aboutsummaryrefslogtreecommitdiff
path: root/engine/lib/database.php
blob: 01767be39522b4b0b60edcdd81a6c40a58572298 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
<?php

	/**
	 * Elgg database
	 * Contains database connection and transfer functionality
	 * 
	 * @package Elgg
	 * @subpackage Core
	 * @license http://www.gnu.org/licenses/old-licenses/gpl-2.0.html GNU Public License version 2
	 * @author Curverider Ltd
	 * @copyright Curverider Ltd 2008-2009
	 * @link http://elgg.org/
	 */

	$DB_PROFILE = array();
	$DB_QUERY_CACHE = array();
	$DB_DELAYED_QUERIES = array();
	
	/**
	 * Connect to the database server and use the Elgg database for a particular database link
	 *
	 * @param string $dblinkname Default "readwrite"; you can change this to set up additional global database links, eg "read" and "write" 
	 */
		function establish_db_link($dblinkname = "readwrite") {
			
			// Get configuration, and globalise database link
		        global $CONFIG, $dblink, $DB_QUERY_CACHE, $dbcalls;
		        
		        if (!isset($dblink)) {
		        	$dblink = array();
		        }
		        
		        if ($dblinkname != "readwrite" && isset($CONFIG->db[$dblinkname])) {
		        	if (is_array($CONFIG->db[$dblinkname])) {
		        		$index = rand(0,sizeof($CONFIG->db[$dblinkname]));
		        		$dbhost = $CONFIG->db[$dblinkname][$index]->dbhost;
						$dbuser = $CONFIG->db[$dblinkname][$index]->dbuser;
						$dbpass = $CONFIG->db[$dblinkname][$index]->dbpass;
						$dbname = $CONFIG->db[$dblinkname][$index]->dbname;
		        	} else {
						$dbhost = $CONFIG->db[$dblinkname]->dbhost;
						$dbuser = $CONFIG->db[$dblinkname]->dbuser;
						$dbpass = $CONFIG->db[$dblinkname]->dbpass;
						$dbname = $CONFIG->db[$dblinkname]->dbname;
		        	}
		        } else {
		        	$dbhost = $CONFIG->dbhost;
					$dbuser = $CONFIG->dbuser;
					$dbpass = $CONFIG->dbpass;
					$dbname = $CONFIG->dbname;
		        }
		        
		    // Connect to database
		        if (!$dblink[$dblinkname] = mysql_connect($CONFIG->dbhost, $CONFIG->dbuser, $CONFIG->dbpass, true))
		        	throw new DatabaseException(sprintf(elgg_echo('DatabaseException:WrongCredentials'), $CONFIG->dbuser, $CONFIG->dbhost, $CONFIG->debug ? $CONFIG->dbpass : "****"));
		        if (!mysql_select_db($CONFIG->dbname, $dblink[$dblinkname]))
		        	throw new DatabaseException(sprintf(elgg_echo('DatabaseException:NoConnect'), $CONFIG->dbname));
			
		    // Set up cache
		    	if (!$DB_QUERY_CACHE) 
		    		$DB_QUERY_CACHE = new ElggStaticVariableCache('db_query_cache'); //array();
		    		//$DB_QUERY_CACHE = select_default_memcache('db_query_cache'); //array();
		    		
		    	//if ($DB_QUERY_CACHE instanceof ElggMemcache)
		    	//	$DB_QUERY_CACHE->setDefaultExpiry(30);
		}
		
	/**
	 * Establish all database connections
	 * 
	 * If the configuration has been set up for multiple read/write databases, set those
	 * links up separately; otherwise just create the one database link
	 *
	 */
		
		function setup_db_connections() {
			
			// Get configuration and globalise database link
				global $CONFIG, $dblink;
				
				if (!empty($CONFIG->db->split)) {
					establish_db_link('read');
					establish_db_link('write');
				} else {
					establish_db_link('readwrite');
				}
			
		}
		
	/**
	 * Shutdown hook to display profiling information about db (debug mode)
	 */
	function db_profiling_shutdown_hook()
	{
		global $CONFIG, $DB_PROFILE, $dbcalls;
		
		if (isset($CONFIG->debug) && $CONFIG->debug)
		{
			error_log("***************** DB PROFILING ********************");
			
			$DB_PROFILE = array_count_values($DB_PROFILE);
			
			foreach ($DB_PROFILE as $k => $v) 
				error_log("$v times: '$k' ");
			
			error_log("DB Queries for this page: $dbcalls");
			error_log("***************************************************");
		}
	}
	
	/**
	 * Execute any delayed queries.
	 */
	function db_delayedexecution_shutdown_hook()
	{
		global $DB_DELAYED_QUERIES, $CONFIG;
		
		foreach ($DB_DELAYED_QUERIES as $query_details) {
			$result = execute_query($query_details['q'], $query_details['l']); // use one of our db functions so it is included in profiling.
			
			try {
				if ( (isset($query_details['h'])) && (is_callable($query_details['h'])))
					$query_details['h']($result);
			} catch (Exception $e) { // Suppress all errors since these can't be delt with here
				if (isset($CONFIG->debug) && $CONFIG->debug) error_log($e);
			}
		}
	}
		
	/**
	 * Alias to setup_db_connections, for use in the event handler
	 *
	 * @param string $event The event type
	 * @param string $object_type The object type
	 * @param mixed $object Used for nothing in this context
	 */
		function init_db($event, $object_type, $object = null) {
			register_shutdown_function('db_delayedexecution_shutdown_hook');
			register_shutdown_function('db_profiling_shutdown_hook');
			//setup_db_connections(); // [Marcus Povey 20090213: Db connection moved to first db connection attempt]
			return true;
		}
		
	/**
	 * Gets the appropriate db link for the operation mode requested
	 *
	 * @param string $dblinktype The type of link we want - "read", "write" or "readwrite" (the default)
	 * @return object Database link
	 */
		function get_db_link($dblinktype) {
			
			global $dblink;
			
				
			if (isset($dblink[$dblinktype])) {
				return $dblink[$dblinktype];
			} else if (isset($dblink['readwrite'])) {
				return $dblink['readwrite'];
			}
			else
			{
				setup_db_connections();
				return get_db_link($dblinktype);
			}
		}
		
		/**
		 * Explain a given query, useful for debug.
		 */
		function explain_query($query, $link)
		{
			if ($result = execute_query("explain " . $query, $link)) {
                return mysql_fetch_object($result);
            }
            
            return false;
		}
		
		/**
		 * Execute a query.
		 *
		 * @param string $query The query
		 * @param link $dblink the DB link
		 * @return Returns a the result of mysql_query
		 */
		function execute_query($query, $dblink)
		{
			global $CONFIG, $dbcalls, $DB_PROFILE, $DB_QUERY_CACHE;
						
            $dbcalls++;
            
        	//if ((isset($CONFIG->debug)) && ($CONFIG->debug==true))
            $DB_PROFILE[] = $query;
            	
            $result = mysql_query($query, $dblink);
            $DB_QUERY_CACHE[$query] = -1; // Set initial cache to -1
            	
            if (mysql_errno($dblink))
				throw new DatabaseException(mysql_error($dblink) . " QUERY: " . $query);
				
			return $result;
				
		}
		
		/**
		 * Queue a query for execution after all output has been sent to the user.
		 *
		 * You can specify a handler function if you care about the result. This function will accept
		 * the raw result from mysql_query();
		 *  
		 * @param string $query The query to execute
		 * @param resource $dblink The database link to use
		 * @param string $handler The handler
		 */
		function execute_delayed_query($query, $dblink, $handler = "")
		{
			global $DB_DELAYED_QUERIES;
			
			if (!isset($DB_DELAYED_QUERIES))
				$DB_DELAYED_QUERIES = array();
			
			// Construct delayed query
			$delayed_query = array();
			$delayed_query['q'] = $query;
			$delayed_query['l'] = $dblink;
			$delayed_query['h'] = $handler;
			
			$DB_DELAYED_QUERIES[] = $delayed_query;
			
			return true;
		}
		
		/**
		 * Write wrapper for execute_delayed_query()
		 *
		 * @param string $query The query to execute
		 * @param string $handler The handler if you care about the result.
		 */
		function execute_delayed_write_query($query, $handler = "") { return execute_delayed_query($query, get_db_link('write'), $handler); }
		
		/**
		 * Read wrapper for execute_delayed_query()
		 *
		 * @param string $query The query to execute
		 * @param string $handler The handler if you care about the result.
		 */
		function execute_delayed_read_query($query, $handler = "") { return execute_delayed_query($query, get_db_link('read'), $handler); }
		
	/**
     * Use this function to get data from the database
     * @param mixed $query The query being passed.
     * @param string $call Optionally, the name of a function to call back to on each row (which takes $row as a single parameter)
     * @return array An array of database result objects
     */
    
        function get_data($query, $callback = "") {
            
            global $CONFIG, $DB_QUERY_CACHE;
            
        	// Is cached?
        	$cached_query = $DB_QUERY_CACHE[$query];
			if ($cached_query) {
       			if ((isset($CONFIG->debug)) && ($CONFIG->debug==true))
            		error_log ("$query results returned from cache");
            		
            	if ($cached_query === -1)
            		return array(); // Last time this query returned nothing, so return an empty array
            		
            	return $cached_query;
            }
            
            $dblink = get_db_link('read');
            
            $resultarray = array();
            
            if ($result = execute_query("$query", $dblink)) {
                while ($row = mysql_fetch_object($result)) {
                	if (!empty($callback) && is_callable($callback)) {
                		$row = $callback($row);
                	}
                    if ($row) $resultarray[] = $row;
                }
            }
            
       		if (empty($resultarray)) {
       			if ((isset($CONFIG->debug)) && ($CONFIG->debug==true))
       				error_log("WARNING: DB query \"$query\" returned no results.");
       				
                return false;
            }
            
            // Cache result
            if ((isset($CONFIG->debug)) && ($CONFIG->debug==true))
            	error_log("$query results cached");
            $DB_QUERY_CACHE[$query] = $resultarray;
            
            return $resultarray;
        }
        
    /**
     * Use this function to get a single data row from the database
     * @param mixed $query The query to run.
     * @return object A single database result object
     */ 
    
        function get_data_row($query) {
            
            global $CONFIG, $DB_QUERY_CACHE;
            
        	// Is cached
       		$cached_query = $DB_QUERY_CACHE[$query];
			if ($cached_query) {
       			if ((isset($CONFIG->debug)) && ($CONFIG->debug==true))
            		error_log ("$query results returned from cache");
            		
            	if ($cached_query === -1)
            		return false; // Last time this query returned nothing, so return false
            		
            	return $cached_query;
            }
            
            $dblink = get_db_link('read');
            
            if ($result = execute_query("$query", $dblink)) {
            	
            	$row = mysql_fetch_object($result);
            	
            	// Cache result (even if query returned no data
            	if ((isset($CONFIG->debug)) && ($CONFIG->debug==true))
                	error_log("$query results cached");
            	$DB_QUERY_CACHE[$query] = $row;
            	
                if ($row) return $row;
            }
            
			if ((isset($CONFIG->debug)) && ($CONFIG->debug==true))
       				error_log("WARNING: DB query \"$query\" returned no results.");
       				
            return false;
        }
        
    /**
     * Use this function to insert database data; returns id or false
     * 
     * @param mixed $query The query to run.
     * @return int $id the database id of the inserted row.
     */ 
    
        function insert_data($query) {
            
            global $CONFIG, $DB_QUERY_CACHE;
            
            $dblink = get_db_link('write');
            
            // Invalidate query cache
            if ($DB_QUERY_CACHE) $DB_QUERY_CACHE->clear();
            if ((isset($CONFIG->debug)) && ($CONFIG->debug==true))
            	error_log("Query cache invalidated");
            
            if (execute_query("$query", $dblink)) 
                return mysql_insert_id($dblink);
                
                
			return false;
        }
        
    /**
     * Update database data
     * 
     * @param mixed $query The query to run.
     * @return int|false Either the number of affected rows, or false on failure
     */ 
    
        function update_data($query) {
            
            global $CONFIG, $DB_QUERY_CACHE;
            
            $dblink = get_db_link('write');
            
            // Invalidate query cache
            if ($DB_QUERY_CACHE) $DB_QUERY_CACHE->clear();
            if ((isset($CONFIG->debug)) && ($CONFIG->debug==true))
            	error_log("Query cache invalidated");
            
            if (execute_query("$query", $dblink))
            	return true; //return mysql_affected_rows();

         	return false;   
            
        }

	/**
	 * Use this function to delete data
	 *
	 * @param mixed $query The SQL query to run
	 * @return int|false Either the number of affected rows, or false on failure
	 */
    
        function delete_data($query) {
            
            global $CONFIG, $DB_QUERY_CACHE;
            
            $dblink = get_db_link('write');
            
            // Invalidate query cache
            if ($DB_QUERY_CACHE) $DB_QUERY_CACHE->clear();
            if ((isset($CONFIG->debug)) && ($CONFIG->debug==true))
            	error_log("Query cache invalidated");
            
            if (execute_query("$query", $dblink)) 
                return mysql_affected_rows($dblink);
        
			return false;      
        }
    
 
	/**
	 * Get the tables currently installed in the Elgg database
	 *
	 * @return array List of tables
	 */
        function get_db_tables() {
        	global $CONFIG;
        	static $tables, $count;
        	
        	if (isset($tables)) {
        		return $tables;
        	}
        	
        	try{
        		$result = get_data("show tables like '" . $CONFIG->dbprefix . "%'");
        	} catch (DatabaseException $d)
        	{
        		// Likely we can't handle an exception here, so just return false.
        		return false;
        	}
        	        	 	
        	$tables = array();
        	
        	if (is_array($result) && !empty($result)) {
        		foreach($result as $row) {
        			$row = (array) $row;
        			if (is_array($row) && !empty($row))
	        			foreach($row as $element) {
	        				$tables[] = $element;
	        			}
        		}
        	}
        	else
        		return false;
        	
        	return $tables;
        }
        
    /**
     * Run an optimize query on a mysql tables. Useful for executing after major data changes. 
     *
     */
    	function optimize_table($table)
    	{
    		$table = sanitise_string($table);
    		return update_data("optimize table $table");
    	}
        
	/**
	 * Get the last database error for a particular database link
	 *
	 * @param database link $dblink
	 * @return string Database error message
	 */
        function get_db_error($dblink) {
        	return mysql_error($dblink);
        }
        
	/**
	 * Runs a full database script from disk
	 *
	 * @uses $CONFIG
	 * @param string $scriptlocation The full path to the script
	 */
        function run_sql_script($scriptlocation) {
        	
        	if ($script = file_get_contents($scriptlocation)) {

        		global $CONFIG;
        		
        		$errors = array();
        		
        		$script = preg_replace('/\-\-.*\n/', '', $script);
        		$sql_statements =  preg_split('/;[\n\r]+/', $script);
        		foreach($sql_statements as $statement) {
        			$statement = trim($statement);
        			$statement = str_replace("prefix_",$CONFIG->dbprefix,$statement);
        			if (!empty($statement)) {
        				try {
        					$result = update_data($statement);
        				} catch (DatabaseException $e) {
        					$errors[] = $e->getMessage();
        				}
        			}
        		}
        		if (!empty($errors)) {
        			$errortxt = "";
        			foreach($errors as $error)
        				$errortxt .= " {$error};";
        			throw new DatabaseException(elgg_echo('DatabaseException:DBSetupIssues') . $errortxt);
        		}
        		
        	} else {
        		throw new DatabaseException(sprintf(elgg_echo('DatabaseException:ScriptNotFound'), $scriptlocation));
        	}
        	
        }
        
        function db_upgrade($version) {
        	
        	global $CONFIG;
        	
        	// Elgg and its database must be installed to upgrade it!
        	if (!is_db_installed() || !is_installed()) return false;
        	
        	$version = (int) $version;
        	
        	if ($handle = opendir($CONFIG->path . 'engine/schema/upgrades/')) {
        		
        		$sqlupgrades = array();
        		
        		while ($sqlfile = readdir($handle)) {
        			
        			if (!is_dir($CONFIG->path . 'engine/schema/upgrades/' . $sqlfile)) {
        				if (preg_match('/([0-9]*)\.sql/',$sqlfile,$matches)) {
        					$sql_version = (int) $matches[1];
        					if ($sql_version > $version) {
        						$sqlupgrades[] = $sqlfile;
        					}
        				}
        			}
        			
        		}
        		
        		asort($sqlupgrades);
        		if (sizeof($sqlupgrades) > 0) {
        			foreach($sqlupgrades as $sqlfile) {
        				try {
        					run_sql_script($CONFIG->path . 'engine/schema/upgrades/' . $sqlfile);
        				} catch (DatabaseException $e) {
        					error_log($e->getmessage());
        				}
        			}
        		}
        		
        	}
        	
        	return true;
        }
        
        /**
         * This function, called by validate_platform(), will check whether the installed version of
         * MySQL meets the minimum required.
         *
         * TODO: If multiple dbs are supported check which db is supported and use the appropriate code to validate
         * the appropriate version.
         * 
         * @return bool
         */
        function db_check_version()
        {
        	$version = mysql_get_server_info();
        	
        	$points = explode('.', $version);
        	
        	if ($points[0] < 5)
        		return false;

        	return true;
        }
        
    /**
     * Sanitise a string for database use, but with the option of escaping extra characters.
     */
        function sanitise_string_special($string, $extra_escapeable = '')
        {
        	$string = sanitise_string($string);
        	
        	for ($n = 0; $n < strlen($extra_escapeable); $n++)
        		$string = str_replace($extra_escapeable[$n], "\\" . $extra_escapeable[$n], $string);
        		
        	return $string;
        }
        
	/**
	 * Sanitise a string for database use
	 *
	 * @param string $string The string to sanitise
	 * @return string Sanitised string
	 */
        function sanitise_string($string) {
        	return mysql_real_escape_string(trim($string));
        }
        
	/**
	 * Wrapper function for alternate English spelling
	 *
	 * @param string $string The string to sanitise
	 * @return string Sanitised string
	 * @uses sanitise_string
	 */
        function sanitize_string($string) {
        	return sanitise_string($string);
        }
        
	/**
	 * Sanitises an integer for database use
	 *
	 * @param int $int
	 * @return int Sanitised integer
	 */
        function sanitise_int($int) {
        	return (int) $int;
        }
        
	/**
	 * Wrapper function for alternate English spelling
	 *
	 * @param int $int
	 * @return int Sanitised integer
	 * @uses sanitise_string
	 */
        function sanitize_int($int) {
        	return (int) $int;
        }
        
	// Stuff for initialisation

		register_elgg_event_handler('boot','system','init_db',0);

?>