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 |
?> |