PG: Skip broken connections (for a while)

qgis · Oct 30, 2019 · 576a917 · 576a917
1 parent 6a7719f
commit 576a917
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Showing 2 changed files with 34 additions and 2 deletions.
diff --git a/src/providers/postgres/qgspostgresconn.cpp b/src/providers/postgres/qgspostgresconn.cpp
@@ -144,6 +144,9 @@ Oid QgsPostgresResult::PQoidValue()
 
 QMap<QString, QgsPostgresConn *> QgsPostgresConn::sConnectionsRO;
 QMap<QString, QgsPostgresConn *> QgsPostgresConn::sConnectionsRW;
+QSet<QString> QgsPostgresConn::sBrokenConnectionsCache;
+QMutex QgsPostgresConn::sBrokenConnectionsCacheMutex;
+
 const int QgsPostgresConn::GEOM_TYPE_SELECT_LIMIT = 100;
 
 QgsPostgresConn *QgsPostgresConn::connectDb( const QString &conninfo, bool readonly, bool shared, bool transaction )
@@ -218,7 +221,20 @@ QgsPostgresConn::QgsPostgresConn( const QString &conninfo, bool readOnly, bool s
   , mTransaction( transaction )
   , mLock( QMutex::Recursive )
 {
-  QgsDebugMsg( QStringLiteral( "New PostgreSQL connection for " ) + conninfo );
+
+  {
+    QMutexLocker locker( &sBrokenConnectionsCacheMutex );
+    if ( sBrokenConnectionsCache.contains( conninfo ) )
+    {
+      QgsDebugMsg( QStringLiteral( "Skipping broken PostgreSQL connection: " ) + conninfo );
+      mRef = 0;
+      return;
+    }
+    else
+    {
+      QgsDebugMsg( QStringLiteral( "New PostgreSQL connection for " ) + conninfo );
+    }
+  }
 
   // expand connectionInfo
   QgsDataSourceUri uri( conninfo );
@@ -286,7 +302,20 @@ QgsPostgresConn::QgsPostgresConn( const QString &conninfo, bool readOnly, bool s
       ++i;
       bool ok = QgsCredentials::instance()->get( conninfo, username, password, PQerrorMessage() );
       if ( !ok )
+      {
+        {
+          QMutexLocker locker( &sBrokenConnectionsCacheMutex );
+          // Insert the connInfo in the cache of broken/ignored connections
+          QgsPostgresConn::sBrokenConnectionsCache.insert( conninfo );
+        }
+        QTimer::singleShot( 5000, [ = ]()
+        {
+          QgsDebugMsgLevel( QStringLiteral( "Removing broken connection from cache: %1" ).arg( conninfo ), 4 );
+          QMutexLocker locker( &sBrokenConnectionsCacheMutex );
+          QgsPostgresConn::sBrokenConnectionsCache.remove( conninfo );
+        } );
         break;
+      }
 
       PQfinish();
 
@@ -360,7 +389,6 @@ QgsPostgresConn::QgsPostgresConn( const QString &conninfo, bool readOnly, bool s
     PQexecNR( QStringLiteral( "SET application_name='QGIS'" ) );
   }
 
-
   PQsetNoticeProcessor( mConn, noticeProcessor, nullptr );
 }
 

diff --git a/src/providers/postgres/qgspostgresconn.h b/src/providers/postgres/qgspostgresconn.h
@@ -435,6 +435,10 @@ class QgsPostgresConn : public QObject
     static QMap<QString, QgsPostgresConn *> sConnectionsRW;
     static QMap<QString, QgsPostgresConn *> sConnectionsRO;
 
+    //! Temporary cache for broken connections, to avoid GUI freezing by multiple credentials requests
+    static QSet<QString> sBrokenConnectionsCache;
+    static QMutex sBrokenConnectionsCacheMutex;
+
     //! Count number of spatial columns in a given relation
     void addColumnInfo( QgsPostgresLayerProperty &layerProperty, const QString &schemaName, const QString &viewName, bool fetchPkCandidates );