PathWatcher executes callback when path is changed

Atom.xcodeproj/project.pbxproj

@@ -78,6 +78,7 @@
 		0487D15D14FEE6D60045E5E3 /* libcef_dll_wrapper2.cc in Sources */ = {isa = PBXBuildFile; fileRef = 0487D12514FEE6D60045E5E3 /* libcef_dll_wrapper2.cc */; };
 		0487D15F14FEE7880045E5E3 /* Resources in Resources */ = {isa = PBXBuildFile; fileRef = 0487D15E14FEE7880045E5E3 /* Resources */; };
 		0487D16014FEE78E0045E5E3 /* Resources in Copy Chrome Resources */ = {isa = PBXBuildFile; fileRef = 0487D15E14FEE7880045E5E3 /* Resources */; };
+		048A2FC7154870DC0051715C /* PathWatcher.m in Sources */ = {isa = PBXBuildFile; fileRef = 048A2FC6154870DC0051715C /* PathWatcher.m */; };
 		04E1DDDD152A0941001A9D07 /* Sparkle.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 04E1DDDC152A0941001A9D07 /* Sparkle.framework */; };
 		04E1DDDF152A09C3001A9D07 /* Sparkle.framework in Copy Sparkle Framework */ = {isa = PBXBuildFile; fileRef = 04E1DDDC152A0941001A9D07 /* Sparkle.framework */; };
 /* End PBXBuildFile section */
@@ -299,6 +300,8 @@
 		0487D12414FEE6D60045E5E3 /* libcef_dll_wrapper.cc */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = libcef_dll_wrapper.cc; sourceTree = "<group>"; };
 		0487D12514FEE6D60045E5E3 /* libcef_dll_wrapper2.cc */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = libcef_dll_wrapper2.cc; sourceTree = "<group>"; };
 		0487D15E14FEE7880045E5E3 /* Resources */ = {isa = PBXFileReference; lastKnownFileType = folder; path = Resources; sourceTree = "<group>"; };
+		048A2FC5154870DC0051715C /* PathWatcher.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = PathWatcher.h; sourceTree = "<group>"; };
+		048A2FC6154870DC0051715C /* PathWatcher.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = PathWatcher.m; sourceTree = "<group>"; };
 		04E1DDDC152A0941001A9D07 /* Sparkle.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Sparkle.framework; path = frameworks/Sparkle.framework; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
@@ -405,6 +408,8 @@
 				0487C93E14FED6090045E5E3 /* AtomController.h */,
 				0487C93F14FED6090045E5E3 /* AtomController.mm */,
 				042180E614FF080D00DF25EA /* BrowserDelegate.h */,
+				048A2FC5154870DC0051715C /* PathWatcher.h */,
+				048A2FC6154870DC0051715C /* PathWatcher.m */,
 				0487C94014FED6090045E5E3 /* client_handler.h */,
 				0487C94114FED6090045E5E3 /* client_handler.mm */,
 				0487C94314FED6090045E5E3 /* native_handler.h */,
@@ -758,6 +763,7 @@
 				0487CD9614FEE1360045E5E3 /* client_handler.mm in Sources */,
 				0487CD9714FEE1380045E5E3 /* main.mm in Sources */,
 				0487CD9814FEE13B0045E5E3 /* native_handler.mm in Sources */,
+				048A2FC7154870DC0051715C /* PathWatcher.m in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

Atom/src/PathWatcher.h

@@ -0,0 +1,12 @@
+#import <Foundation/Foundation.h>
+
+typedef void (^WatchCallback)(NSArray *);
+
+@interface PathWatcher : NSObject {
+  int _kq;
+  NSMutableDictionary *_callbacksByFileDescriptor;
+}
+
++ (void)watchPath:(NSString *)path callback:(WatchCallback)callback;
+
+@end

Atom/src/PathWatcher.m

@@ -0,0 +1,103 @@
+#import "PathWatcher.h"
+
+#import <sys/event.h>
+#import <sys/time.h> 
+#import <fcntl.h>
+
+@interface PathWatcher ()
+- (void)watchPath:(NSString *)path callback:(WatchCallback)callback;
+@end
+
+@implementation PathWatcher
+
++ (void)watchPath:(NSString *)path callback:(WatchCallback)callback {
+  static PathWatcher *pathWatcher;
+  
+  if (!pathWatcher) pathWatcher = [[PathWatcher alloc] init];
+  [pathWatcher watchPath:path callback:callback];
+}
+
+- (void)dealloc {
+  close(_kq);
+  for (NSNumber *fdNumber in [_callbacksByFileDescriptor allKeys]) {
+    close([fdNumber intValue]);
+  }
+  [_callbacksByFileDescriptor release];
+}
+
+- (id)init {
+  self = [super init];
+  
+  _callbacksByFileDescriptor = [[NSMutableDictionary alloc] init];
+  _kq = kqueue();
+  
+  if (_kq == -1) {
+    [NSException raise:@"Could not create kqueue" format:nil];
+  }
+  
+  [self performSelectorInBackground:@selector(watch) withObject:NULL];
+  return self;
+}
+
+- (void)watchPath:(NSString *)path callback:(WatchCallback)callback {
+  struct timespec timeout = { 0, 0 };
+  struct kevent event;
+  int fd = open([path fileSystemRepresentation], O_EVTONLY, 0);
+  
+  if (fd >= 0) {
+    int filter = EVFILT_VNODE;
+    int flags = EV_ADD | EV_ENABLE | EV_CLEAR;
+    int filterFlags = NOTE_ATTRIB | NOTE_WRITE | NOTE_EXTEND | NOTE_RENAME | NOTE_DELETE;
+    
+    EV_SET(&event, fd, filter, flags, filterFlags, 0, (void *)path);    
+    
+    @synchronized(self) {
+      NSNumber *fdNumber = [NSNumber numberWithInt:fd];
+      NSMutableArray *callbacks = [_callbacksByFileDescriptor objectForKey:fdNumber];
+      if (!callbacks) {
+        callbacks = [NSMutableArray array];
+        [_callbacksByFileDescriptor setObject:callbacks forKey:fdNumber];
+      }
+      [callbacks addObject:callback];
+      
+      kevent(_kq, &event, 1, NULL, 0, &timeout);
+    }
+  }
+}
+
+- (void)watch {
+  @autoreleasepool {
+    struct kevent event;    
+    struct timespec timeout = { 5, 0 }; // 5 seconds timeout.
+    
+    while (true) {
+      int numberOfEvents = kevent(_kq, NULL, 0, &event, 1, &timeout);
+      
+      if (numberOfEvents < 0) {
+        [NSException raise:@"KQueue Error" format:@"error %d", numberOfEvents, nil];
+      }
+      if (numberOfEvents == 0) {
+        continue;
+      }
+
+      NSMutableArray *eventFlags = [NSMutableArray array];
+
+      if (event.fflags & NOTE_WRITE) {
+        [eventFlags addObject:@"modified"];
+      }
+      
+      @synchronized(self) {
+        NSNumber *fdNumber = [NSNumber numberWithInt:event.ident];
+        for (WatchCallback callback in [_callbacksByFileDescriptor objectForKey:fdNumber]) {
+          dispatch_async(dispatch_get_main_queue(), ^{
+            callback(eventFlags);
+          });
+        }
+      }
+    }
+    
+    [self release];
+  }
+}
+
+@end

Atom/src/native_handler.mm

@@ -3,6 +3,7 @@
 #import "Atom.h"
 #import "AtomController.h"
 #import "client_handler.h"
+#import "PathWatcher.h"
 
 NSString *stringFromCefV8Value(const CefRefPtr<CefV8Value>& value) {
   std::string cc_value = value->GetStringValue().ToString();
@@ -12,7 +13,7 @@ NSString *stringFromCefV8Value(const CefRefPtr<CefV8Value>& value) {
 NativeHandler::NativeHandler() : CefV8Handler() {  
   m_object = CefV8Value::CreateObject(NULL);
   
-  const char *functionNames[] = {"exists", "read", "write", "absolute", "list", "isFile", "isDirectory", "remove", "asyncList", "open", "openDialog", "quit", "writeToPasteboard", "readFromPasteboard", "showDevTools", "newWindow", "saveDialog", "exit"};
+  const char *functionNames[] = {"exists", "read", "write", "absolute", "list", "isFile", "isDirectory", "remove", "asyncList", "open", "openDialog", "quit", "writeToPasteboard", "readFromPasteboard", "showDevTools", "newWindow", "saveDialog", "exit", "watchPath"};
   NSUInteger arrayLength = sizeof(functionNames) / sizeof(const char *);
   for (NSUInteger i = 0; i < arrayLength; i++) {
     const char *functionName = functionNames[i];
@@ -271,6 +272,34 @@ bool NativeHandler::Execute(const CefString& name,
     exit(exitStatus);
     return true;
   }
+  else if (name == "watchPath") {
+    NSString *path = stringFromCefV8Value(arguments[0]);
+    CefRefPtr<CefV8Value> function = arguments[1];
+
+    CefRefPtr<CefV8Context> context = CefV8Context::GetCurrentContext();
+    
+    WatchCallback callback = ^(NSArray *eventList) {
+      context->Enter();
+      
+      CefV8ValueList args;
+      CefRefPtr<CefV8Value> retval;
+      CefRefPtr<CefV8Exception> e;
+      
+      CefRefPtr<CefV8Value> eventObject = CefV8Value::CreateObject(NULL);
+      for (NSString *event in eventList) {
+        eventObject->SetValue([event UTF8String], CefV8Value::CreateBool(true), V8_PROPERTY_ATTRIBUTE_NONE);
+      }
+      
+      args.push_back(eventObject);
+      function->ExecuteFunction(function, args, retval, e, true);
+      
+      context->Exit();
+    };
+
+    [PathWatcher watchPath:path callback:[[callback copy] autorelease]];
+    
+    return true;
+  }
   
   return false;
 };

spec/extensions/tree-view-spec.coffee

@@ -260,6 +260,7 @@ describe "TreeView", ->
       temporaryFilePath = fs.join(require.resolve('fixtures'), 'temporary')
 
     afterEach ->
+      console.log "REMOVE" if fs.exists(temporaryFilePath)
       fs.remove(temporaryFilePath) if fs.exists(temporaryFilePath)
 
     describe "when a file is added or removed in an expanded directory", ->
@@ -268,8 +269,12 @@ describe "TreeView", ->
 
         fs.write temporaryFilePath, 'hi'
 
-        expect(rootDirectoryView.entries.find('.entry').length).toBe entriesCountBefore + 1
-        expect(rootDirectoryView.entries.find('.file:contains(temporary)')).toExist()
+        waitsFor "file to be added", ->
+          rootDirectoryView.entries.find('.entry').length == entriesCountBefore + 1
+
+        runs ->
+          expect(rootDirectoryView.entries.find('.entry').length).toBe entriesCountBefore + 1
+          expect(rootDirectoryView.entries.find('.file:contains(temporary)')).toExist()
 
     describe "when a file is renamed in an expanded directory", ->
 

src/app/directory.coffee

@@ -34,4 +34,3 @@ class Directory
     $native.unwatchPath(@path)
 
 _.extend Directory.prototype, EventEmitter
-

src/extensions/tree-view.coffee

@@ -119,7 +119,8 @@ class DirectoryView extends View
     @isExpanded = false
 
   watchEntries: ->
-    @directory.on "contents-change.#{@directory.path}", => @buildEntries()
+    @directory.on "contents-change.#{@directory.path}", =>
+      @buildEntries()
 
   unwatchEntries: ->
     @directory.off ".#{@directory.path}"