summaryrefslogtreecommitdiff
path: root/maintenance/convertLinks.inc
blob: 5f8c27a542cddc6922c3e0ff185f76cf9d355d4a (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
<?php
/**
 * @todo document
 * @package MediaWiki
 * @subpackage Maintenance
 */

/** */
function convertLinks() {
	global $wgDBtype;
	if( $wgDBtype == 'postgres' ) {
		print "Links table already ok on Postgres.\n";
		return;
	}

	print "Converting links table to ID-ID...\n";

	global $wgLang, $wgDBserver, $wgDBadminuser, $wgDBadminpassword, $wgDBname;
	global $noKeys, $logPerformance, $fh;

	$numRows = $tuplesAdded = $numBadLinks = $curRowsRead = 0; #counters etc
	$totalTuplesInserted = 0; # total tuples INSERTed into links_temp

	$reportCurReadProgress = true; #whether or not to give progress reports while reading IDs from cur table
	$curReadReportInterval = 1000; #number of rows between progress reports

	$reportLinksConvProgress = true; #whether or not to give progress reports during conversion
	$linksConvInsertInterval = 1000; #number of rows per INSERT

	$initialRowOffset = 0;
	#$finalRowOffset = 0; # not used yet; highest row number from links table to process

	# Overwrite the old links table with the new one.  If this is set to false,
	# the new table will be left at links_temp.
	$overwriteLinksTable = true;

	# Don't create keys, and so allow duplicates in the new links table.
	# This gives a huge speed improvement for very large links tables which are MyISAM. (What about InnoDB?)
	$noKeys = false;


	$logPerformance = false; # output performance data to a file
	$perfLogFilename = "convLinksPerf.txt";
	#--------------------------------------------------------------------

	$dbw =& wfGetDB( DB_MASTER );
	extract( $dbw->tableNames( 'cur', 'links', 'links_temp', 'links_backup' ) );

	$res = $dbw->query( "SELECT l_from FROM $links LIMIT 1" );
	if ( $dbw->fieldType( $res, 0 ) == "int" ) {
		print "Schema already converted\n";
		return;
	}

	$res = $dbw->query( "SELECT COUNT(*) AS count FROM $links" );
	$row = $dbw->fetchObject($res);
	$numRows = $row->count;
	$dbw->freeResult( $res );

	if ( $numRows == 0 ) {
		print "Updating schema (no rows to convert)...\n";
		createTempTable();
	} else {
		if ( $logPerformance ) { $fh = fopen ( $perfLogFilename, "w" ); }
		$baseTime = $startTime = getMicroTime();
		# Create a title -> cur_id map
		print "Loading IDs from $cur table...\n";
		performanceLog ( "Reading $numRows rows from cur table...\n" );
		performanceLog ( "rows read vs seconds elapsed:\n" );

		$dbw->bufferResults( false );
		$res = $dbw->query( "SELECT cur_namespace,cur_title,cur_id FROM $cur" );
		$ids = array();

		while ( $row = $dbw->fetchObject( $res ) ) {
			$title = $row->cur_title;
			if ( $row->cur_namespace ) {
				$title = $wgLang->getNsText( $row->cur_namespace ) . ":$title";
			}
			$ids[$title] = $row->cur_id;
			$curRowsRead++;
			if ($reportCurReadProgress) {
				if (($curRowsRead % $curReadReportInterval) == 0) {
					performanceLog( $curRowsRead . " " . (getMicroTime() - $baseTime) . "\n" );
					print "\t$curRowsRead rows of $cur table read.\n";
				}
			}
		}
		$dbw->freeResult( $res );
		$dbw->bufferResults( true );
		print "Finished loading IDs.\n\n";
		performanceLog( "Took " . (getMicroTime() - $baseTime) . " seconds to load IDs.\n\n" );
	#--------------------------------------------------------------------

		# Now, step through the links table (in chunks of $linksConvInsertInterval rows),
		# convert, and write to the new table.
		createTempTable();
		performanceLog( "Resetting timer.\n\n" );
		$baseTime = getMicroTime();
		print "Processing $numRows rows from $links table...\n";
		performanceLog( "Processing $numRows rows from $links table...\n" );
		performanceLog( "rows inserted vs seconds elapsed:\n" );

		for ($rowOffset = $initialRowOffset; $rowOffset < $numRows; $rowOffset += $linksConvInsertInterval) {
			$sqlRead = "SELECT * FROM $links ";
			$sqlRead = $dbw->limitResult($sqlRead, $linksConvInsertInterval,$rowOffset);
			$res = $dbw->query($sqlRead);
			if ( $noKeys ) {
				$sqlWrite = array("INSERT INTO $links_temp (l_from,l_to) VALUES ");
			} else {
				$sqlWrite = array("INSERT IGNORE INTO $links_temp (l_from,l_to) VALUES ");
			}

			$tuplesAdded = 0; # no tuples added to INSERT yet
			while ( $row = $dbw->fetchObject($res) ) {
				$fromTitle = $row->l_from;
				if ( array_key_exists( $fromTitle, $ids ) ) { # valid title
					$from = $ids[$fromTitle];
					$to = $row->l_to;
					if ( $tuplesAdded != 0 ) {
						$sqlWrite[] = ",";
					}
					$sqlWrite[] = "($from,$to)";
					$tuplesAdded++;
				} else { # invalid title
					$numBadLinks++;
				}
			}
			$dbw->freeResult($res);
			#print "rowOffset: $rowOffset\ttuplesAdded: $tuplesAdded\tnumBadLinks: $numBadLinks\n";
			if ( $tuplesAdded != 0  ) {
				if ($reportLinksConvProgress) {
					print "Inserting $tuplesAdded tuples into $links_temp...";
				}
				$dbw->query( implode("",$sqlWrite) );
				$totalTuplesInserted += $tuplesAdded;
				if ($reportLinksConvProgress)
					print " done. Total $totalTuplesInserted tuples inserted.\n";
					performanceLog( $totalTuplesInserted . " " . (getMicroTime() - $baseTime) . "\n"  );
			}
		}
		print "$totalTuplesInserted valid titles and $numBadLinks invalid titles were processed.\n\n";
		performanceLog( "$totalTuplesInserted valid titles and $numBadLinks invalid titles were processed.\n" );
		performanceLog( "Total execution time: " . (getMicroTime() - $startTime) . " seconds.\n" );
		if ( $logPerformance ) { fclose ( $fh ); }
	}
	#--------------------------------------------------------------------

	if ( $overwriteLinksTable ) {
		$dbConn = Database::newFromParams( $wgDBserver, $wgDBadminuser, $wgDBadminpassword, $wgDBname );
		if (!($dbConn->isOpen())) {
			print "Opening connection to database failed.\n";
			return;
		}
		# Check for existing links_backup, and delete it if it exists.
		print "Dropping backup links table if it exists...";
		$dbConn->query( "DROP TABLE IF EXISTS $links_backup", DB_MASTER);
		print " done.\n";

		# Swap in the new table, and move old links table to links_backup
		print "Swapping tables '$links' to '$links_backup'; '$links_temp' to '$links'...";
		$dbConn->query( "RENAME TABLE links TO $links_backup, $links_temp TO $links", DB_MASTER );
		print " done.\n\n";

		$dbConn->close();
		print "Conversion complete. The old table remains at $links_backup;\n";
		print "delete at your leisure.\n";
	} else {
		print "Conversion complete.  The converted table is at $links_temp;\n";
		print "the original links table is unchanged.\n";
	}
}

#--------------------------------------------------------------------

function createTempTable() {
	global $wgDBserver, $wgDBadminuser, $wgDBadminpassword, $wgDBname;
	global $noKeys;
	$dbConn = Database::newFromParams( $wgDBserver, $wgDBadminuser, $wgDBadminpassword, $wgDBname );

	if (!($dbConn->isOpen())) {
		print "Opening connection to database failed.\n";
		return;
	}
	$links_temp = $dbConn->tableName( 'links_temp' );

	print "Dropping temporary links table if it exists...";
	$dbConn->query( "DROP TABLE IF EXISTS $links_temp");
	print " done.\n";

	print "Creating temporary links table...";
	if ( $noKeys ) {
		$dbConn->query( "CREATE TABLE $links_temp ( " .
		"l_from int(8) unsigned NOT NULL default '0', " .
		"l_to int(8) unsigned NOT NULL default '0')");
	} else {
		$dbConn->query( "CREATE TABLE $links_temp ( " .
		"l_from int(8) unsigned NOT NULL default '0', " .
		"l_to int(8) unsigned NOT NULL default '0', " .
		"UNIQUE KEY l_from(l_from,l_to), " .
		"KEY (l_to))");
	}
	print " done.\n\n";
}

function performanceLog( $text ) {
	global $logPerformance, $fh;
	if ( $logPerformance ) {
		fwrite( $fh, $text );
	}
}

function getMicroTime() { # return time in seconds, with microsecond accuracy
	list($usec, $sec) = explode(" ", microtime());
	return ((float)$usec + (float)$sec);
}



?>