update, text, response

node_modules/@parcel/watcher/src/kqueue/KqueueBackend.cc

@@ -0,0 +1,306 @@
+#include <memory>
+#include <poll.h>
+#include <unistd.h>
+#include <libgen.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include "KqueueBackend.hh"
+
+#if __APPLE__
+#define st_mtim st_mtimespec
+#endif
+
+#if !defined(O_EVTONLY)
+#define O_EVTONLY O_RDONLY
+#endif
+
+#define CONVERT_TIME(ts) ((uint64_t)ts.tv_sec * 1000000000 + ts.tv_nsec)
+
+void KqueueBackend::start() {
+  if ((mKqueue = kqueue()) < 0) {
+    throw std::runtime_error(std::string("Unable to open kqueue: ") + strerror(errno));
+  }
+
+  // Create a pipe that we will write to when we want to end the thread.
+  int err = pipe(mPipe);
+  if (err == -1) {
+    throw std::runtime_error(std::string("Unable to open pipe: ") + strerror(errno));
+  }
+
+  // Subscribe kqueue to this pipe.
+  struct kevent ev;
+  EV_SET(
+    &ev,
+    mPipe[0],
+    EVFILT_READ,
+    EV_ADD | EV_CLEAR,
+    0,
+    0,
+    0
+  );
+
+  if (kevent(mKqueue, &ev, 1, NULL, 0, 0)) {
+    close(mPipe[0]);
+    close(mPipe[1]);
+    throw std::runtime_error(std::string("Unable to watch pipe: ") + strerror(errno));
+  }
+
+  notifyStarted();
+
+  struct kevent events[128];
+
+  while (true) {
+    int event_count = kevent(mKqueue, NULL, 0, events, 128, 0);
+    if (event_count < 0 || events[0].flags == EV_ERROR) {
+      throw std::runtime_error(std::string("kevent error: ") + strerror(errno));
+    }
+
+    // Track all of the watchers that are touched so we can notify them at the end of the events.
+    std::unordered_set<WatcherRef> watchers;
+
+    for (int i = 0; i < event_count; i++) {
+      int flags = events[i].fflags;
+      int fd = events[i].ident;
+      if (fd == mPipe[0]) {
+        // pipe was written to. break out of the loop.
+        goto done;
+      }
+
+      auto it = mFdToEntry.find(fd);
+      if (it == mFdToEntry.end()) {
+        // If fd wasn't in our map, we may have already stopped watching it. Ignore the event.
+        continue;
+      }
+
+      DirEntry *entry = it->second;
+
+      if (flags & NOTE_WRITE && entry && entry->isDir) {
+        // If a write occurred on a directory, we have to diff the contents of that
+        // directory to determine what file was added/deleted.
+        compareDir(fd, entry->path, watchers);
+      } else {
+        std::vector<KqueueSubscription *> subs = findSubscriptions(entry->path);
+        for (auto it = subs.begin(); it != subs.end(); it++) {
+          KqueueSubscription *sub = *it;
+          watchers.insert(sub->watcher);
+          if (flags & (NOTE_DELETE | NOTE_RENAME | NOTE_REVOKE)) {
+            sub->watcher->mEvents.remove(sub->path);
+            sub->tree->remove(sub->path);
+            mFdToEntry.erase((int)(size_t)entry->state);
+            mSubscriptions.erase(sub->path);
+          } else if (flags & (NOTE_WRITE | NOTE_ATTRIB | NOTE_EXTEND)) {
+            struct stat st;
+            lstat(sub->path.c_str(), &st);
+            if (entry->mtime != CONVERT_TIME(st.st_mtim)) {
+              entry->mtime = CONVERT_TIME(st.st_mtim);
+              sub->watcher->mEvents.update(sub->path);
+            }
+          }
+        }
+      }
+    }
+
+    for (auto it = watchers.begin(); it != watchers.end(); it++) {
+      (*it)->notify();
+    }
+  }
+
+done:
+  close(mPipe[0]);
+  close(mPipe[1]);
+  mEndedSignal.notify();
+}
+
+KqueueBackend::~KqueueBackend() {
+  write(mPipe[1], "X", 1);
+  mEndedSignal.wait();
+}
+
+void KqueueBackend::subscribe(WatcherRef watcher) {
+  // Build a full directory tree recursively, and watch each directory.
+  std::shared_ptr<DirTree> tree = getTree(watcher);
+
+  for (auto it = tree->entries.begin(); it != tree->entries.end(); it++) {
+    bool success = watchDir(watcher, it->second.path, tree);
+    if (!success) {
+      throw WatcherError(std::string("error watching " + watcher->mDir + ": " + strerror(errno)), watcher);
+    }
+  }
+}
+
+bool KqueueBackend::watchDir(WatcherRef watcher, std::string path, std::shared_ptr<DirTree> tree) {
+  if (watcher->isIgnored(path)) {
+    return false;
+  }
+
+  DirEntry *entry = tree->find(path);
+  if (!entry) {
+    return false;
+  }
+
+  KqueueSubscription sub = {
+    .watcher = watcher,
+    .path = path,
+    .tree = tree
+  };
+
+  if (!entry->state) {
+    int fd = open(path.c_str(), O_EVTONLY);
+    if (fd <= 0) {
+      return false;
+    }
+
+    struct kevent event;
+    EV_SET(
+      &event,
+      fd,
+      EVFILT_VNODE,
+      EV_ADD | EV_CLEAR | EV_ENABLE,
+      NOTE_DELETE | NOTE_WRITE | NOTE_EXTEND | NOTE_ATTRIB | NOTE_RENAME | NOTE_REVOKE,
+      0,
+      0
+    );
+
+    if (kevent(mKqueue, &event, 1, NULL, 0, 0)) {
+      close(fd);
+      return false;
+    }
+
+    entry->state = (void *)(size_t)fd;
+    mFdToEntry.emplace(fd, entry);
+  }
+
+  sub.fd = (int)(size_t)entry->state;
+  mSubscriptions.emplace(path, sub);
+  return true;
+}
+
+std::vector<KqueueSubscription *> KqueueBackend::findSubscriptions(std::string &path) {
+  // Find the subscriptions affected by this path.
+  // Copy pointers to them into a vector so that modifying mSubscriptions doesn't invalidate the iterator.
+  auto range = mSubscriptions.equal_range(path);
+  std::vector<KqueueSubscription *> subs;
+  for (auto it = range.first; it != range.second; it++) {
+    subs.push_back(&it->second);
+  }
+
+  return subs;
+}
+
+bool KqueueBackend::compareDir(int fd, std::string &path, std::unordered_set<WatcherRef> &watchers) {
+  // macOS doesn't support fdclosedir, so we have to duplicate the file descriptor
+  // to ensure the closedir doesn't also stop watching.
+  #if __APPLE__
+    fd = dup(fd);
+  #endif
+
+  DIR *dir = fdopendir(fd);
+  if (dir == NULL) {
+    return false;
+  }
+
+  // fdopendir doesn't rewind to the beginning.
+  rewinddir(dir);
+
+  std::vector<KqueueSubscription *> subs = findSubscriptions(path);
+  std::string dirStart = path + DIR_SEP;
+
+  std::unordered_set<std::shared_ptr<DirTree>> trees;
+  for (auto it = subs.begin(); it != subs.end(); it++) {
+    trees.emplace((*it)->tree);
+  }
+
+  std::unordered_set<std::string> entries;
+  struct dirent *entry;
+  while ((entry = readdir(dir))) {
+    if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0) {
+      continue;
+    }
+
+    std::string fullpath = dirStart + entry->d_name;
+    entries.emplace(fullpath);
+
+    for (auto it = trees.begin(); it != trees.end(); it++) {
+      std::shared_ptr<DirTree> tree = *it;
+      if (!tree->find(fullpath)) {
+        struct stat st;
+        fstatat(fd, entry->d_name, &st, AT_SYMLINK_NOFOLLOW);
+        tree->add(fullpath, CONVERT_TIME(st.st_mtim), S_ISDIR(st.st_mode));
+
+        // Notify all watchers with the same tree.
+        for (auto i = subs.begin(); i != subs.end(); i++) {
+          KqueueSubscription *sub = *i;
+          if (sub->tree == tree) {
+            if (sub->watcher->isIgnored(fullpath)) {
+              continue;
+            }
+
+            sub->watcher->mEvents.create(fullpath);
+            watchers.emplace(sub->watcher);
+
+            bool success = watchDir(sub->watcher, fullpath, sub->tree);
+            if (!success) {
+              sub->tree->remove(fullpath);
+              return false;
+            }
+          }
+        }
+      }
+    }
+  }
+
+  for (auto it = trees.begin(); it != trees.end(); it++) {
+    std::shared_ptr<DirTree> tree = *it;
+    for (auto entry = tree->entries.begin(); entry != tree->entries.end();) {
+
+      if (
+        entry->first.rfind(dirStart, 0) == 0 &&
+        entry->first.find(DIR_SEP, dirStart.length()) == std::string::npos &&
+        entries.count(entry->first) == 0
+      ) {
+        // Notify all watchers with the same tree.
+        for (auto i = subs.begin(); i != subs.end(); i++) {
+          if ((*i)->tree == tree) {
+            KqueueSubscription *sub = *i;
+            if (!sub->watcher->isIgnored(entry->first)) {
+              sub->watcher->mEvents.remove(entry->first);
+              watchers.emplace(sub->watcher);
+            }
+          }
+        }
+
+        mFdToEntry.erase((int)(size_t)entry->second.state);
+        mSubscriptions.erase(entry->first);
+        entry = tree->entries.erase(entry);
+      } else {
+        entry++;
+      }
+    }
+  }
+
+  #if __APPLE__
+    closedir(dir);
+  #else
+    fdclosedir(dir);
+  #endif
+
+  return true;
+}
+
+void KqueueBackend::unsubscribe(WatcherRef watcher) {
+  // Find any subscriptions pointing to this watcher, and remove them.
+  for (auto it = mSubscriptions.begin(); it != mSubscriptions.end();) {
+    if (it->second.watcher.get() == watcher.get()) {
+      if (mSubscriptions.count(it->first) == 1) {
+        // Closing the file descriptor automatically unwatches it in the kqueue.
+        close(it->second.fd);
+        mFdToEntry.erase(it->second.fd);
+      }
+
+      it = mSubscriptions.erase(it);
+    } else {
+      it++;
+    }
+  }
+}

node_modules/@parcel/watcher/src/kqueue/KqueueBackend.hh

@@ -0,0 +1,35 @@
+#ifndef KQUEUE_H
+#define KQUEUE_H
+
+#include <unordered_map>
+#include <sys/event.h>
+#include "../shared/BruteForceBackend.hh"
+#include "../DirTree.hh"
+#include "../Signal.hh"
+
+struct KqueueSubscription {
+  WatcherRef watcher;
+  std::string path;
+  std::shared_ptr<DirTree> tree;
+  int fd;
+};
+
+class KqueueBackend : public BruteForceBackend {
+public:
+  void start() override;
+  ~KqueueBackend();
+  void subscribe(WatcherRef watcher) override;
+  void unsubscribe(WatcherRef watcher) override;
+private:
+  int mKqueue;
+  int mPipe[2];
+  std::unordered_multimap<std::string, KqueueSubscription> mSubscriptions;
+  std::unordered_map<int, DirEntry *> mFdToEntry;
+  Signal mEndedSignal;
+
+  bool watchDir(WatcherRef watcher, std::string path, std::shared_ptr<DirTree> tree);
+  bool compareDir(int fd, std::string &dir, std::unordered_set<WatcherRef> &watchers);
+  std::vector<KqueueSubscription *> findSubscriptions(std::string &path);
+};
+
+#endif