Use constants for LoadBalancer connection array keys

Also renamed "foreignUsed" to "foreignInUse" for clarity.

Change-Id: Ida35042979a87417b38d256610b726611555d7b2

diff --git a/includes/libs/rdbms/loadbalancer/LoadBalancer.php b/includes/libs/rdbms/loadbalancer/LoadBalancer.php
index 850d59e..677a69f 100644 (file)
--- a/includes/libs/rdbms/loadbalancer/LoadBalancer.php
+++ b/includes/libs/rdbms/loadbalancer/LoadBalancer.php
@@ -126,6 +126,10 @@ class LoadBalancer implements ILoadBalancer {
        /** @var integer Seconds to cache master server read-only status */
        const TTL_CACHE_READONLY = 5;
 
+       const KEY_LOCAL = 'local';
+       const KEY_FOREIGN_FREE = 'foreignFree';
+       const KEY_FOREIGN_INUSE = 'foreignInUse';
+
        public function __construct( array $params ) {
                if ( !isset( $params['servers'] ) ) {
                        throw new InvalidArgumentException( __CLASS__ . ': missing servers parameter' );
@@ -148,9 +152,9 @@ class LoadBalancer implements ILoadBalancer {
 
                $this->mReadIndex = -1;
                $this->mConns = [
-                       'local'       => [],
-                       'foreignUsed' => [],
-                       'foreignFree' => []
+                       self::KEY_LOCAL => [],
+                       self::KEY_FOREIGN_INUSE => [],
+                       self::KEY_FOREIGN_FREE => []
                ];
                $this->mLoads = [];
                $this->mWaitForPos = false;
@@ -711,19 +715,19 @@ class LoadBalancer implements ILoadBalancer {
                }
 
                $domain = $conn->getDomainID();
-               if ( !isset( $this->mConns['foreignUsed'][$serverIndex][$domain] ) ) {
+               if ( !isset( $this->mConns[self::KEY_FOREIGN_INUSE][$serverIndex][$domain] ) ) {
                        throw new InvalidArgumentException( __METHOD__ .
                                ": connection $serverIndex/$domain not found; it may have already been freed." );
-               } elseif ( $this->mConns['foreignUsed'][$serverIndex][$domain] !== $conn ) {
+               } elseif ( $this->mConns[self::KEY_FOREIGN_INUSE][$serverIndex][$domain] !== $conn ) {
                        throw new InvalidArgumentException( __METHOD__ .
                                ": connection $serverIndex/$domain mismatched; it may have already been freed." );
                }
                $conn->setLBInfo( 'foreignPoolRefCount', --$refCount );
                if ( $refCount <= 0 ) {
-                       $this->mConns['foreignFree'][$serverIndex][$domain] = $conn;
-                       unset( $this->mConns['foreignUsed'][$serverIndex][$domain] );
-                       if ( !$this->mConns['foreignUsed'][$serverIndex] ) {
-                               unset( $this->mConns[ 'foreignUsed' ][$serverIndex] ); // clean up
+                       $this->mConns[self::KEY_FOREIGN_FREE][$serverIndex][$domain] = $conn;
+                       unset( $this->mConns[self::KEY_FOREIGN_INUSE][$serverIndex][$domain] );
+                       if ( !$this->mConns[self::KEY_FOREIGN_INUSE][$serverIndex] ) {
+                               unset( $this->mConns[ self::KEY_FOREIGN_INUSE ][$serverIndex] ); // clean up
                        }
                        $this->connLogger->debug( __METHOD__ . ": freed connection $serverIndex/$domain" );
                } else {
@@ -772,8 +776,8 @@ class LoadBalancer implements ILoadBalancer {
 
                if ( $domain !== false ) {
                        $conn = $this->openForeignConnection( $i, $domain );
-               } elseif ( isset( $this->mConns['local'][$i][0] ) ) {
-                       $conn = $this->mConns['local'][$i][0];
+               } elseif ( isset( $this->mConns[self::KEY_LOCAL][$i][0] ) ) {
+                       $conn = $this->mConns[self::KEY_LOCAL][$i][0];
                } else {
                        if ( !isset( $this->mServers[$i] ) || !is_array( $this->mServers[$i] ) ) {
                                throw new InvalidArgumentException( "No server with index '$i'." );
@@ -785,7 +789,7 @@ class LoadBalancer implements ILoadBalancer {
                        $serverName = $this->getServerName( $i );
                        if ( $conn->isOpen() ) {
                                $this->connLogger->debug( "Connected to database $i at '$serverName'." );
-                               $this->mConns['local'][$i][0] = $conn;
+                               $this->mConns[self::KEY_LOCAL][$i][0] = $conn;
                        } else {
                                $this->connLogger->warning( "Failed to connect to database $i at '$serverName'." );
                                $this->errorConnection = $conn;
@@ -830,20 +834,20 @@ class LoadBalancer implements ILoadBalancer {
                $dbName = $domainInstance->getDatabase();
                $prefix = $domainInstance->getTablePrefix();
 
-               if ( isset( $this->mConns['foreignUsed'][$i][$domain] ) ) {
-                       // Reuse an already-used connection
-                       $conn = $this->mConns['foreignUsed'][$i][$domain];
+               if ( isset( $this->mConns[self::KEY_FOREIGN_INUSE][$i][$domain] ) ) {
+                       // Reuse an in-use connection for the same domain that is not in-use
+                       $conn = $this->mConns[self::KEY_FOREIGN_INUSE][$i][$domain];
                        $this->connLogger->debug( __METHOD__ . ": reusing connection $i/$domain" );
-               } elseif ( isset( $this->mConns['foreignFree'][$i][$domain] ) ) {
-                       // Reuse a free connection for the same domain
-                       $conn = $this->mConns['foreignFree'][$i][$domain];
-                       unset( $this->mConns['foreignFree'][$i][$domain] );
-                       $this->mConns['foreignUsed'][$i][$domain] = $conn;
+               } elseif ( isset( $this->mConns[self::KEY_FOREIGN_FREE][$i][$domain] ) ) {
+                       // Reuse a free connection for the same domain that is not in-use
+                       $conn = $this->mConns[self::KEY_FOREIGN_FREE][$i][$domain];
+                       unset( $this->mConns[self::KEY_FOREIGN_FREE][$i][$domain] );
+                       $this->mConns[self::KEY_FOREIGN_INUSE][$i][$domain] = $conn;
                        $this->connLogger->debug( __METHOD__ . ": reusing free connection $i/$domain" );
-               } elseif ( !empty( $this->mConns['foreignFree'][$i] ) ) {
+               } elseif ( !empty( $this->mConns[self::KEY_FOREIGN_FREE][$i] ) ) {
                        // Reuse a connection from another domain
-                       $conn = reset( $this->mConns['foreignFree'][$i] );
-                       $oldDomain = key( $this->mConns['foreignFree'][$i] );
+                       $conn = reset( $this->mConns[self::KEY_FOREIGN_FREE][$i] );
+                       $oldDomain = key( $this->mConns[self::KEY_FOREIGN_FREE][$i] );
                        // The empty string as a DB name means "don't care".
                        // DatabaseMysqlBase::open() already handle this on connection.
                        if ( strlen( $dbName ) && !$conn->selectDB( $dbName ) ) {
@@ -853,8 +857,8 @@ class LoadBalancer implements ILoadBalancer {
                                $conn = false;
                        } else {
                                $conn->tablePrefix( $prefix );
-                               unset( $this->mConns['foreignFree'][$i][$oldDomain] );
-                               $this->mConns['foreignUsed'][$i][$domain] = $conn;
+                               unset( $this->mConns[self::KEY_FOREIGN_FREE][$i][$oldDomain] );
+                               $this->mConns[self::KEY_FOREIGN_INUSE][$i][$domain] = $conn;
                                $this->connLogger->debug( __METHOD__ .
                                        ": reusing free connection from $oldDomain for $domain" );
                        }
@@ -874,7 +878,7 @@ class LoadBalancer implements ILoadBalancer {
                                $conn = false;
                        } else {
                                $conn->tablePrefix( $prefix );
-                               $this->mConns['foreignUsed'][$i][$domain] = $conn;
+                               $this->mConns[self::KEY_FOREIGN_INUSE][$i][$domain] = $conn;
                                $this->connLogger->debug( __METHOD__ . ": opened new connection for $i/$domain" );
                        }
                }
@@ -1085,9 +1089,9 @@ class LoadBalancer implements ILoadBalancer {
                } );
 
                $this->mConns = [
-                       'local' => [],
-                       'foreignFree' => [],
-                       'foreignUsed' => [],
+                       self::KEY_LOCAL => [],
+                       self::KEY_FOREIGN_FREE => [],
+                       self::KEY_FOREIGN_INUSE => [],
                ];
                $this->connsOpened = 0;
        }
@@ -1621,10 +1625,10 @@ class LoadBalancer implements ILoadBalancer {
        }
 
        public function setDomainPrefix( $prefix ) {
-               if ( $this->mConns['foreignUsed'] ) {
+               if ( $this->mConns[self::KEY_FOREIGN_INUSE] ) {
                        // Do not switch connections to explicit foreign domains unless marked as free
                        $domains = [];
-                       foreach ( $this->mConns['foreignUsed'] as $i => $connsByDomain ) {
+                       foreach ( $this->mConns[self::KEY_FOREIGN_INUSE] as $i => $connsByDomain ) {
                                $domains = array_merge( $domains, array_keys( $connsByDomain ) );
                        }
                        $domains = implode( ', ', $domains );