1e5dd7070Spatrick //===- DirectoryWatcher-mac.cpp - Mac-platform directory watching ---------===//
2e5dd7070Spatrick //
3e5dd7070Spatrick // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4e5dd7070Spatrick // See https://llvm.org/LICENSE.txt for license information.
5e5dd7070Spatrick // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6e5dd7070Spatrick //
7e5dd7070Spatrick //===----------------------------------------------------------------------===//
8e5dd7070Spatrick
9e5dd7070Spatrick #include "DirectoryScanner.h"
10e5dd7070Spatrick #include "clang/DirectoryWatcher/DirectoryWatcher.h"
11e5dd7070Spatrick
12e5dd7070Spatrick #include "llvm/ADT/STLExtras.h"
13e5dd7070Spatrick #include "llvm/ADT/StringRef.h"
14e5dd7070Spatrick #include "llvm/Support/Error.h"
15e5dd7070Spatrick #include "llvm/Support/Path.h"
16e5dd7070Spatrick #include <CoreServices/CoreServices.h>
17ec727ea7Spatrick #include <TargetConditionals.h>
18e5dd7070Spatrick
19e5dd7070Spatrick using namespace llvm;
20e5dd7070Spatrick using namespace clang;
21e5dd7070Spatrick
22ec727ea7Spatrick #if TARGET_OS_OSX
23ec727ea7Spatrick
24e5dd7070Spatrick static void stopFSEventStream(FSEventStreamRef);
25e5dd7070Spatrick
26e5dd7070Spatrick namespace {
27e5dd7070Spatrick
28e5dd7070Spatrick /// This implementation is based on FSEvents API which implementation is
29e5dd7070Spatrick /// aggressively coallescing events. This can manifest as duplicate events.
30e5dd7070Spatrick ///
31e5dd7070Spatrick /// For example this scenario has been observed:
32e5dd7070Spatrick ///
33e5dd7070Spatrick /// create foo/bar
34e5dd7070Spatrick /// sleep 5 s
35e5dd7070Spatrick /// create DirectoryWatcherMac for dir foo
36e5dd7070Spatrick /// receive notification: bar EventKind::Modified
37e5dd7070Spatrick /// sleep 5 s
38e5dd7070Spatrick /// modify foo/bar
39e5dd7070Spatrick /// receive notification: bar EventKind::Modified
40e5dd7070Spatrick /// receive notification: bar EventKind::Modified
41e5dd7070Spatrick /// sleep 5 s
42e5dd7070Spatrick /// delete foo/bar
43e5dd7070Spatrick /// receive notification: bar EventKind::Modified
44e5dd7070Spatrick /// receive notification: bar EventKind::Modified
45e5dd7070Spatrick /// receive notification: bar EventKind::Removed
46e5dd7070Spatrick class DirectoryWatcherMac : public clang::DirectoryWatcher {
47e5dd7070Spatrick public:
DirectoryWatcherMac(dispatch_queue_t Queue,FSEventStreamRef EventStream,std::function<void (llvm::ArrayRef<DirectoryWatcher::Event>,bool)> Receiver,llvm::StringRef WatchedDirPath)48e5dd7070Spatrick DirectoryWatcherMac(
49ec727ea7Spatrick dispatch_queue_t Queue, FSEventStreamRef EventStream,
50e5dd7070Spatrick std::function<void(llvm::ArrayRef<DirectoryWatcher::Event>, bool)>
51e5dd7070Spatrick Receiver,
52e5dd7070Spatrick llvm::StringRef WatchedDirPath)
53ec727ea7Spatrick : Queue(Queue), EventStream(EventStream), Receiver(Receiver),
54e5dd7070Spatrick WatchedDirPath(WatchedDirPath) {}
55e5dd7070Spatrick
~DirectoryWatcherMac()56e5dd7070Spatrick ~DirectoryWatcherMac() override {
57ec727ea7Spatrick // FSEventStreamStop and Invalidate must be called after Start and
58ec727ea7Spatrick // SetDispatchQueue to follow FSEvents API contract. The call to Receiver
59ec727ea7Spatrick // also uses Queue to not race with the initial scan.
60ec727ea7Spatrick dispatch_sync(Queue, ^{
61e5dd7070Spatrick stopFSEventStream(EventStream);
62e5dd7070Spatrick EventStream = nullptr;
63ec727ea7Spatrick Receiver(
64ec727ea7Spatrick DirectoryWatcher::Event(
65e5dd7070Spatrick DirectoryWatcher::Event::EventKind::WatcherGotInvalidated, ""),
66e5dd7070Spatrick false);
67ec727ea7Spatrick });
68ec727ea7Spatrick
69ec727ea7Spatrick // Balance initial creation.
70ec727ea7Spatrick dispatch_release(Queue);
71e5dd7070Spatrick }
72e5dd7070Spatrick
73e5dd7070Spatrick private:
74ec727ea7Spatrick dispatch_queue_t Queue;
75e5dd7070Spatrick FSEventStreamRef EventStream;
76e5dd7070Spatrick std::function<void(llvm::ArrayRef<Event>, bool)> Receiver;
77e5dd7070Spatrick const std::string WatchedDirPath;
78e5dd7070Spatrick };
79e5dd7070Spatrick
80e5dd7070Spatrick struct EventStreamContextData {
81e5dd7070Spatrick std::string WatchedPath;
82e5dd7070Spatrick std::function<void(llvm::ArrayRef<DirectoryWatcher::Event>, bool)> Receiver;
83e5dd7070Spatrick
EventStreamContextData__anon0fd2c5240111::EventStreamContextData84e5dd7070Spatrick EventStreamContextData(
85e5dd7070Spatrick std::string &&WatchedPath,
86e5dd7070Spatrick std::function<void(llvm::ArrayRef<DirectoryWatcher::Event>, bool)>
87e5dd7070Spatrick Receiver)
88e5dd7070Spatrick : WatchedPath(std::move(WatchedPath)), Receiver(Receiver) {}
89e5dd7070Spatrick
90e5dd7070Spatrick // Needed for FSEvents
dispose__anon0fd2c5240111::EventStreamContextData91e5dd7070Spatrick static void dispose(const void *ctx) {
92e5dd7070Spatrick delete static_cast<const EventStreamContextData *>(ctx);
93e5dd7070Spatrick }
94e5dd7070Spatrick };
95e5dd7070Spatrick } // namespace
96e5dd7070Spatrick
97e5dd7070Spatrick constexpr const FSEventStreamEventFlags StreamInvalidatingFlags =
98e5dd7070Spatrick kFSEventStreamEventFlagUserDropped | kFSEventStreamEventFlagKernelDropped |
99e5dd7070Spatrick kFSEventStreamEventFlagMustScanSubDirs;
100e5dd7070Spatrick
101e5dd7070Spatrick constexpr const FSEventStreamEventFlags ModifyingFileEvents =
102e5dd7070Spatrick kFSEventStreamEventFlagItemCreated | kFSEventStreamEventFlagItemRenamed |
103e5dd7070Spatrick kFSEventStreamEventFlagItemModified;
104e5dd7070Spatrick
eventStreamCallback(ConstFSEventStreamRef Stream,void * ClientCallBackInfo,size_t NumEvents,void * EventPaths,const FSEventStreamEventFlags EventFlags[],const FSEventStreamEventId EventIds[])105e5dd7070Spatrick static void eventStreamCallback(ConstFSEventStreamRef Stream,
106e5dd7070Spatrick void *ClientCallBackInfo, size_t NumEvents,
107e5dd7070Spatrick void *EventPaths,
108e5dd7070Spatrick const FSEventStreamEventFlags EventFlags[],
109e5dd7070Spatrick const FSEventStreamEventId EventIds[]) {
110e5dd7070Spatrick auto *ctx = static_cast<EventStreamContextData *>(ClientCallBackInfo);
111e5dd7070Spatrick
112e5dd7070Spatrick std::vector<DirectoryWatcher::Event> Events;
113e5dd7070Spatrick for (size_t i = 0; i < NumEvents; ++i) {
114e5dd7070Spatrick StringRef Path = ((const char **)EventPaths)[i];
115e5dd7070Spatrick const FSEventStreamEventFlags Flags = EventFlags[i];
116e5dd7070Spatrick
117e5dd7070Spatrick if (Flags & StreamInvalidatingFlags) {
118e5dd7070Spatrick Events.emplace_back(DirectoryWatcher::Event{
119e5dd7070Spatrick DirectoryWatcher::Event::EventKind::WatcherGotInvalidated, ""});
120e5dd7070Spatrick break;
121e5dd7070Spatrick } else if (!(Flags & kFSEventStreamEventFlagItemIsFile)) {
122e5dd7070Spatrick // Subdirectories aren't supported - if some directory got removed it
123e5dd7070Spatrick // must've been the watched directory itself.
124e5dd7070Spatrick if ((Flags & kFSEventStreamEventFlagItemRemoved) &&
125e5dd7070Spatrick Path == ctx->WatchedPath) {
126e5dd7070Spatrick Events.emplace_back(DirectoryWatcher::Event{
127e5dd7070Spatrick DirectoryWatcher::Event::EventKind::WatchedDirRemoved, ""});
128e5dd7070Spatrick Events.emplace_back(DirectoryWatcher::Event{
129e5dd7070Spatrick DirectoryWatcher::Event::EventKind::WatcherGotInvalidated, ""});
130e5dd7070Spatrick break;
131e5dd7070Spatrick }
132e5dd7070Spatrick // No support for subdirectories - just ignore everything.
133e5dd7070Spatrick continue;
134e5dd7070Spatrick } else if (Flags & kFSEventStreamEventFlagItemRemoved) {
135e5dd7070Spatrick Events.emplace_back(DirectoryWatcher::Event::EventKind::Removed,
136e5dd7070Spatrick llvm::sys::path::filename(Path));
137e5dd7070Spatrick continue;
138e5dd7070Spatrick } else if (Flags & ModifyingFileEvents) {
139*12c85518Srobert if (!getFileStatus(Path).has_value()) {
140e5dd7070Spatrick Events.emplace_back(DirectoryWatcher::Event::EventKind::Removed,
141e5dd7070Spatrick llvm::sys::path::filename(Path));
142e5dd7070Spatrick } else {
143e5dd7070Spatrick Events.emplace_back(DirectoryWatcher::Event::EventKind::Modified,
144e5dd7070Spatrick llvm::sys::path::filename(Path));
145e5dd7070Spatrick }
146e5dd7070Spatrick continue;
147e5dd7070Spatrick }
148e5dd7070Spatrick
149e5dd7070Spatrick // default
150e5dd7070Spatrick Events.emplace_back(DirectoryWatcher::Event{
151e5dd7070Spatrick DirectoryWatcher::Event::EventKind::WatcherGotInvalidated, ""});
152e5dd7070Spatrick llvm_unreachable("Unknown FSEvent type.");
153e5dd7070Spatrick }
154e5dd7070Spatrick
155e5dd7070Spatrick if (!Events.empty()) {
156e5dd7070Spatrick ctx->Receiver(Events, /*IsInitial=*/false);
157e5dd7070Spatrick }
158e5dd7070Spatrick }
159e5dd7070Spatrick
createFSEventStream(StringRef Path,std::function<void (llvm::ArrayRef<DirectoryWatcher::Event>,bool)> Receiver,dispatch_queue_t Queue)160e5dd7070Spatrick FSEventStreamRef createFSEventStream(
161e5dd7070Spatrick StringRef Path,
162e5dd7070Spatrick std::function<void(llvm::ArrayRef<DirectoryWatcher::Event>, bool)> Receiver,
163e5dd7070Spatrick dispatch_queue_t Queue) {
164e5dd7070Spatrick if (Path.empty())
165e5dd7070Spatrick return nullptr;
166e5dd7070Spatrick
167e5dd7070Spatrick CFMutableArrayRef PathsToWatch = [&]() {
168e5dd7070Spatrick CFMutableArrayRef PathsToWatch =
169e5dd7070Spatrick CFArrayCreateMutable(nullptr, 0, &kCFTypeArrayCallBacks);
170e5dd7070Spatrick CFStringRef CfPathStr =
171e5dd7070Spatrick CFStringCreateWithBytes(nullptr, (const UInt8 *)Path.data(),
172e5dd7070Spatrick Path.size(), kCFStringEncodingUTF8, false);
173e5dd7070Spatrick CFArrayAppendValue(PathsToWatch, CfPathStr);
174e5dd7070Spatrick CFRelease(CfPathStr);
175e5dd7070Spatrick return PathsToWatch;
176e5dd7070Spatrick }();
177e5dd7070Spatrick
178e5dd7070Spatrick FSEventStreamContext Context = [&]() {
179e5dd7070Spatrick std::string RealPath;
180e5dd7070Spatrick {
181e5dd7070Spatrick SmallString<128> Storage;
182e5dd7070Spatrick StringRef P = llvm::Twine(Path).toNullTerminatedStringRef(Storage);
183e5dd7070Spatrick char Buffer[PATH_MAX];
184e5dd7070Spatrick if (::realpath(P.begin(), Buffer) != nullptr)
185e5dd7070Spatrick RealPath = Buffer;
186e5dd7070Spatrick else
187ec727ea7Spatrick RealPath = Path.str();
188e5dd7070Spatrick }
189e5dd7070Spatrick
190e5dd7070Spatrick FSEventStreamContext Context;
191e5dd7070Spatrick Context.version = 0;
192e5dd7070Spatrick Context.info = new EventStreamContextData(std::move(RealPath), Receiver);
193e5dd7070Spatrick Context.retain = nullptr;
194e5dd7070Spatrick Context.release = EventStreamContextData::dispose;
195e5dd7070Spatrick Context.copyDescription = nullptr;
196e5dd7070Spatrick return Context;
197e5dd7070Spatrick }();
198e5dd7070Spatrick
199e5dd7070Spatrick FSEventStreamRef Result = FSEventStreamCreate(
200e5dd7070Spatrick nullptr, eventStreamCallback, &Context, PathsToWatch,
201e5dd7070Spatrick kFSEventStreamEventIdSinceNow, /* latency in seconds */ 0.0,
202e5dd7070Spatrick kFSEventStreamCreateFlagFileEvents | kFSEventStreamCreateFlagNoDefer);
203e5dd7070Spatrick CFRelease(PathsToWatch);
204e5dd7070Spatrick
205e5dd7070Spatrick return Result;
206e5dd7070Spatrick }
207e5dd7070Spatrick
stopFSEventStream(FSEventStreamRef EventStream)208e5dd7070Spatrick void stopFSEventStream(FSEventStreamRef EventStream) {
209e5dd7070Spatrick if (!EventStream)
210e5dd7070Spatrick return;
211e5dd7070Spatrick FSEventStreamStop(EventStream);
212e5dd7070Spatrick FSEventStreamInvalidate(EventStream);
213e5dd7070Spatrick FSEventStreamRelease(EventStream);
214e5dd7070Spatrick }
215e5dd7070Spatrick
create(StringRef Path,std::function<void (llvm::ArrayRef<DirectoryWatcher::Event>,bool)> Receiver,bool WaitForInitialSync)216e5dd7070Spatrick llvm::Expected<std::unique_ptr<DirectoryWatcher>> clang::DirectoryWatcher::create(
217e5dd7070Spatrick StringRef Path,
218e5dd7070Spatrick std::function<void(llvm::ArrayRef<DirectoryWatcher::Event>, bool)> Receiver,
219e5dd7070Spatrick bool WaitForInitialSync) {
220e5dd7070Spatrick dispatch_queue_t Queue =
221e5dd7070Spatrick dispatch_queue_create("DirectoryWatcher", DISPATCH_QUEUE_SERIAL);
222e5dd7070Spatrick
223e5dd7070Spatrick if (Path.empty())
224e5dd7070Spatrick llvm::report_fatal_error(
225e5dd7070Spatrick "DirectoryWatcher::create can not accept an empty Path.");
226e5dd7070Spatrick
227e5dd7070Spatrick auto EventStream = createFSEventStream(Path, Receiver, Queue);
228e5dd7070Spatrick assert(EventStream && "EventStream expected to be non-null");
229e5dd7070Spatrick
230e5dd7070Spatrick std::unique_ptr<DirectoryWatcher> Result =
231ec727ea7Spatrick std::make_unique<DirectoryWatcherMac>(Queue, EventStream, Receiver, Path);
232e5dd7070Spatrick
233e5dd7070Spatrick // We need to copy the data so the lifetime is ok after a const copy is made
234e5dd7070Spatrick // for the block.
235ec727ea7Spatrick const std::string CopiedPath = Path.str();
236e5dd7070Spatrick
237e5dd7070Spatrick auto InitWork = ^{
238e5dd7070Spatrick // We need to start watching the directory before we start scanning in order
239e5dd7070Spatrick // to not miss any event. By dispatching this on the same serial Queue as
240e5dd7070Spatrick // the FSEvents will be handled we manage to start watching BEFORE the
241e5dd7070Spatrick // inital scan and handling events ONLY AFTER the scan finishes.
242e5dd7070Spatrick FSEventStreamSetDispatchQueue(EventStream, Queue);
243e5dd7070Spatrick FSEventStreamStart(EventStream);
244e5dd7070Spatrick Receiver(getAsFileEvents(scanDirectory(CopiedPath)), /*IsInitial=*/true);
245e5dd7070Spatrick };
246e5dd7070Spatrick
247e5dd7070Spatrick if (WaitForInitialSync) {
248e5dd7070Spatrick dispatch_sync(Queue, InitWork);
249e5dd7070Spatrick } else {
250e5dd7070Spatrick dispatch_async(Queue, InitWork);
251e5dd7070Spatrick }
252e5dd7070Spatrick
253e5dd7070Spatrick return Result;
254e5dd7070Spatrick }
255ec727ea7Spatrick
256ec727ea7Spatrick #else // TARGET_OS_OSX
257ec727ea7Spatrick
258ec727ea7Spatrick llvm::Expected<std::unique_ptr<DirectoryWatcher>>
create(StringRef Path,std::function<void (llvm::ArrayRef<DirectoryWatcher::Event>,bool)> Receiver,bool WaitForInitialSync)259ec727ea7Spatrick clang::DirectoryWatcher::create(
260ec727ea7Spatrick StringRef Path,
261ec727ea7Spatrick std::function<void(llvm::ArrayRef<DirectoryWatcher::Event>, bool)> Receiver,
262ec727ea7Spatrick bool WaitForInitialSync) {
263ec727ea7Spatrick return llvm::make_error<llvm::StringError>(
264ec727ea7Spatrick "DirectoryWatcher is not implemented for this platform!",
265ec727ea7Spatrick llvm::inconvertibleErrorCode());
266ec727ea7Spatrick }
267ec727ea7Spatrick
268ec727ea7Spatrick #endif // TARGET_OS_OSX
269