From d8c3006cb4ca516dc98bd4006c2a848f77e1e7ee Mon Sep 17 00:00:00 2001
From: Christian Muehlhaeuser <muesli@gmail.com>
Date: Wed, 6 Jun 2012 16:25:44 +0200
Subject: [PATCH] * Added retry blocks for failed (busy) sql queries & commits.

---
 src/libtomahawk/database/TomahawkSqlQuery.cpp | 27 ++++++++++++++++++-
 src/libtomahawk/database/TomahawkSqlQuery.h   |  4 +++
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/src/libtomahawk/database/TomahawkSqlQuery.cpp b/src/libtomahawk/database/TomahawkSqlQuery.cpp
index 5a5ea628a..3fbc28f2d 100644
--- a/src/libtomahawk/database/TomahawkSqlQuery.cpp
+++ b/src/libtomahawk/database/TomahawkSqlQuery.cpp
@@ -18,10 +18,12 @@
 
 #include "database/TomahawkSqlQuery.h"
 
+#include "utils/TomahawkUtils.h"
 #include "utils/Logger.h"
 
 #include <QSqlError>
 #include <QTime>
+#include <QThread>
 #include <QVariant>
 
 #define QUERY_THRESHOLD 60
@@ -35,6 +37,7 @@ TomahawkSqlQuery::TomahawkSqlQuery()
 
 TomahawkSqlQuery::TomahawkSqlQuery( const QSqlDatabase& db )
     : QSqlQuery( db )
+    , m_db( db )
 {
 }
 
@@ -53,12 +56,20 @@ TomahawkSqlQuery::exec()
     QTime t;
     t.start();
 
-    bool ret = QSqlQuery::exec();
+    unsigned int retries = 0;
+    while ( !QSqlQuery::exec() && ++retries < 10 )
+    {
+        tDebug() << "INFO: Retrying failed query:" << this->lastQuery() << this->lastError().text();
+        TomahawkUtils::msleep( 25 );
+    }
+
+    bool ret = ( retries < 10 );
     if ( !ret )
         showError();
 
     int e = t.elapsed();
     bool log = ( e >= QUERY_THRESHOLD );
+
 #ifdef TOMAHAWK_QUERY_ANALYZE
     log = true;
 #endif
@@ -70,6 +81,20 @@ TomahawkSqlQuery::exec()
 }
 
 
+bool
+TomahawkSqlQuery::commitTransaction()
+{
+    unsigned int retries = 0;
+    while ( !m_db.commit() && ++retries < 10 )
+    {
+        tDebug() << "INFO: Retrying failed commit:" << this->lastQuery() << this->lastError().text();
+        TomahawkUtils::msleep( 25 );
+    }
+    
+    return ( retries < 10 );
+}
+
+
 void
 TomahawkSqlQuery::showError()
 {
diff --git a/src/libtomahawk/database/TomahawkSqlQuery.h b/src/libtomahawk/database/TomahawkSqlQuery.h
index 8bf1a1495..adb7153d5 100644
--- a/src/libtomahawk/database/TomahawkSqlQuery.h
+++ b/src/libtomahawk/database/TomahawkSqlQuery.h
@@ -34,9 +34,13 @@ public:
 
     bool exec( const QString& query );
     bool exec();
+    
+    bool commitTransaction();
 
 private:
     void showError();
+    
+    QSqlDatabase m_db;
 };
 
 #endif // TOMAHAWKSQLQUERY_H