1 files changed, 117 insertions, 0 deletions
diff --git a/dom/script/ScriptLoadHandler.h b/dom/script/ScriptLoadHandler.h
new file mode 100644
index 0000000000..96352a11ac
--- /dev/null
+++ b/dom/script/ScriptLoadHandler.h
@@ -0,0 +1,117 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+/*
+ * A class that handles loading and evaluation of <script> elements.
+ */
+
+#ifndef mozilla_dom_ScriptLoadHandler_h
+#define mozilla_dom_ScriptLoadHandler_h
+
+#include "nsIIncrementalStreamLoader.h"
+#include "nsISupports.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/UniquePtr.h"
+
+namespace mozilla {
+
+class Decoder;
+
+namespace dom {
+
+class ScriptLoadRequest;
+class ScriptLoader;
+class SRICheckDataVerifier;
+
+class ScriptLoadHandler final : public nsIIncrementalStreamLoaderObserver {
+ public:
+  explicit ScriptLoadHandler(
+      ScriptLoader* aScriptLoader, ScriptLoadRequest* aRequest,
+      UniquePtr<SRICheckDataVerifier>&& aSRIDataVerifier);
+
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIINCREMENTALSTREAMLOADEROBSERVER
+
+ private:
+  virtual ~ScriptLoadHandler();
+
+  /*
+   * Decode the given data into the already-allocated internal
+   * |ScriptTextBuffer<Unit>|.
+   *
+   * This function is intended to be called only by |DecodeRawData| after
+   * determining which sort of |ScriptTextBuffer<Unit>| has been allocated.
+   */
+  template <typename Unit>
+  nsresult DecodeRawDataHelper(const uint8_t* aData, uint32_t aDataLength,
+                               bool aEndOfStream);
+
+  /*
+   * Once the charset is found by the EnsureDecoder function, we can
+   * incrementally convert the charset to the one expected by the JS Parser.
+   */
+  nsresult DecodeRawData(const uint8_t* aData, uint32_t aDataLength,
+                         bool aEndOfStream);
+
+  /*
+   * Discover the charset by looking at the stream data, the script tag, and
+   * other indicators.  Returns true if charset has been discovered.
+   */
+  bool EnsureDecoder(nsIIncrementalStreamLoader* aLoader, const uint8_t* aData,
+                     uint32_t aDataLength, bool aEndOfStream) {
+    // Check if the decoder has already been created.
+    if (mDecoder) {
+      return true;
+    }
+
+    return TrySetDecoder(aLoader, aData, aDataLength, aEndOfStream);
+  }
+
+  /*
+   * Attempt to determine how script data will be decoded, when such
+   * determination hasn't already been made.  (If you don't know whether it's
+   * been made yet, use |EnsureDecoder| above instead.)  Return false if there
+   * isn't enough information yet to make the determination, or true if a
+   * determination was made.
+   */
+  bool TrySetDecoder(nsIIncrementalStreamLoader* aLoader, const uint8_t* aData,
+                     uint32_t aDataLength, bool aEndOfStream);
+
+  /*
+   * When streaming bytecode, we have the opportunity to fallback early if SRI
+   * does not match the expectation of the document.
+   *
+   * If SRI hash is decoded, `sriLength` is set to the length of the hash.
+   */
+  nsresult MaybeDecodeSRI(uint32_t* sriLength);
+
+  // Query the channel to find the data type associated with the input stream.
+  nsresult EnsureKnownDataType(nsIIncrementalStreamLoader* aLoader);
+
+  // ScriptLoader which will handle the parsed script.
+  RefPtr<ScriptLoader> mScriptLoader;
+
+  // The ScriptLoadRequest for this load. Decoded data are accumulated on it.
+  RefPtr<ScriptLoadRequest> mRequest;
+
+  // SRI data verifier.
+  UniquePtr<SRICheckDataVerifier> mSRIDataVerifier;
+
+  // Status of SRI data operations.
+  nsresult mSRIStatus;
+
+  // Unicode decoder for charset.
+  mozilla::UniquePtr<mozilla::Decoder> mDecoder;
+
+  // Flipped to true after calling NotifyStart the first time
+  bool mPreloadStartNotified = false;
+};
+
+}  // namespace dom
+}  // namespace mozilla
+
+#endif  // mozilla_dom_ScriptLoadHandler_h