Don't report file-system move events on Mac OS, and use no-defer to avoid past events.

runtime/bin/file_system_watcher_macos.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/globals.h"
 #if defined(TARGET_OS_MACOS)
 
 #include "bin/file_system_watcher.h"
 
 #include <errno.h>  // NOLINT
 #include <fcntl.h>  // NOLINT
 #include <unistd.h>  // NOLINT
 #include <CoreServices/CoreServices.h>  // NOLINT
 
 #include "bin/eventhandler.h"
 #include "bin/fdutils.h"
+#include "bin/file.h"
 #include "bin/socket.h"
 #include "bin/thread.h"
 
 
 #ifndef MAC_OS_X_VERSION_10_7
 enum {
   kFSEventStreamCreateFlagFileEvents = 0x00000010
 };
 enum {
   kFSEventStreamEventFlagItemCreated = 0x00000100,
@@ skipping 15 matching lines @@
 namespace bin {
 
 static Mutex* watcher_mutex = new Mutex();
 static Monitor* watcher_monitor = new Monitor();
 
 class FSEventsWatcher;
 static FSEventsWatcher* watcher = NULL;
 
 union FSEvent {
   struct {
+    uint32_t exists;
     uint32_t flags;
     char path[PATH_MAX];
   } data;
-  uint8_t bytes[PATH_MAX + 4];
+  uint8_t bytes[PATH_MAX + 8];
 };
 
 class FSEventsWatcher {
  public:
   class Node {
    public:
     Node(intptr_t base_path_length, int read_fd, int write_fd, bool recursive)
       : base_path_length_(base_path_length),
         read_fd_(read_fd),
         write_fd_(write_fd),
@@ skipping 106 matching lines @@
     context.retain = NULL;
     context.release = NULL;
     context.copyDescription = NULL;
     FSEventStreamRef ref = FSEventStreamCreate(
         NULL,
         Callback,
         &context,
         CFArrayCreate(NULL, reinterpret_cast<const void**>(&path_ref), 1, NULL),
         kFSEventStreamEventIdSinceNow,
         0.10,
-        kFSEventStreamCreateFlagFileEvents);
+        kFSEventStreamCreateFlagNoDefer | kFSEventStreamCreateFlagFileEvents);
 
     node->set_ref(ref);
 
     FSEventStreamScheduleWithRunLoop(
         ref,
         run_loop_,
         kCFRunLoopDefaultMode);
 
     return node;
   }
 
  private:
   static void Callback(ConstFSEventStreamRef ref,
                        void* client,
                        size_t num_events,
                        void* event_paths,
                        const FSEventStreamEventFlags event_flags[],
                        const FSEventStreamEventId event_ids[]) {
     Node* node = reinterpret_cast<Node*>(client);
     for (size_t i = 0; i < num_events; i++) {
       char *path = reinterpret_cast<char**>(event_paths)[i];
+      FSEvent event;
+      event.data.exists = File::Exists(path);
       path += node->base_path_length();
       // If path is longer the base, skip next character ('/').
       if (path[0] != '\0') path += 1;
       if (!node->recursive() && strstr(path, "/") != NULL) continue;
-      FSEvent event;
       event.data.flags = event_flags[i];
       memmove(event.data.path, path, strlen(path) + 1);
       write(node->write_fd(), event.bytes, sizeof(event));
     }
   }
 
   CFRunLoopRef run_loop_;
   int users_;
 };
 
@@ skipping 46 matching lines @@
     }
     size_t path_len = strlen(e.data.path);
     Dart_Handle event = Dart_NewList(4);
     int flags = e.data.flags;
     int mask = 0;
     if (flags & kFSEventStreamEventFlagItemRenamed) {
       if (path_len == 0) {
         // The moved path is the path being watched.
         mask |= kDeleteSelf;
       } else {
-        mask |= kMove;
+        mask |= e.data.exists ? kCreate : kDelete;
       }
     }
     if (flags & kFSEventStreamEventFlagItemModified) mask |= kModifyContent;
     if (flags & kFSEventStreamEventFlagItemXattrMod) mask |= kModefyAttribute;
     if (flags & kFSEventStreamEventFlagItemCreated) mask |= kCreate;
     if (flags & kFSEventStreamEventFlagItemIsDir) mask |= kIsDir;
     if (flags & kFSEventStreamEventFlagItemRemoved) {
       if (path_len == 0) {
         // The removed path is the path being watched.
         mask |= kDeleteSelf;
@@ skipping 10 matching lines @@
   }
   return events;
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_MACOS)