https://www.mediawiki.org/wiki/Special:Code/MediaWiki/113487
Revision: 113487
Author: saper
Date: 2012-03-09 17:24:57 +0000 (Fri, 09 Mar 2012)
Log Message:
-----------
Handle PostgreSQL transaction errors and improve schema detection
* Introduce $wgDebugDBTransactions facility to help
figure out what's going on with transactions.
Currently PostgreSQL only.
PostgresTransactionState can be easily be made more general
to trace all sorts of state machinery.
* Improve r113408: we don't need to full reconnect on error,
rollback is enough.
Rolling back breaks search_path, as PostgreSQL
can manage sessions settings under transaction therefore
we need to improve schema sniffing introduced in r82674
* Introduce few schema handling functions. This could
probably be generalized for other databases like DB2 and Oracle.
* Fix bug 15816 - Add a switch for SETting the search_path
We try to avoid touching search_path at all unless
really necessary. Even in this case we append MediaWiki
core schema to the front of the list.
* No longer add $wgDBmwschema to PostgreSQL role search_path
in the installer. This is no longer necessary as
setting schema on connect should ReallyWorkNow(tm).
* Get rid as much as possible of $wgDBmwschema and
bring us one step closer to fix bug 16794 (wgSharedDB
support).
All references to core MediaWiki schema in PostgreSQL
specific code should now use Database::getCoreSchema()
unless we know what we are doing.
Followup-To: r113408 r82674
Modified Paths:
--------------
trunk/phase3/RELEASE-NOTES-1.20
trunk/phase3/includes/DefaultSettings.php
trunk/phase3/includes/db/Database.php
trunk/phase3/includes/db/DatabasePostgres.php
trunk/phase3/includes/installer/PostgresInstaller.php
trunk/phase3/includes/installer/PostgresUpdater.php
Modified: trunk/phase3/RELEASE-NOTES-1.20
===================================================================
--- trunk/phase3/RELEASE-NOTES-1.20 2012-03-09 17:23:09 UTC (rev 113486)
+++ trunk/phase3/RELEASE-NOTES-1.20 2012-03-09 17:24:57 UTC (rev 113487)
@@ -22,6 +22,7 @@
* (bug 27619) Remove preference option to display broken links as link?
* (bug 34896) Update jQuery JSON plugin to v2.3 (2011-09-17)
* (bug 34302) Add CSS classes to email fields in user preferences
+* Introduced $wgDebugDBTransactions to trace transaction status (currently
PostgreSQL only)
=== Bug fixes in 1.20 ===
* (bug 30245) Use the correct way to construct a log page title.
@@ -42,6 +43,7 @@
Special:MyPage and Special:MyTalk
* (bug 34929) Show the correct diff when a section edit is rejected by the
spam
filter
+* (bug 15816) Add a switch for SETting the search_path (Postgres)
=== API changes in 1.20 ===
* (bug 34316) Add ability to retrieve maximum upload size from MediaWiki API.
Modified: trunk/phase3/includes/DefaultSettings.php
===================================================================
--- trunk/phase3/includes/DefaultSettings.php 2012-03-09 17:23:09 UTC (rev
113486)
+++ trunk/phase3/includes/DefaultSettings.php 2012-03-09 17:24:57 UTC (rev
113487)
@@ -4060,6 +4060,11 @@
$wgDebugComments = false;
/**
+ * Extensive database transaction state debugging
+ */
+$wgDebugDBTransactions = false;
+
+/**
* Write SQL queries to the debug log
*/
$wgDebugDumpSql = false;
Modified: trunk/phase3/includes/db/Database.php
===================================================================
--- trunk/phase3/includes/db/Database.php 2012-03-09 17:23:09 UTC (rev
113486)
+++ trunk/phase3/includes/db/Database.php 2012-03-09 17:24:57 UTC (rev
113487)
@@ -784,7 +784,7 @@
* @return bool
*/
function isWriteQuery( $sql ) {
- return !preg_match(
'/^(?:SELECT|BEGIN|COMMIT|SET|SHOW|\(SELECT)\b/i', $sql );
+ return !preg_match(
'/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SET|SHOW|\(SELECT)\b/i', $sql );
}
/**
Modified: trunk/phase3/includes/db/DatabasePostgres.php
===================================================================
--- trunk/phase3/includes/db/DatabasePostgres.php 2012-03-09 17:23:09 UTC
(rev 113486)
+++ trunk/phase3/includes/db/DatabasePostgres.php 2012-03-09 17:24:57 UTC
(rev 113487)
@@ -16,8 +16,6 @@
* @return null|PostgresField
*/
static function fromText( $db, $table, $field ) {
- global $wgDBmwschema;
-
$q = <<<SQL
SELECT
attnotnull, attlen, COALESCE(conname, '') AS conname,
@@ -42,7 +40,7 @@
$table = $db->tableName( $table, 'raw' );
$res = $db->query(
sprintf( $q,
- $db->addQuotes( $wgDBmwschema ),
+ $db->addQuotes( $db->getCoreSchema() ),
$db->addQuotes( $table ),
$db->addQuotes( $field )
)
@@ -98,8 +96,86 @@
}
/**
+ * Used to debug transaction processing
+ * Only used if $wgDebugDBTransactions is true
+ *
+ * @since 1.20
* @ingroup Database
*/
+class PostgresTransactionState {
+
+ static $WATCHED = array(
+ array(
+ "desc" => "Connection state changed from %s -> %s\n",
+ "states" => array(
+ PGSQL_CONNECTION_OK => "OK",
+ PGSQL_CONNECTION_BAD => "BAD"
+ )
+ ),
+ array(
+ "desc" => "Transaction state changed from %s -> %s\n",
+ "states" => array(
+ PGSQL_TRANSACTION_IDLE => "IDLE",
+ PGSQL_TRANSACTION_ACTIVE => "ACTIVE",
+ PGSQL_TRANSACTION_INTRANS => "TRANS",
+ PGSQL_TRANSACTION_INERROR => "ERROR",
+ PGSQL_TRANSACTION_UNKNOWN => "UNKNOWN"
+ )
+ )
+ );
+
+ public function __construct( $conn ) {
+ $this->mConn = $conn;
+ $this->update();
+ $this->mCurrentState = $this->mNewState;
+ }
+
+ public function update() {
+ $this->mNewState = array(
+ pg_connection_status( $this->mConn ),
+ pg_transaction_status( $this->mConn )
+ );
+ }
+
+ public function check() {
+ global $wgDebugDBTransactions;
+ $this->update();
+ if ( $wgDebugDBTransactions ) {
+ if ( $this->mCurrentState !== $this->mNewState ) {
+ $old = reset( $this->mCurrentState );
+ $new = reset( $this->mNewState );
+ foreach ( self::$WATCHED as $watched ) {
+ if ($old !== $new) {
+ $this->log_changed($old, $new,
$watched);
+ }
+ $old = next( $this->mCurrentState );
+ $new = next( $this->mNewState );
+
+ }
+ }
+ }
+ $this->mCurrentState = $this->mNewState;
+ }
+
+ protected function describe_changed( $status, $desc_table ) {
+ if( isset( $desc_table[$status] ) ) {
+ return $desc_table[$status];
+ } else {
+ return "STATUS " . $status;
+ }
+ }
+
+ protected function log_changed( $old, $new, $watched ) {
+ wfDebug(sprintf($watched["desc"],
+ $this->describe_changed( $old, $watched["states"] ),
+ $this->describe_changed( $new, $watched["states"] ))
+ );
+ }
+}
+
+/**
+ * @ingroup Database
+ */
class DatabasePostgres extends DatabaseBase {
var $mInsertId = null;
var $mLastResult = null;
@@ -136,9 +212,8 @@
}
function hasConstraint( $name ) {
- global $wgDBmwschema;
$SQL = "SELECT 1 FROM pg_catalog.pg_constraint c,
pg_catalog.pg_namespace n WHERE c.connamespace = n.oid AND conname = '" .
- pg_escape_string( $this->mConn, $name ) . "'
AND n.nspname = '" . pg_escape_string( $this->mConn, $wgDBmwschema ) ."'";
+ pg_escape_string( $this->mConn, $name ) . "'
AND n.nspname = '" . pg_escape_string( $this->mConn,
$this->mConn->getCoreSchema() ) ."'";
$res = $this->doQuery( $SQL );
return $this->numRows( $res );
}
@@ -177,10 +252,6 @@
$connectVars['port'] = $port;
}
$this->connectString = $this->makeConnectionString(
$connectVars, PGSQL_CONNECT_FORCE_NEW );
- $this->reOpen();
- }
-
- function reOpen() {
$this->close();
$this->installErrorHandler();
$this->mConn = pg_connect( $this->connectString );
@@ -194,6 +265,7 @@
}
$this->mOpened = true;
+ $this->mTransactionState = new PostgresTransactionState(
$this->mConn );
global $wgCommandLineMode;
# If called from the command-line (e.g. importDump), only show
errors
@@ -207,12 +279,7 @@
$this->query( "SET standard_conforming_strings = on",
__METHOD__ );
global $wgDBmwschema;
- if ( $this->schemaExists( $wgDBmwschema ) ) {
- $safeschema = $this->addIdentifierQuotes( $wgDBmwschema
);
- $this->doQuery( "SET search_path = $safeschema" );
- } else {
- $this->doQuery( "SET search_path = public" );
- }
+ $this->determineCoreSchema( $wgDBmwschema );
return $this->mConn;
}
@@ -248,17 +315,20 @@
}
protected function doQuery( $sql ) {
+ global $wgDebugDBTransactions;
if ( function_exists( 'mb_convert_encoding' ) ) {
$sql = mb_convert_encoding( $sql, 'UTF-8' );
}
+ $this->mTransactionState->check();
$this->mLastResult = pg_query( $this->mConn, $sql );
- $this->mAffectedRows = null; // use
pg_affected_rows(mLastResult)
+ $this->mTransactionState->check();
+ $this->mAffectedRows = null;
return $this->mLastResult;
}
function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore =
false ) {
+ /* Transaction stays in the ERROR state until rolledback */
$this->rollback( __METHOD__ );
- $this->reOpen();
parent::reportQueryError( $error, $errno, $sql, $fname,
$tempIgnore );
}
@@ -502,7 +572,7 @@
$tempsql .= '(' . $this->makeList( $row
) . ')';
if ( $ignore ) {
- pg_query( $this->mConn,
"SAVEPOINT $ignore" );
+ $this->doQuery( "SAVEPOINT
$ignore" );
}
$tempres = (bool)$this->query(
$tempsql, $fname, $ignore );
@@ -510,9 +580,9 @@
if ( $ignore ) {
$bar = pg_last_error();
if ( $bar != false ) {
- pg_query( $this->mConn,
"ROLLBACK TO $ignore" );
+ $this->doQuery(
$this->mConn, "ROLLBACK TO $ignore" );
} else {
- pg_query( $this->mConn,
"RELEASE $ignore" );
+ $this->doQuery(
$this->mConn, "RELEASE $ignore" );
$numrowsinserted++;
}
}
@@ -527,7 +597,7 @@
} else {
// Not multi, just a lone insert
if ( $ignore ) {
- pg_query($this->mConn, "SAVEPOINT $ignore");
+ $this->doQuery( "SAVEPOINT $ignore" );
}
$sql .= '(' . $this->makeList( $args ) . ')';
@@ -535,9 +605,9 @@
if ( $ignore ) {
$bar = pg_last_error();
if ( $bar != false ) {
- pg_query( $this->mConn, "ROLLBACK TO
$ignore" );
+ $this->doQuery( "ROLLBACK TO $ignore" );
} else {
- pg_query( $this->mConn, "RELEASE
$ignore" );
+ $this->doQuery( "RELEASE $ignore" );
$numrowsinserted++;
}
}
@@ -597,7 +667,7 @@
}
$olde = error_reporting( 0 );
$numrowsinserted = 0;
- pg_query( $this->mConn, "SAVEPOINT $ignore");
+ $this->doQuery( "SAVEPOINT $ignore" );
}
$sql = "INSERT INTO $destTable (" . implode( ',', array_keys(
$varMap ) ) . ')' .
@@ -614,9 +684,9 @@
if( $ignore ) {
$bar = pg_last_error();
if( $bar != false ) {
- pg_query( $this->mConn, "ROLLBACK TO $ignore" );
+ $this->doQuery( "ROLLBACK TO $ignore" );
} else {
- pg_query( $this->mConn, "RELEASE $ignore" );
+ $this->doQuery( "RELEASE $ignore" );
$numrowsinserted++;
}
$olde = error_reporting( $olde );
@@ -702,10 +772,8 @@
}
function listTables( $prefix = null, $fname =
'DatabasePostgres::listTables' ) {
- global $wgDBmwschema;
- $eschema = $this->addQuotes( $wgDBmwschema );
+ $eschema = $this->addQuotes( $this->getCoreSchema() );
$result = $this->query( "SELECT tablename FROM pg_tables WHERE
schemaname = $eschema", $fname );
-
$endArray = array();
foreach( $result as $table ) {
@@ -723,6 +791,48 @@
return wfTimestamp( TS_POSTGRES, $ts );
}
+
+ /*
+ * Posted by cc[plus]php[at]c2se[dot]com on 25-Mar-2009 09:12
+ * to http://www.php.net/manual/en/ref.pgsql.php
+ *
+ * Parsing a postgres array can be a tricky problem, he's my
+ * take on this, it handles multi-dimensional arrays plus
+ * escaping using a nasty regexp to determine the limits of each
+ * data-item.
+ *
+ * This should really be handled by PHP PostgreSQL module
+ *
+ * @since 1.20
+ * @param text string: postgreql array returned in a text form like
{a,b}
+ * @param output string
+ * @param limit int
+ * @param offset int
+ * @return string
+ */
+
+ function pg_array_parse( $text, &$output, $limit = false, $offset = 1 )
{
+ if( false === $limit ) {
+ $limit = strlen( $text )-1;
+ $output = array();
+ }
+ if( '{}' != $text )
+ do {
+ if ( '{' != $text{$offset} ) {
+ preg_match(
"/(\\{?\"([^\"\\\\]|\\\\.)*\"|[^,{}]+)+([,}]+)/",
+ $text, $match, 0, $offset );
+ $offset += strlen( $match[0] );
+ $output[] = ( '"' != $match[1]{0}
+ ? $match[1]
+ : stripcslashes( substr(
$match[1], 1, -1 ) ) );
+ if ( '},' == $match[3] )
+ return $output;
+ } else
+ $offset = $this->pg_array_parse( $text,
$output[], $limit, $offset+1 );
+ } while ( $limit > $offset );
+ return $output;
+ }
+
/**
* Return aggregated value function call
*/
@@ -737,7 +847,115 @@
return '[http://www.postgresql.org/ PostgreSQL]';
}
+
/**
+ * Return current schema (executes SELECT current_schema())
+ * Needs transaction
+ *
+ * @since 1.20
+ * @return string return default schema for the current session
+ */
+ function getCurrentSchema() {
+ $res = $this->query( "SELECT current_schema()", __METHOD__);
+ $row = $this->fetchRow( $res );
+ return $row[0];
+ }
+
+ /**
+ * Return list of schemas which are accessible without schema name
+ * This is list does not contain magic keywords like "$user"
+ * Needs transaction
+ *
+ * @seealso getSearchPath()
+ * @seealso setSearchPath()
+ * @since 1.20
+ * @return array list of actual schemas for the current sesson
+ */
+ function getSchemas() {
+ $res = $this->query( "SELECT current_schemas(false)",
__METHOD__);
+ $row = $this->fetchRow( $res );
+ $schemas = array();
+ /* PHP pgsql support does not support array type, "{a,b}"
string is returned */
+ return $this->pg_array_parse($row[0], $schemas);
+ }
+
+ /**
+ * Return search patch for schemas
+ * This is different from getSchemas() since it contain magic keywords
+ * (like "$user").
+ * Needs transaction
+ *
+ * @since 1.20
+ * @return array how to search for table names schemas for the current
user
+ */
+ function getSearchPath() {
+ $res = $this->query( "SHOW search_path", __METHOD__);
+ $row = $this->fetchRow( $res );
+ /* PostgreSQL returns SHOW values as strings */
+ return explode(",", $row[0]);
+ }
+
+ function setSearchPath( $search_path ) {
+ /**
+ * Update search_path, values should already be sanitized
+ * Values may contain magic keywords like "$user"
+ * @since 1.20
+ *
+ * @param array list of schemas to be searched by default
+ */
+ $this->query( "SET search_path = " . implode(", ",
$search_path) );
+ }
+
+ /**
+ * Determine default schema for MediaWiki core
+ * Adjust this session schema search path if desired schema exists
+ * and is not alread there.
+ *
+ * We need to have name of the core schema stored to be able
+ * to query database metadata.
+ *
+ * This will be also called by the installer after the schema is created
+ *
+ * @since 1.20
+ * @param desired_schema string
+ */
+ function determineCoreSchema( $desired_schema ) {
+ $this->begin( __METHOD__ );
+ if ( $this->schemaExists( $desired_schema ) ) {
+ if ( in_array( $desired_schema, $this->getSchemas() ) )
{
+ $this->mCoreSchema = $desired_schema;
+ wfDebug("Schema \"" . $desired_schema . "\"
already in the search path\n");
+ } else {
+ /**
+ * Apped our schema (e.g. 'mediawiki') in front
+ * of the search path
+ * Fixes bug 15816
+ */
+ $search_path = $this->getSearchPath();
+ array_unshift( $search_path,
+ $this->addIdentifierQuotes(
$desired_schema ));
+ $this->setSearchPath( $search_path );
+ wfDebug("Schema \"" . $desired_schema . "\"
added to the search path\n");
+ }
+ } else {
+ $this->mCoreSchema = $this->getCurrentSchema();
+ wfDebug("Schema \"" . $desired_schema . "\" not found,
using current \"". $this->mCoreSchema ."\"\n");
+ }
+ /* Commit SET otherwise it will be rollbacked on error or
IGNORE SELECT */
+ $this->commit( __METHOD__ );
+ }
+
+ /**
+ * Return schema name fore core MediaWiki tables
+ *
+ * @since 1.20
+ * @return string core schema name
+ */
+ function getCoreSchema() {
+ return $this->mCoreSchema;
+ }
+
+ /**
* @return string Version information from the database
*/
function getServerVersion() {
@@ -763,12 +981,11 @@
* @return bool
*/
function relationExists( $table, $types, $schema = false ) {
- global $wgDBmwschema;
if ( !is_array( $types ) ) {
$types = array( $types );
}
if ( !$schema ) {
- $schema = $wgDBmwschema;
+ $schema = $this->getCoreSchema();
}
$table = $this->tableName( $table, 'raw' );
$etable = $this->addQuotes( $table );
@@ -795,8 +1012,6 @@
}
function triggerExists( $table, $trigger ) {
- global $wgDBmwschema;
-
$q = <<<SQL
SELECT 1 FROM pg_class, pg_namespace, pg_trigger
WHERE relnamespace=pg_namespace.oid AND relkind='r'
@@ -806,7 +1021,7 @@
$res = $this->query(
sprintf(
$q,
- $this->addQuotes( $wgDBmwschema ),
+ $this->addQuotes( $this->getCoreSchema() ),
$this->addQuotes( $table ),
$this->addQuotes( $trigger )
)
@@ -819,22 +1034,20 @@
}
function ruleExists( $table, $rule ) {
- global $wgDBmwschema;
$exists = $this->selectField( 'pg_rules', 'rulename',
array(
'rulename' => $rule,
'tablename' => $table,
- 'schemaname' => $wgDBmwschema
+ 'schemaname' => $this->getCoreSchema()
)
);
return $exists === $rule;
}
function constraintExists( $table, $constraint ) {
- global $wgDBmwschema;
$SQL = sprintf( "SELECT 1 FROM
information_schema.table_constraints ".
"WHERE constraint_schema = %s AND table_name = %s
AND constraint_name = %s",
- $this->addQuotes( $wgDBmwschema ),
+ $this->addQuotes( $this->getCoreSchema() ),
$this->addQuotes( $table ),
$this->addQuotes( $constraint )
);
Modified: trunk/phase3/includes/installer/PostgresInstaller.php
===================================================================
--- trunk/phase3/includes/installer/PostgresInstaller.php 2012-03-09
17:23:09 UTC (rev 113486)
+++ trunk/phase3/includes/installer/PostgresInstaller.php 2012-03-09
17:24:57 UTC (rev 113487)
@@ -431,10 +431,6 @@
$conn = $status->value;
$dbName = $this->getVar( 'wgDBname' );
- //$schema = $this->getVar( 'wgDBmwschema' );
- //$user = $this->getVar( 'wgDBuser' );
- //$safeschema = $conn->addIdentifierQuotes( $schema );
- //$safeuser = $conn->addIdentifierQuotes( $user );
$exists = $conn->selectField( '"pg_catalog"."pg_database"', '1',
array( 'datname' => $dbName ), __METHOD__ );
@@ -466,14 +462,8 @@
}
}
- // If we created a user, alter it now to search the new schema
by default
- if ( $this->getVar( '_CreateDBAccount' ) ) {
- $conn->query( "ALTER ROLE $safeuser SET search_path =
$safeschema, public",
- __METHOD__ );
- }
-
// Select the new schema in the current connection
- $conn->query( "SET search_path = $safeschema" );
+ $conn->determineCoreSchema( $schema );
return Status::newGood();
}
@@ -493,10 +483,8 @@
}
$conn = $status->value;
- //$schema = $this->getVar( 'wgDBmwschema' );
$safeuser = $conn->addIdentifierQuotes( $this->getVar(
'wgDBuser' ) );
$safepass = $conn->addQuotes( $this->getVar( 'wgDBpassword' ) );
- //$safeschema = $conn->addIdentifierQuotes( $schema );
// Check if the user already exists
$userExists = $conn->roleExists( $this->getVar( 'wgDBuser' ) );
Modified: trunk/phase3/includes/installer/PostgresUpdater.php
===================================================================
--- trunk/phase3/includes/installer/PostgresUpdater.php 2012-03-09 17:23:09 UTC
(rev 113486)
+++ trunk/phase3/includes/installer/PostgresUpdater.php 2012-03-09 17:24:57 UTC
(rev 113487)
@@ -270,7 +270,6 @@
}
protected function describeTable( $table ) {
- global $wgDBmwschema;
$q = <<<END
SELECT attname, attnum FROM pg_namespace, pg_class, pg_attribute
WHERE pg_class.relnamespace = pg_namespace.oid
@@ -279,7 +278,7 @@
END;
$res = $this->db->query( sprintf( $q,
$this->db->addQuotes( $table ),
- $this->db->addQuotes( $wgDBmwschema ) ) );
+ $this->db->addQuotes(
$this->db->getCoreSchema() ) ) );
if ( !$res ) {
return null;
}
@@ -295,8 +294,6 @@
}
function describeIndex( $idx ) {
- global $wgDBmwschema;
-
// first fetch the key (which is a list of columns ords) and
// the table the index applies to (an oid)
$q = <<<END
@@ -309,7 +306,7 @@
$res = $this->db->query(
sprintf(
$q,
- $this->db->addQuotes( $wgDBmwschema ),
+ $this->db->addQuotes( $this->db->getCoreSchea()
),
$this->db->addQuotes( $idx )
)
);
@@ -346,7 +343,6 @@
}
function fkeyDeltype( $fkey ) {
- global $wgDBmwschema;
$q = <<<END
SELECT confdeltype FROM pg_constraint, pg_namespace
WHERE connamespace=pg_namespace.oid
@@ -356,7 +352,7 @@
$r = $this->db->query(
sprintf(
$q,
- $this->db->addQuotes( $wgDBmwschema ),
+ $this->db->addQuotes(
$this->db->getCoreSchema() ),
$this->db->addQuotes( $fkey )
)
);
@@ -367,7 +363,6 @@
}
function ruleDef( $table, $rule ) {
- global $wgDBmwschema;
$q = <<<END
SELECT definition FROM pg_rules
WHERE schemaname = %s
@@ -377,7 +372,7 @@
$r = $this->db->query(
sprintf(
$q,
- $this->db->addQuotes( $wgDBmwschema ),
+ $this->db->addQuotes(
$this->db->getCoreSchema() ),
$this->db->addQuotes( $table ),
$this->db->addQuotes( $rule )
)
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