Bug 763976 - Add onchange notifications to DeviceStorage - IPC - r=khuey

dom/devicestorage/DeviceStorage.h

@@ -7,18 +7,21 @@
 
 #include "nsIDOMDeviceStorage.h"
 #include "nsIFile.h"
+#include "nsIObserver.h"
 #include "nsDOMEventTargetHelper.h"
 
 class nsDOMDeviceStorage MOZ_FINAL
   : public nsIDOMDeviceStorage
   , public nsIFileUpdateListener
   , public nsDOMEventTargetHelper
+  , public nsIObserver
 {
 public:
   NS_DECL_ISUPPORTS
   NS_DECL_NSIDOMDEVICESTORAGE
 
   NS_DECL_NSIFILEUPDATELISTENER
+  NS_DECL_NSIOBSERVER
   NS_DECL_NSIDOMEVENTTARGET
   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(nsDOMDeviceStorage, nsDOMEventTargetHelper)
   NS_DECL_EVENT_HANDLER(change)

dom/devicestorage/nsDeviceStorage.cpp

@@ -1216,10 +1216,21 @@ public:
 
       case DEVICE_STORAGE_REQUEST_WATCH:
       {
-        if (!mDeviceStorage->mIsWatchingFile) {
-          mFile->mFile->Watch(mDeviceStorage);
-          mDeviceStorage->mIsWatchingFile = true;
-        }
+         if (XRE_GetProcessType() != GeckoProcessType_Default) {
+           nsString fullpath;
+           mFile->mFile->GetPath(fullpath);
+           nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+           obs->AddObserver(mDeviceStorage, "file-watcher-update", false);
+           ContentChild::GetSingleton()->SendAddFileWatch(fullpath);
+         } else {
+           if (!mDeviceStorage->mIsWatchingFile) {
+
+             //TODO
+
+             mFile->mFile->Watch(mDeviceStorage);
+             mDeviceStorage->mIsWatchingFile = true;
+           }
+         }
         return NS_OK;
       }
     }
@@ -1301,6 +1312,7 @@ DOMCI_DATA(DeviceStorage, nsDOMDeviceStorage)
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(nsDOMDeviceStorage)
   NS_INTERFACE_MAP_ENTRY(nsIDOMDeviceStorage)
   NS_INTERFACE_MAP_ENTRY(nsIFileUpdateListener)
+  NS_INTERFACE_MAP_ENTRY(nsIObserver)
   NS_DOM_INTERFACE_MAP_ENTRY_CLASSINFO(DeviceStorage)
 NS_INTERFACE_MAP_END_INHERITING(nsDOMEventTargetHelper)
 
@@ -1345,7 +1357,17 @@ nsDOMDeviceStorage::Shutdown()
   NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
 
   if (mIsWatchingFile) {
-    mFile->Unwatch(this);
+    if (XRE_GetProcessType() != GeckoProcessType_Default) {
+      nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+      obs->RemoveObserver(this, "file-watcher-update");
+
+      nsString fullpath;
+      mFile->GetPath(fullpath);
+      ContentChild::GetSingleton()->SendRemoveFileWatch(fullpath);
+    }
+    else {
+      mFile->Unwatch(this);
+    }
   }
 }
 
@@ -1633,6 +1655,42 @@ nsDOMDeviceStorage::EnumerateInternal(const JS::Value & aName,
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsDOMDeviceStorage::Observe(nsISupports *aSubject, const char *aTopic, const PRUnichar *aData)
+{
+  // data strings will have the format of
+  //  reason:path
+  nsDependentString data(aData);
+
+  nsAString::const_iterator start, end;
+  nsAString::const_iterator colon;
+
+  data.BeginReading(start);
+  data.EndReading(end);
+  colon = end;
+
+  nsString reason;
+  nsString filepath;
+  if (!FindInReadable(NS_LITERAL_STRING(":"), start, colon)) {
+    return NS_OK;
+  }
+   
+  filepath = Substring(colon, end);
+  data.BeginReading(start);
+  reason = Substring(start, --colon);
+
+  nsCOMPtr<nsIFile> f;
+  NS_NewLocalFile(filepath, false, getter_AddRefs(f));
+ 
+  nsCString creason;
+  creason.AssignWithConversion(reason);
+  CopyUTF16toUTF8(reason, creason);
+
+  Update(creason.get(), f);
+ 
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 nsDOMDeviceStorage::Update(const char* aReason, nsIFile* aFile)
 {
@@ -1709,7 +1767,16 @@ nsDOMDeviceStorage::RemoveEventListener(const nsAString & aType,
   nsDOMEventTargetHelper::RemoveEventListener(aType, aListener, false);
 
   if (mIsWatchingFile && !HasListenersFor(NS_LITERAL_STRING("change"))) {
-    mFile->Unwatch(this);
+    if (XRE_GetProcessType() != GeckoProcessType_Default) {
+      nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+      obs->RemoveObserver(this, "file-watcher-update");
+
+      nsString fullpath;
+      mFile->GetPath(fullpath);
+      ContentChild::GetSingleton()->SendRemoveFileWatch(fullpath);
+    } else {
+      mFile->Unwatch(this);
+    }
   }
   return NS_OK;
 }

dom/ipc/ContentChild.cpp

@@ -911,5 +911,20 @@ ContentChild::RecvLastPrivateDocShellDestroyed()
     return true;
 }
 
+bool
+ContentChild::RecvFilePathUpdate(const nsString& path, const nsCString& aReason)
+{
+    // data strings will have the format of
+    //  reason:path
+    nsString data;
+    CopyASCIItoUTF16(aReason, data);
+    data.Append(NS_LITERAL_STRING(":"));
+    data.Append(path);
+
+    nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+    obs->NotifyObservers(nullptr, "file-watcher-update", data.get());
+    return true;
+}
+
 } // namespace dom
-} // namespace mozilla
+} // namespace mozilla

dom/ipc/ContentChild.h

@@ -162,6 +162,8 @@ public:
 
     virtual bool RecvLastPrivateDocShellDestroyed();
 
+    virtual bool RecvFilePathUpdate(const nsString& path, const nsCString& reason);
+
 #ifdef ANDROID
     gfxIntSize GetScreenSize() { return mScreenSize; }
 #endif

dom/ipc/ContentParent.cpp

@@ -528,6 +528,8 @@ ContentParent::ContentParent(const nsAString& aAppManifestURL)
         //Sending all information to content process
         unused << SendAppInfo(version, buildID);
     }
+
+    mFileWatchers.Init();
 }
 
 ContentParent::~ContentParent()
@@ -764,6 +766,9 @@ ContentParent::Observe(nsISupports* aSubject,
                        const PRUnichar* aData)
 {
     if (!strcmp(aTopic, "xpcom-shutdown") && mSubprocess) {
+
+        mFileWatchers.Clear();
+
         Close();
         NS_ASSERTION(!mSubprocess, "Close should have nulled mSubprocess");
     }
@@ -1507,5 +1512,64 @@ ContentParent::RecvPrivateDocShellsExist(const bool& aExist)
   return true;
 }
 
+bool
+ContentParent::RecvAddFileWatch(const nsString& root)
+{
+  nsRefPtr<WatchedFile> f;
+  if (mFileWatchers.Get(root, getter_AddRefs(f))) {
+    f->mUsageCount++;
+    return true;
+  }
+  
+  f = new WatchedFile(this, root);
+  mFileWatchers.Put(root, f);
+
+  f->Watch();
+  return true;
+}
+
+bool
+ContentParent::RecvRemoveFileWatch(const nsString& root)
+{
+  nsRefPtr<WatchedFile> f;
+  bool result = mFileWatchers.Get(root, getter_AddRefs(f));
+  if (!result) {
+    return true;
+  }
+
+  if (!f)
+    return true;
+
+  f->mUsageCount--;
+
+  if (f->mUsageCount > 0) {
+    return true;
+  }
+
+  f->Unwatch();
+  mFileWatchers.Remove(root);
+  return true;
+}
+
+NS_IMPL_ISUPPORTS1(ContentParent::WatchedFile, nsIFileUpdateListener)
+
+nsresult
+ContentParent::WatchedFile::Update(const char* aReason, nsIFile* aFile)
+{
+  NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
+
+  nsString path;
+  aFile->GetPath(path);
+
+  unused << mParent->SendFilePathUpdate(path, nsDependentCString(aReason));
+
+#ifdef DEBUG
+  nsCString cpath;
+  aFile->GetNativePath(cpath);
+  printf("ContentParent::WatchedFile::Update: %s  -- %s\n", cpath.get(), aReason);
+#endif
+  return NS_OK;
+}
+
 } // namespace dom
-} // namespace mozilla
+} // namespace mozilla

dom/ipc/ContentParent.h

@@ -22,6 +22,7 @@
 #include "nsIMemoryReporter.h"
 #include "nsCOMArray.h"
 #include "nsDataHashtable.h"
+#include "nsInterfaceHashtable.h"
 #include "nsHashKeys.h"
 
 class nsFrameMessageManager;
@@ -256,6 +257,10 @@ private:
                                  const nsCString& aCategory);
 
     virtual bool RecvPrivateDocShellsExist(const bool& aExist);
+
+    virtual bool RecvAddFileWatch(const nsString& root);
+    virtual bool RecvRemoveFileWatch(const nsString& root);
+
     GeckoChildProcessHost* mSubprocess;
 
     PRInt32 mGeolocationWatchID;
@@ -274,6 +279,34 @@ private:
     const nsString mAppManifestURL;
     nsRefPtr<nsFrameMessageManager> mMessageManager;
 
+    class WatchedFile : public nsIFileUpdateListener {
+      public:
+        WatchedFile(ContentParent* aParent, const nsString& aPath)
+          : mParent(aParent)
+          , mUsageCount(1)
+        {
+          NS_NewLocalFile(aPath, false, getter_AddRefs(mFile));
+        }
+
+        NS_DECL_ISUPPORTS
+        NS_DECL_NSIFILEUPDATELISTENER
+
+        void Watch() {
+          mFile->Watch(this);
+        }
+
+        void Unwatch() {
+          mFile->Watch(this);
+        }
+
+        nsRefPtr<ContentParent> mParent;
+        PRInt32 mUsageCount;
+        nsCOMPtr<nsIFile> mFile;
+    };
+
+    // This is a cache of all of the registered file watchers.
+    nsInterfaceHashtable<nsStringHashKey, WatchedFile> mFileWatchers;
+
     friend class CrashReporterParent;
 };
 

dom/ipc/PContent.ipdl

@@ -199,6 +199,8 @@ child:
     // Notify child that last-pb-context-exited notification was observed
     LastPrivateDocShellDestroyed();
 
+    FilePathUpdate(nsString filepath, nsCString reasons);
+
 parent:
     PAudio(PRInt32 aNumChannels, PRInt32 aRate, PRInt32 aFormat);
 
@@ -281,6 +283,9 @@ parent:
     // Notify the parent of the presence or absence of private docshells
     PrivateDocShellsExist(bool aExist);
 
+    AddFileWatch(nsString filepath);
+    RemoveFileWatch(nsString filepath);
+
 both:
      AsyncMessage(nsString aMessage, ClonedMessageData aData);
 };