static bool ShouldReplaceWith(const VfsFile& previousFile, const VfsFile& newFile)
{
// 1) priority (override mods)
if(newFile.Priority() < previousFile.Priority())
return false;
if(newFile.Priority() > previousFile.Priority())
return true;
// 2) timestamp
{
const double howMuchNewer = difftime(newFile.MTime(), previousFile.MTime());
const double threshold = 2.0; // FAT timestamp resolution [seconds]
if(howMuchNewer > threshold) // newer
return true;
if(howMuchNewer < -threshold) // older
return false;
// else: "equal" (tolerating small differences due to FAT's low
// mtime resolution)
}
// 3) precedence (efficiency of file provider)
if(newFile.Loader()->Precedence() < previousFile.Loader()->Precedence())
return false;
return true;
}
virtual Status GetRealPath(const VfsPath& pathname, OsPath& realPathname)
{
ScopedLock s;
VfsDirectory* directory; VfsFile* file;
WARN_RETURN_STATUS_IF_ERR(vfs_Lookup(pathname, &m_rootDirectory, directory, &file));
realPathname = file->Loader()->Path() / pathname.Filename();
return INFO::OK;
}
std::wstring FileDescription(const VfsFile& file)
{
wchar_t timestamp[25];
const time_t mtime = file.MTime();
wcsftime(timestamp, ARRAY_SIZE(timestamp), L"%a %b %d %H:%M:%S %Y", localtime(&mtime));
wchar_t buf[200];
swprintf_s(buf, ARRAY_SIZE(buf), L"(%c; %6lu; %ls) %ls", file.Loader()->LocationCode(), (unsigned long)file.Size(), timestamp, file.Name().string().c_str());
return buf;
}
virtual Status LoadFile(const VfsPath& pathname, shared_ptr<u8>& fileContents, size_t& size)
{
ScopedLock s;
const bool isCacheHit = m_fileCache.Retrieve(pathname, fileContents, size);
if(!isCacheHit)
{
VfsDirectory* directory; VfsFile* file;
// per 2010-05-01 meeting, this shouldn't raise 'scary error
// dialogs', which might fail to display the culprit pathname
// instead, callers should log the error, including pathname.
RETURN_STATUS_IF_ERR(vfs_Lookup(pathname, &m_rootDirectory, directory, &file));
fileContents = DummySharedPtr((u8*)0);
size = file->Size();
if(size != 0) // (the file cache can't handle zero-length allocations)
{
if(size < m_cacheSize/2) // (avoid evicting lots of previous data)
fileContents = m_fileCache.Reserve(size);
if(fileContents)
{
RETURN_STATUS_IF_ERR(file->Loader()->Load(file->Name(), fileContents, file->Size()));
m_fileCache.Add(pathname, fileContents, size);
}
else
{
RETURN_STATUS_IF_ERR(AllocateAligned(fileContents, size, maxSectorSize));
RETURN_STATUS_IF_ERR(file->Loader()->Load(file->Name(), fileContents, file->Size()));
}
}
}
stats_io_user_request(size);
stats_cache(isCacheHit? CR_HIT : CR_MISS, size);
m_trace->NotifyLoad(pathname, size);
return INFO::OK;
}