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gecko-dev/parser/html/nsHtml5StreamParser.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set sw=2 ts=2 et tw=79: */
/* 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 "nsHtml5StreamParser.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/Encoding.h"
#include "nsContentUtils.h"
#include "nsHtml5Tokenizer.h"
#include "nsIHttpChannel.h"
#include "nsHtml5Parser.h"
#include "nsHtml5TreeBuilder.h"
#include "nsHtml5AtomTable.h"
#include "nsHtml5Module.h"
#include "nsHtml5StreamParserPtr.h"
#include "nsIScriptError.h"
#include "mozilla/Preferences.h"
#include "mozilla/SystemGroup.h"
#include "mozilla/UniquePtrExtensions.h"
#include "nsHtml5Highlighter.h"
#include "expat_config.h"
#include "expat.h"
#include "nsINestedURI.h"
#include "nsCharsetSource.h"
#include "nsIWyciwygChannel.h"
#include "nsIThreadRetargetableRequest.h"
#include "nsPrintfCString.h"
#include "nsNetUtil.h"
#include "nsXULAppAPI.h"
#include "mozilla/SchedulerGroup.h"
#include "nsJSEnvironment.h"
using namespace mozilla;
int32_t nsHtml5StreamParser::sTimerInitialDelay = 120;
int32_t nsHtml5StreamParser::sTimerSubsequentDelay = 120;
// static
void
nsHtml5StreamParser::InitializeStatics()
{
Preferences::AddIntVarCache(&sTimerInitialDelay,
"html5.flushtimer.initialdelay");
Preferences::AddIntVarCache(&sTimerSubsequentDelay,
"html5.flushtimer.subsequentdelay");
}
/*
* Note that nsHtml5StreamParser implements cycle collecting AddRef and
* Release. Therefore, nsHtml5StreamParser must never be refcounted from
* the parser thread!
*
* To work around this limitation, runnables posted by the main thread to the
* parser thread hold their reference to the stream parser in an
* nsHtml5StreamParserPtr. Upon creation, nsHtml5StreamParserPtr addrefs the object it holds
* just like a regular nsRefPtr. This is OK, since the creation of the
* runnable and the nsHtml5StreamParserPtr happens on the main thread.
*
* When the runnable is done on the parser thread, the destructor of
* nsHtml5StreamParserPtr runs there. It doesn't call Release on the held object
* directly. Instead, it posts another runnable back to the main thread where
* that runnable calls Release on the wrapped object.
*
* When posting runnables in the other direction, the runnables have to be
* created on the main thread when nsHtml5StreamParser is instantiated and
* held for the lifetime of the nsHtml5StreamParser. This works, because the
* same runnabled can be dispatched multiple times and currently runnables
* posted from the parser thread to main thread don't need to wrap any
* runnable-specific data. (In the other direction, the runnables most notably
* wrap the byte data of the stream.)
*/
NS_IMPL_CYCLE_COLLECTING_ADDREF(nsHtml5StreamParser)
NS_IMPL_CYCLE_COLLECTING_RELEASE(nsHtml5StreamParser)
NS_INTERFACE_TABLE_HEAD(nsHtml5StreamParser)
NS_INTERFACE_TABLE(nsHtml5StreamParser,
nsICharsetDetectionObserver)
NS_INTERFACE_TABLE_TO_MAP_SEGUE_CYCLE_COLLECTION(nsHtml5StreamParser)
NS_INTERFACE_MAP_END
NS_IMPL_CYCLE_COLLECTION_CLASS(nsHtml5StreamParser)
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsHtml5StreamParser)
tmp->DropTimer();
NS_IMPL_CYCLE_COLLECTION_UNLINK(mObserver)
NS_IMPL_CYCLE_COLLECTION_UNLINK(mRequest)
NS_IMPL_CYCLE_COLLECTION_UNLINK(mOwner)
tmp->mExecutorFlusher = nullptr;
tmp->mLoadFlusher = nullptr;
tmp->mExecutor = nullptr;
NS_IMPL_CYCLE_COLLECTION_UNLINK(mChardet)
NS_IMPL_CYCLE_COLLECTION_UNLINK_END
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsHtml5StreamParser)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mObserver)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mRequest)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mOwner)
// hack: count the strongly owned edge wrapped in the runnable
if (tmp->mExecutorFlusher) {
NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb, "mExecutorFlusher->mExecutor");
cb.NoteXPCOMChild(static_cast<nsIContentSink*> (tmp->mExecutor));
}
// hack: count the strongly owned edge wrapped in the runnable
if (tmp->mLoadFlusher) {
NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb, "mLoadFlusher->mExecutor");
cb.NoteXPCOMChild(static_cast<nsIContentSink*> (tmp->mExecutor));
}
// hack: count self if held by mChardet
if (tmp->mChardet) {
NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb, "mChardet->mObserver");
cb.NoteXPCOMChild(static_cast<nsICharsetDetectionObserver*>(tmp));
}
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
class nsHtml5ExecutorFlusher : public Runnable
{
private:
RefPtr<nsHtml5TreeOpExecutor> mExecutor;
public:
explicit nsHtml5ExecutorFlusher(nsHtml5TreeOpExecutor* aExecutor)
: Runnable("nsHtml5ExecutorFlusher")
, mExecutor(aExecutor)
{}
NS_IMETHOD Run() override
{
if (!mExecutor->isInList()) {
mExecutor->RunFlushLoop();
}
return NS_OK;
}
};
class nsHtml5LoadFlusher : public Runnable
{
private:
RefPtr<nsHtml5TreeOpExecutor> mExecutor;
public:
explicit nsHtml5LoadFlusher(nsHtml5TreeOpExecutor* aExecutor)
: Runnable("nsHtml5LoadFlusher")
, mExecutor(aExecutor)
{}
NS_IMETHOD Run() override
{
mExecutor->FlushSpeculativeLoads();
return NS_OK;
}
};
nsHtml5StreamParser::nsHtml5StreamParser(nsHtml5TreeOpExecutor* aExecutor,
nsHtml5Parser* aOwner,
eParserMode aMode)
: mSniffingLength(0)
, mBomState(eBomState::BOM_SNIFFING_NOT_STARTED)
, mCharsetSource(kCharsetUninitialized)
, mEncoding(WINDOWS_1252_ENCODING)
, mReparseForbidden(false)
, mLastBuffer(nullptr) // Will be filled when starting
, mExecutor(aExecutor)
, mTreeBuilder(new nsHtml5TreeBuilder((aMode == VIEW_SOURCE_HTML ||
aMode == VIEW_SOURCE_XML) ?
nullptr : mExecutor->GetStage(),
aMode == NORMAL ?
mExecutor->GetStage() : nullptr))
, mTokenizer(new nsHtml5Tokenizer(mTreeBuilder, aMode == VIEW_SOURCE_XML))
, mTokenizerMutex("nsHtml5StreamParser mTokenizerMutex")
, mOwner(aOwner)
, mLastWasCR(false)
, mStreamState(eHtml5StreamState::STREAM_NOT_STARTED)
, mSpeculating(false)
, mAtEOF(false)
, mSpeculationMutex("nsHtml5StreamParser mSpeculationMutex")
, mSpeculationFailureCount(0)
, mTerminated(false)
, mInterrupted(false)
, mTerminatedMutex("nsHtml5StreamParser mTerminatedMutex")
, mEventTarget(nsHtml5Module::GetStreamParserThread()->SerialEventTarget())
, mExecutorFlusher(new nsHtml5ExecutorFlusher(aExecutor))
, mLoadFlusher(new nsHtml5LoadFlusher(aExecutor))
, mFeedChardet(false)
, mInitialEncodingWasFromParentFrame(false)
, mFlushTimer(do_CreateInstance("@mozilla.org/timer;1"))
, mFlushTimerMutex("nsHtml5StreamParser mFlushTimerMutex")
, mFlushTimerArmed(false)
, mFlushTimerEverFired(false)
, mMode(aMode)
{
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
mFlushTimer->SetTarget(mEventTarget);
#ifdef DEBUG
mAtomTable.SetPermittedLookupEventTarget(mEventTarget);
#endif
mTokenizer->setInterner(&mAtomTable);
mTokenizer->setEncodingDeclarationHandler(this);
if (aMode == VIEW_SOURCE_HTML || aMode == VIEW_SOURCE_XML) {
nsHtml5Highlighter* highlighter =
new nsHtml5Highlighter(mExecutor->GetStage());
mTokenizer->EnableViewSource(highlighter); // takes ownership
mTreeBuilder->EnableViewSource(highlighter); // doesn't own
}
// Chardet instantiation adapted from File.
// Chardet is initialized here even if it turns out to be useless
// to make the chardet refcount its observer (nsHtml5StreamParser)
// on the main thread.
nsAutoCString detectorName;
Preferences::GetLocalizedCString("intl.charset.detector", detectorName);
if (!detectorName.IsEmpty()) {
nsAutoCString detectorContractID;
detectorContractID.AssignLiteral(NS_CHARSET_DETECTOR_CONTRACTID_BASE);
detectorContractID += detectorName;
if ((mChardet = do_CreateInstance(detectorContractID.get()))) {
(void) mChardet->Init(this);
mFeedChardet = true;
}
}
// There's a zeroing operator new for everything else
}
nsHtml5StreamParser::~nsHtml5StreamParser()
{
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
mTokenizer->end();
#ifdef DEBUG
{
mozilla::MutexAutoLock flushTimerLock(mFlushTimerMutex);
MOZ_ASSERT(!mFlushTimer, "Flush timer was not dropped before dtor!");
}
mRequest = nullptr;
mObserver = nullptr;
mUnicodeDecoder = nullptr;
mSniffingBuffer = nullptr;
mMetaScanner = nullptr;
mFirstBuffer = nullptr;
mExecutor = nullptr;
mTreeBuilder = nullptr;
mTokenizer = nullptr;
mOwner = nullptr;
#endif
}
nsresult
nsHtml5StreamParser::GetChannel(nsIChannel** aChannel)
{
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
return mRequest ? CallQueryInterface(mRequest, aChannel) :
NS_ERROR_NOT_AVAILABLE;
}
NS_IMETHODIMP
nsHtml5StreamParser::Notify(const char* aCharset, nsDetectionConfident aConf)
{
NS_ASSERTION(IsParserThread(), "Wrong thread!");
if (aConf == eBestAnswer || aConf == eSureAnswer) {
mFeedChardet = false; // just in case
auto encoding = Encoding::ForLabelNoReplacement(
nsDependentCString(aCharset));
if (!encoding) {
return NS_OK;
}
if (HasDecoder()) {
if (mEncoding == encoding) {
NS_ASSERTION(mCharsetSource < kCharsetFromAutoDetection,
"Why are we running chardet at all?");
mCharsetSource = kCharsetFromAutoDetection;
mTreeBuilder->SetDocumentCharset(mEncoding, mCharsetSource);
} else {
// We've already committed to a decoder. Request a reload from the
// docshell.
mTreeBuilder->NeedsCharsetSwitchTo(WrapNotNull(encoding),
kCharsetFromAutoDetection,
0);
FlushTreeOpsAndDisarmTimer();
Interrupt();
}
} else {
// Got a confident answer from the sniffing buffer. That code will
// take care of setting up the decoder.
mEncoding = WrapNotNull(encoding);
mCharsetSource = kCharsetFromAutoDetection;
mTreeBuilder->SetDocumentCharset(mEncoding, mCharsetSource);
}
}
return NS_OK;
}
void
nsHtml5StreamParser::SetViewSourceTitle(nsIURI* aURL)
{
if (aURL) {
nsCOMPtr<nsIURI> temp;
bool isViewSource;
aURL->SchemeIs("view-source", &isViewSource);
if (isViewSource) {
nsCOMPtr<nsINestedURI> nested = do_QueryInterface(aURL);
nested->GetInnerURI(getter_AddRefs(temp));
} else {
temp = aURL;
}
bool isData;
temp->SchemeIs("data", &isData);
if (isData) {
// Avoid showing potentially huge data: URLs. The three last bytes are
// UTF-8 for an ellipsis.
mViewSourceTitle.AssignLiteral("data:\xE2\x80\xA6");
} else {
nsresult rv = temp->GetSpec(mViewSourceTitle);
if (NS_FAILED(rv)) {
mViewSourceTitle.AssignLiteral("\xE2\x80\xA6");
}
}
}
}
nsresult
nsHtml5StreamParser::SetupDecodingAndWriteSniffingBufferAndCurrentSegment(const uint8_t* aFromSegment, // can be null
uint32_t aCount,
uint32_t* aWriteCount)
{
NS_ASSERTION(IsParserThread(), "Wrong thread!");
nsresult rv = NS_OK;
mUnicodeDecoder = mEncoding->NewDecoderWithBOMRemoval();
if (mSniffingBuffer) {
uint32_t writeCount;
rv = WriteStreamBytes(mSniffingBuffer.get(), mSniffingLength, &writeCount);
NS_ENSURE_SUCCESS(rv, rv);
mSniffingBuffer = nullptr;
}
mMetaScanner = nullptr;
if (aFromSegment) {
rv = WriteStreamBytes(aFromSegment, aCount, aWriteCount);
}
return rv;
}
nsresult
nsHtml5StreamParser::SetupDecodingFromBom(NotNull<const Encoding*> aEncoding)
{
NS_ASSERTION(IsParserThread(), "Wrong thread!");
mEncoding = aEncoding;
mUnicodeDecoder = mEncoding->NewDecoderWithBOMRemoval();
mCharsetSource = kCharsetFromByteOrderMark;
mFeedChardet = false;
mTreeBuilder->SetDocumentCharset(mEncoding, mCharsetSource);
mSniffingBuffer = nullptr;
mMetaScanner = nullptr;
mBomState = BOM_SNIFFING_OVER;
return NS_OK;
}
void
nsHtml5StreamParser::SniffBOMlessUTF16BasicLatin(const uint8_t* aFromSegment,
uint32_t aCountToSniffingLimit)
{
// Avoid underspecified heuristic craziness for XHR
if (mMode == LOAD_AS_DATA) {
return;
}
// Make sure there's enough data. Require room for "<title></title>"
if (mSniffingLength + aCountToSniffingLimit < 30) {
return;
}
// even-numbered bytes tracked at 0, odd-numbered bytes tracked at 1
bool byteZero[2] = { false, false };
bool byteNonZero[2] = { false, false };
uint32_t i = 0;
if (mSniffingBuffer) {
for (; i < mSniffingLength; ++i) {
if (mSniffingBuffer[i]) {
if (byteNonZero[1 - (i % 2)]) {
return;
}
byteNonZero[i % 2] = true;
} else {
if (byteZero[1 - (i % 2)]) {
return;
}
byteZero[i % 2] = true;
}
}
}
if (aFromSegment) {
for (uint32_t j = 0; j < aCountToSniffingLimit; ++j) {
if (aFromSegment[j]) {
if (byteNonZero[1 - ((i + j) % 2)]) {
return;
}
byteNonZero[(i + j) % 2] = true;
} else {
if (byteZero[1 - ((i + j) % 2)]) {
return;
}
byteZero[(i + j) % 2] = true;
}
}
}
if (byteNonZero[0]) {
mEncoding = UTF_16LE_ENCODING;
} else {
mEncoding = UTF_16BE_ENCODING;
}
mCharsetSource = kCharsetFromIrreversibleAutoDetection;
mTreeBuilder->SetDocumentCharset(mEncoding, mCharsetSource);
mFeedChardet = false;
mTreeBuilder->MaybeComplainAboutCharset("EncBomlessUtf16",
true,
0);
}
void
nsHtml5StreamParser::SetEncodingFromExpat(const char16_t* aEncoding)
{
if (aEncoding) {
nsDependentString utf16(aEncoding);
nsAutoCString utf8;
CopyUTF16toUTF8(utf16, utf8);
auto encoding = PreferredForInternalEncodingDecl(utf8);
if (encoding) {
mEncoding = WrapNotNull(encoding);
mCharsetSource = kCharsetFromMetaTag; // closest for XML
return;
}
// else the page declared an encoding Gecko doesn't support and we'd
// end up defaulting to UTF-8 anyway. Might as well fall through here
// right away and let the encoding be set to UTF-8 which we'd default to
// anyway.
}
mEncoding = UTF_8_ENCODING; // XML defaults to UTF-8 without a BOM
mCharsetSource = kCharsetFromMetaTag; // means confident
}
// A separate user data struct is used instead of passing the
// nsHtml5StreamParser instance as user data in order to avoid including
// expat.h in nsHtml5StreamParser.h. Doing that would cause naming conflicts.
// Using a separate user data struct also avoids bloating nsHtml5StreamParser
// by one pointer.
struct UserData {
XML_Parser mExpat;
nsHtml5StreamParser* mStreamParser;
};
// Using no-namespace handler callbacks to avoid including expat.h in
// nsHtml5StreamParser.h, since doing so would cause naming conclicts.
static void
HandleXMLDeclaration(void* aUserData,
const XML_Char* aVersion,
const XML_Char* aEncoding,
int aStandalone)
{
UserData* ud = static_cast<UserData*>(aUserData);
ud->mStreamParser->SetEncodingFromExpat(
reinterpret_cast<const char16_t*>(aEncoding));
XML_StopParser(ud->mExpat, false);
}
static void
HandleStartElement(void* aUserData,
const XML_Char* aName,
const XML_Char **aAtts)
{
UserData* ud = static_cast<UserData*>(aUserData);
XML_StopParser(ud->mExpat, false);
}
static void
HandleEndElement(void* aUserData,
const XML_Char* aName)
{
UserData* ud = static_cast<UserData*>(aUserData);
XML_StopParser(ud->mExpat, false);
}
static void
HandleComment(void* aUserData,
const XML_Char* aName)
{
UserData* ud = static_cast<UserData*>(aUserData);
XML_StopParser(ud->mExpat, false);
}
static void
HandleProcessingInstruction(void* aUserData,
const XML_Char* aTarget,
const XML_Char* aData)
{
UserData* ud = static_cast<UserData*>(aUserData);
XML_StopParser(ud->mExpat, false);
}
nsresult
nsHtml5StreamParser::FinalizeSniffing(const uint8_t* aFromSegment, // can be null
uint32_t aCount,
uint32_t* aWriteCount,
uint32_t aCountToSniffingLimit)
{
NS_ASSERTION(IsParserThread(), "Wrong thread!");
NS_ASSERTION(mCharsetSource < kCharsetFromParentForced,
"Should not finalize sniffing when using forced charset.");
if (mMode == VIEW_SOURCE_XML) {
static const XML_Memory_Handling_Suite memsuite =
{
(void *(*)(size_t))moz_xmalloc,
(void *(*)(void *, size_t))moz_xrealloc,
free
};
static const char16_t kExpatSeparator[] = { 0xFFFF, '\0' };
static const char16_t kISO88591[] =
{ 'I', 'S', 'O', '-', '8', '8', '5', '9', '-', '1', '\0' };
UserData ud;
ud.mStreamParser = this;
// If we got this far, the stream didn't have a BOM. UTF-16-encoded XML
// documents MUST begin with a BOM. We don't support EBCDIC and such.
// Thus, at this point, what we have is garbage or something encoded using
// a rough ASCII superset. ISO-8859-1 allows us to decode ASCII bytes
// without throwing errors when bytes have the most significant bit set
// and without triggering expat's unknown encoding code paths. This is
// enough to be able to use expat to parse the XML declaration in order
// to extract the encoding name from it.
ud.mExpat = XML_ParserCreate_MM(kISO88591, &memsuite, kExpatSeparator);
XML_SetXmlDeclHandler(ud.mExpat, HandleXMLDeclaration);
XML_SetElementHandler(ud.mExpat, HandleStartElement, HandleEndElement);
XML_SetCommentHandler(ud.mExpat, HandleComment);
XML_SetProcessingInstructionHandler(ud.mExpat, HandleProcessingInstruction);
XML_SetUserData(ud.mExpat, static_cast<void*>(&ud));
XML_Status status = XML_STATUS_OK;
// aFromSegment points to the data obtained from the current network
// event. mSniffingBuffer (if it exists) contains the data obtained before
// the current event. Thus, mSniffingLenth bytes of mSniffingBuffer
// followed by aCountToSniffingLimit bytes from aFromSegment are the
// first 1024 bytes of the file (or the file as a whole if the file is
// 1024 bytes long or shorter). Thus, we parse both buffers, but if the
// first call succeeds already, we skip parsing the second buffer.
if (mSniffingBuffer) {
status = XML_Parse(ud.mExpat,
reinterpret_cast<const char*>(mSniffingBuffer.get()),
mSniffingLength,
false);
}
if (status == XML_STATUS_OK &&
mCharsetSource < kCharsetFromMetaTag &&
aFromSegment) {
status = XML_Parse(ud.mExpat,
reinterpret_cast<const char*>(aFromSegment),
aCountToSniffingLimit,
false);
}
XML_ParserFree(ud.mExpat);
if (mCharsetSource < kCharsetFromMetaTag) {
// Failed to get an encoding from the XML declaration. XML defaults
// confidently to UTF-8 in this case.
// It is also possible that the document has an XML declaration that is
// longer than 1024 bytes, but that case is not worth worrying about.
mEncoding = UTF_8_ENCODING;
mCharsetSource = kCharsetFromMetaTag; // means confident
}
return SetupDecodingAndWriteSniffingBufferAndCurrentSegment(aFromSegment,
aCount,
aWriteCount);
}
// meta scan failed.
if (mCharsetSource >= kCharsetFromHintPrevDoc) {
mFeedChardet = false;
return SetupDecodingAndWriteSniffingBufferAndCurrentSegment(aFromSegment, aCount, aWriteCount);
}
// Check for BOMless UTF-16 with Basic
// Latin content for compat with IE. See bug 631751.
SniffBOMlessUTF16BasicLatin(aFromSegment, aCountToSniffingLimit);
// the charset may have been set now
// maybe try chardet now;
if (mFeedChardet) {
bool dontFeed;
nsresult rv;
if (mSniffingBuffer) {
rv = mChardet->DoIt((const char*)mSniffingBuffer.get(), mSniffingLength, &dontFeed);
mFeedChardet = !dontFeed;
NS_ENSURE_SUCCESS(rv, rv);
}
if (mFeedChardet && aFromSegment) {
rv = mChardet->DoIt((const char*)aFromSegment,
// Avoid buffer boundary-dependent behavior when
// reparsing is forbidden. If reparse is forbidden,
// act as if we only saw the first 1024 bytes.
// When reparsing isn't forbidden, buffer boundaries
// can have an effect on whether the page is loaded
// once or twice. :-(
mReparseForbidden ? aCountToSniffingLimit : aCount,
&dontFeed);
mFeedChardet = !dontFeed;
NS_ENSURE_SUCCESS(rv, rv);
}
if (mFeedChardet && (!aFromSegment || mReparseForbidden)) {
// mReparseForbidden is checked so that we get to use the sniffing
// buffer with the best guess so far if we aren't allowed to guess
// better later.
mFeedChardet = false;
rv = mChardet->Done();
NS_ENSURE_SUCCESS(rv, rv);
}
// fall thru; callback may have changed charset
}
if (mCharsetSource == kCharsetUninitialized) {
// Hopefully this case is never needed, but dealing with it anyway
mEncoding = WINDOWS_1252_ENCODING;
mCharsetSource = kCharsetFromFallback;
mTreeBuilder->SetDocumentCharset(mEncoding, mCharsetSource);
} else if (mMode == LOAD_AS_DATA &&
mCharsetSource == kCharsetFromFallback) {
NS_ASSERTION(mReparseForbidden, "Reparse should be forbidden for XHR");
NS_ASSERTION(!mFeedChardet, "Should not feed chardet for XHR");
NS_ASSERTION(mEncoding == UTF_8_ENCODING,
"XHR should default to UTF-8");
// Now mark charset source as non-weak to signal that we have a decision
mCharsetSource = kCharsetFromDocTypeDefault;
mTreeBuilder->SetDocumentCharset(mEncoding, mCharsetSource);
}
return SetupDecodingAndWriteSniffingBufferAndCurrentSegment(aFromSegment, aCount, aWriteCount);
}
nsresult
nsHtml5StreamParser::SniffStreamBytes(const uint8_t* aFromSegment,
uint32_t aCount,
uint32_t* aWriteCount)
{
NS_ASSERTION(IsParserThread(), "Wrong thread!");
nsresult rv = NS_OK;
uint32_t writeCount;
// mEncoding and mCharsetSource potentially have come from channel or higher
// by now. If we find a BOM, SetupDecodingFromBom() will overwrite them.
// If we don't find a BOM, the previously set values of mEncoding and
// mCharsetSource are not modified by the BOM sniffing here.
for (uint32_t i = 0; i < aCount && mBomState != BOM_SNIFFING_OVER; i++) {
switch (mBomState) {
case BOM_SNIFFING_NOT_STARTED:
NS_ASSERTION(i == 0, "Bad BOM sniffing state.");
switch (*aFromSegment) {
case 0xEF:
mBomState = SEEN_UTF_8_FIRST_BYTE;
break;
case 0xFF:
mBomState = SEEN_UTF_16_LE_FIRST_BYTE;
break;
case 0xFE:
mBomState = SEEN_UTF_16_BE_FIRST_BYTE;
break;
default:
mBomState = BOM_SNIFFING_OVER;
break;
}
break;
case SEEN_UTF_16_LE_FIRST_BYTE:
if (aFromSegment[i] == 0xFE) {
rv = SetupDecodingFromBom(UTF_16LE_ENCODING); // upper case is the raw form
NS_ENSURE_SUCCESS(rv, rv);
uint32_t count = aCount - (i + 1);
rv = WriteStreamBytes(aFromSegment + (i + 1), count, &writeCount);
NS_ENSURE_SUCCESS(rv, rv);
*aWriteCount = writeCount + (i + 1);
return rv;
}
mBomState = BOM_SNIFFING_OVER;
break;
case SEEN_UTF_16_BE_FIRST_BYTE:
if (aFromSegment[i] == 0xFF) {
rv = SetupDecodingFromBom(UTF_16BE_ENCODING); // upper case is the raw form
NS_ENSURE_SUCCESS(rv, rv);
uint32_t count = aCount - (i + 1);
rv = WriteStreamBytes(aFromSegment + (i + 1), count, &writeCount);
NS_ENSURE_SUCCESS(rv, rv);
*aWriteCount = writeCount + (i + 1);
return rv;
}
mBomState = BOM_SNIFFING_OVER;
break;
case SEEN_UTF_8_FIRST_BYTE:
if (aFromSegment[i] == 0xBB) {
mBomState = SEEN_UTF_8_SECOND_BYTE;
} else {
mBomState = BOM_SNIFFING_OVER;
}
break;
case SEEN_UTF_8_SECOND_BYTE:
if (aFromSegment[i] == 0xBF) {
rv = SetupDecodingFromBom(UTF_8_ENCODING); // upper case is the raw form
NS_ENSURE_SUCCESS(rv, rv);
uint32_t count = aCount - (i + 1);
rv = WriteStreamBytes(aFromSegment + (i + 1), count, &writeCount);
NS_ENSURE_SUCCESS(rv, rv);
*aWriteCount = writeCount + (i + 1);
return rv;
}
mBomState = BOM_SNIFFING_OVER;
break;
default:
mBomState = BOM_SNIFFING_OVER;
break;
}
}
// if we get here, there either was no BOM or the BOM sniffing isn't complete
// yet
MOZ_ASSERT(mCharsetSource != kCharsetFromByteOrderMark,
"Should not come here if BOM was found.");
MOZ_ASSERT(mCharsetSource != kCharsetFromOtherComponent,
"kCharsetFromOtherComponent is for XSLT.");
if (mBomState == BOM_SNIFFING_OVER &&
mCharsetSource == kCharsetFromChannel) {
// There was no BOM and the charset came from channel. mEncoding
// still contains the charset from the channel as set by an
// earlier call to SetDocumentCharset(), since we didn't find a BOM and
// overwrite mEncoding. (Note that if the user has overridden the charset,
// we don't come here but check <meta> for XSS-dangerous charsets first.)
mFeedChardet = false;
mTreeBuilder->SetDocumentCharset(mEncoding, mCharsetSource);
return SetupDecodingAndWriteSniffingBufferAndCurrentSegment(aFromSegment,
aCount, aWriteCount);
}
if (!mMetaScanner && (mMode == NORMAL ||
mMode == VIEW_SOURCE_HTML ||
mMode == LOAD_AS_DATA)) {
mMetaScanner = new nsHtml5MetaScanner(mTreeBuilder);
}
if (mSniffingLength + aCount >= NS_HTML5_STREAM_PARSER_SNIFFING_BUFFER_SIZE) {
// this is the last buffer
uint32_t countToSniffingLimit =
NS_HTML5_STREAM_PARSER_SNIFFING_BUFFER_SIZE - mSniffingLength;
if (mMode == NORMAL || mMode == VIEW_SOURCE_HTML || mMode == LOAD_AS_DATA) {
nsHtml5ByteReadable readable(aFromSegment, aFromSegment +
countToSniffingLimit);
nsAutoCString charset;
auto encoding = mMetaScanner->sniff(&readable);
// Due to the way nsHtml5Portability reports OOM, ask the tree buider
nsresult rv;
if (NS_FAILED((rv = mTreeBuilder->IsBroken()))) {
MarkAsBroken(rv);
return rv;
}
if (encoding) {
// meta scan successful; honor overrides unless meta is XSS-dangerous
if ((mCharsetSource == kCharsetFromParentForced ||
mCharsetSource == kCharsetFromUserForced) &&
(encoding->IsAsciiCompatible() ||
encoding == ISO_2022_JP_ENCODING)) {
// Honor override
return SetupDecodingAndWriteSniffingBufferAndCurrentSegment(
aFromSegment, aCount, aWriteCount);
}
mEncoding = WrapNotNull(encoding);
mCharsetSource = kCharsetFromMetaPrescan;
mFeedChardet = false;
mTreeBuilder->SetDocumentCharset(mEncoding, mCharsetSource);
return SetupDecodingAndWriteSniffingBufferAndCurrentSegment(
aFromSegment, aCount, aWriteCount);
}
}
if (mCharsetSource == kCharsetFromParentForced ||
mCharsetSource == kCharsetFromUserForced) {
// meta not found, honor override
return SetupDecodingAndWriteSniffingBufferAndCurrentSegment(
aFromSegment, aCount, aWriteCount);
}
return FinalizeSniffing(aFromSegment, aCount, aWriteCount,
countToSniffingLimit);
}
// not the last buffer
if (mMode == NORMAL || mMode == VIEW_SOURCE_HTML || mMode == LOAD_AS_DATA) {
nsHtml5ByteReadable readable(aFromSegment, aFromSegment + aCount);
auto encoding = mMetaScanner->sniff(&readable);
// Due to the way nsHtml5Portability reports OOM, ask the tree buider
nsresult rv;
if (NS_FAILED((rv = mTreeBuilder->IsBroken()))) {
MarkAsBroken(rv);
return rv;
}
if (encoding) {
// meta scan successful; honor overrides unless meta is XSS-dangerous
if ((mCharsetSource == kCharsetFromParentForced ||
mCharsetSource == kCharsetFromUserForced) &&
(encoding->IsAsciiCompatible() ||
encoding == ISO_2022_JP_ENCODING)) {
// Honor override
return SetupDecodingAndWriteSniffingBufferAndCurrentSegment(aFromSegment,
aCount, aWriteCount);
}
mEncoding = WrapNotNull(encoding);
mCharsetSource = kCharsetFromMetaPrescan;
mFeedChardet = false;
mTreeBuilder->SetDocumentCharset(mEncoding, mCharsetSource);
return SetupDecodingAndWriteSniffingBufferAndCurrentSegment(aFromSegment,
aCount, aWriteCount);
}
}
if (!mSniffingBuffer) {
mSniffingBuffer =
MakeUniqueFallible<uint8_t[]>(NS_HTML5_STREAM_PARSER_SNIFFING_BUFFER_SIZE);
if (!mSniffingBuffer) {
return NS_ERROR_OUT_OF_MEMORY;
}
}
memcpy(&mSniffingBuffer[mSniffingLength], aFromSegment, aCount);
mSniffingLength += aCount;
*aWriteCount = aCount;
return NS_OK;
}
nsresult
nsHtml5StreamParser::WriteStreamBytes(const uint8_t* aFromSegment,
uint32_t aCount,
uint32_t* aWriteCount)
{
NS_ASSERTION(IsParserThread(), "Wrong thread!");
// mLastBuffer should always point to a buffer of the size
// NS_HTML5_STREAM_PARSER_READ_BUFFER_SIZE.
if (!mLastBuffer) {
NS_WARNING("mLastBuffer should not be null!");
MarkAsBroken(NS_ERROR_NULL_POINTER);
return NS_ERROR_NULL_POINTER;
}
size_t totalRead = 0;
auto src = MakeSpan(aFromSegment, aCount);
for (;;) {
auto dst = mLastBuffer->TailAsSpan(NS_HTML5_STREAM_PARSER_READ_BUFFER_SIZE);
uint32_t result;
size_t read;
size_t written;
bool hadErrors;
Tie(result, read, written, hadErrors) =
mUnicodeDecoder->DecodeToUTF16(src, dst, false);
Unused << hadErrors;
src = src.From(read);
totalRead += read;
mLastBuffer->AdvanceEnd(written);
if (result == kOutputFull) {
RefPtr<nsHtml5OwningUTF16Buffer> newBuf =
nsHtml5OwningUTF16Buffer::FalliblyCreate(
NS_HTML5_STREAM_PARSER_READ_BUFFER_SIZE);
if (!newBuf) {
MarkAsBroken(NS_ERROR_OUT_OF_MEMORY);
return NS_ERROR_OUT_OF_MEMORY;
}
mLastBuffer = (mLastBuffer->next = newBuf.forget());
} else {
MOZ_ASSERT(totalRead == aCount,
"The Unicode decoder consumed the wrong number of bytes.");
*aWriteCount = totalRead;
return NS_OK;
}
}
}
class MaybeRunCollector : public Runnable
{
public:
explicit MaybeRunCollector(nsIDocShell* aDocShell)
: Runnable("MaybeRunCollector")
, mDocShell(aDocShell)
{
}
NS_IMETHOD Run()
{
nsJSContext::MaybeRunNextCollectorSlice(mDocShell, JS::gcreason::HTML_PARSER);
return NS_OK;
}
nsCOMPtr<nsIDocShell> mDocShell;
};
nsresult
nsHtml5StreamParser::OnStartRequest(nsIRequest* aRequest, nsISupports* aContext)
{
NS_PRECONDITION(STREAM_NOT_STARTED == mStreamState,
"Got OnStartRequest when the stream had already started.");
NS_PRECONDITION(
!mExecutor->HasStarted(),
"Got OnStartRequest at the wrong stage in the executor life cycle.");
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
if (mObserver) {
mObserver->OnStartRequest(aRequest, aContext);
}
mRequest = aRequest;
mStreamState = STREAM_BEING_READ;
if (mMode == VIEW_SOURCE_HTML || mMode == VIEW_SOURCE_XML) {
mTokenizer->StartViewSource(NS_ConvertUTF8toUTF16(mViewSourceTitle));
}
// For View Source, the parser should run with scripts "enabled" if a normal
// load would have scripts enabled.
bool scriptingEnabled = mMode == LOAD_AS_DATA ?
false : mExecutor->IsScriptEnabled();
mOwner->StartTokenizer(scriptingEnabled);
bool isSrcdoc = false;
nsCOMPtr<nsIChannel> channel;
nsresult rv = GetChannel(getter_AddRefs(channel));
if (NS_SUCCEEDED(rv)) {
isSrcdoc = NS_IsSrcdocChannel(channel);
}
mTreeBuilder->setIsSrcdocDocument(isSrcdoc);
mTreeBuilder->setScriptingEnabled(scriptingEnabled);
mTreeBuilder->SetPreventScriptExecution(!((mMode == NORMAL) &&
scriptingEnabled));
mTokenizer->start();
mExecutor->Start();
mExecutor->StartReadingFromStage();
if (mMode == PLAIN_TEXT) {
mTreeBuilder->StartPlainText();
mTokenizer->StartPlainText();
} else if (mMode == VIEW_SOURCE_PLAIN) {
nsAutoString viewSourceTitle;
CopyUTF8toUTF16(mViewSourceTitle, viewSourceTitle);
mTreeBuilder->EnsureBufferSpace(viewSourceTitle.Length());
mTreeBuilder->StartPlainTextViewSource(viewSourceTitle);
mTokenizer->StartPlainText();
}
/*
* If you move the following line, be very careful not to cause
* WillBuildModel to be called before the document has had its
* script global object set.
*/
rv = mExecutor->WillBuildModel(eDTDMode_unknown);
NS_ENSURE_SUCCESS(rv, rv);
RefPtr<nsHtml5OwningUTF16Buffer> newBuf =
nsHtml5OwningUTF16Buffer::FalliblyCreate(
NS_HTML5_STREAM_PARSER_READ_BUFFER_SIZE);
if (!newBuf) {
// marks this stream parser as terminated,
// which prevents entry to code paths that
// would use mFirstBuffer or mLastBuffer.
return mExecutor->MarkAsBroken(NS_ERROR_OUT_OF_MEMORY);
}
NS_ASSERTION(!mFirstBuffer, "How come we have the first buffer set?");
NS_ASSERTION(!mLastBuffer, "How come we have the last buffer set?");
mFirstBuffer = mLastBuffer = newBuf;
rv = NS_OK;
// The line below means that the encoding can end up being wrong if
// a view-source URL is loaded without having the encoding hint from a
// previous normal load in the history.
mReparseForbidden = !(mMode == NORMAL || mMode == PLAIN_TEXT);
mDocGroup = mExecutor->GetDocument()->GetDocGroup();
nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(mRequest, &rv));
if (NS_SUCCEEDED(rv)) {
// Non-HTTP channels are bogus enough that we let them work with unlabeled
// runnables for now. Asserting for HTTP channels only.
MOZ_ASSERT(mDocGroup || mMode == LOAD_AS_DATA, "How come the doc group is still null?");
nsAutoCString method;
Unused << httpChannel->GetRequestMethod(method);
// XXX does Necko have a way to renavigate POST, etc. without hitting
// the network?
if (!method.EqualsLiteral("GET")) {
// This is the old Gecko behavior but the HTML5 spec disagrees.
// Don't reparse on POST.
mReparseForbidden = true;
mFeedChardet = false; // can't restart anyway
}
}
// Attempt to retarget delivery of data (via OnDataAvailable) to the parser
// thread, rather than through the main thread.
nsCOMPtr<nsIThreadRetargetableRequest> threadRetargetableRequest =
do_QueryInterface(mRequest, &rv);
if (threadRetargetableRequest) {
rv = threadRetargetableRequest->RetargetDeliveryTo(mEventTarget);
if (NS_SUCCEEDED(rv)) {
// Parser thread should be now ready to get data from necko and parse it
// and main thread might have a chance to process a collector slice.
// We need to do this asynchronously so that necko may continue processing
// the request.
nsCOMPtr<nsIRunnable> runnable =
new MaybeRunCollector(mExecutor->GetDocument()->GetDocShell());
mozilla::SystemGroup::Dispatch(mozilla::TaskCategory::GarbageCollection,
runnable.forget());
}
}
if (NS_FAILED(rv)) {
NS_WARNING("Failed to retarget HTML data delivery to the parser thread.");
}
if (mCharsetSource == kCharsetFromParentFrame) {
// Remember this in case chardet overwrites mCharsetSource
mInitialEncodingWasFromParentFrame = true;
}
if (mCharsetSource >= kCharsetFromAutoDetection) {
mFeedChardet = false;
}
nsCOMPtr<nsIWyciwygChannel> wyciwygChannel(do_QueryInterface(mRequest));
if (mCharsetSource < kCharsetFromUtf8OnlyMime && !wyciwygChannel) {
// we aren't ready to commit to an encoding yet
// leave converter uninstantiated for now
return NS_OK;
}
// We are reloading a document.open()ed doc or loading JSON/WebVTT/etc. into
// a browsing context. In the latter case, there's no need to remove the
// BOM manually here, because the UTF-8 decoder removes it.
mReparseForbidden = true;
mFeedChardet = false;
// Instantiate the converter here to avoid BOM sniffing.
mUnicodeDecoder = mEncoding->NewDecoderWithBOMRemoval();
return NS_OK;
}
nsresult
nsHtml5StreamParser::CheckListenerChain()
{
NS_ASSERTION(NS_IsMainThread(), "Should be on the main thread!");
if (!mObserver) {
return NS_OK;
}
nsresult rv;
nsCOMPtr<nsIThreadRetargetableStreamListener> retargetable =
do_QueryInterface(mObserver, &rv);
if (NS_SUCCEEDED(rv) && retargetable) {
rv = retargetable->CheckListenerChain();
}
return rv;
}
void
nsHtml5StreamParser::DoStopRequest()
{
NS_ASSERTION(IsParserThread(), "Wrong thread!");
NS_PRECONDITION(STREAM_BEING_READ == mStreamState,
"Stream ended without being open.");
mTokenizerMutex.AssertCurrentThreadOwns();
if (IsTerminated()) {
return;
}
mStreamState = STREAM_ENDED;
if (!mUnicodeDecoder) {
uint32_t writeCount;
nsresult rv;
if (NS_FAILED(rv = FinalizeSniffing(nullptr, 0, &writeCount, 0))) {
MarkAsBroken(rv);
return;
}
} else if (mFeedChardet) {
mChardet->Done();
}
MOZ_ASSERT(mUnicodeDecoder, "Should have a decoder after finalizing sniffing.");
// mLastBuffer should always point to a buffer of the size
// NS_HTML5_STREAM_PARSER_READ_BUFFER_SIZE.
if (!mLastBuffer) {
NS_WARNING("mLastBuffer should not be null!");
MarkAsBroken(NS_ERROR_NULL_POINTER);
return;
}
Span<uint8_t> src; // empty span
for (;;) {
auto dst = mLastBuffer->TailAsSpan(NS_HTML5_STREAM_PARSER_READ_BUFFER_SIZE);
uint32_t result;
size_t read;
size_t written;
bool hadErrors;
Tie(result, read, written, hadErrors) =
mUnicodeDecoder->DecodeToUTF16(src, dst, true);
Unused << hadErrors;
MOZ_ASSERT(read == 0, "How come an empty span was read form?");
mLastBuffer->AdvanceEnd(written);
if (result == kOutputFull) {
RefPtr<nsHtml5OwningUTF16Buffer> newBuf =
nsHtml5OwningUTF16Buffer::FalliblyCreate(
NS_HTML5_STREAM_PARSER_READ_BUFFER_SIZE);
if (!newBuf) {
MarkAsBroken(NS_ERROR_OUT_OF_MEMORY);
return;
}
mLastBuffer = (mLastBuffer->next = newBuf.forget());
} else {
break;
}
}
if (IsTerminatedOrInterrupted()) {
return;
}
ParseAvailableData();
}
class nsHtml5RequestStopper : public Runnable
{
private:
nsHtml5StreamParserPtr mStreamParser;
public:
explicit nsHtml5RequestStopper(nsHtml5StreamParser* aStreamParser)
: Runnable("nsHtml5RequestStopper")
, mStreamParser(aStreamParser)
{}
NS_IMETHOD Run() override
{
mozilla::MutexAutoLock autoLock(mStreamParser->mTokenizerMutex);
mStreamParser->DoStopRequest();
return NS_OK;
}
};
nsresult
nsHtml5StreamParser::OnStopRequest(nsIRequest* aRequest,
nsISupports* aContext,
nsresult status)
{
NS_ASSERTION(mRequest == aRequest, "Got Stop on wrong stream.");
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
if (mObserver) {
mObserver->OnStopRequest(aRequest, aContext, status);
}
nsCOMPtr<nsIRunnable> stopper = new nsHtml5RequestStopper(this);
if (NS_FAILED(mEventTarget->Dispatch(stopper, nsIThread::DISPATCH_NORMAL))) {
NS_WARNING("Dispatching StopRequest event failed.");
}
return NS_OK;
}
void
nsHtml5StreamParser::DoDataAvailable(const uint8_t* aBuffer, uint32_t aLength)
{
NS_ASSERTION(IsParserThread(), "Wrong thread!");
NS_PRECONDITION(STREAM_BEING_READ == mStreamState,
"DoDataAvailable called when stream not open.");
mTokenizerMutex.AssertCurrentThreadOwns();
if (IsTerminated()) {
return;
}
uint32_t writeCount;
nsresult rv;
if (HasDecoder()) {
if (mFeedChardet) {
bool dontFeed;
mChardet->DoIt((const char*)aBuffer, aLength, &dontFeed);
mFeedChardet = !dontFeed;
}
rv = WriteStreamBytes(aBuffer, aLength, &writeCount);
} else {
rv = SniffStreamBytes(aBuffer, aLength, &writeCount);
}
if (NS_FAILED(rv)) {
MarkAsBroken(rv);
return;
}
NS_ASSERTION(writeCount == aLength, "Wrong number of stream bytes written/sniffed.");
if (IsTerminatedOrInterrupted()) {
return;
}
ParseAvailableData();
if (mFlushTimerArmed || mSpeculating) {
return;
}
{
mozilla::MutexAutoLock flushTimerLock(mFlushTimerMutex);
mFlushTimer->InitWithNamedFuncCallback(
nsHtml5StreamParser::TimerCallback,
static_cast<void*>(this),
mFlushTimerEverFired ? sTimerInitialDelay : sTimerSubsequentDelay,
nsITimer::TYPE_ONE_SHOT,
"nsHtml5StreamParser::DoDataAvailable");
}
mFlushTimerArmed = true;
}
class nsHtml5DataAvailable : public Runnable
{
private:
nsHtml5StreamParserPtr mStreamParser;
UniquePtr<uint8_t[]> mData;
uint32_t mLength;
public:
nsHtml5DataAvailable(nsHtml5StreamParser* aStreamParser,
UniquePtr<uint8_t[]> aData,
uint32_t aLength)
: Runnable("nsHtml5DataAvailable")
, mStreamParser(aStreamParser)
, mData(Move(aData))
, mLength(aLength)
{}
NS_IMETHOD Run() override
{
mozilla::MutexAutoLock autoLock(mStreamParser->mTokenizerMutex);
mStreamParser->DoDataAvailable(mData.get(), mLength);
return NS_OK;
}
};
nsresult
nsHtml5StreamParser::OnDataAvailable(nsIRequest* aRequest,
nsISupports* aContext,
nsIInputStream* aInStream,
uint64_t aSourceOffset,
uint32_t aLength)
{
nsresult rv;
if (NS_FAILED(rv = mExecutor->IsBroken())) {
return rv;
}
NS_ASSERTION(mRequest == aRequest, "Got data on wrong stream.");
uint32_t totalRead;
// Main thread to parser thread dispatch requires copying to buffer first.
if (NS_IsMainThread()) {
auto data = MakeUniqueFallible<uint8_t[]>(aLength);
if (!data) {
return mExecutor->MarkAsBroken(NS_ERROR_OUT_OF_MEMORY);
}
rv = aInStream->Read(reinterpret_cast<char*>(data.get()),
aLength, &totalRead);
NS_ENSURE_SUCCESS(rv, rv);
NS_ASSERTION(totalRead <= aLength, "Read more bytes than were available?");
nsCOMPtr<nsIRunnable> dataAvailable = new nsHtml5DataAvailable(this,
Move(data),
totalRead);
if (NS_FAILED(mEventTarget->Dispatch(dataAvailable, nsIThread::DISPATCH_NORMAL))) {
NS_WARNING("Dispatching DataAvailable event failed.");
}
return rv;
} else {
NS_ASSERTION(IsParserThread(), "Wrong thread!");
mozilla::MutexAutoLock autoLock(mTokenizerMutex);
// Read directly from response buffer.
rv = aInStream->ReadSegments(CopySegmentsToParser, this, aLength,
&totalRead);
if (NS_FAILED(rv)) {
NS_WARNING("Failed reading response data to parser");
return rv;
}
return NS_OK;
}
}
/* static */ nsresult
nsHtml5StreamParser::CopySegmentsToParser(nsIInputStream *aInStream,
void *aClosure,
const char *aFromSegment,
uint32_t aToOffset,
uint32_t aCount,
uint32_t *aWriteCount)
{
nsHtml5StreamParser* parser = static_cast<nsHtml5StreamParser*>(aClosure);
parser->DoDataAvailable((const uint8_t*)aFromSegment, aCount);
// Assume DoDataAvailable consumed all available bytes.
*aWriteCount = aCount;
return NS_OK;
}
const Encoding*
nsHtml5StreamParser::PreferredForInternalEncodingDecl(const nsACString& aEncoding)
{
const Encoding* newEncoding = Encoding::ForLabel(aEncoding);
if (!newEncoding) {
// the encoding name is bogus
mTreeBuilder->MaybeComplainAboutCharset("EncMetaUnsupported",
true,
mTokenizer->getLineNumber());
return nullptr;
}
if (newEncoding == UTF_16BE_ENCODING ||
newEncoding == UTF_16LE_ENCODING) {
mTreeBuilder->MaybeComplainAboutCharset("EncMetaUtf16",
true,
mTokenizer->getLineNumber());
newEncoding = UTF_8_ENCODING;
}
if (newEncoding == X_USER_DEFINED_ENCODING) {
// WebKit/Blink hack for Indian and Armenian legacy sites
mTreeBuilder->MaybeComplainAboutCharset("EncMetaUserDefined",
true,
mTokenizer->getLineNumber());
newEncoding = WINDOWS_1252_ENCODING;
}
if (newEncoding == mEncoding) {
if (mCharsetSource < kCharsetFromMetaPrescan) {
if (mInitialEncodingWasFromParentFrame) {
mTreeBuilder->MaybeComplainAboutCharset("EncLateMetaFrame",
false,
mTokenizer->getLineNumber());
} else {
mTreeBuilder->MaybeComplainAboutCharset("EncLateMeta",
false,
mTokenizer->getLineNumber());
}
}
mCharsetSource = kCharsetFromMetaTag; // become confident
mFeedChardet = false; // don't feed chardet when confident
return nullptr;
}
return newEncoding;
}
bool
nsHtml5StreamParser::internalEncodingDeclaration(nsHtml5String aEncoding)
{
// This code needs to stay in sync with
// nsHtml5MetaScanner::tryCharset. Unfortunately, the
// trickery with member fields there leads to some copy-paste reuse. :-(
NS_ASSERTION(IsParserThread(), "Wrong thread!");
if (mCharsetSource >= kCharsetFromMetaTag) { // this threshold corresponds to "confident" in the HTML5 spec
return false;
}
nsString newEncoding16; // Not Auto, because using it to hold nsStringBuffer*
aEncoding.ToString(newEncoding16);
nsAutoCString newEncoding;
CopyUTF16toUTF8(newEncoding16, newEncoding);
auto encoding = PreferredForInternalEncodingDecl(newEncoding);
if (!encoding) {
return false;
}
if (mReparseForbidden) {
// This mReparseForbidden check happens after the call to
// PreferredForInternalEncodingDecl so that if that method calls
// MaybeComplainAboutCharset, its charset complaint wins over the one
// below.
mTreeBuilder->MaybeComplainAboutCharset("EncLateMetaTooLate",
true,
mTokenizer->getLineNumber());
return false; // not reparsing even if we wanted to
}
// Avoid having the chardet ask for another restart after this restart
// request.
mFeedChardet = false;
mTreeBuilder->NeedsCharsetSwitchTo(WrapNotNull(encoding),
kCharsetFromMetaTag,
mTokenizer->getLineNumber());
FlushTreeOpsAndDisarmTimer();
Interrupt();
// the tree op executor will cause the stream parser to terminate
// if the charset switch request is accepted or it'll uninterrupt
// if the request failed. Note that if the restart request fails,
// we don't bother trying to make chardet resume. Might as well
// assume that chardet-requested restarts would fail, too.
return true;
}
void
nsHtml5StreamParser::FlushTreeOpsAndDisarmTimer()
{
NS_ASSERTION(IsParserThread(), "Wrong thread!");
if (mFlushTimerArmed) {
// avoid calling Cancel if the flush timer isn't armed to avoid acquiring
// a mutex
{
mozilla::MutexAutoLock flushTimerLock(mFlushTimerMutex);
mFlushTimer->Cancel();
}
mFlushTimerArmed = false;
}
if (mMode == VIEW_SOURCE_HTML || mMode == VIEW_SOURCE_XML) {
mTokenizer->FlushViewSource();
}
mTreeBuilder->Flush();
nsCOMPtr<nsIRunnable> runnable(mExecutorFlusher);
if (NS_FAILED(DispatchToMain(runnable.forget()))) {
NS_WARNING("failed to dispatch executor flush event");
}
}
void
nsHtml5StreamParser::ParseAvailableData()
{
NS_ASSERTION(IsParserThread(), "Wrong thread!");
mTokenizerMutex.AssertCurrentThreadOwns();
if (IsTerminatedOrInterrupted()) {
return;
}
if (mSpeculating && !IsSpeculationEnabled()) {
return;
}
for (;;) {
if (!mFirstBuffer->hasMore()) {
if (mFirstBuffer == mLastBuffer) {
switch (mStreamState) {
case STREAM_BEING_READ:
// never release the last buffer.
if (!mSpeculating) {
// reuse buffer space if not speculating
mFirstBuffer->setStart(0);
mFirstBuffer->setEnd(0);
}
mTreeBuilder->FlushLoads();
{
// Dispatch this runnable unconditionally, because the loads
// that need flushing may have been flushed earlier even if the
// flush right above here did nothing.
nsCOMPtr<nsIRunnable> runnable(mLoadFlusher);
if (NS_FAILED(
DispatchToMain(runnable.forget()))) {
NS_WARNING("failed to dispatch load flush event");
}
}
return; // no more data for now but expecting more
case STREAM_ENDED:
if (mAtEOF) {
return;
}
mAtEOF = true;
if (mCharsetSource < kCharsetFromMetaTag) {
if (mInitialEncodingWasFromParentFrame) {
// Unfortunately, this check doesn't take effect for
// cross-origin frames, so cross-origin ad frames that have
// no text and only an image or a Flash embed get the more
// severe message from the next if block. The message is
// technically accurate, though.
mTreeBuilder->MaybeComplainAboutCharset("EncNoDeclarationFrame",
false,
0);
} else if (mMode == NORMAL) {
mTreeBuilder->MaybeComplainAboutCharset("EncNoDeclaration",
true,
0);
} else if (mMode == PLAIN_TEXT) {
mTreeBuilder->MaybeComplainAboutCharset("EncNoDeclarationPlain",
true,
0);
}
}
if (NS_SUCCEEDED(mTreeBuilder->IsBroken())) {
mTokenizer->eof();
nsresult rv;
if (NS_FAILED((rv = mTreeBuilder->IsBroken()))) {
MarkAsBroken(rv);
} else {
mTreeBuilder->StreamEnded();
if (mMode == VIEW_SOURCE_HTML || mMode == VIEW_SOURCE_XML) {
mTokenizer->EndViewSource();
}
}
}
FlushTreeOpsAndDisarmTimer();
return; // no more data and not expecting more
default:
NS_NOTREACHED("It should be impossible to reach this.");
return;
}
}
mFirstBuffer = mFirstBuffer->next;
continue;
}
// now we have a non-empty buffer
mFirstBuffer->adjust(mLastWasCR);
mLastWasCR = false;
if (mFirstBuffer->hasMore()) {
if (!mTokenizer->EnsureBufferSpace(mFirstBuffer->getLength())) {
MarkAsBroken(NS_ERROR_OUT_OF_MEMORY);
return;
}
mLastWasCR = mTokenizer->tokenizeBuffer(mFirstBuffer);
nsresult rv;
if (NS_FAILED((rv = mTreeBuilder->IsBroken()))) {
MarkAsBroken(rv);
return;
}
// At this point, internalEncodingDeclaration() may have called
// Terminate, but that never happens together with script.
// Can't assert that here, though, because it's possible that the main
// thread has called Terminate() while this thread was parsing.
if (mTreeBuilder->HasScript()) {
// HasScript() cannot return true if the tree builder is preventing
// script execution.
MOZ_ASSERT(mMode == NORMAL);
mozilla::MutexAutoLock speculationAutoLock(mSpeculationMutex);
nsHtml5Speculation* speculation =
new nsHtml5Speculation(mFirstBuffer,
mFirstBuffer->getStart(),
mTokenizer->getLineNumber(),
mTreeBuilder->newSnapshot());
mTreeBuilder->AddSnapshotToScript(speculation->GetSnapshot(),
speculation->GetStartLineNumber());
FlushTreeOpsAndDisarmTimer();
mTreeBuilder->SetOpSink(speculation);
mSpeculations.AppendElement(speculation); // adopts the pointer
mSpeculating = true;
}
if (IsTerminatedOrInterrupted()) {
return;
}
}
}
}
class nsHtml5StreamParserContinuation : public Runnable
{
private:
nsHtml5StreamParserPtr mStreamParser;
public:
explicit nsHtml5StreamParserContinuation(nsHtml5StreamParser* aStreamParser)
: Runnable("nsHtml5StreamParserContinuation")
, mStreamParser(aStreamParser)
{}
NS_IMETHOD Run() override
{
mozilla::MutexAutoLock autoLock(mStreamParser->mTokenizerMutex);
mStreamParser->Uninterrupt();
mStreamParser->ParseAvailableData();
return NS_OK;
}
};
void
nsHtml5StreamParser::ContinueAfterScripts(nsHtml5Tokenizer* aTokenizer,
nsHtml5TreeBuilder* aTreeBuilder,
bool aLastWasCR)
{
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
NS_ASSERTION(!(mMode == VIEW_SOURCE_HTML || mMode == VIEW_SOURCE_XML),
"ContinueAfterScripts called in view source mode!");
if (NS_FAILED(mExecutor->IsBroken())) {
return;
}
#ifdef DEBUG
mExecutor->AssertStageEmpty();
#endif
bool speculationFailed = false;
{
mozilla::MutexAutoLock speculationAutoLock(mSpeculationMutex);
if (mSpeculations.IsEmpty()) {
NS_NOTREACHED("ContinueAfterScripts called without speculations.");
return;
}
nsHtml5Speculation* speculation = mSpeculations.ElementAt(0);
if (aLastWasCR || !aTokenizer->isInDataState() ||
!aTreeBuilder->snapshotMatches(speculation->GetSnapshot())) {
speculationFailed = true;
// We've got a failed speculation :-(
MaybeDisableFutureSpeculation();
Interrupt(); // Make the parser thread release the tokenizer mutex sooner
// now fall out of the speculationAutoLock into the tokenizerAutoLock block
} else {
// We've got a successful speculation!
if (mSpeculations.Length() > 1) {
// the first speculation isn't the current speculation, so there's
// no need to bother the parser thread.
speculation->FlushToSink(mExecutor);
NS_ASSERTION(!mExecutor->IsScriptExecuting(),
"ParseUntilBlocked() was supposed to ensure we don't come "
"here when scripts are executing.");
NS_ASSERTION(mExecutor->IsInFlushLoop(), "How are we here if "
"RunFlushLoop() didn't call ParseUntilBlocked() which is the "
"only caller of this method?");
mSpeculations.RemoveElementAt(0);
return;
}
// else
Interrupt(); // Make the parser thread release the tokenizer mutex sooner
// now fall through
// the first speculation is the current speculation. Need to
// release the the speculation mutex and acquire the tokenizer
// mutex. (Just acquiring the other mutex here would deadlock)
}
}
{
mozilla::MutexAutoLock tokenizerAutoLock(mTokenizerMutex);
#ifdef DEBUG
{
mAtomTable.SetPermittedLookupEventTarget(GetMainThreadSerialEventTarget());
}
#endif
// In principle, the speculation mutex should be acquired here,
// but there's no point, because the parser thread only acquires it
// when it has also acquired the tokenizer mutex and we are already
// holding the tokenizer mutex.
if (speculationFailed) {
// Rewind the stream
mAtEOF = false;
nsHtml5Speculation* speculation = mSpeculations.ElementAt(0);
mFirstBuffer = speculation->GetBuffer();
mFirstBuffer->setStart(speculation->GetStart());
mTokenizer->setLineNumber(speculation->GetStartLineNumber());
nsContentUtils::ReportToConsole(nsIScriptError::warningFlag,
NS_LITERAL_CSTRING("DOM Events"),
mExecutor->GetDocument(),
nsContentUtils::eDOM_PROPERTIES,
"SpeculationFailed",
nullptr, 0,
nullptr,
EmptyString(),
speculation->GetStartLineNumber());
nsHtml5OwningUTF16Buffer* buffer = mFirstBuffer->next;
while (buffer) {
buffer->setStart(0);
buffer = buffer->next;
}
mSpeculations.Clear(); // potentially a huge number of destructors
// run here synchronously on the main thread...
mTreeBuilder->flushCharacters(); // empty the pending buffer
mTreeBuilder->ClearOps(); // now get rid of the failed ops
mTreeBuilder->SetOpSink(mExecutor->GetStage());
mExecutor->StartReadingFromStage();
mSpeculating = false;
// Copy state over
mLastWasCR = aLastWasCR;
mTokenizer->loadState(aTokenizer);
mTreeBuilder->loadState(aTreeBuilder, &mAtomTable);
} else {
// We've got a successful speculation and at least a moment ago it was
// the current speculation
mSpeculations.ElementAt(0)->FlushToSink(mExecutor);
NS_ASSERTION(!mExecutor->IsScriptExecuting(),
"ParseUntilBlocked() was supposed to ensure we don't come "
"here when scripts are executing.");
NS_ASSERTION(mExecutor->IsInFlushLoop(), "How are we here if "
"RunFlushLoop() didn't call ParseUntilBlocked() which is the "
"only caller of this method?");
mSpeculations.RemoveElementAt(0);
if (mSpeculations.IsEmpty()) {
// yes, it was still the only speculation. Now stop speculating
// However, before telling the executor to read from stage, flush
// any pending ops straight to the executor, because otherwise
// they remain unflushed until we get more data from the network.
mTreeBuilder->SetOpSink(mExecutor);
mTreeBuilder->Flush(true);
mTreeBuilder->SetOpSink(mExecutor->GetStage());
mExecutor->StartReadingFromStage();
mSpeculating = false;
}
}
nsCOMPtr<nsIRunnable> event = new nsHtml5StreamParserContinuation(this);
if (NS_FAILED(mEventTarget->Dispatch(event, nsIThread::DISPATCH_NORMAL))) {
NS_WARNING("Failed to dispatch nsHtml5StreamParserContinuation");
}
// A stream event might run before this event runs, but that's harmless.
#ifdef DEBUG
mAtomTable.SetPermittedLookupEventTarget(mEventTarget);
#endif
}
}
void
nsHtml5StreamParser::ContinueAfterFailedCharsetSwitch()
{
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
nsCOMPtr<nsIRunnable> event = new nsHtml5StreamParserContinuation(this);
if (NS_FAILED(mEventTarget->Dispatch(event, nsIThread::DISPATCH_NORMAL))) {
NS_WARNING("Failed to dispatch nsHtml5StreamParserContinuation");
}
}
class nsHtml5TimerKungFu : public Runnable
{
private:
nsHtml5StreamParserPtr mStreamParser;
public:
explicit nsHtml5TimerKungFu(nsHtml5StreamParser* aStreamParser)
: Runnable("nsHtml5TimerKungFu")
, mStreamParser(aStreamParser)
{}
NS_IMETHOD Run() override
{
mozilla::MutexAutoLock flushTimerLock(mStreamParser->mFlushTimerMutex);
if (mStreamParser->mFlushTimer) {
mStreamParser->mFlushTimer->Cancel();
mStreamParser->mFlushTimer = nullptr;
}
return NS_OK;
}
};
void
nsHtml5StreamParser::DropTimer()
{
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
/*
* Simply nulling out the timer wouldn't work, because if the timer is
* armed, it needs to be canceled first. Simply canceling it first wouldn't
* work, because nsTimerImpl::Cancel is not safe for calling from outside
* the thread where nsTimerImpl::Fire would run. It's not safe to
* dispatch a runnable to cancel the timer from the destructor of this
* class, because the timer has a weak (void*) pointer back to this instance
* of the stream parser and having the timer fire before the runnable
* cancels it would make the timer access a deleted object.
*
* This DropTimer method addresses these issues. This method must be called
* on the main thread before the destructor of this class is reached.
* The nsHtml5TimerKungFu object has an nsHtml5StreamParserPtr that addrefs this
* stream parser object to keep it alive until the runnable is done.
* The runnable cancels the timer on the parser thread, drops the timer
* and lets nsHtml5StreamParserPtr send a runnable back to the main thread to
* release the stream parser.
*/
mozilla::MutexAutoLock flushTimerLock(mFlushTimerMutex);
if (mFlushTimer) {
nsCOMPtr<nsIRunnable> event = new nsHtml5TimerKungFu(this);
if (NS_FAILED(mEventTarget->Dispatch(event, nsIThread::DISPATCH_NORMAL))) {
NS_WARNING("Failed to dispatch TimerKungFu event");
}
}
}
// Using a static, because the method name Notify is taken by the chardet
// callback.
void
nsHtml5StreamParser::TimerCallback(nsITimer* aTimer, void* aClosure)
{
(static_cast<nsHtml5StreamParser*> (aClosure))->TimerFlush();
}
void
nsHtml5StreamParser::TimerFlush()
{
NS_ASSERTION(IsParserThread(), "Wrong thread!");
mozilla::MutexAutoLock autoLock(mTokenizerMutex);
NS_ASSERTION(!mSpeculating, "Flush timer fired while speculating.");
// The timer fired if we got here. No need to cancel it. Mark it as
// not armed, though.
mFlushTimerArmed = false;
mFlushTimerEverFired = true;
if (IsTerminatedOrInterrupted()) {
return;
}
if (mMode == VIEW_SOURCE_HTML || mMode == VIEW_SOURCE_XML) {
mTreeBuilder->Flush(); // delete useless ops
if (mTokenizer->FlushViewSource()) {
nsCOMPtr<nsIRunnable> runnable(mExecutorFlusher);
if (NS_FAILED(
DispatchToMain(runnable.forget()))) {
NS_WARNING("failed to dispatch executor flush event");
}
}
} else {
// we aren't speculating and we don't know when new data is
// going to arrive. Send data to the main thread.
if (mTreeBuilder->Flush(true)) {
nsCOMPtr<nsIRunnable> runnable(mExecutorFlusher);
if (NS_FAILED(
DispatchToMain(runnable.forget()))) {
NS_WARNING("failed to dispatch executor flush event");
}
}
}
}
void
nsHtml5StreamParser::MarkAsBroken(nsresult aRv)
{
NS_ASSERTION(IsParserThread(), "Wrong thread!");
mTokenizerMutex.AssertCurrentThreadOwns();
Terminate();
mTreeBuilder->MarkAsBroken(aRv);
mozilla::DebugOnly<bool> hadOps = mTreeBuilder->Flush(false);
NS_ASSERTION(hadOps, "Should have had the markAsBroken op!");
nsCOMPtr<nsIRunnable> runnable(mExecutorFlusher);
if (NS_FAILED(DispatchToMain(runnable.forget()))) {
NS_WARNING("failed to dispatch executor flush event");
}
}
nsresult
nsHtml5StreamParser::DispatchToMain(already_AddRefed<nsIRunnable>&& aRunnable)
{
if (mDocGroup) {
return mDocGroup->Dispatch(TaskCategory::Network, Move(aRunnable));
}
return SchedulerGroup::UnlabeledDispatch(TaskCategory::Network, Move(aRunnable));
}
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