lyx_mirror/src/support/FileMonitor.cpp
Abdelrazak Younes e7bb71ff4e header cleanup.
git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@22178 a592a061-630c-0410-9148-cb99ea01b6c8
2007-12-16 22:09:28 +00:00

182 lines
3.2 KiB
C++

/**
* \file FileMonitor.cpp
* This file is part of LyX, the document processor.
* Licence details can be found in the file COPYING.
*
* \author Angus Leeming
*
* Full author contact details are available in file CREDITS.
*/
#include <config.h>
#include "support/FileMonitor.h"
#include "support/FileName.h"
#include "support/Timeout.h"
#include <boost/bind.hpp>
#include <boost/signals/trackable.hpp>
using namespace std;
namespace lyx {
namespace support {
class FileMonitor::Impl : public boost::signals::trackable {
public:
///
Impl(FileName const & file_with_path, int interval);
///
void monitorFile();
///
FileName filename_;
///
Timeout timer_;
/// This signal is emitted if the file is modified (has a new checksum).
FileMonitor::FileChangedSig fileChanged_;
/** We use these to ascertain whether a file (once loaded successfully)
* has changed.
*/
time_t timestamp_;
///
unsigned long checksum_;
};
FileMonitor::FileMonitor(FileName const & file_with_path, int interval)
: pimpl_(new Impl(file_with_path, interval))
{}
FileMonitor::~FileMonitor()
{
delete pimpl_;
}
void FileMonitor::reset(FileName const & file_with_path) const
{
if (pimpl_->filename_ == file_with_path)
return;
bool const monitor = pimpl_->timer_.running();
if (monitor)
stop();
pimpl_->filename_ = file_with_path;
if (monitor)
start();
}
FileName const & FileMonitor::filename() const
{
return pimpl_->filename_;
}
void FileMonitor::start() const
{
if (monitoring())
return;
if (!pimpl_->filename_.exists())
return;
pimpl_->timestamp_ = pimpl_->filename_.lastModified();
pimpl_->checksum_ = pimpl_->filename_.checksum();
if (pimpl_->timestamp_ && pimpl_->checksum_) {
pimpl_->timer_.start();
} else {
pimpl_->timestamp_ = 0;
pimpl_->checksum_ = 0;
}
}
void FileMonitor::stop() const
{
pimpl_->timestamp_ = 0;
pimpl_->checksum_ = 0;
pimpl_->timer_.stop();
}
bool FileMonitor::monitoring() const
{
return pimpl_->timer_.running();
}
unsigned long FileMonitor::checksum() const
{
// If we aren't actively monitoring the file, then recompute the
// checksum explicitly.
if (!pimpl_->timer_.running() && !pimpl_->filename_.empty())
return pimpl_->filename_.checksum();
return pimpl_->checksum_;
}
boost::signals::connection FileMonitor::connect(slot_type const & slot) const
{
return pimpl_->fileChanged_.connect(slot);
}
//------------------------------
// Implementation details follow
//------------------------------
FileMonitor::Impl::Impl(FileName const & file_with_path, int interval)
: filename_(file_with_path),
timer_(interval, Timeout::ONETIME),
timestamp_(0),
checksum_(0)
{
timer_.timeout.connect(boost::bind(&Impl::monitorFile, this));
}
void FileMonitor::Impl::monitorFile()
{
bool changed = false;
if (!filename_.exists()) {
changed = timestamp_ || checksum_;
timestamp_ = 0;
checksum_ = 0;
} else {
time_t const new_timestamp = filename_.lastModified();
if (new_timestamp != timestamp_) {
timestamp_ = new_timestamp;
unsigned long const new_checksum = filename_.checksum();
if (new_checksum != checksum_) {
checksum_ = new_checksum;
changed = true;
}
}
}
timer_.start();
if (changed)
fileChanged_();
}
} // namespace support
} // namespace lyx