1 files changed, 121 insertions, 0 deletions
diff --git a/netwerk/base/nsAsyncRedirectVerifyHelper.h b/netwerk/base/nsAsyncRedirectVerifyHelper.h
new file mode 100644
index 0000000000..3e1afa8c69
--- /dev/null
+++ b/netwerk/base/nsAsyncRedirectVerifyHelper.h
@@ -0,0 +1,121 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#ifndef nsAsyncRedirectVerifyHelper_h
+#define nsAsyncRedirectVerifyHelper_h
+
+#include "nsIRunnable.h"
+#include "nsIChannelEventSink.h"
+#include "nsIAsyncVerifyRedirectCallback.h"
+#include "nsINamed.h"
+#include "nsCOMPtr.h"
+#include "nsCycleCollectionParticipant.h"
+#include "mozilla/Attributes.h"
+
+class nsIChannel;
+
+namespace mozilla {
+namespace net {
+
+/**
+ * This class simplifies call of OnChannelRedirect of IOService and
+ * the sink bound with the channel being redirected while the result of
+ * redirect decision is returned through the callback.
+ */
+class nsAsyncRedirectVerifyHelper final
+    : public nsIRunnable,
+      public nsINamed,
+      public nsIAsyncVerifyRedirectCallback {
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIRUNNABLE
+  NS_DECL_NSINAMED
+  NS_DECL_NSIASYNCVERIFYREDIRECTCALLBACK
+
+ public:
+  nsAsyncRedirectVerifyHelper() = default;
+
+  /*
+   * Calls AsyncOnChannelRedirect() on the given sink with the given
+   * channels and flags. Keeps track of number of async callbacks to expect.
+   */
+  nsresult DelegateOnChannelRedirect(nsIChannelEventSink* sink,
+                                     nsIChannel* oldChannel,
+                                     nsIChannel* newChannel, uint32_t flags);
+
+  /**
+   * Initialize and run the chain of AsyncOnChannelRedirect calls. OldChannel
+   * is QI'ed for nsIAsyncVerifyRedirectCallback. The result of the redirect
+   * decision is passed through this interface back to the oldChannel.
+   *
+   * @param oldChan
+   *    channel being redirected, MUST implement
+   *    nsIAsyncVerifyRedirectCallback
+   * @param newChan
+   *    target of the redirect channel
+   * @param flags
+   *    redirect flags
+   * @param mainThreadEventTarget
+   *    a labeled event target for dispatching runnables
+   * @param synchronize
+   *    set to TRUE if you want the Init method wait synchronously for
+   *    all redirect callbacks
+   */
+  nsresult Init(nsIChannel* oldChan, nsIChannel* newChan, uint32_t flags,
+                nsIEventTarget* mainThreadEventTarget,
+                bool synchronize = false);
+
+ protected:
+  nsCOMPtr<nsIChannel> mOldChan;
+  nsCOMPtr<nsIChannel> mNewChan;
+  uint32_t mFlags{0};
+  bool mWaitingForRedirectCallback{false};
+  nsCOMPtr<nsIEventTarget> mCallbackEventTarget;
+  bool mCallbackInitiated{false};
+  int32_t mExpectedCallbacks{0};
+  nsresult mResult{NS_OK};  // value passed to callback
+
+  void InitCallback();
+
+  /**
+   * Calls back to |oldChan| as described in Init()
+   */
+  void ExplicitCallback(nsresult result);
+
+ private:
+  ~nsAsyncRedirectVerifyHelper();
+
+  bool IsOldChannelCanceled();
+};
+
+/*
+ * Helper to make the call-stack handle some control-flow for us
+ */
+class nsAsyncRedirectAutoCallback {
+ public:
+  explicit nsAsyncRedirectAutoCallback(
+      nsIAsyncVerifyRedirectCallback* aCallback)
+      : mCallback(aCallback) {
+    mResult = NS_OK;
+  }
+  ~nsAsyncRedirectAutoCallback() {
+    if (mCallback) mCallback->OnRedirectVerifyCallback(mResult);
+  }
+  /*
+   * Call this is you want it to call back with a different result-code
+   */
+  void SetResult(nsresult aRes) { mResult = aRes; }
+  /*
+   * Call this is you want to avoid the callback
+   */
+  void DontCallback() { mCallback = nullptr; }
+
+ private:
+  nsIAsyncVerifyRedirectCallback* mCallback;
+  nsresult mResult;
+};
+
+}  // namespace net
+}  // namespace mozilla
+#endif