gecko-dev/dom/devicestorage/nsDeviceStorage.cpp

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsDeviceStorage.h"
#include "nsServiceManagerUtils.h"
#include "nsIFile.h"
#include "nsIDirectoryEnumerator.h"
#include "nsAppDirectoryServiceDefs.h"
#include "nsDirectoryServiceDefs.h"
#include "nsIDOMFile.h"
#include "nsDOMBlobBuilder.h"
#include "nsNetUtil.h"
#include "nsCycleCollectionParticipant.h"
#include "nsIPrincipal.h"
#include "mozilla/Preferences.h"
#include "nsJSUtils.h"
#include "DictionaryHelpers.h"
#include "mozilla/Attributes.h"
#include "nsContentUtils.h"
#include "nsXULAppAPI.h"
#include "TabChild.h"
#include "DeviceStorageRequestChild.h"

// Microsoft's API Name hackery sucks
#undef CreateEvent

#ifdef MOZ_WIDGET_GONK
#include "nsIVolumeService.h"
#endif

using namespace mozilla::dom;
using namespace mozilla::dom::devicestorage;

#include "nsDirectoryServiceDefs.h"

DeviceStorageFile::DeviceStorageFile(nsIFile* aFile, const nsAString& aPath)
  : mPath(aPath)
  , mEditable(false)
{
  NS_ASSERTION(aFile, "Must not create a DeviceStorageFile with a null nsIFile");
  // always take a clone
  nsCOMPtr<nsIFile> file;
  aFile->Clone(getter_AddRefs(mFile));

  AppendRelativePath();
  NormalizeFilePath();
}

DeviceStorageFile::DeviceStorageFile(nsIFile* aFile)
  : mEditable(false)
{
  NS_ASSERTION(aFile, "Must not create a DeviceStorageFile with a null nsIFile");
  // always take a clone
  nsCOMPtr<nsIFile> file;
  aFile->Clone(getter_AddRefs(mFile));
}

void
DeviceStorageFile::SetPath(const nsAString& aPath) {
  mPath.Assign(aPath);
  NormalizeFilePath();
}

void
DeviceStorageFile::SetEditable(bool aEditable) {
  mEditable = aEditable;
}

// we want to make sure that the names of file can't reach
// outside of the type of storage the user asked for.
bool
DeviceStorageFile::IsSafePath()
{
  nsAString::const_iterator start, end;
  mPath.BeginReading(start);
  mPath.EndReading(end);

  // if the path has a ~ or \ in it, return false.
  NS_NAMED_LITERAL_STRING(tilde, "~");
  NS_NAMED_LITERAL_STRING(bslash, "\\");
  if (FindInReadable(tilde, start, end) ||
      FindInReadable(bslash, start, end)) {
    return false;
   }
  // split on /.  if any token is "", ., or .., return false.
  NS_ConvertUTF16toUTF8 cname(mPath);
  char* buffer = cname.BeginWriting();
  const char* token;

  while ((token = nsCRT::strtok(buffer, "/", &buffer))) {
    if (PL_strcmp(token, "") == 0 ||
	PL_strcmp(token, ".") == 0 ||
	PL_strcmp(token, "..") == 0 ) {
      return false;
    }
  }
  return true;
}

void
DeviceStorageFile::NormalizeFilePath() {
#if defined(XP_WIN)
  PRUnichar* cur = mPath.BeginWriting();
  PRUnichar* end = mPath.EndWriting();
  for (; cur < end; ++cur) {
    if (PRUnichar('\\') == *cur)
      *cur = PRUnichar('/');
  }
#endif
}

void
DeviceStorageFile::AppendRelativePath() {
#if defined(XP_WIN)
  // replace forward slashes with backslashes,
  // since nsLocalFileWin chokes on them
  nsString temp;
  temp.Assign(mPath);

  PRUnichar* cur = temp.BeginWriting();
  PRUnichar* end = temp.EndWriting();

  for (; cur < end; ++cur) {
    if (PRUnichar('/') == *cur)
      *cur = PRUnichar('\\');
  }
  mFile->AppendRelativePath(temp);
#else
  mFile->AppendRelativePath(mPath);
#endif
}

nsresult
DeviceStorageFile::Write(nsIDOMBlob* aBlob)
{
  nsresult rv = mFile->Create(nsIFile::NORMAL_FILE_TYPE, 00600);
  if (NS_FAILED(rv)) {
    return rv;
  }
  nsCOMPtr<nsIInputStream> stream;
  aBlob->GetInternalStream(getter_AddRefs(stream));

  PRUint32 bufSize;
  stream->Available(&bufSize);

  nsCOMPtr<nsIOutputStream> outputStream;
  NS_NewLocalFileOutputStream(getter_AddRefs(outputStream), mFile);

  if (!outputStream) {
    return NS_ERROR_FAILURE;
  }

  nsCOMPtr<nsIOutputStream> bufferedOutputStream;
  NS_NewBufferedOutputStream(getter_AddRefs(bufferedOutputStream),
			     outputStream,
			     4096*4);

  if (!bufferedOutputStream) {
    return NS_ERROR_FAILURE;
  }

  PRUint32 wrote;
  bufferedOutputStream->WriteFrom(stream, bufSize, &wrote);
  bufferedOutputStream->Close();
  outputStream->Close();
  if (bufSize != wrote) {
    return NS_ERROR_FAILURE;
  }
  return NS_OK;
}

nsresult
DeviceStorageFile::Write(InfallibleTArray<PRUint8>& aBits) {

  nsresult rv = mFile->Create(nsIFile::NORMAL_FILE_TYPE, 00600);
  if (NS_FAILED(rv)) {
    return rv;
  }

  nsCOMPtr<nsIOutputStream> outputStream;
  NS_NewLocalFileOutputStream(getter_AddRefs(outputStream), mFile);

  if (!outputStream) {
    return NS_ERROR_FAILURE;
  }

  PRUint32 wrote;
  outputStream->Write((char*) aBits.Elements(), aBits.Length(), &wrote);
  outputStream->Close();

  if (aBits.Length() != wrote) {
    return NS_ERROR_FAILURE;
  }
  return NS_OK;
}

void
DeviceStorageFile::CollectFiles(nsTArray<nsRefPtr<DeviceStorageFile> > &aFiles,
				PRUint64 aSince)
{
  nsString rootPath;
  mFile->GetPath(rootPath);

  return collectFilesInternal(aFiles, aSince, rootPath);
}

void
DeviceStorageFile::collectFilesInternal(nsTArray<nsRefPtr<DeviceStorageFile> > &aFiles,
					PRUint64 aSince,
					nsAString& aRootPath)
{
  nsCOMPtr<nsISimpleEnumerator> e;
  mFile->GetDirectoryEntries(getter_AddRefs(e));

  if (!e) {
    return;
  }

  nsCOMPtr<nsIDirectoryEnumerator> files = do_QueryInterface(e);
  nsCOMPtr<nsIFile> f;

  while (NS_SUCCEEDED(files->GetNextFile(getter_AddRefs(f))) && f) {

    PRInt64 msecs;
    f->GetLastModifiedTime(&msecs);

    if (msecs < aSince) {
      continue;
     }

    bool isDir;
    f->IsDirectory(&isDir);

    bool isFile;
    f->IsFile(&isFile);

    nsString fullpath;
    f->GetPath(fullpath);

    if (!StringBeginsWith(fullpath, aRootPath)) {
      NS_ERROR("collectFiles returned a path that does not belong!");
      continue;
    }

    nsAString::size_type len = aRootPath.Length() + 1; // +1 for the trailing /
    nsDependentSubstring newPath = Substring(fullpath, len);

    if (isDir) {
      DeviceStorageFile dsf(f);
      dsf.SetPath(newPath);
      dsf.collectFilesInternal(aFiles, aSince, aRootPath);
    } else if (isFile) {
      nsRefPtr<DeviceStorageFile> dsf = new DeviceStorageFile(f);
      dsf->SetPath(newPath);
      aFiles.AppendElement(dsf);
    }
  }
}

NS_IMPL_THREADSAFE_ISUPPORTS0(DeviceStorageFile)


// TODO - eventually, we will want to factor this method
// out into different system specific subclasses (or
// something)
PRInt32
nsDOMDeviceStorage::SetRootFileForType(const nsAString& aType, const PRInt32 aIndex)
{
  PRInt32 typeResult = DEVICE_STORAGE_TYPE_DEFAULT;

  nsCOMPtr<nsIFile> f;
  nsCOMPtr<nsIProperties> dirService = do_GetService(NS_DIRECTORY_SERVICE_CONTRACTID);
  NS_ASSERTION(dirService, "Must have directory service");

#ifdef MOZ_WIDGET_GONK
  mFile = nsnull;

  nsCOMPtr<nsIVolumeService> vs = do_GetService(NS_VOLUMESERVICE_CONTRACTID);
  if (!vs) {
    return typeResult;
  }

  nsCOMPtr<nsIVolume> v;
  vs->GetVolumeByPath(NS_LITERAL_STRING("/sdcard"), getter_AddRefs(v));
  
  if (!v) {
    return typeResult;
  }

  PRInt32 state;
  v->GetState(&state);

  if (state != nsIVolume::STATE_MOUNTED) {
    return typeResult;
  }
#endif

  // Picture directory
  if (aType.Equals(NS_LITERAL_STRING("pictures"))) {
#ifdef MOZ_WIDGET_GONK
    if (aIndex == 0) {
      NS_NewLocalFile(NS_LITERAL_STRING("/sdcard/DCIM"), false, getter_AddRefs(f));
    }
#elif defined (MOZ_WIDGET_COCOA)
    if (aIndex == 0) {
      dirService->Get(NS_OSX_PICTURE_DOCUMENTS_DIR, NS_GET_IID(nsIFile), getter_AddRefs(f));
    }
#elif defined (XP_UNIX)
    if (aIndex == 0) {
      dirService->Get(NS_UNIX_XDG_PICTURES_DIR, NS_GET_IID(nsIFile), getter_AddRefs(f));
    }
#endif
  }

  // Video directory
  if (aType.Equals(NS_LITERAL_STRING("videos"))) {
#ifdef MOZ_WIDGET_GONK
    if (aIndex == 0) {
      NS_NewLocalFile(NS_LITERAL_STRING("/sdcard/Movies"), false, getter_AddRefs(f));
    }
#elif defined (MOZ_WIDGET_COCOA)
    if (aIndex == 0) {
      dirService->Get(NS_OSX_MOVIE_DOCUMENTS_DIR, NS_GET_IID(nsIFile), getter_AddRefs(f));
    }
#elif defined (XP_UNIX)
    if (aIndex == 0) {
      dirService->Get(NS_UNIX_XDG_VIDEOS_DIR, NS_GET_IID(nsIFile), getter_AddRefs(f));
    }
#endif
  }

  // Music directory
  if (aType.Equals(NS_LITERAL_STRING("music"))) {
#ifdef MOZ_WIDGET_GONK
    if (aIndex == 0) {
      NS_NewLocalFile(NS_LITERAL_STRING("/sdcard/Music"), false, getter_AddRefs(f));
    }
#elif defined (MOZ_WIDGET_COCOA)
    if (aIndex == 0) {
      dirService->Get(NS_OSX_MUSIC_DOCUMENTS_DIR, NS_GET_IID(nsIFile), getter_AddRefs(f));
    }
#elif defined (XP_UNIX)
    if (aIndex == 0) {
      dirService->Get(NS_UNIX_XDG_MUSIC_DIR, NS_GET_IID(nsIFile), getter_AddRefs(f));
    }
#endif
  }

  // in testing, we have access to a few more directory locations
  if (mozilla::Preferences::GetBool("device.storage.testing", false)) {

    // testing directory
    if (aType.Equals(NS_LITERAL_STRING("testing")) && aIndex == 0) {
      dirService->Get(NS_OS_TEMP_DIR, NS_GET_IID(nsIFile), getter_AddRefs(f));
      if (f) {
	f->AppendRelativeNativePath(NS_LITERAL_CSTRING("device-storage-testing"));
	f->Create(nsIFile::DIRECTORY_TYPE, 0777);
      }
    }
  } 

  mFile = f;
  return typeResult;
}

static jsval nsIFileToJsval(nsPIDOMWindow* aWindow, DeviceStorageFile* aFile)
{
  NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
  NS_ASSERTION(aWindow, "Null Window");

  if (aFile->mEditable) {
    // TODO - needs janv's file handle support.
    return JSVAL_NULL;
  }

  if (aFile == nsnull) {
    return JSVAL_NULL;
  }

  nsCOMPtr<nsIDOMBlob> blob = new nsDOMFileFile(aFile->mFile, aFile->mPath);
  return BlobToJsval(aWindow, blob);
}


jsval BlobToJsval(nsPIDOMWindow* aWindow, nsIDOMBlob* aBlob)
{
  nsCOMPtr<nsIScriptGlobalObject> sgo = do_QueryInterface(aWindow);
  if (!sgo) {
    return JSVAL_NULL;
  }

  nsIScriptContext *scriptContext = sgo->GetScriptContext();
  if (!scriptContext) {
    return JSVAL_NULL;
  }

  JSContext *cx = scriptContext->GetNativeContext();
  if (!cx) {
    return JSVAL_NULL;
  }

  jsval wrappedFile;
  nsresult rv = nsContentUtils::WrapNative(cx,
                                           JS_GetGlobalObject(cx),
                                           aBlob,
                                           &NS_GET_IID(nsIDOMFile),
                                           &wrappedFile);
  if (NS_FAILED(rv)) {
    return JSVAL_NULL;
  }

  return wrappedFile;
}

jsval StringToJsval(nsPIDOMWindow* aWindow, nsAString& aString)
{
  NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
  NS_ASSERTION(aWindow, "Null Window");

  nsCOMPtr<nsIScriptGlobalObject> sgo = do_QueryInterface(aWindow);
  if (!sgo) {
    return JSVAL_NULL;
  }

  nsIScriptContext *scriptContext = sgo->GetScriptContext();
  if (!scriptContext) {
    return JSVAL_NULL;
  }

  JSContext *cx = scriptContext->GetNativeContext();
  if (!cx) {
    return JSVAL_NULL;
  }

  JSAutoRequest ar(cx);

  jsval result = JSVAL_NULL;
  if (!xpc::StringToJsval(cx, aString, &result)) {
    return JSVAL_NULL;
  }

  return result;
}

class DeviceStorageCursorRequest MOZ_FINAL
  : public nsIContentPermissionRequest
  , public PCOMContentPermissionRequestChild
{
public:
  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(DeviceStorageCursorRequest, nsIContentPermissionRequest)

  NS_FORWARD_NSICONTENTPERMISSIONREQUEST(mCursor->);

  DeviceStorageCursorRequest(nsDOMDeviceStorageCursor* aCursor)
    : mCursor(aCursor) { }

  ~DeviceStorageCursorRequest() {}

  bool Recv__delete__(const bool& allow)
  {
    if (allow) {
      Allow();
    }
    else {
      Cancel();
    }
    return true;
  }

  void IPDLRelease()
  {
    Release();
  }

private:
  nsRefPtr<nsDOMDeviceStorageCursor> mCursor;
};

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DeviceStorageCursorRequest)
  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIContentPermissionRequest)
  NS_INTERFACE_MAP_ENTRY(nsIContentPermissionRequest)
NS_INTERFACE_MAP_END

NS_IMPL_CYCLE_COLLECTING_ADDREF(DeviceStorageCursorRequest)
NS_IMPL_CYCLE_COLLECTING_RELEASE(DeviceStorageCursorRequest)
NS_IMPL_CYCLE_COLLECTION_CLASS(DeviceStorageCursorRequest)

NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(DeviceStorageCursorRequest)
NS_IMPL_CYCLE_COLLECTION_UNLINK_NSCOMPTR(mCursor)
NS_IMPL_CYCLE_COLLECTION_UNLINK_END

NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(DeviceStorageCursorRequest)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMPTR_AMBIGUOUS(mCursor, nsIDOMDeviceStorageCursor)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END


class PostErrorEvent : public nsRunnable
{
public:
  PostErrorEvent(nsRefPtr<DOMRequest>& aRequest, const char* aMessage, DeviceStorageFile* aFile)
  {
    mRequest.swap(aRequest);
    BuildErrorString(aMessage, aFile);
  }

  PostErrorEvent(DOMRequest* aRequest, const char* aMessage, DeviceStorageFile* aFile)
    : mRequest(aRequest)
  {
    BuildErrorString(aMessage, aFile);
  }

  ~PostErrorEvent() {}

  void BuildErrorString(const char* aMessage, DeviceStorageFile* aFile)
  {
    nsAutoString fullPath;

    if (aFile && aFile->mFile) {
      aFile->mFile->GetPath(fullPath);
    }
    else {
      fullPath.Assign(NS_LITERAL_STRING("null file"));
    }

    mError = NS_ConvertASCIItoUTF16(aMessage);
    mError.Append(NS_LITERAL_STRING(" file path = "));
    mError.Append(fullPath.get());
    mError.Append(NS_LITERAL_STRING(" path = "));

    if (aFile) {
      mError.Append(aFile->mPath);
    }
    else {
      mError.Append(NS_LITERAL_STRING("null path"));
    }
  }

  NS_IMETHOD Run()
  {
    NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");

    mRequest->FireError(mError);
    mRequest = nsnull;
    return NS_OK;
  }

private:
  nsRefPtr<DOMRequest> mRequest;
  nsString mError;
};

ContinueCursorEvent::ContinueCursorEvent(nsRefPtr<DOMRequest>& aRequest)
{
  mRequest.swap(aRequest);
}

ContinueCursorEvent::ContinueCursorEvent(DOMRequest* aRequest)
  : mRequest(aRequest)
{
}

ContinueCursorEvent::~ContinueCursorEvent() {}

NS_IMETHODIMP
ContinueCursorEvent::Run() {
  NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");

  jsval val;

  nsDOMDeviceStorageCursor* cursor = static_cast<nsDOMDeviceStorageCursor*>(mRequest.get());
  if (cursor->mFiles.Length() == 0) {
    val = JSVAL_NULL;
  }
  else {
    nsRefPtr<DeviceStorageFile> file = cursor->mFiles[0];
    cursor->mFiles.RemoveElementAt(0);

    // todo, this blob needs to be opened in the parent.  This will be signifincally easier when bent lands
    val = nsIFileToJsval(cursor->GetOwner(), file);
    cursor->mOkToCallContinue = true;
  }

  mRequest->FireSuccess(val);
  mRequest = nsnull;
  return NS_OK;
}

class InitCursorEvent : public nsRunnable
{
public:
    InitCursorEvent(DOMRequest* aRequest, DeviceStorageFile* aFile)
    : mFile(aFile)
    , mRequest(aRequest)
  {
  }

  ~InitCursorEvent() {}

  NS_IMETHOD Run() {
    NS_ASSERTION(!NS_IsMainThread(), "Wrong thread!");

    bool check;
    mFile->mFile->IsDirectory(&check);
    if (!check) {
      nsCOMPtr<PostErrorEvent> event = new PostErrorEvent(mRequest,
                                                          POST_ERROR_EVENT_FILE_NOT_ENUMERABLE,
                                                          mFile);
      NS_DispatchToMainThread(event);
      return NS_OK;
    }

    nsDOMDeviceStorageCursor* cursor = static_cast<nsDOMDeviceStorageCursor*>(mRequest.get());
    mFile->CollectFiles(cursor->mFiles, cursor->mSince);

    nsCOMPtr<ContinueCursorEvent> event = new ContinueCursorEvent(mRequest);
    NS_DispatchToMainThread(event);

    return NS_OK;
  }


private:
  nsRefPtr<DeviceStorageFile> mFile;
  nsRefPtr<DOMRequest> mRequest;
};

DOMCI_DATA(DeviceStorageCursor, nsDOMDeviceStorageCursor)

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(nsDOMDeviceStorageCursor)
  NS_INTERFACE_MAP_ENTRY(nsIDOMDeviceStorageCursor)
  NS_INTERFACE_MAP_ENTRY(nsIContentPermissionRequest)
  NS_INTERFACE_MAP_ENTRY(nsIDOMDOMRequest)
  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIDOMDeviceStorageCursor)
  NS_DOM_INTERFACE_MAP_ENTRY_CLASSINFO(DeviceStorageCursor)
NS_INTERFACE_MAP_END_INHERITING(DOMRequest)

NS_IMPL_ADDREF_INHERITED(nsDOMDeviceStorageCursor, DOMRequest)
NS_IMPL_RELEASE_INHERITED(nsDOMDeviceStorageCursor, DOMRequest)

nsDOMDeviceStorageCursor::nsDOMDeviceStorageCursor(nsIDOMWindow* aWindow,
                                                   nsIURI* aURI,
                                                   DeviceStorageFile* aFile,
                                                   PRUint64 aSince)
  : DOMRequest(aWindow)
  , mOkToCallContinue(false)
  , mSince(aSince)
  , mFile(aFile)
  , mURI(aURI)
{
}

nsDOMDeviceStorageCursor::~nsDOMDeviceStorageCursor()
{
}

NS_IMETHODIMP
nsDOMDeviceStorageCursor::GetType(nsACString & aType)
{
  aType = "device-storage";
  return NS_OK;
}

NS_IMETHODIMP
nsDOMDeviceStorageCursor::GetUri(nsIURI * *aRequestingURI)
{
  NS_IF_ADDREF(*aRequestingURI = mURI);
  return NS_OK;
}

NS_IMETHODIMP
nsDOMDeviceStorageCursor::GetWindow(nsIDOMWindow * *aRequestingWindow)
{
  NS_IF_ADDREF(*aRequestingWindow = GetOwner());
  return NS_OK;
}

NS_IMETHODIMP
nsDOMDeviceStorageCursor::GetElement(nsIDOMElement * *aRequestingElement)
{
  *aRequestingElement = nsnull;
  return NS_OK;
}

NS_IMETHODIMP
nsDOMDeviceStorageCursor::Cancel()
{
  nsCOMPtr<PostErrorEvent> event = new PostErrorEvent(this,
                                                      POST_ERROR_EVENT_PERMISSION_DENIED,
                                                      mFile);
  NS_DispatchToMainThread(event);
  return NS_OK;
}

NS_IMETHODIMP
nsDOMDeviceStorageCursor::Allow()
{
  if (!mFile->IsSafePath()) {
    nsCOMPtr<nsIRunnable> r = new PostErrorEvent(this,
                                                 POST_ERROR_EVENT_ILLEGAL_FILE_NAME,
                                                 mFile);
    NS_DispatchToMainThread(r);
    return NS_OK;
  }

  if (XRE_GetProcessType() != GeckoProcessType_Default) {

    nsString fullpath;
    mFile->mFile->GetPath(fullpath);

    PDeviceStorageRequestChild* child = new DeviceStorageRequestChild(this, mFile);
    DeviceStorageEnumerationParams params(fullpath, mSince);
    ContentChild::GetSingleton()->SendPDeviceStorageRequestConstructor(child, params);
    return NS_OK;
  }

  nsCOMPtr<nsIEventTarget> target = do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID);
  NS_ASSERTION(target, "Must have stream transport service");

  nsCOMPtr<InitCursorEvent> event = new InitCursorEvent(this, mFile);
  target->Dispatch(event, NS_DISPATCH_NORMAL);
  return NS_OK;
}

NS_IMETHODIMP
nsDOMDeviceStorageCursor::Continue()
{
  if (!mOkToCallContinue) {
    return NS_ERROR_UNEXPECTED;
  }

  if (mRooted) {
    // We call onsuccess multiple times. clear the last
    // rooted result.
    NS_DROP_JS_OBJECTS(this, nsDOMDeviceStorageCursor);
    mResult = JSVAL_VOID;
    mDone = false;
    mRooted = false;
  }

  nsCOMPtr<ContinueCursorEvent> event = new ContinueCursorEvent(this);
  NS_DispatchToMainThread(event);

  mOkToCallContinue = false;
  return NS_OK;
}

bool
nsDOMDeviceStorageCursor::Recv__delete__(const bool& allow)
{
  if (allow) {
    Allow();
  }
  else {
    Cancel();
  }
  return true;
}

void
nsDOMDeviceStorageCursor::IPDLRelease()
{
  Release();
}

class PostResultEvent : public nsRunnable
{
public:
  PostResultEvent(nsRefPtr<DOMRequest>& aRequest, DeviceStorageFile* aFile)
    : mFile(aFile)
    {
      mRequest.swap(aRequest);
    }

  PostResultEvent(nsRefPtr<DOMRequest>& aRequest, const nsAString & aPath)
    : mPath(aPath)
    {
      mRequest.swap(aRequest);
    }

  ~PostResultEvent() {}

  NS_IMETHOD Run()
  {
    NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");

    jsval result = JSVAL_NULL;
    if (mFile) {
      result = nsIFileToJsval(mRequest->GetOwner(), mFile);
    } else {
      result = StringToJsval(mRequest->GetOwner(), mPath);
    }

    mRequest->FireSuccess(result);
    mRequest = nsnull;
    return NS_OK;
  }

private:
  nsRefPtr<DeviceStorageFile> mFile;
  nsString mPath;
  nsRefPtr<DOMRequest> mRequest;
};

class WriteFileEvent : public nsRunnable
{
public:
  WriteFileEvent(nsIDOMBlob* aBlob,
                 DeviceStorageFile *aFile,
                 nsRefPtr<DOMRequest>& aRequest)
  : mBlob(aBlob)
  , mFile(aFile)
    {
      mRequest.swap(aRequest);
    }

  ~WriteFileEvent() {}

  NS_IMETHOD Run()
  {
    NS_ASSERTION(!NS_IsMainThread(), "Wrong thread!");

    nsresult rv = mFile->Write(mBlob);

    if (NS_FAILED(rv)) {
      mFile->mFile->Remove(false);

      nsCOMPtr<PostErrorEvent> event = new PostErrorEvent(mRequest,
							  POST_ERROR_EVENT_UNKNOWN,
							  mFile);
      NS_DispatchToMainThread(event);
      return NS_OK;
    }

    nsCOMPtr<PostResultEvent> event = new PostResultEvent(mRequest,
							  mFile->mPath);
    NS_DispatchToMainThread(event);

    return NS_OK;
  }

private:
  nsCOMPtr<nsIDOMBlob> mBlob;
  nsRefPtr<DeviceStorageFile> mFile;
  nsRefPtr<DOMRequest> mRequest;
};
class ReadFileEvent : public nsRunnable
{
public:
    ReadFileEvent(DeviceStorageFile* aFile,
                  nsRefPtr<DOMRequest>& aRequest)
  : mFile(aFile)
    {
      mRequest.swap(aRequest);
    }

  ~ReadFileEvent() {}

  NS_IMETHOD Run()
  {
    NS_ASSERTION(!NS_IsMainThread(), "Wrong thread!");

    nsRefPtr<nsRunnable> r;

    if (!mFile->mEditable) {
      bool check = false;
      mFile->mFile->Exists(&check);
      if (!check) {
        r = new PostErrorEvent(mRequest, POST_ERROR_EVENT_FILE_DOES_NOT_EXIST, mFile);
      }
    }

    if (!r) {
      r = new PostResultEvent(mRequest, mFile);
    }
    NS_DispatchToMainThread(r);
    return NS_OK;
  }

private:
  nsRefPtr<DeviceStorageFile> mFile;
  nsRefPtr<DOMRequest> mRequest;
};

class DeleteFileEvent : public nsRunnable
{
public:
  DeleteFileEvent(DeviceStorageFile* aFile,
                  nsRefPtr<DOMRequest>& aRequest)
  : mFile(aFile)
    {
      mRequest.swap(aRequest);
    }

  ~DeleteFileEvent() {}

  NS_IMETHOD Run()
  {
    NS_ASSERTION(!NS_IsMainThread(), "Wrong thread!");

    mFile->mFile->Remove(true);

    nsRefPtr<nsRunnable> r;

    bool check = false;
    mFile->mFile->Exists(&check);
    if (check) {
      r = new PostErrorEvent(mRequest, POST_ERROR_EVENT_UNKNOWN, mFile);
    }
    else {
      r = new PostResultEvent(mRequest, mFile->mPath);
    }
    NS_DispatchToMainThread(r);
    return NS_OK;
  }

private:
  nsRefPtr<DeviceStorageFile> mFile;
  nsRefPtr<DOMRequest> mRequest;
};

class DeviceStorageRequest MOZ_FINAL
  : public nsIContentPermissionRequest
  , public nsIRunnable
  , public PCOMContentPermissionRequestChild
{
public:

    enum {
        DEVICE_STORAGE_REQUEST_READ,
        DEVICE_STORAGE_REQUEST_WRITE,
        DEVICE_STORAGE_REQUEST_DELETE
    };
    DeviceStorageRequest(const PRInt32 aRequestType,
                         nsPIDOMWindow *aWindow,
                         nsIURI *aURI,
                         DeviceStorageFile *aFile,
                         DOMRequest* aRequest,
                         nsIDOMBlob *aBlob = nsnull)
        : mRequestType(aRequestType)
        , mWindow(aWindow)
        , mURI(aURI)
        , mFile(aFile)
        , mRequest(aRequest)
        , mBlob(aBlob) {}

  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(DeviceStorageRequest, nsIContentPermissionRequest)

  NS_IMETHOD Run() {

    if (mozilla::Preferences::GetBool("device.storage.prompt.testing", false)) {
      Allow();
      return NS_OK;
    }

    if (XRE_GetProcessType() == GeckoProcessType_Content) {

      // because owner implements nsITabChild, we can assume that it is
      // the one and only TabChild.
      TabChild* child = GetTabChildFrom(mWindow->GetDocShell());
      if (!child)
	return false;

      // Retain a reference so the object isn't deleted without IPDL's knowledge.
      // Corresponding release occurs in DeallocPContentPermissionRequest.
      AddRef();

      nsCString type = NS_LITERAL_CSTRING("device-storage");
      child->SendPContentPermissionRequestConstructor(this, type, IPC::URI(mURI));

      Sendprompt();
      return NS_OK;
    }

    nsCOMPtr<nsIContentPermissionPrompt> prompt = do_GetService(NS_CONTENT_PERMISSION_PROMPT_CONTRACTID);
    if (prompt) {
      prompt->Prompt(this);
    }
    return NS_OK;
  }

  NS_IMETHOD GetType(nsACString & aType)
  {
    aType = "device-storage";
    return NS_OK;
  }

  NS_IMETHOD GetUri(nsIURI * *aRequestingURI)
  {
    NS_IF_ADDREF(*aRequestingURI = mURI);
    return NS_OK;
  }

  NS_IMETHOD GetWindow(nsIDOMWindow * *aRequestingWindow)
  {
    NS_IF_ADDREF(*aRequestingWindow = mWindow);
    return NS_OK;
  }

  NS_IMETHOD GetElement(nsIDOMElement * *aRequestingElement)
  {
    *aRequestingElement = nsnull;
    return NS_OK;
  }

  NS_IMETHOD Cancel()
  {
    nsCOMPtr<PostErrorEvent> event = new PostErrorEvent(mRequest,
                                                        POST_ERROR_EVENT_PERMISSION_DENIED,
                                                        mFile);
    NS_DispatchToMainThread(event);
    return NS_OK;
  }

  NS_IMETHOD Allow()
  {
    nsCOMPtr<nsIRunnable> r;

    if (!mRequest) {
      return NS_ERROR_FAILURE;
    }

    nsString fullpath;
    mFile->mFile->GetPath(fullpath);

    switch(mRequestType) {
      case DEVICE_STORAGE_REQUEST_WRITE:
      {
        if (!mBlob) {
          return NS_ERROR_FAILURE;
        }

	if (XRE_GetProcessType() != GeckoProcessType_Default) {
	  PDeviceStorageRequestChild* child = new DeviceStorageRequestChild(mRequest, mFile);

	  nsCOMPtr<nsIInputStream> stream;
	  mBlob->GetInternalStream(getter_AddRefs(stream));

	  InfallibleTArray<PRUint8> bits;
	  PRUint32 bufSize, numRead;

	  stream->Available(&bufSize);
	  bits.SetCapacity(bufSize);

	  void* buffer = (void*) bits.Elements();

	  stream->Read((char*)buffer, bufSize, &numRead);

	  DeviceStorageAddParams params(fullpath, bits);
	  ContentChild::GetSingleton()->SendPDeviceStorageRequestConstructor(child, params);
	  return NS_OK;
	}
	r = new WriteFileEvent(mBlob, mFile, mRequest);
        break;
      }
      case DEVICE_STORAGE_REQUEST_READ:
      {
	if (XRE_GetProcessType() != GeckoProcessType_Default) {
	  PDeviceStorageRequestChild* child = new DeviceStorageRequestChild(mRequest, mFile);
	  DeviceStorageGetParams params(fullpath);
	  ContentChild::GetSingleton()->SendPDeviceStorageRequestConstructor(child, params);
	  return NS_OK;
	}

        r = new ReadFileEvent(mFile, mRequest);
        break;
      }
      case DEVICE_STORAGE_REQUEST_DELETE:
      {
	if (XRE_GetProcessType() != GeckoProcessType_Default) {
	  PDeviceStorageRequestChild* child = new DeviceStorageRequestChild(mRequest, mFile);
	  DeviceStorageDeleteParams params(fullpath);
	  ContentChild::GetSingleton()->SendPDeviceStorageRequestConstructor(child, params);
	  return NS_OK;
	}
        r = new DeleteFileEvent(mFile, mRequest);
        break;
      }
    }

    if (r) {
      nsCOMPtr<nsIEventTarget> target = do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID);
      NS_ASSERTION(target, "Must have stream transport service");
      target->Dispatch(r, NS_DISPATCH_NORMAL);
    }
    return NS_OK;
  }

  bool Recv__delete__(const bool& allow)
  {
    if (allow) {
      Allow();
    }
    else {
      Cancel();
    }
    return true;
  }

  void IPDLRelease()
  {
    Release();
  }

private:
  PRInt32 mRequestType;
  nsCOMPtr<nsPIDOMWindow> mWindow;
  nsCOMPtr<nsIURI> mURI;
  nsRefPtr<DeviceStorageFile> mFile;

  nsRefPtr<DOMRequest> mRequest;
  nsCOMPtr<nsIDOMBlob> mBlob;
};

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DeviceStorageRequest)
  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIContentPermissionRequest)
  NS_INTERFACE_MAP_ENTRY(nsIContentPermissionRequest)
  NS_INTERFACE_MAP_ENTRY(nsIRunnable)
NS_INTERFACE_MAP_END

NS_IMPL_CYCLE_COLLECTING_ADDREF(DeviceStorageRequest)
NS_IMPL_CYCLE_COLLECTING_RELEASE(DeviceStorageRequest)
NS_IMPL_CYCLE_COLLECTION_CLASS(DeviceStorageRequest)

NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(DeviceStorageRequest)
NS_IMPL_CYCLE_COLLECTION_UNLINK_NSCOMPTR(mRequest)
NS_IMPL_CYCLE_COLLECTION_UNLINK_NSCOMPTR(mWindow)
NS_IMPL_CYCLE_COLLECTION_UNLINK_NSCOMPTR(mBlob)
NS_IMPL_CYCLE_COLLECTION_UNLINK_END

NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(DeviceStorageRequest)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMPTR_AMBIGUOUS(mRequest, nsIDOMDOMRequest)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMPTR_AMBIGUOUS(mWindow, nsPIDOMWindow)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMPTR_AMBIGUOUS(mBlob, nsIDOMBlob)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END

DOMCI_DATA(DeviceStorage, nsDOMDeviceStorage)

NS_INTERFACE_MAP_BEGIN(nsDOMDeviceStorage)
  NS_INTERFACE_MAP_ENTRY(nsIDOMDeviceStorage)
  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIDOMDeviceStorage)
  NS_DOM_INTERFACE_MAP_ENTRY_CLASSINFO(DeviceStorage)
NS_INTERFACE_MAP_END

NS_IMPL_THREADSAFE_ADDREF(nsDOMDeviceStorage)
NS_IMPL_THREADSAFE_RELEASE(nsDOMDeviceStorage)

nsDOMDeviceStorage::nsDOMDeviceStorage()
 : mStorageType(DEVICE_STORAGE_TYPE_DEFAULT)
{
}

nsresult
nsDOMDeviceStorage::Init(nsPIDOMWindow* aWindow, const nsAString &aType, const PRInt32 aIndex)
{
  NS_ASSERTION(aWindow, "Must have a content dom");

  mStorageType = SetRootFileForType(aType, aIndex);
  if (!mFile) {
    return NS_ERROR_NOT_AVAILABLE;
  }

  mOwner = do_GetWeakReference(aWindow);
  if (!mOwner) {
    return NS_ERROR_FAILURE;
  }

  // Grab the uri of the document
  nsCOMPtr<nsIDOMDocument> domdoc;
  aWindow->GetDocument(getter_AddRefs(domdoc));
  nsCOMPtr<nsIDocument> doc = do_QueryInterface(domdoc);
  if (!doc) {
    return NS_ERROR_FAILURE;
  }
  doc->NodePrincipal()->GetURI(getter_AddRefs(mURI));
  return NS_OK;
}

nsDOMDeviceStorage::~nsDOMDeviceStorage()
{
}

void
nsDOMDeviceStorage::CreateDeviceStoragesFor(nsPIDOMWindow* aWin,
                                            const nsAString &aType,
                                            nsIVariant** _retval)
{
  nsTArray<nsRefPtr<nsIDOMDeviceStorage> > stores;

  PRInt32 index = 0;
  while (1) {
    nsresult rv;
    nsRefPtr<nsDOMDeviceStorage> storage = new nsDOMDeviceStorage();
    rv = storage->Init(aWin, aType, index++);
    if (NS_FAILED(rv))
      break;
    stores.AppendElement(storage);
  }

  nsCOMPtr<nsIWritableVariant> result = do_CreateInstance("@mozilla.org/variant;1");
  if (!result) {
    return;
  }

  result->SetAsArray(nsIDataType::VTYPE_INTERFACE,
                     &NS_GET_IID(nsIDOMDeviceStorage),
                     stores.Length(),
                     const_cast<void*>(static_cast<const void*>(stores.Elements())));
  NS_ADDREF(*_retval = result);
}

NS_IMETHODIMP
nsDOMDeviceStorage::GetType(nsAString & aType)
{
  switch(mStorageType) {
    case DEVICE_STORAGE_TYPE_EXTERNAL:
      aType.AssignLiteral("external");
      break;
    case DEVICE_STORAGE_TYPE_SHARED:
      aType.AssignLiteral("shared");
      break;
    case DEVICE_STORAGE_TYPE_DEFAULT:
    default:
      aType.AssignLiteral("default");
      break;
  }
  return NS_OK;
}

NS_IMETHODIMP
nsDOMDeviceStorage::Add(nsIDOMBlob *aBlob, nsIDOMDOMRequest * *_retval)
{
  // possible race here w/ unique filename
  char buffer[128];
  NS_MakeRandomString(buffer, 128);

  nsString path;
  path.AssignWithConversion(nsDependentCString(buffer));

  return AddNamed(aBlob, path, _retval);
}

NS_IMETHODIMP
nsDOMDeviceStorage::AddNamed(nsIDOMBlob *aBlob,
                             const nsAString & aPath,
                             nsIDOMDOMRequest * *_retval)
{
  // if the blob is null here, bail
  if (aBlob == nsnull)
    return NS_OK;

  nsCOMPtr<nsPIDOMWindow> win = do_QueryReferent(mOwner);
  if (!win) {
    return NS_ERROR_UNEXPECTED;
  }

  nsRefPtr<DOMRequest> request = new DOMRequest(win);
  NS_ADDREF(*_retval = request);

  nsCOMPtr<nsIRunnable> r;

  nsRefPtr<DeviceStorageFile> dsf = new DeviceStorageFile(mFile, aPath);

  if (!dsf->IsSafePath()) {
    r = new PostErrorEvent(request, POST_ERROR_EVENT_ILLEGAL_FILE_NAME, dsf);
  }
  else {
    r = new DeviceStorageRequest(DeviceStorageRequest::DEVICE_STORAGE_REQUEST_WRITE,
                                 win, mURI, dsf, request, aBlob);
  }
  NS_DispatchToMainThread(r);
  return NS_OK;
}

NS_IMETHODIMP
nsDOMDeviceStorage::Get(const JS::Value & aPath,
                        JSContext* aCx,
                        nsIDOMDOMRequest * *_retval)
{
  return GetInternal(aPath, aCx, _retval, false);
}

NS_IMETHODIMP
nsDOMDeviceStorage::GetEditable(const JS::Value & aPath,
                                JSContext* aCx,
                                nsIDOMDOMRequest * *_retval)
{
  return GetInternal(aPath, aCx, _retval, true);
}

nsresult
nsDOMDeviceStorage::GetInternal(const JS::Value & aPath,
                                JSContext* aCx,
                                nsIDOMDOMRequest * *_retval,
                                bool aEditable)
{
  nsCOMPtr<nsPIDOMWindow> win = do_QueryReferent(mOwner);
  if (!win) {
    return NS_ERROR_UNEXPECTED;
  }

  nsRefPtr<DOMRequest> request = new DOMRequest(win);
  NS_ADDREF(*_retval = request);

  nsCOMPtr<nsIRunnable> r;

  JSString* jsstr = JS_ValueToString(aCx, aPath);
  nsDependentJSString path;
  if (!path.init(aCx, jsstr)) {
    nsRefPtr<DeviceStorageFile> dsf = new DeviceStorageFile(mFile);
    r = new PostErrorEvent(request,
                           POST_ERROR_EVENT_NON_STRING_TYPE_UNSUPPORTED,
                           dsf);
    NS_DispatchToMainThread(r);
    return NS_OK;
  }

  nsRefPtr<DeviceStorageFile> dsf = new DeviceStorageFile(mFile, path);
  dsf->SetEditable(aEditable);

  if (!dsf->IsSafePath()) {
    r = new PostErrorEvent(request, POST_ERROR_EVENT_ILLEGAL_FILE_NAME, dsf);
  } else {
    r = new DeviceStorageRequest(DeviceStorageRequest::DEVICE_STORAGE_REQUEST_READ,
                                 win, mURI, dsf, request);
  }
  NS_DispatchToMainThread(r);
  return NS_OK;
}

NS_IMETHODIMP
nsDOMDeviceStorage::Delete(const JS::Value & aPath, JSContext* aCx, nsIDOMDOMRequest * *_retval)
{
  nsCOMPtr<nsIRunnable> r;

  nsCOMPtr<nsPIDOMWindow> win = do_QueryReferent(mOwner);
  if (!win) {
    return NS_ERROR_UNEXPECTED;
  }

  nsRefPtr<DOMRequest> request = new DOMRequest(win);
  NS_ADDREF(*_retval = request);

  JSString* jsstr = JS_ValueToString(aCx, aPath);
  nsDependentJSString path;
  if (!path.init(aCx, jsstr)) {
    nsRefPtr<DeviceStorageFile> dsf = new DeviceStorageFile(mFile);
    r = new PostErrorEvent(request, POST_ERROR_EVENT_NON_STRING_TYPE_UNSUPPORTED, dsf);
    NS_DispatchToMainThread(r);
    return NS_OK;
  }

  nsRefPtr<DeviceStorageFile> dsf = new DeviceStorageFile(mFile, path);

  if (!dsf->IsSafePath()) {
    r = new PostErrorEvent(request, POST_ERROR_EVENT_ILLEGAL_FILE_NAME, dsf);
  }
  else {
    r = new DeviceStorageRequest(DeviceStorageRequest::DEVICE_STORAGE_REQUEST_DELETE,
                                 win, mURI, dsf, request);
  }
  NS_DispatchToMainThread(r);
  return NS_OK;
}

NS_IMETHODIMP
nsDOMDeviceStorage::Enumerate(const JS::Value & aName,
                             const JS::Value & aOptions,
                             JSContext* aCx,
                             PRUint8 aArgc,
                             nsIDOMDeviceStorageCursor** aRetval)
{
  return EnumerateInternal(aName, aOptions, aCx, aArgc, false, aRetval);
}

NS_IMETHODIMP
nsDOMDeviceStorage::EnumerateEditable(const JS::Value & aName,
                                     const JS::Value & aOptions,
                                     JSContext* aCx,
                                     PRUint8 aArgc,
                                     nsIDOMDeviceStorageCursor** aRetval)
{
  return EnumerateInternal(aName, aOptions, aCx, aArgc, true, aRetval);
}


static PRTime
ExtractDateFromOptions(JSContext* aCx, const JS::Value& aOptions)
{
  PRTime result = 0;
  DeviceStorageEnumerationParameters params;
  if (!JSVAL_IS_VOID(aOptions) && !aOptions.isNull()) {
    nsresult rv = params.Init(aCx, &aOptions);
    if (NS_SUCCEEDED(rv) && !JSVAL_IS_VOID(params.since) && !params.since.isNull() && params.since.isObject()) {
      JSObject* obj = JSVAL_TO_OBJECT(params.since);
      if (JS_ObjectIsDate(aCx, obj) && js_DateIsValid(aCx, obj)) {
        result = js_DateGetMsecSinceEpoch(aCx, obj);
      }
    }
  }
  return result;
}

nsresult
nsDOMDeviceStorage::EnumerateInternal(const JS::Value & aName,
                                     const JS::Value & aOptions,
                                     JSContext* aCx,
                                     PRUint8 aArgc,
                                     bool aEditable,
                                     nsIDOMDeviceStorageCursor** aRetval)
{
  nsCOMPtr<nsPIDOMWindow> win = do_QueryReferent(mOwner);
  if (!win)
    return NS_ERROR_UNEXPECTED;

  PRTime since = 0;
  nsString path;
  path.SetIsVoid(true);

  if (aArgc > 0) {
    // inspect the first value to see if it is a string
    if (JSVAL_IS_STRING(aName)) {
      JSString* jsstr = JS_ValueToString(aCx, aName);
      nsDependentJSString jspath;
      jspath.init(aCx, jsstr);
      path.Assign(jspath);
    } else if (!JSVAL_IS_PRIMITIVE(aName)) {
      // it also might be an options object
      since = ExtractDateFromOptions(aCx, aName);
    } else {
      return NS_ERROR_FAILURE;
    }

    if (aArgc == 2 && (JSVAL_IS_VOID(aOptions) || aOptions.isNull() || !aOptions.isObject())) {
      return NS_ERROR_FAILURE;
    }
    since = ExtractDateFromOptions(aCx, aOptions);
  }

  nsRefPtr<DeviceStorageFile> dsf = new DeviceStorageFile(mFile, path);
  dsf->SetEditable(aEditable);

  nsRefPtr<nsDOMDeviceStorageCursor> cursor = new nsDOMDeviceStorageCursor(win, mURI, dsf, since);
  nsRefPtr<DeviceStorageCursorRequest> r = new DeviceStorageCursorRequest(cursor);

  NS_ADDREF(*aRetval = cursor);

  if (mozilla::Preferences::GetBool("device.storage.prompt.testing", false)) {
    r->Allow();
    return NS_OK;
  }

  if (XRE_GetProcessType() == GeckoProcessType_Content) {
    // because owner implements nsITabChild, we can assume that it is
    // the one and only TabChild.
    TabChild* child = GetTabChildFrom(win->GetDocShell());
    if (!child)
      return false;

    // Retain a reference so the object isn't deleted without IPDL's knowledge.
    // Corresponding release occurs in DeallocPContentPermissionRequest.
    r->AddRef();

    nsCString type = NS_LITERAL_CSTRING("device-storage");
    child->SendPContentPermissionRequestConstructor(r, type, IPC::URI(mURI));

    r->Sendprompt();

    return NS_OK;
  }

  nsCOMPtr<nsIContentPermissionPrompt> prompt = do_GetService(NS_CONTENT_PERMISSION_PROMPT_CONTRACTID);
  if (prompt) {
    prompt->Prompt(r);
  }

  return NS_OK;
}