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/******************************************************************************
*
* package:
* file: appenderskeleton.cpp
* created: September 2007
* author: Martin Heinrich
*
*
* Copyright 2007 Martin Heinrich
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
******************************************************************************/
/******************************************************************************
* Dependencies
******************************************************************************/
#include "appenderskeleton.h"
#include <QtCore/QDebug>
#include "layout.h"
#include "loggingevent.h"
#include "logmanager.h"
#include "spi/filter.h"
namespace Log4Qt
{
/**************************************************************************
* Declarations
***************************************************************************/
/*!
* \brief The class RecursionGuardLocker controls a boolean flag.
*
* It is a helper class to control a boolean flag. The class sets the flag
* on creation and resets it on destruction.
*/
class RecursionGuardLocker
{
public:
RecursionGuardLocker(bool *pGuard);
~RecursionGuardLocker();
private:
RecursionGuardLocker(const RecursionGuardLocker &rOther); // Not implemented
RecursionGuardLocker &operator=(const RecursionGuardLocker &rOther); // Not implemented
private:
bool *mpGuard;
};
/**************************************************************************
* C helper functions
**************************************************************************/
/**************************************************************************
* Class implementation: RecursionGuardLocker
***************************************************************************/
inline RecursionGuardLocker::RecursionGuardLocker(bool *pGuard)
{
Q_ASSERT_X(pGuard != 0, "RecursionGuardLocker::RecursionGuardLocker()", "Pointer to guard bool must not be null");
mpGuard = pGuard;
*mpGuard = true;
}
inline RecursionGuardLocker::~RecursionGuardLocker()
{
*mpGuard = false;
}
/**************************************************************************
* Class implementation: AppenderSkeleton
**************************************************************************/
AppenderSkeleton::AppenderSkeleton(QObject *pParent) :
Appender(pParent),
mObjectGuard(QMutex::Recursive), // Recursive for doAppend()
mAppendRecursionGuard(false),
mIsActive(true),
mIsClosed(false),
mpLayout(0),
mThreshold(Level::NULL_INT),
mpHeadFilter(0),
mpTailFilter(0)
{
}
AppenderSkeleton::AppenderSkeleton(const bool isActive,
QObject *pParent) :
Appender(pParent),
mObjectGuard(QMutex::Recursive), // Recursive for doAppend()
mAppendRecursionGuard(false),
mIsActive(isActive),
mIsClosed(false),
mpLayout(0),
mThreshold(Level::NULL_INT),
mpHeadFilter(0),
mpTailFilter(0)
{
}
void AppenderSkeleton::activateOptions()
{
QMutexLocker locker(&mObjectGuard);
if (requiresLayout() && !layout())
{
LogError e = LOG4QT_QCLASS_ERROR(QT_TR_NOOP("Activation of appender '%1' that requires layout and has no layout set"),
APPENDER_ACTIVATE_MISSING_LAYOUT_ERROR);
e << name();
logger()->error(e);
return;
}
mIsActive = true;
}
void AppenderSkeleton::addFilter(Filter *pFilter)
{
if(!pFilter)
{
logger()->warn("Adding null Filter to Appender '%1'", name());
return;
}
QMutexLocker locker(&mObjectGuard);
mpTailFilter = pFilter;
if (mpHeadFilter)
mpHeadFilter->setNext(pFilter);
else
mpHeadFilter = pFilter;
}
void AppenderSkeleton::clearFilters()
{
QMutexLocker locker(&mObjectGuard);
mpTailFilter = 0;
mpHeadFilter = 0;
}
void AppenderSkeleton::close()
{
QMutexLocker locker(&mObjectGuard);
mIsClosed = true;
mIsActive = false;
}
void AppenderSkeleton::customEvent(QEvent* event)
{
if (event->type() == LoggingEvent::eventId) {
LoggingEvent *logEvent = static_cast<LoggingEvent*>(event);
doAppend(*logEvent);
return ;
}
QObject::customEvent(event);
}
void AppenderSkeleton::doAppend(const LoggingEvent &rEvent)
{
// The mutex serialises concurrent access from multiple threads.
// - e.g. two threads using the same logger
// - e.g. two threads using different logger with the same appender
//
// A call from the same thread will pass the mutex (QMutex::Recursive)
// and get to the recursion guard. The recursion guard blocks recursive
// invocation and prevents a possible endless loop.
// - e.g. an appender logs an error with a logger that uses it
QMutexLocker locker(&mObjectGuard);
if (mAppendRecursionGuard)
return;
RecursionGuardLocker recursion_locker(&mAppendRecursionGuard);
if (!checkEntryConditions())
return;
if (!isAsSevereAsThreshold(rEvent.level()))
return;
Filter *p_filter = mpHeadFilter;
while(p_filter)
{
Filter::Decision decision = p_filter->decide(rEvent);
if (decision == Filter::ACCEPT)
break;
else if (decision == Filter::DENY)
return;
else
p_filter = p_filter->next();
}
append(rEvent);
}
bool AppenderSkeleton::checkEntryConditions() const
{
// Q_ASSERT_X(, "WriterAppender::checkEntryConditions()", "Lock must be held by caller")
if (!isActive())
{
LogError e = LOG4QT_QCLASS_ERROR(QT_TR_NOOP("Use of non activated appender '%1'"),
APPENDER_NOT_ACTIVATED_ERROR);
e << name();
logger()->error(e);
return false;
}
if (isClosed())
{
LogError e = LOG4QT_QCLASS_ERROR(QT_TR_NOOP("Use of closed appender '%1'"),
APPENDER_CLOSED_ERROR);
e << name();
logger()->error(e);
return false;
}
if (requiresLayout() && !layout())
{
LogError e = LOG4QT_QCLASS_ERROR(QT_TR_NOOP("Use of appender '%1' that requires layout and has no layout set"),
APPENDER_USE_MISSING_LAYOUT_ERROR);
e << name();
logger()->error(e);
return false;
}
return true;
}
/**************************************************************************
* Implementation: Operators, Helper
**************************************************************************/
} // namespace Log4Qt
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