filewatch.hpp
#ifndef FILEWATCHER_H
#define FILEWATCHER_H
#include <cstdio>
#include <fstream>
#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
#ifndef NOMINMAX
#define NOMINMAX
#endif
#include <windows.h>
#include <stdlib.h>
#include <stdio.h>
#include <tchar.h>
#include <Pathcch.h>
#include <shlwapi.h>
#endif // WIN32
#if __unix__
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/inotify.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <dirent.h>
#include <unistd.h>
#endif // __unix__
#ifdef __linux__
#include <linux/limits.h>
#endif
#if defined(__APPLE__) || defined(__MACH__)
#include <CoreFoundation/CoreFoundation.h>
#include <CoreServices/CoreServices.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <dirent.h>
#define FILEWATCH_PLATFORM_MAC 1
#endif
#include <functional>
#include <atomic>
#include <thread>
#include <mutex>
#include <condition_variable>
#include <utility>
#include <vector>
#include <array>
#include <unordered_map>
#include <unordered_set>
#include <system_error>
#include <string>
#include <algorithm>
#include <type_traits>
#include <future>
#include <regex>
#include <cstddef>
#include <cstring>
#include <cwchar>
#include <cassert>
#include <cstdlib>
#include <iostream>
#ifdef FILEWATCH_PLATFORM_MAC
extern "C" int __getdirentries64(int, char *, int, long *);
#endif // FILEWATCH_PLATFORM_MAC
namespace filewatch {
enum class Event {
added,
removed,
modified,
renamed_old,
renamed_new
};
template<typename StringType>
struct IsWChar {
static constexpr bool value = false;
};
template<>
struct IsWChar<wchar_t> {
static constexpr bool value = true;
};
template<typename Fn, typename... Args>
struct Invokable {
static Fn make() {
return (Fn*)0;
}
template<typename T>
static T defaultValue() {
return *(T*)0;
}
static void call(int) {
make()(defaultValue<Args...>());
}
static int call(long value);
static constexpr bool value = std::is_same<decltype(call(0)), int>::value;
};
#define _FILEWATCH_TO_STRING(x) #x
#define FILEWATCH_TO_STRING(x) _FILEWATCH_TO_STRING(x)
[[maybe_unused]] static const char* event_to_string(Event event) {
switch (event) {
case Event::added:
return FILEWATCH_TO_STRING(Event::added);
case Event::removed:
return FILEWATCH_TO_STRING(Event::removed);
case Event::modified:
return FILEWATCH_TO_STRING(Event::modified);
case Event::renamed_old:
return FILEWATCH_TO_STRING(Event:renamed_old);
case Event::renamed_new:
return FILEWATCH_TO_STRING(Event::renamed_new);
}
assert(false);
}
template<typename StringType>
static typename std::enable_if<std::is_same<typename StringType::value_type, wchar_t>::value, bool>::type
isParentOrSelfDirectory(const StringType& path) {
return path == L"." || path == L"..";
}
template<typename StringType>
static typename std::enable_if<std::is_same<typename StringType::value_type, char>::value, bool>::type
isParentOrSelfDirectory(const StringType& path) {
return path == "." || path == "..";
}
/**
* \class FileWatch
*
* \brief Watches a folder or file, and will notify of changes via function callback.
*
* \author Thomas Monkman
*
*/
template<class StringType>
class FileWatch
{
typedef typename StringType::value_type C;
typedef std::basic_string<C, std::char_traits<C>> UnderpinningString;
typedef std::basic_regex<C, std::regex_traits<C>> UnderpinningRegex;
public:
FileWatch(StringType path, UnderpinningRegex pattern, std::function<void(const StringType& file, const Event event_type)> callback) :
_path(absolute_path_of(path)),
_pattern(pattern),
_callback(callback),
_directory(get_directory(path))
{
init();
}
FileWatch(StringType path, std::function<void(const StringType& file, const Event event_type)> callback) :
FileWatch<StringType>(path, UnderpinningRegex(_regex_all), callback) {}
~FileWatch() {
destroy();
}
FileWatch(const FileWatch<StringType>& other) : FileWatch<StringType>(other._path, other._callback) {}
FileWatch<StringType>& operator=(const FileWatch<StringType>& other)
{
if (this == &other) { return *this; }
destroy();
_path = other._path;
_callback = other._callback;
_directory = get_directory(other._path);
init();
return *this;
}
// Const memeber varibles don't let me implent moves nicely, if moves are really wanted std::unique_ptr should be used and move that.
FileWatch<StringType>(FileWatch<StringType> delete;
FileWatch<StringType>& operator=(FileWatch<StringType> delete;
private:
static constexpr C _regex_all[] = { '.', '*', '\0' };
static constexpr C _this_directory[] = { '.', '/', '\0' };
struct PathParts
{
PathParts(StringType directory, StringType filename) : directory(directory), filename(filename) {}
StringType directory;
StringType filename;
};
const StringType _path;
UnderpinningRegex _pattern;
static constexpr std::size_t _buffer_size = { 1024 * 256 };
// only used if watch a single file
StringType _filename;
std::function<void(const StringType& file, const Event event_type)> _callback;
std::thread _watch_thread;
std::condition_variable _cv;
std::mutex _callback_mutex;
std::vector<std::pair<StringType, Event>> _callback_information;
std::thread _callback_thread;
std::promise<void> _running;
std::atomic<bool> _destory = { false };
bool _watching_single_file = { false };
#pragma mark "Platform specific data"
#ifdef _WIN32
HANDLE _directory = { nullptr };
HANDLE _close_event = { nullptr };
const DWORD _listen_filters =
FILE_NOTIFY_CHANGE_SECURITY |
FILE_NOTIFY_CHANGE_CREATION |
FILE_NOTIFY_CHANGE_LAST_ACCESS |
FILE_NOTIFY_CHANGE_LAST_WRITE |
FILE_NOTIFY_CHANGE_SIZE |
FILE_NOTIFY_CHANGE_ATTRIBUTES |
FILE_NOTIFY_CHANGE_DIR_NAME |
FILE_NOTIFY_CHANGE_FILE_NAME;
const std::unordered_map<DWORD, Event> _event_type_mapping = {
{ FILE_ACTION_ADDED, Event::added },
{ FILE_ACTION_REMOVED, Event::removed },
{ FILE_ACTION_MODIFIED, Event::modified },
{ FILE_ACTION_RENAMED_OLD_NAME, Event::renamed_old },
{ FILE_ACTION_RENAMED_NEW_NAME, Event::renamed_new }
};
#endif // WIN32
#if __unix__
struct FolderInfo {
int folder;
int watch;
};
FolderInfo _directory;
const std::uint32_t _listen_filters = IN_MODIFY | IN_CREATE | IN_DELETE;
const static std::size_t event_size = (sizeof(struct inotify_event));
#endif // __unix__
#if FILEWATCH_PLATFORM_MAC
struct FileState
{
int fd;
uint32_t nlink;
time_t last_modification;
FileState(int fd, uint32_t nlink, time_t lt)
: fd(fd), nlink(nlink),
last_modification(lt)
{
}
FileState(const FileState delete;
FileState& operator=(const FileState delete;
FileState(FileState&& other) : fd(other.fd), nlink(other.nlink), last_modification(other.last_modification)
{
other.fd = -1;
}
FileState invalidate_and_clone() {
int fd = this->fd;
this->fd = -1;
return FileState {fd, nlink, last_modification};
}
~FileState()
{
if (fd != -1) {
close(fd);
}
}
};
std::unordered_map<StringType, FileState> _directory_snapshot{};
bool _previous_event_is_rename = false;
CFRunLoopRef _run_loop = nullptr;
int _file_fd = -1;
struct timespec _last_modification_time = {};
FSEventStreamRef _directory;
// fd for single file
#endif // FILEWATCH_PLATFORM_MAC
void init()
{
#ifdef _WIN32
_close_event = CreateEvent(NULL, TRUE, FALSE, NULL);
if (!_close_event) {
throw std::system_error(GetLastError(), std::system_category());
}
#endif // WIN32
_callback_thread = std::thread([this]() {
try {
callback_thread();
} catch (...) {
try {
_running.set_exception(std::current_exception());
}
catch (...) {} // set_exception() may throw too
}
});
_watch_thread = std::thread([this]() {
try {
monitor_directory();
} catch (...) {
try {
_running.set_exception(std::current_exception());
}
catch (...) {} // set_exception() may throw too
}
});
std::future<void> future = _running.get_future();
future.get(); //block until the monitor_directory is up and running
}
void destroy()
{
_destory = true;
_running = std::promise<void>();
#ifdef _WIN32
SetEvent(_close_event);
#elif __unix__
inotify_rm_watch(_directory.folder, _directory.watch);
#elif FILEWATCH_PLATFORM_MAC
if (_run_loop) {
CFRunLoopStop(_run_loop);
}
#endif // __unix__
_cv.notify_all();
_watch_thread.join();
_callback_thread.join();
#ifdef _WIN32
CloseHandle(_directory);
#elif __unix__
close(_directory.folder);
#elif FILEWATCH_PLATFORM_MAC
FSEventStreamStop(_directory);
FSEventStreamInvalidate(_directory);
FSEventStreamRelease(_directory);
_directory = nullptr;
#endif // FILEWATCH_PLATFORM_MAC
}
const PathParts split_directory_and_file(const StringType& path) const
{
const auto predict = [](C character) {
#ifdef _WIN32
return character == C('\\') || character == C('/');
#elif __unix__ || FILEWATCH_PLATFORM_MAC
return character == C('/');
#endif // __unix__
};
UnderpinningString path_string = path;
const auto pivot = std::find_if(path_string.rbegin(), path_string.rend(), predict).base();
//if the path is something like "test.txt" there will be no directory part, however we still need one, so insert './'
const StringType directory = [&]() {
const auto extracted_directory = UnderpinningString(path_string.begin(), pivot);
return (extracted_directory.size() > 0) ? extracted_directory : UnderpinningString(_this_directory);
}();
const StringType filename = UnderpinningString(pivot, path_string.end());
return PathParts(directory, filename);
}
bool pass_filter(const UnderpinningString& file_path)
{
if (_watching_single_file) {
const UnderpinningString extracted_filename = { split_directory_and_file(file_path).filename };
//if we are watching a single file, only that file should trigger action
return extracted_filename == _filename;
}
return std::regex_match(file_path, _pattern);
}
#ifdef _WIN32
template<typename... Args> DWORD GetFileAttributesX(const char* lpFileName, Args... args) {
return GetFileAttributesA(lpFileName, args...);
}
template<typename... Args> DWORD GetFileAttributesX(const wchar_t* lpFileName, Args... args) {
return GetFileAttributesW(lpFileName, args...);
}
template<typename... Args> HANDLE CreateFileX(const char* lpFileName, Args... args) {
return CreateFileA(lpFileName, args...);
}
template<typename... Args> HANDLE CreateFileX(const wchar_t* lpFileName, Args... args) {
return CreateFileW(lpFileName, args...);
}
HANDLE get_directory(const StringType& path)
{
auto file_info = GetFileAttributesX(path.c_str());
if (file_info == INVALID_FILE_ATTRIBUTES)
{
throw std::system_error(GetLastError(), std::system_category());
}
_watching_single_file = (file_info & FILE_ATTRIBUTE_DIRECTORY) == false;
const StringType watch_path = [this, &path]() {
if (_watching_single_file)
{
const auto parsed_path = split_directory_and_file(path);
_filename = parsed_path.filename;
return parsed_path.directory;
}
else
{
return path;
}
}();
HANDLE directory = CreateFileX(
watch_path.c_str(), // pointer to the file name
FILE_LIST_DIRECTORY, // access (read/write) mode
FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, // share mode
nullptr, // security descriptor
OPEN_EXISTING, // how to create
FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OVERLAPPED, // file attributes
HANDLE(0)); // file with attributes to copy
if (directory == INVALID_HANDLE_VALUE)
{
throw std::system_error(GetLastError(), std::system_category());
}
return directory;
}
void convert_wstring(const std::wstring& wstr, std::string& out)
{
int size_needed = WideCharToMultiByte(CP_UTF8, 0, &wstr[0], (int)wstr.size(), NULL, 0, NULL, NULL);
out.resize(size_needed, '\0');
WideCharToMultiByte(CP_UTF8, 0, &wstr[0], (int)wstr.size(), &out[0], size_needed, NULL, NULL);
}
void convert_wstring(const std::wstring& wstr, std::wstring& out)
{
out = wstr;
}
void monitor_directory()
{
std::vector<BYTE> buffer(_buffer_size);
DWORD bytes_returned = 0;
OVERLAPPED overlapped_buffer{ 0 };
overlapped_buffer.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
if (!overlapped_buffer.hEvent) {
std::cerr << "Error creating monitor event" << std::endl;
}
std::array<HANDLE, 2> handles{ overlapped_buffer.hEvent, _close_event };
auto async_pending = false;
_running.set_value();
do {
std::vector<std::pair<StringType, Event>> parsed_information;
ReadDirectoryChangesW(
_directory,
buffer.data(), static_cast<DWORD>(buffer.size()),
TRUE,
_listen_filters,
&bytes_returned,
&overlapped_buffer, NULL);
async_pending = true;
switch (WaitForMultipleObjects(2, handles.data(), FALSE, INFINITE))
{
case WAIT_OBJECT_0:
{
if (!GetOverlappedResult(_directory, &overlapped_buffer, &bytes_returned, TRUE)) {
throw std::system_error(GetLastError(), std::system_category());
}
async_pending = false;
if (bytes_returned == 0) {
break;
}
FILE_NOTIFY_INFORMATION *file_information = reinterpret_cast<FILE_NOTIFY_INFORMATION*>(
do
{
std::wstring changed_file_w{ file_information->FileName, file_information->FileNameLength / sizeof(file_information->FileName[0]) };
UnderpinningString changed_file;
convert_wstring(changed_file_w, changed_file);
if (pass_filter(changed_file))
{
parsed_information.emplace_back(StringType{ changed_file }, _event_type_mapping.at(file_information->Action));
}
if (file_information->NextEntryOffset == 0) {
break;
}
file_information = reinterpret_cast<FILE_NOTIFY_INFORMATION*>(reinterpret_cast<BYTE*>(file_information) + file_information->NextEntryOffset);
} while (true);
break;
}
case WAIT_OBJECT_0 + 1:
// quit
break;
case WAIT_FAILED:
break;
}
//dispatch callbacks
{
std::lock_guard<std::mutex> lock(_callback_mutex);
_callback_information.insert(_callback_information.end(), parsed_information.begin(), parsed_information.end());
}
_cv.notify_all();
} while (_destory == false);
if (async_pending)
{
//clean up running async io
CancelIo(_directory);
GetOverlappedResult(_directory, &overlapped_buffer, &bytes_returned, TRUE);
}
}
#endif // WIN32
#if __unix__
bool is_file(const StringType& path) const
{
struct stat statbuf = {};
if (stat(path.c_str(), &statbuf) != 0)
{
throw std::system_error(errno, std::system_category());
}
return S_ISREG(statbuf.st_mode);
}
FolderInfo get_directory(const StringType& path)
{
const auto folder = inotify_init();
if (folder < 0)
{
throw std::system_error(errno, std::system_category());
}
_watching_single_file = is_file(path);
const StringType watch_path = [this, &path]() {
if (_watching_single_file)
{
const auto parsed_path = split_directory_and_file(path);
_filename = parsed_path.filename;
return parsed_path.directory;
}
else
{
return path;
}
}();
const auto watch = inotify_add_watch(folder, watch_path.c_str(), IN_MODIFY | IN_CREATE | IN_DELETE);
if (watch < 0)
{
throw std::system_error(errno, std::system_category());
}
return { folder, watch };
}
void monitor_directory()
{
std::vector<char> buffer(_buffer_size);
_running.set_value();
while (_destory == false)
{
const auto length = read(_directory.folder, static_cast<void*>(buffer.data()), buffer.size());
if (length > 0)
{
int i = 0;
std::vector<std::pair<StringType, Event>> parsed_information;
while (i < length)
{
struct inotify_event *event = reinterpret_cast<struct inotify_event *>( // NOLINT
if (event->len)
{
const UnderpinningString changed_file{ event->name };
if (pass_filter(changed_file))
{
if (event->mask & IN_CREATE)
{
parsed_information.emplace_back(StringType{ changed_file }, Event::added);
}
else if (event->mask & IN_DELETE)
{
parsed_information.emplace_back(StringType{ changed_file }, Event::removed);
}
else if (event->mask & IN_MODIFY)
{
parsed_information.emplace_back(StringType{ changed_file }, Event::modified);
}
}
}
i += event_size + event->len;
}
//dispatch callbacks
{
std::lock_guard<std::mutex> lock(_callback_mutex);
_callback_information.insert(_callback_information.end(), parsed_information.begin(), parsed_information.end());
}
_cv.notify_all();
}
}
}
#endif // __unix__
#if FILEWATCH_PLATFORM_MAC
static StringType absolute_path_of(const StringType& path) {
char buf[PATH_MAX];
int fd = open((const char*)path.c_str(), O_RDONLY);
const char* str = buf;
struct stat stat;
mbstate_t state;
assert(fd != -1);
fcntl(fd, F_GETPATH, buf);
fstat(fd,
if (stat.st_mode & S_IFREG || stat.st_mode & S_IFLNK) {
size_t len = strlen(buf);
for (size_t i = len - 1; i >= 0; i--) {
if (buf[i] == '/') {
buf[i] = '\0';
break;
}
}
}
close(fd);
if (IsWChar<C>::value) {
size_t needed = mbsrtowcs(nullptr, &str, 0, &state) + 1;
StringType s;
s.reserve(needed);
mbsrtowcs((wchar_t*)&s[0], &str, s.size(),
return s;
}
return StringType {buf};
}
#elif defined(__unix__)
static StringType absolute_path_of(const StringType& path) {
char buf[PATH_MAX];
const char* str = buf;
struct stat stat;
mbstate_t state;
realpath((const char*)path.c_str(), buf);
::stat((const char*)path.c_str(),
if (stat.st_mode & S_IFREG || stat.st_mode & S_IFLNK) {
size_t len = strlen(buf);
for (size_t i = len - 1; i >= 0; i--) {
if (buf[i] == '/') {
buf[i] = '\0';
break;
}
}
}
if (IsWChar<C>::value) {
size_t needed = mbsrtowcs(nullptr, &str, 0, &state) + 1;
StringType s;
s.reserve(needed);
mbsrtowcs((wchar_t*)&s[0], &str, s.size(),
return s;
}
return StringType {buf};
}
#elif _WIN32
static StringType absolute_path_of(const StringType& path) {
constexpr size_t size = IsWChar<C>::value? MAX_PATH : 32767 * sizeof(wchar_t);
char buf[size];
DWORD length = IsWChar<C>::value?
GetFullPathNameW((LPCWSTR)path.c_str(),
size / sizeof(TCHAR),
(LPWSTR)buf,
nullptr) :
GetFullPathNameA((LPCSTR)path.c_str(),
size / sizeof(TCHAR),
buf,
nullptr);
return StringType{(C*)buf, length};
}
#endif
#if FILEWATCH_PLATFORM_MAC
static StringType utf8StringToUtf32String(const char* buffer) {
mbstate_t state{};
StringType s{};
size_t needed = mbsrtowcs(nullptr, &buffer, 0, &state) + 1;
s.reserve(needed);
mbsrtowcs((wchar_t*)&s[0], &buffer, s.size(),
return s;
}
template<typename Fn, class = std::enable_if<Invokable<Fn, StringType>::value>>
static void walkDirectory(const StringType& path, Fn callback) {
int fd = open(path.c_str(), O_RDONLY);
char buf[1024];
long basep = 0;
if (fd == -1) {
return;
}
int ret = __getdirentries64(fd, buf, sizeof(buf),
while (ret > 0) {
char* current = buf;
int offset = 0;
while (offset < ret) {
struct dirent* dirent = (struct dirent*)current;
StringType name = IsWChar<C>::value?
utf8StringToUtf32String(dirent->d_name)
: StringType(dirent->d_name);
callback(std::move(name));
current += dirent->d_reclen;
offset += dirent->d_reclen;
}
ret = __getdirentries64(fd, buf, sizeof(buf),
}
close(fd);
}
static StringType nameofFd(int fd) {
size_t len = 0;
char buf[MAXPATHLEN];
if (fcntl(fd, F_GETPATH, buf) == -1) {
return StringType{};
}
if (IsWChar<C>::value) {
return utf8StringToUtf32String(buf);
}
len = strnlen(buf, MAXPATHLEN);
for (int i = len - 1; i >= 0; i--) {
if(buf[i] == '/') {
return StringType{buf + i + 1, len - i - 1};
}
}
return StringType{buf, len};
}
static StringType fullPathOfFd(int fd) {
char buf[MAXPATHLEN];
if (fcntl(fd, F_GETPATH, buf) == -1) {
return StringType{};
}
if (IsWChar<C>::value) {
return utf8StringToUtf32String(buf);
}
return StringType{(C*)buf};
}
static StringType pathOfFd(int fd) {
size_t len = 0;
char buf[MAXPATHLEN];
if (fcntl(fd, F_GETPATH, buf) == -1) {
return StringType{};
}
if (IsWChar<C>::value) {
return utf8StringToUtf32String(buf);
}
len = strnlen(buf, MAXPATHLEN);
for (int i = len - 1; i >= 0; i--) {
if(buf[i] == '/') {
return StringType{buf, static_cast<size_t>(i)};
}
}
return StringType{buf, len};
}
static bool fdIsRemoved(int fd) {
char buf[MAXPATHLEN];
return fcntl(fd, F_GETPATH, buf) == -1;
}
FileState makeFileState(const StringType& path) {
int fd = openFile(path);
struct stat stat;
fstat(fd,
return FileState {
openFile(path),
stat.st_nlink,
stat.st_mtimespec.tv_sec
};
}
static StringType filenameOf(const StringType& file) {
for (int i = file.size() - 1; i >= 0; i--) {
if(file[i] == '/') {
return file.substr(i + 1);
}
}
return file;
}
static bool isInDirectory(const StringType& file, const StringType& path) {
if (file.size() < path.size()) {
return false;
}
return strncmp(file.data(), path.data(), path.size()) == 0;
}
PathParts splitPath(const StringType& path) {
PathParts split = split_directory_and_file(path);
if (split.directory.size() > 0 && split.directory[split.directory.size() - 1] == '/') {
split.directory.erase(split.directory.size() - 1);
}
return split;
}
StringType fullPathOf(const StringType& file) {
return _path + '/' + file;
}
int openFile(const StringType& file) {
int fd = open(fullPathOf(file).c_str(), O_RDONLY);
assert(fd != -1);
return fd;
}
void walkAndSeeChanges() {
struct RenamedPair {
StringType old;
StringType current;
};
struct EventInfo {
StringType file;
struct timespec time;
Event event;
};
std::unordered_map<StringType, FileState> newSnapshot{};
std::vector<EventInfo> events{};
for (auto& entry : _directory_snapshot) {
struct stat stat;
fstat(entry.second.fd,
if (fdIsRemoved(entry.second.fd)) {
events.push_back(EventInfo {
.event = Event::removed,
.file = entry.first,
.time = stat.st_ctimespec
});
continue;
}
StringType fullPath = fullPathOfFd(entry.second.fd);
PathParts pathPair = splitPath(fullPath);
if (pathPair.directory != _path) {
events.push_back(EventInfo {
.event = Event::removed,
.file = entry.first,
.time = stat.st_ctimespec
});
continue;
}
if (entry.first != pathPair.filename) {
events.push_back(EventInfo {
.event = Event::renamed_old,
.file = entry.first,
.time = stat.st_ctimespec
});
events.push_back(EventInfo {
.event = Event::renamed_new,
.file = pathPair.filename,
.time = stat.st_ctimespec
});
}
else {
if (stat.st_mtimespec.tv_sec > entry.second.last_modification) {
entry.second.last_modification = stat.st_mtimespec.tv_sec;
events.push_back(EventInfo {
.event = Event::modified,
.file = pathPair.filename,
.time = stat.st_mtimespec
});
}
}
newSnapshot.insert(std::make_pair(std::move(pathPair.filename),
std::move(entry.second.invalidate_and_clone())));
}
walkDirectory(_path, [&](StringType file) {
if (isParentOrSelfDirectory(file) || !std::regex_match(file, _pattern)) {
return;
}
if (newSnapshot.count(file) == 0) {
FileState state = makeFileState(file);
struct stat stat;
fstat(state.fd,
events.push_back(EventInfo {
.event = Event::added,
.file = file,
.time = stat.st_mtimespec
});
newSnapshot.insert(std::make_pair(file, std::move(state)));
}
});
std::swap(_directory_snapshot, newSnapshot);
std::sort(events.begin(), events.end(), [] (const EventInfo& a, EventInfo& b) {
if (a.time.tv_sec == b.time.tv_sec) {
return a.time.tv_nsec < b.time.tv_nsec;
}
return a.time.tv_sec < b.time.tv_sec;
});
{
std::lock_guard<std::mutex> lock(_callback_mutex);
for (const auto& event : events) {
_callback_information.push_back(std::make_pair(event.file, event.event));
}
}
_cv.notify_all();
}
void seeSingleFileChanges() {
struct EventInfo {
StringType file;
Event event;
};
int eventCount = 1;
EventInfo eventInfos[2];
if (fdIsRemoved(_file_fd)) {
eventInfos[0].event = Event::removed;
eventInfos[0].file = _filename;
}
else {
StringType absPath = pathOfFd(_file_fd);
PathParts split = splitPath(absPath);
if (split.directory != _path) {
eventInfos[0].event = Event::removed;
eventInfos[0].file = _filename;
}
else if (split.filename != _filename) {
eventInfos[0].event = Event::renamed_old;
eventInfos[0].file = std::move(_filename);
eventInfos[1].event = Event::renamed_new;
eventInfos[1].file = split.filename;
eventCount = 2;
_filename = std::move(split.filename);
}
else {
struct stat stat;
fstat(_file_fd,
if (stat.st_mtimespec.tv_sec > _last_modification_time.tv_sec) {
eventInfos[0].event = Event::modified;
eventInfos[0].file = _filename;
_last_modification_time = stat.st_mtimespec;
}
else if (stat.st_mtimespec.tv_nsec > _last_modification_time.tv_nsec) {
eventInfos[0].event = Event::modified;
eventInfos[0].file = _filename;
_last_modification_time = stat.st_mtimespec;
}
else {
return;
}
}
}
{
std::lock_guard<std::mutex> lock(_callback_mutex);
for (int i = 0; i < eventCount; i++) {
_callback_information.push_back(
std::make_pair(eventInfos[i].file, eventInfos[i].event));
}
}
_cv.notify_all();
}
void notify(CFStringRef path, const FSEventStreamEventFlags flags) {
CFIndex pathLength = CFStringGetLength(path);
CFIndex written = 0;
char buffer[PATH_MAX + 1];
CFStringGetBytes(path,
CFRange {
.location = 0,
.length = pathLength,
},
IsWChar<C>::value? kCFStringEncodingUTF32 : kCFStringEncodingUTF8,
0,
false,
(UInt8*)buffer,
PATH_MAX,
buffer[written] = 0;
StringType absolutePath{(const C*)buffer, static_cast<size_t>(pathLength)};
PathParts pathPair = splitPath(absolutePath);
if (_watching_single_file && pathPair.filename != _filename) {
return;
}
if (pathPair.directory != _path || !std::regex_match(pathPair.filename, _pattern)) {
return;
}
Event event = Event::modified;
if (_previous_event_is_rename) {
event = Event::renamed_new;
_directory_snapshot.insert(std::make_pair(pathPair.filename,
std::move(makeFileState(pathPair.filename))));
_previous_event_is_rename = false;
}
else if (flags & kFSEventStreamEventFlagItemRenamed) {
const auto state = _directory_snapshot.find(pathPair.filename);
assert(state != _directory_snapshot.end());
StringType fdPath = pathOfFd(state->second.fd);
// moved/delete to Trash folder
if (!isInDirectory(absolutePath, fdPath)) {
event = Event::removed;
_directory_snapshot.erase(pathPair.filename);
}
else {
event = Event::renamed_old;
_previous_event_is_rename = true;
}
}
else if (flags & kFSEventStreamEventFlagItemCreated) {
_directory_snapshot.insert(std::make_pair(pathPair.filename,
std::move(makeFileState(pathPair.filename))));
event = Event::added;
}
else if (flags & kFSEventStreamEventFlagItemRemoved) {
_directory_snapshot.erase(pathPair.filename);
event = Event::removed;
}
{
std::lock_guard<std::mutex> lock(_callback_mutex);
_callback_information.push_back(std::make_pair(std::move(pathPair.filename), event));
}
_cv.notify_all();
}
static void handleFsEvent(__attribute__((unused)) ConstFSEventStreamRef streamFef,
void* clientCallBackInfo,
size_t numEvents,
CFArrayRef eventPaths,
const FSEventStreamEventFlags* eventFlags,
__attribute__((unused)) const FSEventStreamEventId* eventIds) {
FileWatch<StringType>* self = (FileWatch<StringType>*)clientCallBackInfo;
for (size_t i = 0; i < numEvents; i++) {
FSEventStreamEventFlags flag = eventFlags[i];
CFStringRef path = (CFStringRef)CFArrayGetValueAtIndex(eventPaths, i);
if (self->_watching_single_file) {
self->seeSingleFileChanges();
}
else if (flag & kFSEventStreamEventFlagMustScanSubDirs) {
self->walkAndSeeChanges();
}
else {
self->notify(path, flag);
}
}
}
FSEventStreamRef openStream(const StringType& directory) {
CFStringEncoding encoding = IsWChar<C>::value?
kCFStringEncodingUTF32 : kCFStringEncodingASCII;
CFStringRef path = CFStringCreateWithBytes(kCFAllocatorDefault,
(const UInt8*)directory.data(),
directory.size(),
encoding,
false);
CFArrayRef paths = CFArrayCreate(
kCFAllocatorDefault,
(const void**)&path,
1,
nullptr);
FSEventStreamContext context {
.info = (void*)this
};
FSEventStreamRef event = FSEventStreamCreate(
kCFAllocatorDefault,
(FSEventStreamCallback)handleFsEvent,
&context,
paths,
kFSEventStreamEventIdSinceNow,
0,
kFSEventStreamCreateFlagNoDefer | kFSEventStreamCreateFlagFileEvents |
kFSEventStreamCreateFlagUseCFTypes);
CFRelease(path);
CFRelease(paths);
return event;
}
FSEventStreamRef openStreamForDirectory(const StringType& directory) {
FSEventStreamRef stream = openStream(directory);
walkDirectory(directory, [this] (StringType path) mutable {
if (!isParentOrSelfDirectory(path) && std::regex_match(path, _pattern)) {
_directory_snapshot.insert(std::make_pair(std::move(path),
std::move(makeFileState(path))));
}
});
return stream;
}
FSEventStreamRef openStreamForFile(const StringType& file) {
PathParts split = splitPath(file);
_watching_single_file = true;
_filename = std::move(split.filename);
_file_fd = openFile(file);
return openStreamForDirectory(split.directory);
}
FSEventStreamRef get_directory(const StringType& directory) {
struct stat stat;
::stat((const char*)directory.c_str(),
if (stat.st_mode & S_IFDIR) {
return openStreamForDirectory(directory);
}
_last_modification_time = stat.st_mtimespec;
return openStreamForFile(directory);
}
void monitor_directory() {
_run_loop = CFRunLoopGetCurrent();
FSEventStreamScheduleWithRunLoop(_directory,
_run_loop,
kCFRunLoopDefaultMode);
FSEventStreamStart(_directory);
_running.set_value();
CFRunLoopRun();
}
#endif // FILEWATCH_PLATFORM_MAC
void callback_thread()
{
while (_destory == false) {
std::unique_lock<std::mutex> lock(_callback_mutex);
if (_callback_information.empty() && _destory == false) {
_cv.wait(lock, [this] { return _callback_information.size() > 0 || _destory; });
}
decltype(_callback_information) callback_information = {};
std::swap(callback_information, _callback_information);
lock.unlock();
for (const auto& file : callback_information) {
if (_callback) {
try
{
_callback(file.first, file.second);
}
catch (const std::exception&)
{
}
}
}
}
}
};
template<class StringType> constexpr typename FileWatch<StringType>::C FileWatch<StringType>::_regex_all[];
template<class StringType> constexpr typename FileWatch<StringType>::C FileWatch<StringType>::_this_directory[];
}
#endif
测试
include "filewatch.hpp"
#include <future>
#include <algorithm>
#include <mutex>
#include <vector>
#include <set>
#include <iostream>
#include <fstream>
#include <thread>
int main() {
std::promise<test_string> promise;
std::future<test_string> future = promise.get_future();
filewatch::FileWatch<test_string> watch(L"./", [&promise](const test_string& path, const filewatch::Event change_type) {
promise.set_value(path);
switch (change_type) {
case filewatch::Event::added:
break;
case filewatch::Event::removed:
break;
case filewatch::Event::modified:
break;
case filewatch::Event::renamed_old:
break;
case filewatch::Event::renamed_new:
break;
default:
break;
}
});
std::ofstream file("./test.txt");
file << "test" << std::endl;
file.close();
}参考
多标签文件管理器-CSDN博客
GitHub - ThomasMonkman/filewatch: File watcher in c++
创作不易，小小的支持一下吧！
