widgets/data_source/ProxyDataSource.inc

<?php

/**
 * This file contains the ProxyDataSource child class
 * that uses the Data::Driver::Proxy object to talk to a remote rpc server.
 *
 * Data::Driver::Proxy uses a PEAR XML::RPC object to actually
 * talk HTTP and serialize data chunks to and from XML,
 * but adds some caching to this "process of fetching data from a remote side".
 * It "proxies" arbitrary data chunks a) inside a native php4 session, 
 * b) by talking to a rdbms (single proxy-table) or c) [TODO] using PEAR::Cache.
 *
 * @author Andreas Motl <andreas.motl@ilo.de>
 * @author Sebastian Utz <seut@tunemedia.de>
 * @package phpHtmlLib
 */

/**
 * $Id$
 *
 * $Log$
 *
 */

/**
 * This requires the MemoryDataSource base class
 *
 */
include_once($phphtmllib."/widgets/data_source/MemoryDataSource.inc");

/**
 * Have to have PEAR and DB included
 * the pear dir must be in the 
 * include path.
 */
//require_once("PEAR.php");   // FIXME: what about PEAR::XML::RPC?
//require_once("DB.php");

/**
 * This ProxyDataSource child class is *completely* independent
 * of a specific storage implementation and intended to be a wrapper
 * class on the way from phpHtmlLib to Xyz.
 *    ("Yyz" gets represented by Data::Storage by now.....)
 *
 * ProxyDataSource interacts with an intermediate "proxy" object 
 * (e.g. Data::Driver::Proxy) when doing queries.
 *    Don't mix this up with a persistent database handle which gets
 *    reused each and every time for different queries.
 *    Here *is* a new instance of Data::Driver::Proxy for *each* query.
 *
 * But the point is: Caching! The actual *data* isn't read redundant!
 *
 * Data::Driver::Proxy instantiates "handlers" below itself
 * which act as encapsulated workers to actually do the stuff to do.
 * It can cache data for "disconnected mode" using the
 * php PEAR DB abstraction objects.
 * One worker already implemented is Data::Driver::RPC::Remote, which
 * talks to a RPC::XML server (todo: talk SOAP!) using PEAR::XML::RPC.
 *
 * How to use?
 *
 * Pass an array holding "locator metadata" to the constructor.
 * ProxyDataSource takes care of the rest.
 *
 * Pass an array to the constructor: (e.g.)
 *
 *  1. doing rpc-calls....
 *    $locator = array(
 *      type => 'rpc',
 *      metadata => array( Host => 'localhost', Port => '8765' ),
 *    );
 *    $source = new ProxyDataSource($locator);
 *    $this->set_data_source( &$source );
 *
 *  2. [proposal] common datahandles....
 *    $locator = array(
 *      type => 'mysql',
 *      dsn => 'known dsn markup',
 *    );
 *    $source = new ProxyDataSource($locator);
 *    $this->set_data_source( &$source );
 *
 * @author Andreas Motl <andreas.motl@ilo.de>
 * @author Sebastian Utz <seut@tunemedia.de>
 * @package phpHtmlLib
 */

/**
 * Todo:
 *
 *  o mungle this to be able to be wrapped around phpHtmlLib's own storage-handles
 *  o implement another Data::Driver::Proxy container
 *
 */

class ProxyDataSource extends MemoryDataSource {

        /**
         * This var holds the locator metadata hash
         * that is used to feed metadata to a per-query-instance
         * of a Data::Driver::Proxy object.
         */
        var $_locator = NULL;

        /**
         * This var holds the query hash
         * that is used to feed as query to a per-query-instance
         * of a Data::Driver::Proxy object.
         */
        var $_query = NULL;


        /**
         * This var holds the Proxy object
         * that is used to do the work.
         * It acts as a dispatcher combining result caching.
         * It is assumed that this provides 4 methods:
         * queryData() - execute a query against a data storage
         * querySchema() - execute a query against underlying storage metadata
         * sendCommand() - send a command against an arbitrary execution engine
         */
        var $_proxy = NULL;

        /**
         * this holds the query result from the
         * Data::Driver::Proxy->queryXyz() call
         *
         */
        var $_result = NULL;


        /**
         * The constructor is used to pass in the
         * locator metadata hash.
         *
         * @param LocatorMetadataHash array - layout: array( type => '', metadata => '', dsn => '' )
         * @param Query array - layout: array( type => '', metadata => '', dsn => '' )
         */
        function ProxyDataSource( &$locator, $query ) {
                $this->set_locator( $locator );
                $this->set_query( $query );
        }
        
        /**
     * Set the locator metadata hash we will feed *partly*
     * to an encapsulated Data::Driver::Proxy instance.
     *
     * @param LocatorMetadataHash array - 
     *
     */
    function set_locator( &$locator ) {
        $this->_locator = &$locator;
    }

        /**
     * Set the query metadata hash we will feed *completely*
     * to an encapsulated Data::Driver::Proxy instance.
     *
     * @param QueryDeclaration array - 
     *
     */
    function set_query( $query ) {
        $this->_query = $query;
    }

        /**
     * Directly inject a Data::Driver::Proxy instance to use.
     *
     * @param Data::Driver::Proxy object - &$proxy
     *
     */
    function set_proxy( &$proxy ) {
        $this->_proxy = &$proxy;
    }

        /**
     * Issue remote/proxy call
     * Stolen from Application_AbstractBackend::_remote_method (RefactoringProposal?)
     * Tweaked a bit: proxy package now taken from $this->_proxy_name
     *
     * Create a new instance of a proxy and store it for later reuse.
     * Read the locator metadata hash and create 
     * the proxy handler instance using passed-in name.
     *
     * @param string - $proxy_name (namespaced classname - perl syntax - e.g.: Data::Driver::Proxy)
     *
     */
    function call_proxy_method() {


      // 1. read args

        $arg_list = func_get_args();
        $command = array_shift($arg_list);
        $cache_key = join("-", array(session_id(), $command, join('_', $arg_list) ));
        //print "cache_key: $cache_key<br>";
  
        // FIXME: what if arg_list still contains more elements after doing this?
        $query = array_shift($arg_list);


      // 2. prepare proxy-options

        // read from locator metadata
          $proxy_name = $this->_locator[metadata][package];
          $rpcinfo = array( Host => $this->_locator[metadata][Host], Port => $this->_locator[metadata][Port] );

        // FIXME! implement this into Data::Driver::RPC::Remote!
          //$rpcinfo[to_latin] = 1;
          
        // FIXME! patch query
        if (sizeof($query) == 1) {
          $query = $query[0];
        }
      
      // --------------------   clone this & modify  ----------
      $proxy = mkObject($proxy_name, $cache_key, array( key => 1, command => $command, query => $query, remote => 1, rpcinfo => $rpcinfo, cache => array( db => 0, session => 1 ) ) );
      $this->set_proxy( $proxy );
      //$result = $resultHandle->getAttributes();
      //return $result;
      //$this->_result = $resultHandle->getAttributes();
      //$this->_result = $this->_proxy->getAttributes();
      // --------------------   clone this & modify  ----------
  
    }

        function O_do_query() {
                $this->_result = $this->_db->query($this->_query);
                if (DB::isError($this->_result)) {
                        $msg = $this->_result->getMessage();
                        user_error("PEARSQLDataListSource::do_query() - query failed : ".$msg);
                }
        }

        function call_proxy() {
      
      // make up a command from metadata
      // FIXME: abstract this some more (e.g. via a CommandMapper|Registry)
        switch ($this->_query[metatype]) {
          case 'data':
            //$command = 'queryData';
            $command = 'getObjects';   // FIXME!!!
            $args = array();
            switch ($this->_query[vartype]) {
              case 'object':
                if (!$this->_query[classname]) {
                  $msg = "_query[vartype] == 'object' requires _query[classname]";
                  user_error("ProxyDataSource::do_query() - failed: " . $msg);
                }
                array_push($args, $this->_query[classname]);
                break;
            }
            break;
          case 'schema':
            $command = 'querySchema';
            break;
        }
      
      // trace
      if ($this->trace) {
        print "ProxyDataSource->do_query()<br/>";
        print "_locator = " . Dumper($this->_locator);
        print "_query = " . Dumper($this->_query);
        print "<b>\$command = " . $command . "</b><br/>";
        print "<b>\$args = " . Dumper($args) . "</b><br/>";
      }
      
      // pre-flight checks
        if (!$command) {
          $msg = "Remote command could not be resolved, please pass in or check configuration.";
                        user_error("ProxyDataSource::do_query() - failed: " . $msg);
          return;
        }
      
      // do remote call here and get result
      // FIXME: handle synchronous/asynchronous mode here!!!
        $this->call_proxy_method($command, $args);
        // TODO: ... = $this->poll_proxy_result  and  $this->get_proxy_result
        $this->_result = $this->_proxy->getAttributes();

      // trace
        //print "_result = " . Dumper($this->_result);
        print "_result - count = " . sizeof($this->_result) . "<br/>";

      // pass data to MemoryDataSource

        // V1 - doesn't work!
        //$this->_data_list = $this->_result;

        // V2 - ???
        //$this->MemoryDataSource();

        // V3 - copy & paste
        /*
                foreach ($this->_result as $value) {
                  print Dumper($value);
                        if ($this->add_data_row($value)) {
                                $count++;
                        }
                }
                $this->set_total_rows( $count );
                $this->sort();
                */

        }


    function O_do_prequery() {
                //print "prequery!<br/>";
                // HACK!!!
      // modify behaviour here: for now it is needed to call for the schem
      // eventually modify here to get schema from some registry component (already locally available)
      $this->call_proxy();
      //print Dumper($this->_result);
      //print Dumper($this->_result[0]);
      //exit;
      
      //$this->_get_header();
    }

    function do_query() {
                //print "query!<br/>";
           $this->handle_result();
    }      
        
        function _get_header() {
                  //$this->do_prequery();
                  // FIXME: prevent multi-calls by base class
         $this->call_proxy();
                  foreach($this->_result[0] as $key => $value) {
                                array_push($this->_data_keys, $key);
                        }             

    $this->set_schema($this->_result[0]);
    
    //$this->_get_header();
    //return $this->_data_keys;

        }


        /**
         * This function gets the next data row
         * from the query()
         *
         * @return array()
         */
        function O_get_next_data_row() {
                return $this->_result->fetchRow(DB_FETCHMODE_ASSOC);
        }

        /**
     * This function builds the limit
     * clause portion of a DB query.
     *
     * @return string - the limit portion of 
     *                  the query.
     */
    function O_build_limit_clause($offset, $limit) {
        if ($this->get_limit() != -1 ) {
                        if ($offset == '' || $offset == "none") {
                                $offset = 0;
                        }
                        switch(get_class($this->_db)) {
                        case "db_mysql":
                                $clause = " LIMIT $offset, $limit ";
                                break;
                        case "db_pgsql":
                                $clause = " LIMIT $limit, $offset ";
                                break;
                        default:
                                $clause = " LIMIT $offset, $limit ";
                                break;
                        }
            return $clause;
        } else {
            return NULL;
        }
    }
    
    /**
     * find the number of rows to be returned 
     * from a query from a table and where clause
     *
     * @param string $table - the table to count from
     * @param string $where_clause - a where clause
     *
     * @return int the # of rows
     */
    function O_count($tables, $where_clause='', $count_clause='*') {
                $query = "select count(".$count_clause.") as COUNT from ".$tables." ".$where_clause;
        $result = $this->_db->query($query);
                if (DB::isError($this->_result)) {
                        $msg = $result->getMessage();
                        user_error("PEARSQLDataListSource::count() - query failed : ".$msg);
                }
                $value = $result->fetchRow(DB_FETCHMODE_ASSOC);
        return ($value ? (int)$value["COUNT"] : NULL);
    }
    
}

?>
1	joko	1.1	<?php
2
3			/**
4			* This file contains the ProxyDataSource child class
5			* that uses the Data::Driver::Proxy object to talk to a remote rpc server.
6			*
7			* Data::Driver::Proxy uses a PEAR XML::RPC object to actually
8			* talk HTTP and serialize data chunks to and from XML,
9			* but adds some caching to this "process of fetching data from a remote side".
10			* It "proxies" arbitrary data chunks a) inside a native php4 session,
11			* b) by talking to a rdbms (single proxy-table) or c) [TODO] using PEAR::Cache.
12			*
13			* @author Andreas Motl <andreas.motl@ilo.de>
14			* @author Sebastian Utz <seut@tunemedia.de>
15			* @package phpHtmlLib
16			*/
17
18			/**
19			* $Id$
20			*
21			* $Log$
22			*
23			*/
24
25			/**
26			* This requires the MemoryDataSource base class
27			*
28			*/
29			include_once($phphtmllib."/widgets/data_source/MemoryDataSource.inc");
30
31			/**
32			* Have to have PEAR and DB included
33			* the pear dir must be in the
34			* include path.
35			*/
36			//require_once("PEAR.php"); // FIXME: what about PEAR::XML::RPC?
37			//require_once("DB.php");
38
39			/**
40			* This ProxyDataSource child class is completely independent
41			* of a specific storage implementation and intended to be a wrapper
42			* class on the way from phpHtmlLib to Xyz.
43			* ("Yyz" gets represented by Data::Storage by now.....)
44			*
45			* ProxyDataSource interacts with an intermediate "proxy" object
46			* (e.g. Data::Driver::Proxy) when doing queries.
47			* Don't mix this up with a persistent database handle which gets
48			* reused each and every time for different queries.
49			* Here is a new instance of Data::Driver::Proxy for each query.
50			*
51			* But the point is: Caching! The actual data isn't read redundant!
52			*
53			* Data::Driver::Proxy instantiates "handlers" below itself
54			* which act as encapsulated workers to actually do the stuff to do.
55			* It can cache data for "disconnected mode" using the
56			* php PEAR DB abstraction objects.
57			* One worker already implemented is Data::Driver::RPC::Remote, which
58			* talks to a RPC::XML server (todo: talk SOAP!) using PEAR::XML::RPC.
59			*
60			* How to use?
61			*
62			* Pass an array holding "locator metadata" to the constructor.
63			* ProxyDataSource takes care of the rest.
64			*
65			* Pass an array to the constructor: (e.g.)
66			*
67			* 1. doing rpc-calls....
68			* $locator = array(
69			* type => 'rpc',
70			* metadata => array( Host => 'localhost', Port => '8765' ),
71			* );
72			* $source = new ProxyDataSource($locator);
73			* $this->set_data_source( &$source );
74			*
75			* 2. [proposal] common datahandles....
76			* $locator = array(
77			* type => 'mysql',
78			* dsn => 'known dsn markup',
79			* );
80			* $source = new ProxyDataSource($locator);
81			* $this->set_data_source( &$source );
82			*
83			* @author Andreas Motl <andreas.motl@ilo.de>
84			* @author Sebastian Utz <seut@tunemedia.de>
85			* @package phpHtmlLib
86			*/
87
88			/**
89			* Todo:
90			*
91			* o mungle this to be able to be wrapped around phpHtmlLib's own storage-handles
92			* o implement another Data::Driver::Proxy container
93			*
94			*/
95
96			class ProxyDataSource extends MemoryDataSource {
97
98			/**
99			* This var holds the locator metadata hash
100			* that is used to feed metadata to a per-query-instance
101			* of a Data::Driver::Proxy object.
102			*/
103			var $_locator = NULL;
104
105			/**
106			* This var holds the query hash
107			* that is used to feed as query to a per-query-instance
108			* of a Data::Driver::Proxy object.
109			*/
110			var $_query = NULL;
111
112
113			/**
114			* This var holds the Proxy object
115			* that is used to do the work.
116			* It acts as a dispatcher combining result caching.
117			* It is assumed that this provides 4 methods:
118			* queryData() - execute a query against a data storage
119			* querySchema() - execute a query against underlying storage metadata
120			* sendCommand() - send a command against an arbitrary execution engine
121			*/
122			var $_proxy = NULL;
123
124			/**
125			* this holds the query result from the
126			* Data::Driver::Proxy->queryXyz() call
127			*
128			*/
129			var $_result = NULL;
130
131
132			/**
133			* The constructor is used to pass in the
134			* locator metadata hash.
135			*
136			* @param LocatorMetadataHash array - layout: array( type => '', metadata => '', dsn => '' )
137			* @param Query array - layout: array( type => '', metadata => '', dsn => '' )
138			*/
139			function ProxyDataSource( &$locator, $query ) {
140			$this->set_locator( $locator );
141			$this->set_query( $query );
142			}
143
144			/**
145			* Set the locator metadata hash we will feed partly
146			* to an encapsulated Data::Driver::Proxy instance.
147			*
148			* @param LocatorMetadataHash array -
149			*
150			*/
151			function set_locator( &$locator ) {
152			$this->_locator = &$locator;
153			}
154
155			/**
156			* Set the query metadata hash we will feed completely
157			* to an encapsulated Data::Driver::Proxy instance.
158			*
159			* @param QueryDeclaration array -
160			*
161			*/
162			function set_query( $query ) {
163			$this->_query = $query;
164			}
165
166			/**
167			* Directly inject a Data::Driver::Proxy instance to use.
168			*
169			* @param Data::Driver::Proxy object - &$proxy
170			*
171			*/
172			function set_proxy( &$proxy ) {
173			$this->_proxy = &$proxy;
174			}
175
176			/**
177			* Issue remote/proxy call
178			* Stolen from Application_AbstractBackend::_remote_method (RefactoringProposal?)
179			* Tweaked a bit: proxy package now taken from $this->_proxy_name
180			*
181			* Create a new instance of a proxy and store it for later reuse.
182			* Read the locator metadata hash and create
183			* the proxy handler instance using passed-in name.
184			*
185			* @param string - $proxy_name (namespaced classname - perl syntax - e.g.: Data::Driver::Proxy)
186			*
187			*/
188			function call_proxy_method() {
189
190
191			// 1. read args
192
193			$arg_list = func_get_args();
194			$command = array_shift($arg_list);
195			$cache_key = join("-", array(session_id(), $command, join('_', $arg_list) ));
196			//print "cache_key: $cache_key<br>";
197
198			// FIXME: what if arg_list still contains more elements after doing this?
199			$query = array_shift($arg_list);
200
201
202			// 2. prepare proxy-options
203
204			// read from locator metadata
205			$proxy_name = $this->_locator[metadata][package];
206			$rpcinfo = array( Host => $this->_locator[metadata][Host], Port => $this->_locator[metadata][Port] );
207
208			// FIXME! implement this into Data::Driver::RPC::Remote!
209			//$rpcinfo[to_latin] = 1;
210
211			// FIXME! patch query
212			if (sizeof($query) == 1) {
213			$query = $query[0];
214			}
215
216			// -------------------- clone this & modify ----------
217			$proxy = mkObject($proxy_name, $cache_key, array( key => 1, command => $command, query => $query, remote => 1, rpcinfo => $rpcinfo, cache => array( db => 0, session => 1 ) ) );
218			$this->set_proxy( $proxy );
219			//$result = $resultHandle->getAttributes();
220			//return $result;
221			//$this->_result = $resultHandle->getAttributes();
222			//$this->_result = $this->_proxy->getAttributes();
223			// -------------------- clone this & modify ----------
224
225			}
226
227			function O_do_query() {
228			$this->_result = $this->_db->query($this->_query);
229			if (DB::isError($this->_result)) {
230			$msg = $this->_result->getMessage();
231			user_error("PEARSQLDataListSource::do_query() - query failed : ".$msg);
232			}
233			}
234
235			function call_proxy() {
236
237			// make up a command from metadata
238			// FIXME: abstract this some more (e.g. via a CommandMapper\|Registry)
239			switch ($this->_query[metatype]) {
240			case 'data':
241			//$command = 'queryData';
242			$command = 'getObjects'; // FIXME!!!
243			$args = array();
244			switch ($this->_query[vartype]) {
245			case 'object':
246			if (!$this->_query[classname]) {
247			$msg = "_query[vartype] == 'object' requires _query[classname]";
248			user_error("ProxyDataSource::do_query() - failed: " . $msg);
249			}
250			array_push($args, $this->_query[classname]);
251			break;
252			}
253			break;
254			case 'schema':
255			$command = 'querySchema';
256			break;
257			}
258
259			// trace
260			if ($this->trace) {
261			print "ProxyDataSource->do_query()<br/>";
262			print "_locator = " . Dumper($this->_locator);
263			print "_query = " . Dumper($this->_query);
264			print "<b>\$command = " . $command . "</b><br/>";
265			print "<b>\$args = " . Dumper($args) . "</b><br/>";
266			}
267
268			// pre-flight checks
269			if (!$command) {
270			$msg = "Remote command could not be resolved, please pass in or check configuration.";
271			user_error("ProxyDataSource::do_query() - failed: " . $msg);
272			return;
273			}
274
275			// do remote call here and get result
276			// FIXME: handle synchronous/asynchronous mode here!!!
277			$this->call_proxy_method($command, $args);
278			// TODO: ... = $this->poll_proxy_result and $this->get_proxy_result
279			$this->_result = $this->_proxy->getAttributes();
280
281			// trace
282			//print "_result = " . Dumper($this->_result);
283			print "_result - count = " . sizeof($this->_result) . "<br/>";
284
285			// pass data to MemoryDataSource
286
287			// V1 - doesn't work!
288			//$this->_data_list = $this->_result;
289
290			// V2 - ???
291			//$this->MemoryDataSource();
292
293			// V3 - copy & paste
294			/*
295			foreach ($this->_result as $value) {
296			print Dumper($value);
297			if ($this->add_data_row($value)) {
298			$count++;
299			}
300			}
301			$this->set_total_rows( $count );
302			$this->sort();
303			*/
304
305			}
306
307
308
309			function O_do_prequery() {
310			//print "prequery!<br/>";
311			// HACK!!!
312			// modify behaviour here: for now it is needed to call for the schem
313			// eventually modify here to get schema from some registry component (already locally available)
314			$this->call_proxy();
315			//print Dumper($this->_result);
316			//print Dumper($this->_result[0]);
317			//exit;
318
319			//$this->_get_header();
320			}
321
322			function do_query() {
323			//print "query!<br/>";
324			$this->handle_result();
325			}
326
327			function _get_header() {
328			//$this->do_prequery();
329			// FIXME: prevent multi-calls by base class
330			$this->call_proxy();
331			foreach($this->_result[0] as $key => $value) {
332			array_push($this->_data_keys, $key);
333			}
334
335			$this->set_schema($this->_result[0]);
336
337			//$this->_get_header();
338			//return $this->_data_keys;
339
340			}
341
342
343			/**
344			* This function gets the next data row
345			* from the query()
346			*
347			* @return array()
348			*/
349			function O_get_next_data_row() {
350			return $this->_result->fetchRow(DB_FETCHMODE_ASSOC);
351			}
352
353			/**
354			* This function builds the limit
355			* clause portion of a DB query.
356			*
357			* @return string - the limit portion of
358			* the query.
359			*/
360			function O_build_limit_clause($offset, $limit) {
361			if ($this->get_limit() != -1 ) {
362			if ($offset == '' \|\| $offset == "none") {
363			$offset = 0;
364			}
365			switch(get_class($this->_db)) {
366			case "db_mysql":
367			$clause = " LIMIT $offset, $limit ";
368			break;
369			case "db_pgsql":
370			$clause = " LIMIT $limit, $offset ";
371			break;
372			default:
373			$clause = " LIMIT $offset, $limit ";
374			break;
375			}
376			return $clause;
377			} else {
378			return NULL;
379			}
380			}
381
382			/**
383			* find the number of rows to be returned
384			* from a query from a table and where clause
385			*
386			* @param string $table - the table to count from
387			* @param string $where_clause - a where clause
388			*
389			* @return int the # of rows
390			*/
391			function O_count($tables, $where_clause='', $count_clause='*') {
392			$query = "select count(".$count_clause.") as COUNT from ".$tables." ".$where_clause;
393			$result = $this->_db->query($query);
394			if (DB::isError($this->_result)) {
395			$msg = $result->getMessage();
396			user_error("PEARSQLDataListSource::count() - query failed : ".$msg);
397			}
398			$value = $result->fetchRow(DB_FETCHMODE_ASSOC);
399			return ($value ? (int)$value["COUNT"] : NULL);
400			}
401
402			}
403
404			?>
MailToCvsAdmin">MailToCvsAdmin	ViewVC Help
Powered by ViewVC 1.1.26