Rewrite file-system-watcher to better handle the different system APIs.

runtime/bin/file_system_watcher_android.cc

Index: runtime/bin/file_system_watcher_android.cc
diff --git a/runtime/bin/file_system_watcher_android.cc b/runtime/bin/file_system_watcher_android.cc
index 5971ed0ad8cd63cd537fc0d0262c34843d9c1c97..96fd325bd6f59ca8fb069bdcbf09fd9d33c52943 100644
--- a/runtime/bin/file_system_watcher_android.cc
+++ b/runtime/bin/file_system_watcher_android.cc
@@ -21,42 +21,54 @@ bool FileSystemWatcher::IsSupported() {
 }
 
 
-intptr_t FileSystemWatcher::WatchPath(const char* path,
-                                      int events,
-                                      bool recursive) {
-  int fd = TEMP_FAILURE_RETRY(inotify_init());
-  if (fd < 0 || !FDUtils::SetCloseOnExec(fd)) {
+intptr_t FileSystemWatcher::Init() {
+  int id = TEMP_FAILURE_RETRY(inotify_init());
+  if (id < 0 || !FDUtils::SetCloseOnExec(id)) {
     return -1;
   }
   // Some systems dosn't support setting this as non-blocking. Since watching
   // internals are kept away from the user, we know it's possible to continue,
   // even if setting non-blocking fails.
-  FDUtils::SetNonBlocking(fd);
+  FDUtils::SetNonBlocking(id);
+  return id;
+}
+
+
+void FileSystemWatcher::Close(intptr_t id) {
+  USE(id);
+}
+
+
+intptr_t FileSystemWatcher::WatchPath(intptr_t id,
+                                      const char* path,
+                                      int events,
+                                      bool recursive) {
   int list_events = IN_DELETE_SELF | IN_MOVE_SELF;
   if (events & kCreate) list_events |= IN_CREATE;
-  if (events & kModifyContent) list_events |= IN_MODIFY | IN_ATTRIB;
+  if (events & kModifyContent) list_events |= IN_CLOSE_WRITE | IN_ATTRIB;
   if (events & kDelete) list_events |= IN_DELETE;
   if (events & kMove) list_events |= IN_MOVE;
-  int path_fd = TEMP_FAILURE_RETRY(inotify_add_watch(fd, path, list_events));
-  if (path_fd < 0) {
-    close(fd);
+  int path_id = TEMP_FAILURE_RETRY(inotify_add_watch(id, path, list_events));
+  if (path_id < 0) {
     return -1;
   }
-  return fd;
+  return path_id;
 }
 
 
-void FileSystemWatcher::UnwatchPath(intptr_t id) {
-  // Nothing to do.
+void FileSystemWatcher::UnwatchPath(intptr_t id, intptr_t path_id) {
+  VOID_TEMP_FAILURE_RETRY(inotify_rm_watch(id, path_id));
 }
 
 
-intptr_t FileSystemWatcher::GetSocketId(intptr_t id) {
+intptr_t FileSystemWatcher::GetSocketId(intptr_t id, intptr_t path_id) {
+  USE(path_id);
   return id;
 }
 
 
-Dart_Handle FileSystemWatcher::ReadEvents(intptr_t id) {
+Dart_Handle FileSystemWatcher::ReadEvents(intptr_t id, intptr_t path_id) {
+  USE(path_id);
   const intptr_t kEventSize = sizeof(struct inotify_event);
   const intptr_t kBufferSize = kEventSize + NAME_MAX + 1;
   uint8_t buffer[kBufferSize];
@@ -64,33 +76,36 @@ Dart_Handle FileSystemWatcher::ReadEvents(intptr_t id) {
   if (bytes < 0) {
     return DartUtils::NewDartOSError();
   }
-  const intptr_t kMaxCount = kBufferSize / kEventSize + 1;
+  const intptr_t kMaxCount = bytes / kEventSize;
   Dart_Handle events = Dart_NewList(kMaxCount);
   intptr_t offset = 0;
   intptr_t i = 0;
   while (offset < bytes) {
     struct inotify_event* e =
         reinterpret_cast<struct inotify_event*>(buffer + offset);
-    Dart_Handle event = Dart_NewList(4);
-    int mask = 0;
-    if (e->mask & IN_CLOSE_WRITE) mask |= kModifyContent;
-    if (e->mask & IN_ATTRIB) mask |= kModefyAttribute;
-    if (e->mask & IN_CREATE) mask |= kCreate;
-    if (e->mask & IN_MOVE) mask |= kMove;
-    if (e->mask & IN_DELETE) mask |= kDelete;
-    if (e->mask & (IN_DELETE_SELF | IN_MOVE_SELF)) mask |= kDeleteSelf;
-    if (e->mask & IN_ISDIR) mask |= kIsDir;
-    Dart_ListSetAt(event, 0, Dart_NewInteger(mask));
-    Dart_ListSetAt(event, 1, Dart_NewInteger(e->cookie));
-    if (e->len > 0) {
-      Dart_ListSetAt(event, 2, Dart_NewStringFromUTF8(
-          reinterpret_cast<uint8_t*>(e->name), strlen(e->name)));
-    } else {
-      Dart_ListSetAt(event, 2, Dart_Null());
+    if ((e->mask & IN_IGNORED) == 0) {;
+      Dart_Handle event = Dart_NewList(5);
+      int mask = 0;
+      if (e->mask & IN_CLOSE_WRITE) mask |= kModifyContent;
+      if (e->mask & IN_ATTRIB) mask |= kModefyAttribute;
+      if (e->mask & IN_CREATE) mask |= kCreate;
+      if (e->mask & IN_MOVE) mask |= kMove;
+      if (e->mask & IN_DELETE) mask |= kDelete;
+      if (e->mask & (IN_DELETE_SELF | IN_MOVE_SELF)) mask |= kDeleteSelf;
+      if (e->mask & IN_ISDIR) mask |= kIsDir;
+      Dart_ListSetAt(event, 0, Dart_NewInteger(mask));
+      Dart_ListSetAt(event, 1, Dart_NewInteger(e->cookie));
+      if (e->len > 0) {
+        Dart_ListSetAt(event, 2, Dart_NewStringFromUTF8(
+            reinterpret_cast<uint8_t*>(e->name), strlen(e->name)));
+      } else {
+        Dart_ListSetAt(event, 2, Dart_Null());
+      }
+      Dart_ListSetAt(event, 3, Dart_NewBoolean(e->mask & IN_MOVED_TO));
+      Dart_ListSetAt(event, 4, Dart_NewInteger(e->wd));
+      Dart_ListSetAt(events, i, event);
+      i++;
     }
-    Dart_ListSetAt(event, 3, Dart_NewBoolean(e->mask & IN_MOVED_TO));
-    Dart_ListSetAt(events, i, event);
-    i++;
     offset += kEventSize + e->len;
   }
   ASSERT(offset == bytes);