos($url, $skip) !== false) {

        return false;

      }

    }

    return true;

  }



  /*  */

  

  function createStream($path, $data = '') {

    $this->base = $this->calcBase($path);

    $this->stream = ($data) ? $this->getDataStream($data) : $this->getSocketStream($this->base);

  }



  function getDataStream($data) {

    return array('type' => 'data', 'pos' => 0, 'headers' => array(), 'size' => strlen($data), 'data' => $data, 'buffer' => '');

  }

  

  function getSocketStream($url) {

    if ($url == 'file://') {

      return $this->addError('Error: file does not exists or is not accessible');

    }

    $parts = parse_url($url);

    $mappings = array('file' => 'File', 'http' => 'HTTP', 'https' => 'HTTP');

    if ($scheme = $this->v(strtolower($parts['scheme']), '', $mappings)) {

      return $this->m('get' . $scheme . 'Socket', $url, $this->getDataStream(''));

    }

  }

  

  function getFileSocket($url) {

    $parts = parse_url($url);

    $s = file_exists($parts['path']) ? @fopen($parts['path'], 'rb') : false;

    if (!$s) {

      return $this->addError('Socket error: Could not open "' . $parts['path'] . '"');

    }

    return array('type' => 'socket', 'socket' =>& $s, 'headers' => array(), 'pos' => 0, 'size' => filesize($parts['path']), 'buffer' => '');

  }

  

  function getHTTPSocket($url, $redirs = 0) {

    $parts = parse_url($url);

    if (!isset($parts['scheme'])) {

      return $this->addError('Socket error: No supported URI scheme detected.');

    }

    $parts['port'] = ($parts['scheme'] == 'https') ? $this->v1('port', 443, $parts) : $this->v1('port', 80, $parts);

    $nl = "\r\n";

    $http_mthd = strtoupper($this->http_method);

    if ($this->v1('user', 0, $parts) || $this->useProxy($url)) {

      $h_code = $http_mthd . ' ' . $url;

    }

    else {

      $h_code = $http_mthd . ' ' . $this->v1('path', '/', $parts) . (($v = $this->v1('query', 0, $parts)) ? '?' . $v : '') . (($v = $this->v1('fragment', 0, $parts)) ? '#' . $v : '');

    }

    $h_code .= ' HTTP/1.0' . $nl.

      'Host: ' . $parts['host'] . $nl.

      (($v = $this->http_accept_header) ? $v . $nl : '') .

      (($v = $this->http_user_agent_header) && !preg_match('/User\-Agent\:/', $this->http_custom_headers) ? $v . $nl : '') .

      (($http_mthd == 'POST') ? 'Content-Length: ' . strlen($this->message_body) . $nl : '') .

      ($this->http_custom_headers ? trim($this->http_custom_headers) . $nl : '') .

      $nl .

    '';

    /* post body */

    if ($http_mthd == 'POST') {

      $h_code .= $this->message_body . $nl;

    }

    /* connect */

    if ($this->useProxy($url)) {

      $s = @fsockopen($this->a['proxy_host'], $this->a['proxy_port']);

    }

    elseif ($parts['scheme'] == 'https') {

      $s = @fsockopen('ssl://' . $parts['host'], $parts['port']);

    }

    elseif ($parts['scheme'] == 'http') {

      $s = @fsockopen($parts['host'], $parts['port']);

    }

    if (!$s) {

      return $this->addError('Socket error: Could not connect to  "' . $url . '" (proxy: ' . ($this->useProxy($url) ? '1' : '0') . ')');

    }

    /* request */

    fwrite($s, $h_code);

    /* timeout */

    if ($this->timeout) stream_set_timeout($s, $this->timeout);

    /* response headers */

    $h = array();

    if (!$this->ping_only) {

      do {

        $line = trim(fgets($s, 256));

        if (preg_match("/^HTTP[^\s]+\s+([0-9]{1})([0-9]{2})(.*)$/i", $line, $m)) {/* response code */

          $error = in_array($m[1], array('4', '5')) ? $m[1] . $m[2] . ' ' . $m[3] : '';

          $error = ($m[1].$m[2] == '304') ? '304 '.$m[3] : $error;

          $h['response-code'] = $m[1] . $m[2];

          $h['error'] = $error;

          $h['redirect'] = ($m[1] == '3') ? true : false;

        }

        elseif (preg_match('/^([^\:]+)\:\s*(.*)$/', $line, $m)) {/* header */

          $h[strtolower($m[1])] = trim($m[2]);

        }

      } while(!feof($s) && $line);

      $h['format'] = strtolower(preg_replace('/^([^\s]+).*$/', '\\1', $this->v('content-type', '', $h)));

      $h['encoding'] = preg_match('/(utf\-8|iso\-8859\-1|us\-ascii)/', $this->v('content-type', '', $h), $m) ? strtoupper($m[1]) : '';

      $h['encoding'] = preg_match('/charset=\s*([^\s]+)/si', $this->v('content-type', '', $h), $m) ? strtoupper($m[1]) : $h['encoding'];

      /* result */

      if ($v = $this->v('error', 0, $h)) {

        //return $this->addError($error);

        return $this->addError($error . ' "' . (!feof($s) ? trim(strip_tags(fread($s, 64))) . '..."' : ''));

      }

      if ($this->v('redirect', 0, $h) && ($new_url = $this->v1('location', 0, $h))) {

        fclose($s);

        $this->redirects[$url] = $new_url;

        $this->base = $new_url;

        if ($redirs > $this->max_redirects) {

          return $this->addError('Max numbers of redirects exceeded.');

        }

        return $this->getHTTPSocket($new_url, $redirs+1);

      }

    }

    return array('type' => 'socket', 'url' => $url, 'socket' =>& $s, 'headers' => $h, 'pos' => 0, 'size' => $this->v('content-length', 0, $h), 'buffer' => '');

  }



  function readStream($buffer_xml = true, $d_size = 1024) {

    //if (!$s = $this->v('stream')) return '';

    if (!$s = $this->v('stream')) return $this->addError('missing stream in "readStream" ' . $this->uri);

    $s_type = $this->v('type', '', $s);

    $r = $s['buffer'];

    $s['buffer'] = '';

    if ($s['size']) $d_size = min($d_size, $s['size'] - $s['pos']);

    /* data */

    if ($s_type == 'data') {

      $d = ($d_size > 0) ? substr($s['data'], $s['pos'], $d_size) : '';

    }

    /* socket */

    elseif ($s_type == 'socket') {

      $d = ($d_size > 0) && !feof($s['socket']) ? fread($s['socket'], $d_size) : '';

    }

    $eof = $d ? false : true;

    /* chunked despite HTTP 1.0 request */

    if (isset($s['headers']) && isset($s['headers']['transfer-encoding']) && ($s['headers']['transfer-encoding'] == 'chunked')) {

      $d = preg_replace('/(^|[\r\n]+)[0-9a-f]{1,4}[\r\n]+/', '', $d);

    }

    $s['pos'] += strlen($d);

    if ($buffer_xml) {/* stop after last closing xml tag (if available) */

      if (preg_match('/^(.*\>)([^\>]*)$/s', $d, $m)) {

        $d = $m[1];

        $s['buffer'] = $m[2];

      }

      elseif (!$eof) {

        $s['buffer'] = $r . $d;

        $this->stream = $s;

        return $this->readStream(true, $d_size);

      }

    }

    $this->stream = $s;

    return $r . $d;

  }

  

  function closeStream() {

    if (isset($this->stream)) {

      if ($this->v('type', 0, $this->stream) == 'socket') {

        @fclose($this->stream['socket']);

      }

      unset($this->stream);

    }

  }

  

  /*  */

  

  function getFormat() {

    if (!$this->format) {

      if (!$this->v('stream')) {

        return $this->addError('missing stream in "getFormat"');

      }

      $v = $this->readStream(false);

      $mtype = $this->v('format', '', $this->stream['headers']);

      $this->stream['buffer'] = $v . $this->stream['buffer'];

      $ext = preg_match('/\.([^\.]+)$/', $this->uri, $m) ? $m[1] : '';

      $this->format = ARC2::getFormat($v, $mtype, $ext);

    }

    return $this->format;

  }

    

  /*  */

  

  function getEncoding($default = 'UTF-8') {

    return $this->v1('encoding', $default, $this->stream['headers']);

  }



  function getRedirects() {

    return $this->redirects;

  }

  

  /*  */

  

}