Sqlite: Add busy handler

A busy handler is much more flexible than a timeout. In most cases we can
remove the busy exception handling code.

Change-Id: I59666ccfbd380a341412e3d25e6716b07097bf3c
Reviewed-by: Thomas Hartmann <[email protected]>

1 files changed, 24 insertions, 13 deletions

diff --git a/src/libs/sqlite/sqlitedatabasebackend.cpp b/src/libs/sqlite/sqlitedatabasebackend.cpp
index 20af7589dbd..46097406e8c 100644
--- a/src/libs/sqlite/sqlitedatabasebackend.cpp
+++ b/src/libs/sqlite/sqlitedatabasebackend.cpp
@@ -37,15 +37,24 @@
 
 #include "sqlite3.h"
 
+#include <chrono>
+#include <thread>
+
 extern "C" {
 int sqlite3_carray_init(sqlite3 *db, char **pzErrMsg, const sqlite3_api_routines *pApi);
 }
 
 namespace Sqlite {
 
+using namespace std::literals;
+
 DatabaseBackend::DatabaseBackend(Database &database)
     : m_database(database)
     , m_databaseHandle(nullptr)
+    , m_busyHandler([](int) {
+        std::this_thread::sleep_for(10ms);
+        return true;
+    })
 {
 }
 
@@ -197,26 +206,22 @@ void DatabaseBackend::closeWithoutException()
     }
 }
 
-void DatabaseBackend::registerBusyHandler()
+namespace {
+
+int busyHandlerCallback(void *userData, int counter)
 {
-    int resultCode = sqlite3_busy_handler(sqliteDatabaseHandle(), &busyHandlerCallback, nullptr);
+    auto &&busyHandler = *static_cast<DatabaseBackend::BusyHandler *>(userData);
 
-    checkIfBusyTimeoutWasSet(resultCode);
+    return busyHandler(counter);
 }
 
-void DatabaseBackend::registerRankingFunction()
-{
-}
+} // namespace
 
-int DatabaseBackend::busyHandlerCallback(void *, int counter)
+void DatabaseBackend::registerBusyHandler()
 {
-    Q_UNUSED(counter)
-#ifdef QT_DEBUG
-    //qWarning() << "Busy handler invoked" << counter << "times!";
-#endif
-    QThread::msleep(10);
+    int resultCode = sqlite3_busy_handler(sqliteDatabaseHandle(), &busyHandlerCallback, &m_busyHandler);
 
-    return true;
+    checkIfBusyTimeoutWasSet(resultCode);
 }
 
 void DatabaseBackend::checkForOpenDatabaseWhichCanBeClosed()
@@ -416,6 +421,12 @@ void DatabaseBackend::resetUpdateHook()
     sqlite3_update_hook(m_databaseHandle, nullptr, nullptr);
 }
 
+void DatabaseBackend::setBusyHandler(DatabaseBackend::BusyHandler &&busyHandler)
+{
+    m_busyHandler = std::move(busyHandler);
+    registerBusyHandler();
+}
+
 void DatabaseBackend::throwExceptionStatic(const char *whatHasHappens)
 {
     throw Exception(whatHasHappens);