diff options
Diffstat (limited to 'dom/script/ScriptLoadHandler.cpp')
| -rw-r--r-- | dom/script/ScriptLoadHandler.cpp | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/dom/script/ScriptLoadHandler.cpp b/dom/script/ScriptLoadHandler.cpp new file mode 100644 index 000000000..80fb70f6a --- /dev/null +++ b/dom/script/ScriptLoadHandler.cpp @@ -0,0 +1,216 @@ +/* -*- 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. + */ + +#include "ScriptLoadHandler.h" +#include "ScriptLoader.h" +#include "nsContentUtils.h" + +#include "mozilla/dom/EncodingUtils.h" + +namespace mozilla { +namespace dom { + +ScriptLoadHandler::ScriptLoadHandler(ScriptLoader *aScriptLoader, + ScriptLoadRequest *aRequest, + mozilla::dom::SRICheckDataVerifier *aSRIDataVerifier) + : mScriptLoader(aScriptLoader), + mRequest(aRequest), + mSRIDataVerifier(aSRIDataVerifier), + mSRIStatus(NS_OK), + mDecoder(), + mBuffer() +{} + +ScriptLoadHandler::~ScriptLoadHandler() +{} + +NS_IMPL_ISUPPORTS(ScriptLoadHandler, nsIIncrementalStreamLoaderObserver) + +NS_IMETHODIMP +ScriptLoadHandler::OnIncrementalData(nsIIncrementalStreamLoader* aLoader, + nsISupports* aContext, + uint32_t aDataLength, + const uint8_t* aData, + uint32_t *aConsumedLength) +{ + if (mRequest->IsCanceled()) { + // If request cancelled, ignore any incoming data. + *aConsumedLength = aDataLength; + return NS_OK; + } + + if (!EnsureDecoder(aLoader, aData, aDataLength, + /* aEndOfStream = */ false)) { + return NS_OK; + } + + // Below we will/shall consume entire data chunk. + *aConsumedLength = aDataLength; + + // Decoder has already been initialized. -- trying to decode all loaded bytes. + nsresult rv = TryDecodeRawData(aData, aDataLength, + /* aEndOfStream = */ false); + NS_ENSURE_SUCCESS(rv, rv); + + // If SRI is required for this load, appending new bytes to the hash. + if (mSRIDataVerifier && NS_SUCCEEDED(mSRIStatus)) { + mSRIStatus = mSRIDataVerifier->Update(aDataLength, aData); + } + + return rv; +} + +nsresult +ScriptLoadHandler::TryDecodeRawData(const uint8_t* aData, + uint32_t aDataLength, + bool aEndOfStream) +{ + int32_t srcLen = aDataLength; + const char* src = reinterpret_cast<const char *>(aData); + int32_t dstLen; + nsresult rv = + mDecoder->GetMaxLength(src, srcLen, &dstLen); + + NS_ENSURE_SUCCESS(rv, rv); + + uint32_t haveRead = mBuffer.length(); + + CheckedInt<uint32_t> capacity = haveRead; + capacity += dstLen; + + if (!capacity.isValid() || !mBuffer.reserve(capacity.value())) { + return NS_ERROR_OUT_OF_MEMORY; + } + + rv = mDecoder->Convert(src, + &srcLen, + mBuffer.begin() + haveRead, + &dstLen); + + NS_ENSURE_SUCCESS(rv, rv); + + haveRead += dstLen; + MOZ_ASSERT(haveRead <= capacity.value(), "mDecoder produced more data than expected"); + MOZ_ALWAYS_TRUE(mBuffer.resizeUninitialized(haveRead)); + + return NS_OK; +} + +bool +ScriptLoadHandler::EnsureDecoder(nsIIncrementalStreamLoader *aLoader, + const uint8_t* aData, + uint32_t aDataLength, + bool aEndOfStream) +{ + // Check if decoder has already been created. + if (mDecoder) { + return true; + } + + nsAutoCString charset; + + // JavaScript modules are always UTF-8. + if (mRequest->IsModuleRequest()) { + charset = "UTF-8"; + mDecoder = EncodingUtils::DecoderForEncoding(charset); + return true; + } + + // Determine if BOM check should be done. This occurs either + // if end-of-stream has been reached, or at least 3 bytes have + // been read from input. + if (!aEndOfStream && (aDataLength < 3)) { + return false; + } + + // Do BOM detection. + if (nsContentUtils::CheckForBOM(aData, aDataLength, charset)) { + mDecoder = EncodingUtils::DecoderForEncoding(charset); + return true; + } + + // BOM detection failed, check content stream for charset. + nsCOMPtr<nsIRequest> req; + nsresult rv = aLoader->GetRequest(getter_AddRefs(req)); + NS_ASSERTION(req, "StreamLoader's request went away prematurely"); + NS_ENSURE_SUCCESS(rv, false); + + nsCOMPtr<nsIChannel> channel = do_QueryInterface(req); + + if (channel && + NS_SUCCEEDED(channel->GetContentCharset(charset)) && + EncodingUtils::FindEncodingForLabel(charset, charset)) { + mDecoder = EncodingUtils::DecoderForEncoding(charset); + return true; + } + + // Check the hint charset from the script element or preload + // request. + nsAutoString hintCharset; + if (!mRequest->IsPreload()) { + mRequest->mElement->GetScriptCharset(hintCharset); + } else { + nsTArray<ScriptLoader::PreloadInfo>::index_type i = + mScriptLoader->mPreloads.IndexOf(mRequest, 0, + ScriptLoader::PreloadRequestComparator()); + + NS_ASSERTION(i != mScriptLoader->mPreloads.NoIndex, + "Incorrect preload bookkeeping"); + hintCharset = mScriptLoader->mPreloads[i].mCharset; + } + + if (EncodingUtils::FindEncodingForLabel(hintCharset, charset)) { + mDecoder = EncodingUtils::DecoderForEncoding(charset); + return true; + } + + // Get the charset from the charset of the document. + if (mScriptLoader->mDocument) { + charset = mScriptLoader->mDocument->GetDocumentCharacterSet(); + mDecoder = EncodingUtils::DecoderForEncoding(charset); + return true; + } + + // Curiously, there are various callers that don't pass aDocument. The + // fallback in the old code was ISO-8859-1, which behaved like + // windows-1252. Saying windows-1252 for clarity and for compliance + // with the Encoding Standard. + charset = "windows-1252"; + mDecoder = EncodingUtils::DecoderForEncoding(charset); + return true; +} + +NS_IMETHODIMP +ScriptLoadHandler::OnStreamComplete(nsIIncrementalStreamLoader* aLoader, + nsISupports* aContext, + nsresult aStatus, + uint32_t aDataLength, + const uint8_t* aData) +{ + if (!mRequest->IsCanceled()) { + DebugOnly<bool> encoderSet = + EnsureDecoder(aLoader, aData, aDataLength, /* aEndOfStream = */ true); + MOZ_ASSERT(encoderSet); + DebugOnly<nsresult> rv = TryDecodeRawData(aData, aDataLength, + /* aEndOfStream = */ true); + + // If SRI is required for this load, appending new bytes to the hash. + if (mSRIDataVerifier && NS_SUCCEEDED(mSRIStatus)) { + mSRIStatus = mSRIDataVerifier->Update(aDataLength, aData); + } + } + + // we have to mediate and use mRequest. + return mScriptLoader->OnStreamComplete(aLoader, mRequest, aStatus, mSRIStatus, + mBuffer, mSRIDataVerifier); +} + +} // dom namespace +} // mozilla namespace
\ No newline at end of file |