xref: /plugin/sqlite/helper.php (revision fd69a32c016ce02ddc42177a639af2079ff519c1) 
1<?php
2/**
3 * DokuWiki Plugin sqlite (Helper Component)
4 *
5 * @license GPL 2 http://www.gnu.org/licenses/gpl-2.0.html
6 * @author  Andreas Gohr <gohr@cosmocode.de>
7 */
8
9// must be run within Dokuwiki
10if (!defined('DOKU_INC')) die();
11
12if (!defined('DOKU_LF')) define('DOKU_LF', "\n");
13if (!defined('DOKU_TAB')) define('DOKU_TAB', "\t");
14if (!defined('DOKU_PLUGIN')) define('DOKU_PLUGIN',DOKU_INC.'lib/plugins/');
15
16class helper_plugin_sqlite extends DokuWiki_Plugin {
17    var $db     = null;
18    var $dbname = '';
19
20    function getInfo() {
21        return confToHash(dirname(__FILE__).'plugin.info.txt');
22    }
23
24    /**
25     * constructor
26     */
27    function helper_plugin_sqlite(){
28        if (!extension_loaded('sqlite')) {
29            $prefix = (PHP_SHLIB_SUFFIX === 'dll') ? 'php_' : '';
30            if(function_exists('dl')) @dl($prefix . 'sqlite.' . PHP_SHLIB_SUFFIX);
31        }
32
33        if(!function_exists('sqlite_open')){
34            msg('SQLite support missing in this PHP install - plugin will not work',-1);
35        }
36    }
37
38    /**
39     * Initializes and opens the database
40     *
41     * Needs to be called right after loading this helper plugin
42     */
43    function init($dbname,$updatedir){
44        global $conf;
45
46        // check for already open DB
47        if($this->db){
48            if($this->dbname == $dbname){
49                // db already open
50                return true;
51            }
52            // close other db
53            sqlite_close($this->db);
54            $this->db     = null;
55            $this->dbname = '';
56        }
57
58        $this->dbname = $dbname;
59        $dbfile = $conf['metadir'].'/'.$dbname.'.sqlite';
60        $init   = (!@file_exists($dbfile) || ((int) @filesize($dbfile)) < 3);
61
62        $error='';
63        $this->db = sqlite_open($dbfile, 0666, $error);
64        if(!$this->db){
65            msg("SQLite: failed to open SQLite ".$this->dbname." database ($error)",-1);
66            return false;
67        }
68
69        // register our custom aggregate function
70        sqlite_create_aggregate($this->db,'group_concat',
71                                array($this,'_sqlite_group_concat_step'),
72                                array($this,'_sqlite_group_concat_finalize'), 2);
73
74        $this->_updatedb($init,$updatedir);
75        return true;
76    }
77
78    /**
79     * Return the current Database Version
80     */
81    function _currentDBversion(){
82        $sql = "SELECT val FROM opts WHERE opt = 'dbversion';";
83        $res = $this->query($sql);
84        if(!$res) return false;
85        $row = $this->res2row($res,0);
86        return (int) $row['val'];
87    }
88    /**
89     * Update the database if needed
90     *
91     * @param bool   $init      - true if this is a new database to initialize
92     * @param string $updatedir - Database update infos
93     */
94    function _updatedb($init,$updatedir){
95        if($init){
96            $current = 0;
97        }else{
98            $current = $this->_currentDBversion();
99            if(!$current){
100                msg('SQLite: no DB version found. '.$this->dbname.' DB probably broken.',-1);
101                return false;
102            }
103        }
104
105        // in case of init, add versioning table
106        if($init){
107            if(!$this->_runupdatefile(dirname(__FILE__).'/db.sql',0)){
108                msg('SQLite: '.$this->dbname.' database upgrade failed for version '.$i, -1);
109                return false;
110            }
111        }
112
113        $latest  = (int) trim(io_readFile($updatedir.'/latest.version'));
114
115        // all up to date?
116        if($current >= $latest) return true;
117        for($i=$current+1; $i<=$latest; $i++){
118            $file = sprintf($updatedir.'/update%04d.sql',$i);
119            if(file_exists($file)){
120                if(!$this->_runupdatefile($file,$i)){
121                    msg('SQLite: '.$this->dbname.' database upgrade failed for version '.$i, -1);
122
123
124                    return false;
125                }
126            }
127        }
128        return true;
129    }
130
131    /**
132     * Updates the database structure using the given file to
133     * the given version.
134     */
135    function _runupdatefile($file,$version){
136        $sql  = io_readFile($file,false);
137
138        $sql = explode(";",$sql);
139        array_unshift($sql,'BEGIN TRANSACTION');
140        array_push($sql,"INSERT OR REPLACE INTO opts (val,opt) VALUES ($version,'dbversion')");
141        array_push($sql,"COMMIT TRANSACTION");
142
143        foreach($sql as $s){
144            $s = preg_replace('!^\s*--.*$!m', '', $s);
145            $s = trim($s);
146            if(!$s) continue;
147
148
149            $res = $this->query("$s;");
150            if ($res === false) {
151                sqlite_query($this->db, 'ROLLBACK TRANSACTION');
152                return false;
153            }
154        }
155
156        return ($version == $this->_currentDBversion());
157    }
158
159    /**
160     * Emulate ALTER TABLE
161     *
162     * The ALTER TABLE syntax is parsed and then emulated using a
163     * temporary table
164     *
165     * @author <jon@jenseng.com>
166     * @link   http://code.jenseng.com/db/
167     */
168    function _altertable($table,$alterdefs){
169        $result = $this->query("SELECT sql,name,type
170                                  FROM sqlite_master
171                                 WHERE tbl_name = '$table'
172                              ORDER BY type DESC");
173        if(!$result || sqlite_num_rows($result)<=0){
174            msg("ALTER TABLE failed, no such table '".hsc($table)."'",-1);
175            return false;
176        }
177
178        $row = sqlite_fetch_array($result); //table sql
179        $tmpname = 't'.time();
180
181        $origsql = trim(preg_replace("/[\s]+/"," ",
182                        str_replace(",",", ",
183                        preg_replace('/\)$/',' )',
184                        preg_replace("/[\(]/","( ",$row['sql'],1)))));
185        $createtemptableSQL = 'CREATE TEMPORARY '.substr(trim(preg_replace("'".$table."'",$tmpname,$origsql,1)),6);
186        $createindexsql = array();
187        $i = 0;
188        $defs = preg_split("/[,]+/",$alterdefs,-1,PREG_SPLIT_NO_EMPTY);
189        $prevword = $table;
190        $oldcols = preg_split("/[,]+/",substr(trim($createtemptableSQL),strpos(trim($createtemptableSQL),'(')+1),-1,PREG_SPLIT_NO_EMPTY);
191        $newcols = array();
192
193        for($i=0;$i<sizeof($oldcols);$i++){
194            $colparts = preg_split("/[\s]+/",$oldcols[$i],-1,PREG_SPLIT_NO_EMPTY);
195            $oldcols[$i] = $colparts[0];
196            $newcols[$colparts[0]] = $colparts[0];
197        }
198        $newcolumns = '';
199        $oldcolumns = '';
200        reset($newcols);
201        while(list($key,$val) = each($newcols)){
202            $newcolumns .= ($newcolumns?', ':'').$val;
203            $oldcolumns .= ($oldcolumns?', ':'').$key;
204        }
205        $copytotempsql = 'INSERT INTO '.$tmpname.'('.$newcolumns.') SELECT '.$oldcolumns.' FROM '.$table;
206        $dropoldsql = 'DROP TABLE '.$table;
207        $createtesttableSQL = $createtemptableSQL;
208
209        foreach($defs as $def){
210            $defparts = preg_split("/[\s]+/",$def,-1,PREG_SPLIT_NO_EMPTY);
211            $action = strtolower($defparts[0]);
212            switch($action){
213                case 'add':
214                    if(sizeof($defparts) < 2){
215                        msg('ALTER TABLE: not enough arguments for ADD statement',-1);
216                        return false;
217                    }
218                    $createtesttableSQL = substr($createtesttableSQL,0,strlen($createtesttableSQL)-1).',';
219                    for($i=1;$i<sizeof($defparts);$i++)
220                        $createtesttableSQL.=' '.$defparts[$i];
221                    $createtesttableSQL.=')';
222                    break;
223
224                case 'change':
225                    if(sizeof($defparts) <= 3){
226                        msg('ALTER TABLE: near "'.$defparts[0].($defparts[1]?' '.$defparts[1]:'').($defparts[2]?' '.$defparts[2]:'').'": syntax error',-1);
227                        return false;
228                    }
229
230                    if($severpos = strpos($createtesttableSQL,' '.$defparts[1].' ')){
231                        if($newcols[$defparts[1]] != $defparts[1]){
232                            msg('ALTER TABLE: unknown column "'.$defparts[1].'" in "'.$table.'"',-1);
233                            return false;
234                        }
235                        $newcols[$defparts[1]] = $defparts[2];
236                        $nextcommapos = strpos($createtesttableSQL,',',$severpos);
237                        $insertval = '';
238                        for($i=2;$i<sizeof($defparts);$i++)
239                            $insertval.=' '.$defparts[$i];
240                        if($nextcommapos)
241                            $createtesttableSQL = substr($createtesttableSQL,0,$severpos).$insertval.substr($createtesttableSQL,$nextcommapos);
242                        else
243                            $createtesttableSQL = substr($createtesttableSQL,0,$severpos-(strpos($createtesttableSQL,',')?0:1)).$insertval.')';
244                    } else {
245                        msg('ALTER TABLE: unknown column "'.$defparts[1].'" in "'.$table.'"',-1);
246                        return false;
247                    }
248                    break;
249                case 'drop':
250                    if(sizeof($defparts) < 2){
251                        msg('ALTER TABLE: near "'.$defparts[0].($defparts[1]?' '.$defparts[1]:'').'": syntax error',-1);
252                        return false;
253                    }
254                    if($severpos = strpos($createtesttableSQL,' '.$defparts[1].' ')){
255                        $nextcommapos = strpos($createtesttableSQL,',',$severpos);
256                        if($nextcommapos)
257                            $createtesttableSQL = substr($createtesttableSQL,0,$severpos).substr($createtesttableSQL,$nextcommapos + 1);
258                        else
259                            $createtesttableSQL = substr($createtesttableSQL,0,$severpos-(strpos($createtesttableSQL,',')?0:1) - 1).')';
260                        unset($newcols[$defparts[1]]);
261                    }else{
262                        msg('ALTER TABLE: unknown column "'.$defparts[1].'" in "'.$table.'"',-1);
263                        return false;
264                    }
265                    break;
266                default:
267                    msg('ALTER TABLE: near "'.$prevword.'": syntax error',-1);
268                    return false;
269            }
270            $prevword = $defparts[sizeof($defparts)-1];
271        }
272
273        // this block of code generates a test table simply to verify that the
274        // columns specifed are valid in an sql statement
275        // this ensures that no reserved words are used as columns, for example
276        $res = $this->query($createtesttableSQL);
277        if($res === false) return false;
278
279        $droptempsql = 'DROP TABLE '.$tmpname;
280        $res = $this->query($droptempsql);
281        if($res === false) return false;
282
283
284        $createnewtableSQL = 'CREATE '.substr(trim(preg_replace("'".$tmpname."'",$table,$createtesttableSQL,1)),17);
285        $newcolumns = '';
286        $oldcolumns = '';
287        reset($newcols);
288        while(list($key,$val) = each($newcols)){
289            $newcolumns .= ($newcolumns?', ':'').$val;
290            $oldcolumns .= ($oldcolumns?', ':'').$key;
291        }
292
293        $copytonewsql = 'INSERT INTO '.$table.'('.$newcolumns.') SELECT '.$oldcolumns.' FROM '.$tmpname;
294
295        $res = $this->query($createtemptableSQL); //create temp table
296        if($res === false) return false;
297        $res = $this->query($copytotempsql); //copy to table
298        if($res === false) return false;
299        $res = $this->query($dropoldsql); //drop old table
300        if($res === false) return false;
301
302        $res = $this->query($createnewtableSQL); //recreate original table
303        if($res === false) return false;
304        $res = $this->query($copytonewsql); //copy back to original table
305        if($res === false) return false;
306        $res = $this->query($droptempsql); //drop temp table
307        if($res === false) return false;
308
309        return $res; // return a valid resource
310    }
311
312    /**
313     * Execute a query with the given parameters.
314     *
315     * Takes care of escaping
316     *
317     * @param string $sql - the statement
318     * @param arguments...
319     */
320    function query(){
321        if(!$this->db) return false;
322
323        // get function arguments
324        $args = func_get_args();
325        $sql  = trim(array_shift($args));
326        $sql  = rtrim($sql,';');
327
328        if(!$sql){
329            msg('No SQL statement given',-1);
330            return false;
331        }
332
333        if(is_array($args[0])) $args = $args[0];
334        $argc = count($args);
335
336        // check number of arguments
337        if($argc < substr_count($sql,'?')){
338            msg('Not enough arguments passed for statement. '.
339                'Expected '.substr_count($sql,'?').' got '.
340                $argc.' - '.hsc($sql),-1);
341            return false;
342        }
343
344        // explode at wildcard, then join again
345        $parts = explode('?',$sql,$argc+1);
346        $args  = array_map(array($this,'quote_string'),$args);
347        $sql   = '';
348
349        while( ($part = array_shift($parts)) !== null ){
350            $sql .= $part;
351            $sql .= array_shift($args);
352        }
353
354        // intercept ALTER TABLE statements
355        if(preg_match('/^ALTER\s+TABLE\s+([\w\.]+)\s+(.*)/i',$sql,$match)){
356            return $this->_altertable($match[1],$match[2]);
357        }
358
359        // execute query
360        $err = '';
361        $res = @sqlite_query($this->db,$sql,SQLITE_ASSOC,$err);
362        if($err){
363            msg($err.':<br /><pre>'.hsc($sql).'</pre>',-1);
364            return false;
365        }elseif(!$res){
366            msg(sqlite_error_string(sqlite_last_error($this->db)).
367                ':<br /><pre>'.hsc($sql).'</pre>',-1);
368            return false;
369        }
370
371        return $res;
372    }
373
374    /**
375     * Returns a complete result set as array
376     */
377    function res2arr($res){
378        $data = array();
379        if(!sqlite_num_rows($res)) return $data;
380        sqlite_rewind($res);
381        while(($row = sqlite_fetch_array($res)) !== false){
382            $data[] = $row;
383        }
384        return $data;
385    }
386
387    /**
388     * Return the wanted row from a given result set as
389     * associative array
390     */
391    function res2row($res,$rownum=0){
392        if(!@sqlite_seek($res,$rownum)){
393            return false;
394        }
395        return sqlite_fetch_array($res);
396    }
397
398
399    /**
400     * Join the given values and quote them for SQL insertion
401     */
402    function quote_and_join($vals,$sep=',') {
403        $vals = array_map(array('helper_plugin_sqlite','quote_string'),$vals);
404        return join($sep,$vals);
405    }
406
407    /**
408     * Run sqlite_escape_string() on the given string and surround it
409     * with quotes
410     */
411    function quote_string($string){
412        return "'".sqlite_escape_string($string)."'";
413    }
414
415
416    /**
417     * Aggregation function for SQLite
418     *
419     * @link http://devzone.zend.com/article/863-SQLite-Lean-Mean-DB-Machine
420     */
421    function _sqlite_group_concat_step(&$context, $string, $separator = ',') {
422         $context['sep']    = $separator;
423         $context['data'][] = $string;
424    }
425
426    /**
427     * Aggregation function for SQLite
428     *
429     * @link http://devzone.zend.com/article/863-SQLite-Lean-Mean-DB-Machine
430     */
431    function _sqlite_group_concat_finalize(&$context) {
432         $context['data'] = array_unique($context['data']);
433         return join($context['sep'],$context['data']);
434    }
435
436
437}
438
439// vim:ts=4:sw=4:et:enc=utf-8:
440