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/* -*- 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
/*
* 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/Encoding.h"
#include "mozilla/Maybe.h"
#include "mozilla/RefPtr.h"
#include "mozilla/UniquePtr.h"
namespace JS::loader {
class ScriptLoadRequest;
}
namespace mozilla {
class Decoder;
namespace dom {
class ScriptLoader;
class SRICheckDataVerifier;
class ScriptDecoder {
public:
enum BOMHandling { Ignore, Remove };
ScriptDecoder(const Encoding* aEncoding,
ScriptDecoder::BOMHandling handleBOM);
~ScriptDecoder() = default;
/*
* 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(JS::loader::ScriptLoadRequest* aRequest,
const uint8_t* aData, uint32_t aDataLength,
bool aEndOfStream);
private:
/*
* 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(JS::loader::ScriptLoadRequest* aRequest,
const uint8_t* aData, uint32_t aDataLength,
bool aEndOfStream);
// Unicode decoder for charset.
mozilla::UniquePtr<mozilla::Decoder> mDecoder;
};
class ScriptLoadHandler final : public nsIIncrementalStreamLoaderObserver {
public:
explicit ScriptLoadHandler(
ScriptLoader* aScriptLoader, JS::loader::ScriptLoadRequest* aRequest,
UniquePtr<SRICheckDataVerifier>&& aSRIDataVerifier);
NS_DECL_ISUPPORTS
NS_DECL_NSIINCREMENTALSTREAMLOADEROBSERVER
private:
virtual ~ScriptLoadHandler();
/*
* 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<JS::loader::ScriptLoadRequest> mRequest;
// SRI data verifier.
UniquePtr<SRICheckDataVerifier> mSRIDataVerifier;
// Status of SRI data operations.
nsresult mSRIStatus;
UniquePtr<ScriptDecoder> mDecoder;
// Flipped to true after calling NotifyStart the first time
bool mPreloadStartNotified = false;
};
} // namespace dom
} // namespace mozilla
#endif // mozilla_dom_ScriptLoadHandler_h