std::shared_ptr<FileWatch> FileMonitorWin::Watch(const std::filesystem::path& path, const t_callbackFunc& callback, FileWatch::State states) {
try {
if(!std::filesystem::exists(path))
return nullptr;
} catch (...) {
return nullptr;
}
std::filesystem::path directory = (std::filesystem::is_directory(path) || !path.has_parent_path()) ? path : path.parent_path();
// Ugh.
std::wstring wpath;
#if _MSC_VER >= 1900
wpath = directory.wstring();
#else
auto str = directory.string();
wpath.assign(str.begin(), str.end());
#endif
// Open the handle to the directory we were asked to watch with the
// correct permissions so that we can actually conduct asynchronous
// read operations.
HANDLE hFile = CreateFileW(
wpath.c_str(),
GENERIC_READ,
FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
nullptr,
OPEN_EXISTING,
FILE_FLAG_OVERLAPPED | FILE_FLAG_BACKUP_SEMANTICS,
nullptr
);
if (hFile == INVALID_HANDLE_VALUE)
// No such file, what else can we do?
return nullptr;
// Compose the notification filter based on the user's request
DWORD dwNotifyFilter = 0;
if(states & FileWatch::State::RENAMED || states & FileWatch::State::DELETED)
dwNotifyFilter |= FILE_NOTIFY_CHANGE_FILE_NAME;
if(states & FileWatch::State::MODIFIED)
dwNotifyFilter |= FILE_NOTIFY_CHANGE_LAST_WRITE;
// Need a second-order shared pointer so we can preserve references
Entry* pEntry;
auto key = m_nextKey++;
{
std::lock_guard<std::mutex> lk(GetLock());
pEntry = &m_outstanding[key];
pEntry->key = key;
}
// Need an overlapped structure to track this operation. We'll also be using this to decide
// how to notify the true caller.
auto watcher = std::shared_ptr<FileWatchWin>(
new FileWatchWin(path, callback, dwNotifyFilter, hFile),
[this, key](FileWatchWin* fileWatch) {
--m_numWatchers;
delete fileWatch;
m_outstanding.erase(key);
}
);
pEntry->watcherWeak = watcher;
// Attach to the completion port with the FileWatchWin we just constructed
if (!CreateIoCompletionPort(hFile, m_hCompletion, key, 0)) {
// Something went wrong, can't attach a watcher at this point
m_outstanding.erase(key);
return nullptr;
}
// Initial pend, and then return to the controller
watcher->ReadDirectoryChanges();
++m_numWatchers;
return watcher;
}
// The processPath ends with dotnet.exe or dotnet
// like: C:\Program Files\dotnet\dotnet.exe, C:\Program Files\dotnet\dotnet, dotnet.exe, or dotnet.
// Get the absolute path to dotnet. If the path is already an absolute path, it will return that path
fs::path
HOSTFXR_UTILITY::GetAbsolutePathToDotnet(
const fs::path & applicationPath,
const fs::path & requestedPath
)
{
LOG_INFOF(L"Resolving absolute path to dotnet.exe from '%ls'", requestedPath.c_str());
auto processPath = requestedPath;
if (processPath.is_relative())
{
processPath = applicationPath / processPath;
}
//
// If we are given an absolute path to dotnet.exe, we are done
//
if (is_regular_file(processPath))
{
LOG_INFOF(L"Found dotnet.exe at '%ls'", processPath.c_str());
return processPath;
}
// At this point, we are calling where.exe to find dotnet.
// If we encounter any failures, try getting dotnet.exe from the
// backup location.
// Only do it if no path is specified
if (requestedPath.has_parent_path())
{
LOG_INFOF(L"Absolute path to dotnet.exe was not found at '%ls'", requestedPath.c_str());
throw InvalidOperationException(format(L"Could not find dotnet.exe at '%s'", processPath.c_str()));
}
const auto dotnetViaWhere = InvokeWhereToFindDotnet();
if (dotnetViaWhere.has_value())
{
LOG_INFOF(L"Found dotnet.exe via where.exe invocation at '%ls'", dotnetViaWhere.value().c_str());
return dotnetViaWhere.value();
}
const auto programFilesLocation = GetAbsolutePathToDotnetFromProgramFiles();
if (programFilesLocation.has_value())
{
LOG_INFOF(L"Found dotnet.exe in Program Files at '%ls'", programFilesLocation.value().c_str());
return programFilesLocation.value();
}
LOG_INFOF(L"dotnet.exe not found");
throw InvalidOperationException(format(
L"Could not find dotnet.exe at '%s' or using the system PATH environment variable."
" Check that a valid path to dotnet is on the PATH and the bitness of dotnet matches the bitness of the IIS worker process.",
processPath.c_str()));
}