// Copyright (c) 2010 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #ifndef APP_SQL_DIAGNOSTIC_ERROR_DELEGATE_H_ #define APP_SQL_DIAGNOSTIC_ERROR_DELEGATE_H_ #pragma once #include "app/sql/connection.h" #include "base/logging.h" #include "base/metrics/histogram.h" namespace sql { // This class handles the exceptional sqlite errors that we might encounter // if for example the db is corrupted. Right now we just generate a UMA // histogram for release and an assert for debug builds. // // Why is it a template you ask? well, that is a funny story. The histograms // need to be singletons that is why they are always static at the function // scope, but we cannot use the Singleton class because they are not default // constructible. The template parameter makes the compiler to create unique // classes that don't share the same static variable. template <class UniqueT> class DiagnosticErrorDelegate : public ErrorDelegate { public: virtual int OnError(int error, Connection* connection, Statement* stmt) { NOTREACHED() << "sqlite error " << error << ", errno " << connection->GetLastErrno() << ": " << connection->GetErrorMessage(); RecordErrorInHistogram(error); return error; } private: static void RecordErrorInHistogram(int error) { // Trim off the extended error codes. error &= 0xff; // The histogram values from sqlite result codes go currently from 1 to // 26 currently but 50 gives them room to grow. UMA_HISTOGRAM_ENUMERATION(UniqueT::name(), error, 50); } }; } // namespace sql #endif // APP_SQL_DIAGNOSTIC_ERROR_DELEGATE_H_