org.netfrag.glib/DesignPattern/RemoteProxy.php

<?php
/**
 * This file contains the DesignPattern::RemoteProxy class
 *
 * @author Andreas Motl <andreas.motl@ilo.de>
 * @package org.netfrag.glib
 * @name DesignPattern::RemoteProxy
 *
 *
 */


/**
 * <b>Cvs-Log:</b>
 *
 * <pre>
 * -------------------------------------------------------------------------
 *    $Id: RemoteProxy.php,v 1.9 2003/03/10 23:05:25 joko Exp $
 * -------------------------------------------------------------------------
 *    $Log: RemoteProxy.php,v $
 *    Revision 1.9  2003/03/10 23:05:25  joko
 *    + fixed metadata for phpDocumentor
 *
 *    Revision 1.8  2003/03/10 22:31:56  joko
 *    + fixed metadata for phpDocumentor
 *
 *    Revision 1.7  2003/03/09 15:51:44  joko
 *    + additional metadata for Autodia
 *
 *    Revision 1.6  2003/03/05 17:28:43  joko
 *    updated docu (phpDocumentor testing....)
 *
 *    Revision 1.5  2003/03/05 17:02:22  joko
 *    updated docu (phpDocumentor testing....)
 *
 *    Revision 1.4  2003/03/05 16:32:19  joko
 *    updated docu (phpDocumentor testing....)
 *
 *    Revision 1.3  2003/03/05 16:10:17  joko
 *    updated docu (phpDocumentor testing....)
 *
 *    Revision 1.2  2003/03/05 12:14:02  joko
 *    renamed method
 *    constructor argument expansion
 *
 *    Revision 1.1  2003/03/03 22:06:46  joko
 *    refactored from Data::Driver::Proxy
 *
 *    Revision 1.3  2003/03/01 04:56:38  joko
 *    new comment style for large blocks - stolen from phpHtmlLib
 *    commit-log encapsulated into such a block
 *    introduced some documentation
 *    refactored todo (now also inside a stylish block)
 *
 *    Revision 1.2  2003/02/13 21:48:09  joko
 *    + caching mechanisms more configurable now
 *
 *    Revision 1.1  2003/02/09 17:23:21  joko
 *    + refactored from flib/Application/RPC/ProxyObject.php
 *
 *    Revision 1.7  2003/02/03 03:31:38  jonen
 *    - moved '$encoder->toISO()' to 'Remote.php'
 *
 *    Revision 1.6  2002/12/22 13:26:20  jonen
 *    + added support of tangram independent id (e.g. Data::UUID) toggled by option at conrtuctor
 *
 *    Revision 1.5  2002/12/18 22:36:49  jonen
 *    + added support to get remote objects via backend via 'guid'
 *    + renamed '_loadBackend' to '_loadRemote'
 *    + constructor now accepts additional options:
 *      + remote: try to get object via '_loadRemote' ...
 *      + oid: use the given identifier as an 'oid' when doing '_loadRemote'
 *      + guid: use the given identifier as a 'guid' when doing '_loadRemote'
 *
 *    Revision 1.4  2002/12/12 02:46:31  joko
 *    + state (session) gets flushed when data was successfully loaded from remote side
 *    + fixed _loadBackend
 *    + fixed flushState
 *
 *    Revision 1.3  2002/12/06 04:12:54  joko
 *    + replaced 'xyzCache' through 'xyzProxy'
 *    + function store(...)
 *
 *    Revision 1.2  2002/12/05 21:44:09  joko
 *    + debugging
 *
 *    Revision 1.1  2002/12/01 17:23:58  joko
 *    + initial check-in
 *
 *    Revision 1.11  2002/11/12 06:05:58  cvsjoko
 *    + renamed class: Text_Encode -> TextEncode
 *
 *    Revision 1.10  2002/10/29 19:15:33  cvsjoko
 *    - moved utf8/iso-conversion to lib/utils/Text_Encode.php
 *
 *    Revision 1.9  2002/10/26 12:32:36  cvsjoko
 *    - removed debugging via "print"
 *    + added generic logging via PEAR::Log
 *
 *    Revision 1.8  2002/10/22 09:51:38  cvsmax
 *    + moved semi-method 'createBackend' to method $site->user->create at User.class.php
 *
 *    Revision 1.7  2002/10/21 18:27:09  cvsjoko
 *    - manually disabled any form of caching
 *
 *    Revision 1.6  2002/10/17 03:48:47  cvsmax
 *    + new
 *       + function _createBackend      create new Backend
 *       + function _create             api-create
 *
 *    Revision 1.5  2002/10/16 03:37:54  cvsjoko
 *    + bugfix: wrong comparison in restriction to save to array
 *
 *    Revision 1.4  2002/10/10 03:04:23  cvsjoko
 *    + no debug-output
 *
 *    Revision 1.3  2002/10/10 03:03:27  cvsjoko
 *    + bugfix: save object to cache only if payload from backend isn't empty
 *
 *    Revision 1.2  2002/10/10 02:40:06  cvsjoko
 *    + new level of data-caching (session and persistant)
 *        + function _loadState loads data from session
 *        + function _saveState saves data to session
 *        + function save               api-save (session & backend)
 *        + function _commit    saves data to backend
 *    + handy utils
 *        + function _setAttributes
 *        + function flushState
 *
 *    Revision 1.1  2002/10/09 00:51:39  cvsjoko
 *    + new
 * -------------------------------------------------------------------------
 * </pre>
 *
 */


/**
 * Load required modules:
 *
 */
loadModule('DesignPattern::Proxy');


/**
 * DesignPattern::RemoteProxy  --  Multiple stage data fetching and caching
 *
 *
 * This class (DesignPattern::RemoteProxy) provides an abstract framework 
 * for loading/saving arbitrary data from/to data storages interfaced 
 * by storage *proxy*-drivers.
 * Don't mix these up with the concrete storage *handle*-drivers 
 * doing the lowlevel stuff (opening files, talking sql, etc.).
 * These proxy-drivers are "just" wrappers around them 
 * providing a more highlevel, consistent API making
 * it easier for Data::Driver::Proxy to do its main work:
 *
 * quote from: http://home.earthlink.net/~huston2/dp/proxy.html
 * "A remote proxy provides a local representative for an 
 * object that resides in a different address space. This is 
 * what the "stub" code in RPC and CORBA provides."
 *
 *
 * Multiple stage data fetching and caching:
 *
 * <pre>
 *
 * DATA, ...
 *    ... also refered to as data, should be handled as 
 *    something called data.
 *
 * STAGES
 *    x native php4 session: serialized payload
 *    x single rdbms table: serialized payload
 *       x ... via custom database wrapper
 *          x included php-file, included php-library
 *          o object, component, package, callbacks
 *       x ... via php PEAR DB abstraction objects
 *    x remote objects (items): flat attribute hash
 *       o use Data::Object::Identity
 *       o via Data::Driver::Proxy::RPC or others
 *       o Data::Object::Encoder: encodes/decodes values
 *       o Data::Object::Interpolator: interpolates/resolves references
 * 
 * WORK
 *    x move data transparently around between these stages
 *
 * TOOLS
 *
 * x Overview - Packages, Handlers and Stages:
 *     This is weird.  ;-)
 *     - A Package can be instantiated by its namespaced classname
 *       e.g.: "mkObject('My::Package');"
 *     - A Package can be a Handler for Data::Driver::Proxy
 *     - A Handler implements exactly one Stage
 *     - Data::Driver::Proxy itself embeds these Stages:
 *        x php4-session
 *        x rdbms-table
 *     - An example Handler is Data::Driver::RPC::Remote
 *
 * x Handlers:
 *    x Data::Driver::RPC::Remote
 *        Interacts with a RPC::XML server (todo: talk SOAP!) 
 *        using PEAR::XML::RPC.
 *        It can cache data for "disconnected mode" using the
 *    o Data::Driver::phpHtmlLib
 *    o Data::Driver::PEAR::DB
 *    x Data::Driver::PEAR::Tree (via Data::Lift)
 *
 * </pre>
 *
 *
 * An attempt to implement some software design patterns
 * --- RemoteProxyPattern
 *
 * @link http://www.agcs.com/supportv2/techpapers/patterns/papers/tutnotes/sld017.htm
 * @link http://home.earthlink.net/~huston2/dp/proxy.html
 * @link http://wiki.cs.uiuc.edu/PatternStories/RemoteObject
 * @link http://c2.com/cgi-bin/wiki?ProxyPattern
 * @link http://c2.com/cgi-bin/wiki?LazyProxies
 *
 * @author Andreas Motl <andreas.motl@ilo.de>
 * @link http://www.netfrag.org/~joko/
 *
 * @copyright (c) 2003 - All Rights reserved.
 * @license GNU LGPL (GNU Lesser General Public License)
 * @link http://www.gnu.org/licenses/lgpl.txt
 *
 * @package org.netfrag.glib
 * @subpackage DesignPattern
 * @name DesignPattern::RemoteProxy
 *
 *
 * @todo extend options to en-/disable caching via a) session and/or b) database
 *           make feature available via runtime setter-method to these options
 * @todo PEAR::Cache for caching purposes!!!
 * @todo refactor database access: use PEAR for this! no more 'connectdb' here!!!
 * @todo make database connection more flexible to make possible
 *           to have different (probably named) proxy databases (besides a "main database")
 * @todo rename this to Data::Proxy? or split into Data::Query, Data::Result and Data::Wrapper?
 * @todo refactor this to a "RemoteObject" class!!! (inheriting from DesignPattern::RemoteObject)
 * @todo rename this to "DesignPattern::LazyRemoteProxy"???
 *
 */
class DesignPattern_RemoteProxy extends DesignPattern_Proxy {

  var $objectId;
  // purpose ...
  var $meta;
  var $payload;
  var $attributes;
  var $backend;

  function DesignPattern_RemoteProxy($objectId = "", $options = array() ) {
    logp(get_class($this) . "->new()", PEAR_LOG_INFO);
    global $proxy;

    // 2003-03-05 - modified constructor
    // expand objectId
    if (is_array($objectId)) {
      $options = $objectId[1];
      $objectId = $objectId[0];
    }

    // trace
      //print Dumper($objectId, $options);

    // initialization/startup
      $this->_init_meta_options($objectId, $options);
      $this->_init_caching();
      $this->_init_load();

    //print Dumper($this);

  }

  function _init_meta_options( $objectId="", $options = array() ) {
    $this->meta = $options;

    if ($objectId) {
      $this->objectId = $objectId;
      
      // set default load mechanism
      if ( $this->meta[remote] && ((!$this->meta[oid] && !$this->meta[guid]) || ($this->meta[oid] && $this->meta[guid])) && (!$this->meta[key]) ) {
        $this->meta[oid] = 1;
      }
      
    }
  }

  function _init_caching() {
    
    if ($this->meta[cache][session]) {
      session_register_safe("proxy");
    }  

    /**
     * <!-- Autodia -->
     * can do: (this is metadata supplied for Autodia, don't delete!)
     *  $this->backend = new DataSource_Proxy_XMLRPC()
     *
     */

    if ($this->meta[remote]) {
      //$this->backend = mkObject('Data::Driver::RPC::Remote', $this->meta[rpcinfo]);
      $this->backend = php::mkComponent('DataSource::Proxy::XMLRPC', $this->meta[rpcinfo]);
    }
  }

  function _init_load() {
    if ($this->objectId) {
      $this->load();
      //$this->_saveProxy();
    }
  }


  function load() {
    logp(get_class($this) . "->load()", PEAR_LOG_INFO);
    if (!$this->_loadState()) {
      if (!$this->_loadProxy()) {

        // just load object from remote side if its flagged to be a remote one ...
        if ($this->meta[remote]) {
          $this->_loadRemote();
        }

      }
    }
  }  

  function save($data, $type) {
    $this->_setAttributes($data);
    $this->_saveState();
    if ($type == 'commit') {
      $this->_commit();
    }
    if ($type == 'create') {
      $this->_create();
    }
  }  

  function flush() {
    $this->flushState();
    $this->flushProxy();
  }      

  function _commit() {
    $this->_saveBackend($this->attributes);
    $this->flushState();
    $this->flushProxy();
  }  


  // TODO: make this work
  /*
  function _create() {
    $this->_createBackend($this->attributes);
    $this->flushState();
    $this->flushProxy();
  }  
  */

  function getResult() {
    if (!$this->meta[decoded]) {
      $this->_decode();
      $this->_saveState();
    }
    return $this->attributes;
  }

  function _setAttributes($data) {
    $this->attributes = $data;
  }

  function flushProxy() {
        connectdb();
    $sql = "DELETE FROM f_proxy WHERE oid='$this->objectId'";
    send_sql($sql);
  }
  
  function flushState() {
    global $proxy;
    unset($proxy[$this->objectId]);
    $this->meta[decoded] = 0;
  }

  function _loadState() {
    global $proxy;

    // trace
      //print Dumper($this);

    // debug
      logp(get_class($this) . "->_loadState()");
      
    if ($this->attributes = $proxy[$this->objectId]) {
      //print "_loadState:" . dumpVar($this->attributes);
      $this->meta[decoded] = 1;
      // TODO: make a parameter from this (0 deactivates session-layer)
      return 0;
    }
  }

  function _saveState() {
    global $proxy;
    logp(get_class($this) . "->_saveState()");
    $proxy[$this->objectId] = $this->attributes;
    //print "_saveState: " . dumpVar($this->attributes);
    // TODO: throw exception-message back to user if operation fails
  }

  function _loadProxy() {
    
    // FIXME!
    if (!$this->meta[cache][db]) { return; }
    
    // trace & debug
      //print Dumper($this);
      logp(get_class($this) . "->_loadProxy()");
      
    connectdb();
    $sql = "SELECT payload FROM f_proxy WHERE oid='$this->objectId'";
    if ($res = send_sql($sql)) {
      $row = mysql_fetch_array($res, MYSQL_ASSOC);
      if ($row) {
        $this->payload = $row[payload];
        // TODO: make a parameter from this (0 deactivates mysqldb-layer)
        return 0;
      }
    }
  }
  
  // TODO: use PEAR here
  function _saveProxy() {

    // FIXME!
    if (!$this->meta[cache][db]) { return; }

    logp(get_class($this) . "->_saveProxy()");
        connectdb();
        if ($this->payload) {
      //$sql = "INSERT INTO f_proxy SET payload='$this->payload' WHERE oid='$this->objectId'";
      $sql = "INSERT INTO f_proxy SET oid='$this->objectId', payload='$this->payload'";
      if (!send_sql($sql)) {
        $sql = "UPDATE f_proxy SET payload='$this->payload' WHERE oid='$this->objectId'";
        send_sql($sql);
      }
    }
  }
  
  function _loadRemote() {
    logp(get_class($this) . "->_loadRemote()");
    
    // trace
      //print Dumper($this->meta);
        
    // TODO: test backend for reachability first (eventually cache this information and "reset" it by another party)
    
    // 1. check backend-handle
    if (!$this->backend) {
      logp(get_class($this) . "->_loadRemote: no backend handle, please check argument 'rpcinfo'", PEAR_LOG_CRIT);
      return;
    }
    
    // determine backend action by metadata
      // check for guid or oid
      if ($this->meta[guid]) {
        if (!$this->objectId) {
          logp(get_class($this) . "->_loadRemote: argument 'guid' requires valid objectId", PEAR_LOG_WARNING);
          return;
        }
        if (!$this->meta[classname]) {
          logp(get_class($this) . "->_loadRemote: argument 'guid' requires 'classname'", PEAR_LOG_WARNING);
          return;
        }
        logp(get_class($this) . "->_loadRemote: getObjectByGuid", PEAR_LOG_DEBUG);
        $args = array( guid => $this->objectId, classname => $this->meta[classname] );
        $result = $this->backend->send('getObjectByGuid', $args );

      } elseif ($this->meta[oid]) {
        if (!$this->objectId) {
          logp(get_class($this) . "->_loadRemote: argument 'oid' requires valid objectId", PEAR_LOG_WARNING);
          return;
        }
        logp(get_class($this) . "->_loadRemote: getObject", PEAR_LOG_DEBUG);
        $result = $this->backend->send('getObject', $this->objectId);

      } elseif ($this->meta[key]) {
        if (!$this->meta[command]) {
          logp(get_class($this) . "->_loadRemote: argument 'key' requires 'command'", PEAR_LOG_WARNING);
          return;
        }
        /*
        if (!$this->meta[query]) {
          logp(get_class($this) . "->_loadRemote: argument 'key' requires 'query'", PEAR_LOG_WARNING);
          return;
        }
        */
        //logp(get_class($this) . "->_loadRemote: $this->meta[command](" . join(' ', $this->meta[query]) . ")", PEAR_LOG_DEBUG);
        //print Dumper(array($this->meta[command], $this->meta[query]));
        $result = $this->backend->send($this->meta[command], $this->meta[query]);
        
      }

    //print "result: " . dumpVar($result) . "<br>";

    $status = $this->backend->getStatus();
    //print Dumper($status);
    
    $style = html_style("text/css", '.caption { color: yellow }');
    
    $statusbox = html_div();
    $statusbox->set_style('background: #558856; border: 2px black groove; width:640px; padding:10px; margin:40px;');
    $statusbox->add( html_b("Connected:"), $status[connected], html_br() );
    $statusbox->add( html_span('caption', "Connected:"), $status[connected], html_br() );
    foreach ($status[errors] as $error) {
      $statusbox->add( html_span('caption', "Error[$error[code]]:"), $error[message], html_br() );
    }
    
    if (is_array($result)) {
      $good = 1;
    } else {
      $message = get_class($this) . "->_loadRemote: Error while trying to talk to remote side. Please check wire, socket or api.";
      $statusbox->add( $message, html_br() );
      logp($message, PEAR_LOG_CRIT);
    }

    if ($good && sizeof($result)) {
      
      // FIXME: this is dangerous!
      if ($_GET[debug]) {
        print Dumper($result);
      }
      
      $this->payload = serialize($result);
      // ----- move this to _encode some times
      
      $this->_saveProxy();
      //print "oid: $this->objectId<br>";
      $this->flushState();
    
    } else {
      print $style->render();
      print $statusbox->render();
    
    }
    
  }
  
  function _saveBackend($result) {
    logp(get_class($this) . "->_saveBackend()");

    //$encoder = new TextEncode($result);
    //$encoder->toUTF8();

    // check for guid or oid
    if($this->meta[guid]) {
      $args = array( 'guid' => $this->objectId, 'classname' => $this->meta[classname], 'data' => $result );
      $response = $this->backend->send('saveObjectByGuid', $args, array( utf8 => 1) );
    }
    if($this->meta[oid]) {
      $response = $this->backend->send('saveObject', array('oid' => $this->objectId, 'data' => $result), array( utf8 => 1)  );
    }
  }

  function _decode() {
    // fill attributes-hashtable from message-hashtable
    if (!$this->payload) { return; }
    //if ($this->attributes = $backend->decodeData($this->payload)) {
    if ($this->attributes = unserialize($this->payload)) {
      $this->meta[decoded] = 1;
    }
  }
  
  function store($struct) {
    $this->payload = serialize($struct);
    $this->_saveProxy();
  }

}

?>
1	joko	1.1	<?php
2	joko	1.3	/**
3			* This file contains the DesignPattern::RemoteProxy class
4			*
5			* @author Andreas Motl <andreas.motl@ilo.de>
6			* @package org.netfrag.glib
7			* @name DesignPattern::RemoteProxy
8			*
9	joko	1.4	*
10	joko	1.9	*/
11
12
13			/**
14	joko	1.4	* <b>Cvs-Log:</b>
15			*
16			* <pre>
17	joko	1.1	* -------------------------------------------------------------------------
18	joko	1.10	* $Id: RemoteProxy.php,v 1.9 2003/03/10 23:05:25 joko Exp $
19	joko	1.1	* -------------------------------------------------------------------------
20	joko	1.2	* $Log: RemoteProxy.php,v $
21	joko	1.10	* Revision 1.9 2003/03/10 23:05:25 joko
22			* + fixed metadata for phpDocumentor
23			*
24	joko	1.9	* Revision 1.8 2003/03/10 22:31:56 joko
25			* + fixed metadata for phpDocumentor
26			*
27	joko	1.8	* Revision 1.7 2003/03/09 15:51:44 joko
28			* + additional metadata for Autodia
29			*
30	joko	1.7	* Revision 1.6 2003/03/05 17:28:43 joko
31			* updated docu (phpDocumentor testing....)
32			*
33	joko	1.6	* Revision 1.5 2003/03/05 17:02:22 joko
34			* updated docu (phpDocumentor testing....)
35			*
36	joko	1.5	* Revision 1.4 2003/03/05 16:32:19 joko
37			* updated docu (phpDocumentor testing....)
38			*
39	joko	1.4	* Revision 1.3 2003/03/05 16:10:17 joko
40			* updated docu (phpDocumentor testing....)
41			*
42	joko	1.3	* Revision 1.2 2003/03/05 12:14:02 joko
43			* renamed method
44			* constructor argument expansion
45			*
46	joko	1.2	* Revision 1.1 2003/03/03 22:06:46 joko
47			* refactored from Data::Driver::Proxy
48			*
49	joko	1.1	* Revision 1.3 2003/03/01 04:56:38 joko
50			* new comment style for large blocks - stolen from phpHtmlLib
51			* commit-log encapsulated into such a block
52			* introduced some documentation
53			* refactored todo (now also inside a stylish block)
54			*
55			* Revision 1.2 2003/02/13 21:48:09 joko
56			* + caching mechanisms more configurable now
57			*
58			* Revision 1.1 2003/02/09 17:23:21 joko
59			* + refactored from flib/Application/RPC/ProxyObject.php
60			*
61			* Revision 1.7 2003/02/03 03:31:38 jonen
62			* - moved '$encoder->toISO()' to 'Remote.php'
63			*
64			* Revision 1.6 2002/12/22 13:26:20 jonen
65			* + added support of tangram independent id (e.g. Data::UUID) toggled by option at conrtuctor
66			*
67			* Revision 1.5 2002/12/18 22:36:49 jonen
68			* + added support to get remote objects via backend via 'guid'
69			* + renamed '_loadBackend' to '_loadRemote'
70			* + constructor now accepts additional options:
71			* + remote: try to get object via '_loadRemote' ...
72			* + oid: use the given identifier as an 'oid' when doing '_loadRemote'
73			* + guid: use the given identifier as a 'guid' when doing '_loadRemote'
74			*
75			* Revision 1.4 2002/12/12 02:46:31 joko
76			* + state (session) gets flushed when data was successfully loaded from remote side
77			* + fixed _loadBackend
78			* + fixed flushState
79			*
80			* Revision 1.3 2002/12/06 04:12:54 joko
81			* + replaced 'xyzCache' through 'xyzProxy'
82			* + function store(...)
83			*
84			* Revision 1.2 2002/12/05 21:44:09 joko
85			* + debugging
86			*
87			* Revision 1.1 2002/12/01 17:23:58 joko
88			* + initial check-in
89			*
90			* Revision 1.11 2002/11/12 06:05:58 cvsjoko
91			* + renamed class: Text_Encode -> TextEncode
92			*
93			* Revision 1.10 2002/10/29 19:15:33 cvsjoko
94			* - moved utf8/iso-conversion to lib/utils/Text_Encode.php
95			*
96			* Revision 1.9 2002/10/26 12:32:36 cvsjoko
97			* - removed debugging via "print"
98			* + added generic logging via PEAR::Log
99			*
100			* Revision 1.8 2002/10/22 09:51:38 cvsmax
101			* + moved semi-method 'createBackend' to method $site->user->create at User.class.php
102			*
103			* Revision 1.7 2002/10/21 18:27:09 cvsjoko
104			* - manually disabled any form of caching
105			*
106			* Revision 1.6 2002/10/17 03:48:47 cvsmax
107			* + new
108			* + function _createBackend create new Backend
109			* + function _create api-create
110			*
111			* Revision 1.5 2002/10/16 03:37:54 cvsjoko
112			* + bugfix: wrong comparison in restriction to save to array
113			*
114			* Revision 1.4 2002/10/10 03:04:23 cvsjoko
115			* + no debug-output
116			*
117			* Revision 1.3 2002/10/10 03:03:27 cvsjoko
118			* + bugfix: save object to cache only if payload from backend isn't empty
119			*
120			* Revision 1.2 2002/10/10 02:40:06 cvsjoko
121			* + new level of data-caching (session and persistant)
122			* + function _loadState loads data from session
123			* + function _saveState saves data to session
124			* + function save api-save (session & backend)
125			* + function _commit saves data to backend
126			* + handy utils
127			* + function _setAttributes
128			* + function flushState
129			*
130			* Revision 1.1 2002/10/09 00:51:39 cvsjoko
131			* + new
132			* -------------------------------------------------------------------------
133	joko	1.4	* </pre>
134			*
135	joko	1.1	*/
136
137	joko	1.4
138
139
140			/**
141			* Load required modules:
142			*
143			*/
144			loadModule('DesignPattern::Proxy');
145
146
147	joko	1.1	/**
148	joko	1.7	* DesignPattern::RemoteProxy -- Multiple stage data fetching and caching
149	joko	1.1	*
150			*
151	joko	1.7	* This class (DesignPattern::RemoteProxy) provides an abstract framework
152	joko	1.1	* for loading/saving arbitrary data from/to data storages interfaced
153			* by storage proxy-drivers.
154			* Don't mix these up with the concrete storage handle-drivers
155			* doing the lowlevel stuff (opening files, talking sql, etc.).
156			* These proxy-drivers are "just" wrappers around them
157			* providing a more highlevel, consistent API making
158			* it easier for Data::Driver::Proxy to do its main work:
159			*
160	joko	1.7	* quote from: http://home.earthlink.net/~huston2/dp/proxy.html
161			* "A remote proxy provides a local representative for an
162			* object that resides in a different address space. This is
163			* what the "stub" code in RPC and CORBA provides."
164			*
165			*
166	joko	1.1	* Multiple stage data fetching and caching:
167			*
168	joko	1.4	* <pre>
169			*
170	joko	1.1	* DATA, ...
171			* ... also refered to as data, should be handled as
172			* something called data.
173			*
174			* STAGES
175			* x native php4 session: serialized payload
176			* x single rdbms table: serialized payload
177			* x ... via custom database wrapper
178			* x included php-file, included php-library
179			* o object, component, package, callbacks
180			* x ... via php PEAR DB abstraction objects
181			* x remote objects (items): flat attribute hash
182			* o use Data::Object::Identity
183			* o via Data::Driver::Proxy::RPC or others
184			* o Data::Object::Encoder: encodes/decodes values
185			* o Data::Object::Interpolator: interpolates/resolves references
186			*
187			* WORK
188			* x move data transparently around between these stages
189			*
190			* TOOLS
191			*
192			* x Overview - Packages, Handlers and Stages:
193			* This is weird. ;-)
194			* - A Package can be instantiated by its namespaced classname
195			* e.g.: "mkObject('My::Package');"
196			* - A Package can be a Handler for Data::Driver::Proxy
197			* - A Handler implements exactly one Stage
198			* - Data::Driver::Proxy itself embeds these Stages:
199			* x php4-session
200			* x rdbms-table
201			* - An example Handler is Data::Driver::RPC::Remote
202			*
203			* x Handlers:
204			* x Data::Driver::RPC::Remote
205			* Interacts with a RPC::XML server (todo: talk SOAP!)
206			* using PEAR::XML::RPC.
207			* It can cache data for "disconnected mode" using the
208			* o Data::Driver::phpHtmlLib
209			* o Data::Driver::PEAR::DB
210			* x Data::Driver::PEAR::Tree (via Data::Lift)
211			*
212	joko	1.4	* </pre>
213			*
214			*
215			* An attempt to implement some software design patterns
216	joko	1.3	* --- RemoteProxyPattern
217			*
218	joko	1.7	* @link http://www.agcs.com/supportv2/techpapers/patterns/papers/tutnotes/sld017.htm
219			* @link http://home.earthlink.net/~huston2/dp/proxy.html
220			* @link http://wiki.cs.uiuc.edu/PatternStories/RemoteObject
221	joko	1.3	* @link http://c2.com/cgi-bin/wiki?ProxyPattern
222	joko	1.7	* @link http://c2.com/cgi-bin/wiki?LazyProxies
223	joko	1.3	*
224			* @author Andreas Motl <andreas.motl@ilo.de>
225			* @link http://www.netfrag.org/~joko/
226			*
227			* @copyright (c) 2003 - All Rights reserved.
228			* @license GNU LGPL (GNU Lesser General Public License)
229			* @link http://www.gnu.org/licenses/lgpl.txt
230			*
231			* @package org.netfrag.glib
232	joko	1.6	* @subpackage DesignPattern
233	joko	1.3	* @name DesignPattern::RemoteProxy
234			*
235	joko	1.4	*
236	joko	1.7	* @todo extend options to en-/disable caching via a) session and/or b) database
237			* make feature available via runtime setter-method to these options
238			* @todo PEAR::Cache for caching purposes!!!
239			* @todo refactor database access: use PEAR for this! no more 'connectdb' here!!!
240			* @todo make database connection more flexible to make possible
241			* to have different (probably named) proxy databases (besides a "main database")
242			* @todo rename this to Data::Proxy? or split into Data::Query, Data::Result and Data::Wrapper?
243			* @todo refactor this to a "RemoteObject" class!!! (inheriting from DesignPattern::RemoteObject)
244			* @todo rename this to "DesignPattern::LazyRemoteProxy"???
245	joko	1.1	*
246			*/
247			class DesignPattern_RemoteProxy extends DesignPattern_Proxy {
248
249			var $objectId;
250			// purpose ...
251			var $meta;
252			var $payload;
253			var $attributes;
254			var $backend;
255
256			function DesignPattern_RemoteProxy($objectId = "", $options = array() ) {
257			logp(get_class($this) . "->new()", PEAR_LOG_INFO);
258			global $proxy;
259
260	joko	1.2	// 2003-03-05 - modified constructor
261			// expand objectId
262			if (is_array($objectId)) {
263			$options = $objectId[1];
264			$objectId = $objectId[0];
265			}
266
267	joko	1.1	// trace
268			//print Dumper($objectId, $options);
269
270			// initialization/startup
271			$this->_init_meta_options($objectId, $options);
272			$this->_init_caching();
273			$this->_init_load();
274
275	joko	1.2	//print Dumper($this);
276
277	joko	1.1	}
278
279			function _init_meta_options( $objectId="", $options = array() ) {
280			$this->meta = $options;
281
282			if ($objectId) {
283			$this->objectId = $objectId;
284
285			// set default load mechanism
286			if ( $this->meta[remote] && ((!$this->meta[oid] && !$this->meta[guid]) \|\| ($this->meta[oid] && $this->meta[guid])) && (!$this->meta[key]) ) {
287			$this->meta[oid] = 1;
288			}
289
290			}
291			}
292
293			function _init_caching() {
294
295			if ($this->meta[cache][session]) {
296			session_register_safe("proxy");
297			}
298	joko	1.7
299			/**
300			* <!-- Autodia -->
301			* can do: (this is metadata supplied for Autodia, don't delete!)
302			* $this->backend = new DataSource_Proxy_XMLRPC()
303			*
304			*/
305	joko	1.1
306			if ($this->meta[remote]) {
307			//$this->backend = mkObject('Data::Driver::RPC::Remote', $this->meta[rpcinfo]);
308	joko	1.2	$this->backend = php::mkComponent('DataSource::Proxy::XMLRPC', $this->meta[rpcinfo]);
309	joko	1.1	}
310			}
311
312			function _init_load() {
313			if ($this->objectId) {
314			$this->load();
315			//$this->_saveProxy();
316			}
317			}
318
319
320			function load() {
321			logp(get_class($this) . "->load()", PEAR_LOG_INFO);
322			if (!$this->_loadState()) {
323			if (!$this->_loadProxy()) {
324
325			// just load object from remote side if its flagged to be a remote one ...
326			if ($this->meta[remote]) {
327			$this->_loadRemote();
328			}
329
330			}
331			}
332			}
333
334			function save($data, $type) {
335			$this->_setAttributes($data);
336			$this->_saveState();
337			if ($type == 'commit') {
338			$this->_commit();
339			}
340			if ($type == 'create') {
341			$this->_create();
342			}
343			}
344
345			function flush() {
346			$this->flushState();
347			$this->flushProxy();
348			}
349
350			function _commit() {
351			$this->_saveBackend($this->attributes);
352			$this->flushState();
353			$this->flushProxy();
354			}
355
356
357			// TODO: make this work
358			/*
359			function _create() {
360			$this->_createBackend($this->attributes);
361			$this->flushState();
362			$this->flushProxy();
363			}
364			*/
365
366	joko	1.2	function getResult() {
367	joko	1.1	if (!$this->meta[decoded]) {
368			$this->_decode();
369			$this->_saveState();
370			}
371			return $this->attributes;
372			}
373
374			function _setAttributes($data) {
375			$this->attributes = $data;
376			}
377
378			function flushProxy() {
379			connectdb();
380			$sql = "DELETE FROM f_proxy WHERE oid='$this->objectId'";
381			send_sql($sql);
382			}
383
384			function flushState() {
385			global $proxy;
386			unset($proxy[$this->objectId]);
387			$this->meta[decoded] = 0;
388			}
389
390			function _loadState() {
391			global $proxy;
392
393			// trace
394			//print Dumper($this);
395
396			// debug
397			logp(get_class($this) . "->_loadState()");
398
399			if ($this->attributes = $proxy[$this->objectId]) {
400			//print "_loadState:" . dumpVar($this->attributes);
401			$this->meta[decoded] = 1;
402			// TODO: make a parameter from this (0 deactivates session-layer)
403			return 0;
404			}
405			}
406
407			function _saveState() {
408			global $proxy;
409			logp(get_class($this) . "->_saveState()");
410			$proxy[$this->objectId] = $this->attributes;
411			//print "_saveState: " . dumpVar($this->attributes);
412			// TODO: throw exception-message back to user if operation fails
413			}
414
415			function _loadProxy() {
416
417			// FIXME!
418			if (!$this->meta[cache][db]) { return; }
419
420			// trace & debug
421			//print Dumper($this);
422			logp(get_class($this) . "->_loadProxy()");
423
424			connectdb();
425			$sql = "SELECT payload FROM f_proxy WHERE oid='$this->objectId'";
426			if ($res = send_sql($sql)) {
427			$row = mysql_fetch_array($res, MYSQL_ASSOC);
428			if ($row) {
429			$this->payload = $row[payload];
430			// TODO: make a parameter from this (0 deactivates mysqldb-layer)
431			return 0;
432			}
433			}
434			}
435
436			// TODO: use PEAR here
437			function _saveProxy() {
438
439			// FIXME!
440			if (!$this->meta[cache][db]) { return; }
441
442			logp(get_class($this) . "->_saveProxy()");
443			connectdb();
444			if ($this->payload) {
445			//$sql = "INSERT INTO f_proxy SET payload='$this->payload' WHERE oid='$this->objectId'";
446			$sql = "INSERT INTO f_proxy SET oid='$this->objectId', payload='$this->payload'";
447			if (!send_sql($sql)) {
448			$sql = "UPDATE f_proxy SET payload='$this->payload' WHERE oid='$this->objectId'";
449			send_sql($sql);
450			}
451			}
452			}
453
454			function _loadRemote() {
455			logp(get_class($this) . "->_loadRemote()");
456
457			// trace
458			//print Dumper($this->meta);
459
460			// TODO: test backend for reachability first (eventually cache this information and "reset" it by another party)
461
462			// 1. check backend-handle
463			if (!$this->backend) {
464			logp(get_class($this) . "->_loadRemote: no backend handle, please check argument 'rpcinfo'", PEAR_LOG_CRIT);
465			return;
466			}
467
468			// determine backend action by metadata
469			// check for guid or oid
470			if ($this->meta[guid]) {
471			if (!$this->objectId) {
472			logp(get_class($this) . "->_loadRemote: argument 'guid' requires valid objectId", PEAR_LOG_WARNING);
473			return;
474			}
475			if (!$this->meta[classname]) {
476			logp(get_class($this) . "->_loadRemote: argument 'guid' requires 'classname'", PEAR_LOG_WARNING);
477			return;
478			}
479	joko	1.10	logp(get_class($this) . "->_loadRemote: getObjectByGuid", PEAR_LOG_DEBUG);
480	joko	1.1	$args = array( guid => $this->objectId, classname => $this->meta[classname] );
481			$result = $this->backend->send('getObjectByGuid', $args );
482
483			} elseif ($this->meta[oid]) {
484			if (!$this->objectId) {
485			logp(get_class($this) . "->_loadRemote: argument 'oid' requires valid objectId", PEAR_LOG_WARNING);
486			return;
487			}
488	joko	1.10	logp(get_class($this) . "->_loadRemote: getObject", PEAR_LOG_DEBUG);
489	joko	1.1	$result = $this->backend->send('getObject', $this->objectId);
490
491			} elseif ($this->meta[key]) {
492			if (!$this->meta[command]) {
493			logp(get_class($this) . "->_loadRemote: argument 'key' requires 'command'", PEAR_LOG_WARNING);
494			return;
495			}
496			/*
497			if (!$this->meta[query]) {
498			logp(get_class($this) . "->_loadRemote: argument 'key' requires 'query'", PEAR_LOG_WARNING);
499			return;
500			}
501			*/
502	joko	1.10	//logp(get_class($this) . "->_loadRemote: $this->meta[command](" . join(' ', $this->meta[query]) . ")", PEAR_LOG_DEBUG);
503			//print Dumper(array($this->meta[command], $this->meta[query]));
504	joko	1.1	$result = $this->backend->send($this->meta[command], $this->meta[query]);
505
506			}
507
508	joko	1.10	//print "result: " . dumpVar($result) . "<br>";
509	joko	1.1
510	joko	1.10	$status = $this->backend->getStatus();
511			//print Dumper($status);
512
513			$style = html_style("text/css", '.caption { color: yellow }');
514
515			$statusbox = html_div();
516			$statusbox->set_style('background: #558856; border: 2px black groove; width:640px; padding:10px; margin:40px;');
517			$statusbox->add( html_b("Connected:"), $status[connected], html_br() );
518			$statusbox->add( html_span('caption', "Connected:"), $status[connected], html_br() );
519			foreach ($status[errors] as $error) {
520			$statusbox->add( html_span('caption', "Error[$error[code]]:"), $error[message], html_br() );
521			}
522	joko	1.1
523	joko	1.10	if (is_array($result)) {
524			$good = 1;
525			} else {
526			$message = get_class($this) . "->_loadRemote: Error while trying to talk to remote side. Please check wire, socket or api.";
527			$statusbox->add( $message, html_br() );
528			logp($message, PEAR_LOG_CRIT);
529			}
530
531			if ($good && sizeof($result)) {
532	joko	1.1
533			// FIXME: this is dangerous!
534			if ($_GET[debug]) {
535			print Dumper($result);
536			}
537
538			$this->payload = serialize($result);
539			// ----- move this to _encode some times
540
541			$this->_saveProxy();
542			//print "oid: $this->objectId<br>";
543			$this->flushState();
544	joko	1.10
545	joko	1.1	} else {
546	joko	1.10	print $style->render();
547			print $statusbox->render();
548
549	joko	1.1	}
550
551			}
552
553			function _saveBackend($result) {
554			logp(get_class($this) . "->_saveBackend()");
555
556			//$encoder = new TextEncode($result);
557			//$encoder->toUTF8();
558
559			// check for guid or oid
560			if($this->meta[guid]) {
561			$args = array( 'guid' => $this->objectId, 'classname' => $this->meta[classname], 'data' => $result );
562			$response = $this->backend->send('saveObjectByGuid', $args, array( utf8 => 1) );
563			}
564			if($this->meta[oid]) {
565			$response = $this->backend->send('saveObject', array('oid' => $this->objectId, 'data' => $result), array( utf8 => 1) );
566			}
567			}
568
569			function _decode() {
570			// fill attributes-hashtable from message-hashtable
571			if (!$this->payload) { return; }
572			//if ($this->attributes = $backend->decodeData($this->payload)) {
573			if ($this->attributes = unserialize($this->payload)) {
574			$this->meta[decoded] = 1;
575			}
576			}
577
578			function store($struct) {
579			$this->payload = serialize($struct);
580			$this->_saveProxy();
581			}
582
583			}
584
585			?>
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