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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
commit36d22d82aa202bb199967e9512281e9a53db42c9 (patch)
tree105e8c98ddea1c1e4784a60a5a6410fa416be2de /parser/htmlparser/nsParser.cpp
parentInitial commit. (diff)
downloadfirefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz
firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'parser/htmlparser/nsParser.cpp')
-rw-r--r--parser/htmlparser/nsParser.cpp1075
1 files changed, 1075 insertions, 0 deletions
diff --git a/parser/htmlparser/nsParser.cpp b/parser/htmlparser/nsParser.cpp
new file mode 100644
index 0000000000..04d02e2084
--- /dev/null
+++ b/parser/htmlparser/nsParser.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=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/. */
+
+#include "nsAtom.h"
+#include "nsParser.h"
+#include "nsString.h"
+#include "nsCRT.h"
+#include "nsScanner.h"
+#include "plstr.h"
+#include "nsIChannel.h"
+#include "nsIInputStream.h"
+#include "CNavDTD.h"
+#include "prenv.h"
+#include "prlock.h"
+#include "prcvar.h"
+#include "nsReadableUtils.h"
+#include "nsCOMPtr.h"
+#include "nsExpatDriver.h"
+#include "nsIFragmentContentSink.h"
+#include "nsStreamUtils.h"
+#include "nsXPCOMCIDInternal.h"
+#include "nsMimeTypes.h"
+#include "nsCharsetSource.h"
+#include "nsThreadUtils.h"
+#include "nsIHTMLContentSink.h"
+
+#include "mozilla/BinarySearch.h"
+#include "mozilla/CondVar.h"
+#include "mozilla/dom/ScriptLoader.h"
+#include "mozilla/Encoding.h"
+#include "mozilla/Mutex.h"
+
+using namespace mozilla;
+
+#define NS_PARSER_FLAG_PENDING_CONTINUE_EVENT 0x00000001
+#define NS_PARSER_FLAG_CAN_TOKENIZE 0x00000002
+
+//-------------- Begin ParseContinue Event Definition ------------------------
+/*
+The parser can be explicitly interrupted by passing a return value of
+NS_ERROR_HTMLPARSER_INTERRUPTED from BuildModel on the DTD. This will cause
+the parser to stop processing and allow the application to return to the event
+loop. The data which was left at the time of interruption will be processed
+the next time OnDataAvailable is called. If the parser has received its final
+chunk of data then OnDataAvailable will no longer be called by the networking
+module, so the parser will schedule a nsParserContinueEvent which will call
+the parser to process the remaining data after returning to the event loop.
+If the parser is interrupted while processing the remaining data it will
+schedule another ParseContinueEvent. The processing of data followed by
+scheduling of the continue events will proceed until either:
+
+ 1) All of the remaining data can be processed without interrupting
+ 2) The parser has been cancelled.
+
+
+This capability is currently used in CNavDTD and nsHTMLContentSink. The
+nsHTMLContentSink is notified by CNavDTD when a chunk of tokens is going to be
+processed and when each token is processed. The nsHTML content sink records
+the time when the chunk has started processing and will return
+NS_ERROR_HTMLPARSER_INTERRUPTED if the token processing time has exceeded a
+threshold called max tokenizing processing time. This allows the content sink
+to limit how much data is processed in a single chunk which in turn gates how
+much time is spent away from the event loop. Processing smaller chunks of data
+also reduces the time spent in subsequent reflows.
+
+This capability is most apparent when loading large documents. If the maximum
+token processing time is set small enough the application will remain
+responsive during document load.
+
+A side-effect of this capability is that document load is not complete when
+the last chunk of data is passed to OnDataAvailable since the parser may have
+been interrupted when the last chunk of data arrived. The document is complete
+when all of the document has been tokenized and there aren't any pending
+nsParserContinueEvents. This can cause problems if the application assumes
+that it can monitor the load requests to determine when the document load has
+been completed. This is what happens in Mozilla. The document is considered
+completely loaded when all of the load requests have been satisfied. To delay
+the document load until all of the parsing has been completed the
+nsHTMLContentSink adds a dummy parser load request which is not removed until
+the nsHTMLContentSink's DidBuildModel is called. The CNavDTD will not call
+DidBuildModel until the final chunk of data has been passed to the parser
+through the OnDataAvailable and there aren't any pending
+nsParserContineEvents.
+
+Currently the parser is ignores requests to be interrupted during the
+processing of script. This is because a document.write followed by JavaScript
+calls to manipulate the DOM may fail if the parser was interrupted during the
+document.write.
+
+For more details @see bugzilla bug 76722
+*/
+
+class nsParserContinueEvent : public Runnable {
+ public:
+ RefPtr<nsParser> mParser;
+
+ explicit nsParserContinueEvent(nsParser* aParser)
+ : mozilla::Runnable("nsParserContinueEvent"), mParser(aParser) {}
+
+ NS_IMETHOD Run() override {
+ mParser->HandleParserContinueEvent(this);
+ return NS_OK;
+ }
+};
+
+//-------------- End ParseContinue Event Definition ------------------------
+
+/**
+ * default constructor
+ */
+nsParser::nsParser() : mCharset(WINDOWS_1252_ENCODING) { Initialize(); }
+
+nsParser::~nsParser() { Cleanup(); }
+
+void nsParser::Initialize() {
+ mContinueEvent = nullptr;
+ mCharsetSource = kCharsetUninitialized;
+ mCharset = WINDOWS_1252_ENCODING;
+ mInternalState = NS_OK;
+ mStreamStatus = NS_OK;
+ mCommand = eViewNormal;
+ mBlocked = 0;
+ mFlags = NS_PARSER_FLAG_CAN_TOKENIZE;
+
+ mProcessingNetworkData = false;
+ mIsAboutBlank = false;
+}
+
+void nsParser::Cleanup() {
+ // It should not be possible for this flag to be set when we are getting
+ // destroyed since this flag implies a pending nsParserContinueEvent, which
+ // has an owning reference to |this|.
+ NS_ASSERTION(!(mFlags & NS_PARSER_FLAG_PENDING_CONTINUE_EVENT), "bad");
+}
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(nsParser)
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsParser)
+ NS_IMPL_CYCLE_COLLECTION_UNLINK(mDTD)
+ NS_IMPL_CYCLE_COLLECTION_UNLINK(mSink)
+ NS_IMPL_CYCLE_COLLECTION_UNLINK_WEAK_REFERENCE
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsParser)
+ NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mDTD)
+ NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mSink)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(nsParser)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(nsParser)
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsParser)
+ NS_INTERFACE_MAP_ENTRY(nsIStreamListener)
+ NS_INTERFACE_MAP_ENTRY(nsIParser)
+ NS_INTERFACE_MAP_ENTRY(nsIRequestObserver)
+ NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
+ NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIParser)
+NS_INTERFACE_MAP_END
+
+// The parser continue event is posted only if
+// all of the data to parse has been passed to ::OnDataAvailable
+// and the parser has been interrupted by the content sink
+// because the processing of tokens took too long.
+
+nsresult nsParser::PostContinueEvent() {
+ if (!(mFlags & NS_PARSER_FLAG_PENDING_CONTINUE_EVENT)) {
+ // If this flag isn't set, then there shouldn't be a live continue event!
+ NS_ASSERTION(!mContinueEvent, "bad");
+
+ // This creates a reference cycle between this and the event that is
+ // broken when the event fires.
+ nsCOMPtr<nsIRunnable> event = new nsParserContinueEvent(this);
+ if (NS_FAILED(NS_DispatchToCurrentThread(event))) {
+ NS_WARNING("failed to dispatch parser continuation event");
+ } else {
+ mFlags |= NS_PARSER_FLAG_PENDING_CONTINUE_EVENT;
+ mContinueEvent = event;
+ }
+ }
+ return NS_OK;
+}
+
+NS_IMETHODIMP_(void)
+nsParser::GetCommand(nsCString& aCommand) { aCommand = mCommandStr; }
+
+/**
+ * Call this method once you've created a parser, and want to instruct it
+ * about the command which caused the parser to be constructed. For example,
+ * this allows us to select a DTD which can do, say, view-source.
+ *
+ * @param aCommand the command string to set
+ */
+NS_IMETHODIMP_(void)
+nsParser::SetCommand(const char* aCommand) {
+ mCommandStr.Assign(aCommand);
+ if (mCommandStr.EqualsLiteral("view-source")) {
+ mCommand = eViewSource;
+ } else if (mCommandStr.EqualsLiteral("view-fragment")) {
+ mCommand = eViewFragment;
+ } else {
+ mCommand = eViewNormal;
+ }
+}
+
+/**
+ * Call this method once you've created a parser, and want to instruct it
+ * about the command which caused the parser to be constructed. For example,
+ * this allows us to select a DTD which can do, say, view-source.
+ *
+ * @param aParserCommand the command to set
+ */
+NS_IMETHODIMP_(void)
+nsParser::SetCommand(eParserCommands aParserCommand) {
+ mCommand = aParserCommand;
+}
+
+/**
+ * Call this method once you've created a parser, and want to instruct it
+ * about what charset to load
+ *
+ * @param aCharset- the charset of a document
+ * @param aCharsetSource- the source of the charset
+ */
+void nsParser::SetDocumentCharset(NotNull<const Encoding*> aCharset,
+ int32_t aCharsetSource,
+ bool aForceAutoDetection) {
+ mCharset = aCharset;
+ mCharsetSource = aCharsetSource;
+ if (mParserContext) {
+ mParserContext->mScanner.SetDocumentCharset(aCharset, aCharsetSource);
+ }
+}
+
+void nsParser::SetSinkCharset(NotNull<const Encoding*> aCharset) {
+ if (mSink) {
+ mSink->SetDocumentCharset(aCharset);
+ }
+}
+
+/**
+ * This method gets called in order to set the content
+ * sink for this parser to dump nodes to.
+ *
+ * @param nsIContentSink interface for node receiver
+ */
+NS_IMETHODIMP_(void)
+nsParser::SetContentSink(nsIContentSink* aSink) {
+ MOZ_ASSERT(aSink, "sink cannot be null!");
+ mSink = aSink;
+
+ if (mSink) {
+ mSink->SetParser(this);
+ nsCOMPtr<nsIHTMLContentSink> htmlSink = do_QueryInterface(mSink);
+ if (htmlSink) {
+ mIsAboutBlank = true;
+ }
+ }
+}
+
+/**
+ * retrieve the sink set into the parser
+ * @return current sink
+ */
+NS_IMETHODIMP_(nsIContentSink*)
+nsParser::GetContentSink() { return mSink; }
+
+////////////////////////////////////////////////////////////////////////
+
+/**
+ * This gets called just prior to the model actually
+ * being constructed. It's important to make this the
+ * last thing that happens right before parsing, so we
+ * can delay until the last moment the resolution of
+ * which DTD to use (unless of course we're assigned one).
+ */
+nsresult nsParser::WillBuildModel() {
+ if (!mParserContext) return NS_ERROR_HTMLPARSER_INVALIDPARSERCONTEXT;
+
+ if (mInternalState == NS_ERROR_OUT_OF_MEMORY) {
+ // Checking NS_ERROR_OUT_OF_MEMORY instead of NS_FAILED
+ // to avoid introducing unintentional changes to behavior.
+ return mInternalState;
+ }
+
+ if (eUnknownDetect != mParserContext->mAutoDetectStatus) return NS_OK;
+
+ if (eDTDMode_autodetect == mParserContext->mDTDMode) {
+ if (mIsAboutBlank) {
+ mParserContext->mDTDMode = eDTDMode_quirks;
+ mParserContext->mDocType = eHTML_Quirks;
+ } else {
+ mParserContext->mDTDMode = eDTDMode_full_standards;
+ mParserContext->mDocType = eXML;
+ }
+ } // else XML fragment with nested parser context
+
+ // We always find a DTD.
+ mParserContext->mAutoDetectStatus = ePrimaryDetect;
+
+ // Quick check for view source.
+ MOZ_ASSERT(mParserContext->mParserCommand != eViewSource,
+ "The old parser is not supposed to be used for View Source "
+ "anymore.");
+
+ // Now see if we're parsing XML or HTML (which, as far as we're concerned,
+ // simply means "not XML").
+ if (mParserContext->mDocType == eXML) {
+ RefPtr<nsExpatDriver> expat = new nsExpatDriver();
+ nsresult rv = expat->Initialize(mParserContext->mScanner.GetURI(), mSink);
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ mDTD = expat.forget();
+ } else {
+ mDTD = new CNavDTD();
+ }
+
+ return mSink->WillBuildModel(mParserContext->mDTDMode);
+}
+
+/**
+ * This gets called when the parser is done with its input.
+ */
+void nsParser::DidBuildModel() {
+ if (IsComplete() && mParserContext) {
+ // Let sink know if we're about to end load because we've been terminated.
+ // In that case we don't want it to run deferred scripts.
+ bool terminated = mInternalState == NS_ERROR_HTMLPARSER_STOPPARSING;
+ if (mDTD && mSink) {
+ mDTD->DidBuildModel();
+ mSink->DidBuildModel(terminated);
+ }
+
+ // Ref. to bug 61462.
+ mParserContext->mRequest = nullptr;
+ }
+}
+
+/**
+ * Call this when you want to *force* the parser to terminate the
+ * parsing process altogether. This is binary -- so once you terminate
+ * you can't resume without restarting altogether.
+ */
+NS_IMETHODIMP
+nsParser::Terminate(void) {
+ // We should only call DidBuildModel once, so don't do anything if this is
+ // the second time that Terminate has been called.
+ if (mInternalState == NS_ERROR_HTMLPARSER_STOPPARSING) {
+ return NS_OK;
+ }
+
+ nsresult result = NS_OK;
+ // XXX - [ until we figure out a way to break parser-sink circularity ]
+ // Hack - Hold a reference until we are completely done...
+ nsCOMPtr<nsIParser> kungFuDeathGrip(this);
+ mInternalState = result = NS_ERROR_HTMLPARSER_STOPPARSING;
+
+ // @see bug 108049
+ // If NS_PARSER_FLAG_PENDING_CONTINUE_EVENT is set then reset it so
+ // DidBuildModel will call DidBuildModel on the DTD. Note: The IsComplete()
+ // call inside of DidBuildModel looks at the pendingContinueEvents flag.
+ if (mFlags & NS_PARSER_FLAG_PENDING_CONTINUE_EVENT) {
+ NS_ASSERTION(mContinueEvent, "mContinueEvent is null");
+ // Revoke the pending continue parsing event
+ mContinueEvent = nullptr;
+ mFlags &= ~NS_PARSER_FLAG_PENDING_CONTINUE_EVENT;
+ }
+
+ if (mDTD) {
+ mDTD->Terminate();
+ DidBuildModel();
+ } else if (mSink) {
+ // We have no parser context or no DTD yet (so we got terminated before we
+ // got any data). Manually break the reference cycle with the sink.
+ result = mSink->DidBuildModel(true);
+ NS_ENSURE_SUCCESS(result, result);
+ }
+
+ return NS_OK;
+}
+
+NS_IMETHODIMP
+nsParser::ContinueInterruptedParsing() {
+ if (mInternalState == NS_ERROR_OUT_OF_MEMORY) {
+ // Checking NS_ERROR_OUT_OF_MEMORY instead of NS_FAILED
+ // to avoid introducing unintentional changes to behavior.
+ return mInternalState;
+ }
+
+ // If there are scripts executing, then the content sink is jumping the gun
+ // (probably due to a synchronous XMLHttpRequest) and will re-enable us
+ // later, see bug 460706.
+ if (!IsOkToProcessNetworkData()) {
+ return NS_OK;
+ }
+
+ // If the stream has already finished, there's a good chance
+ // that we might start closing things down when the parser
+ // is reenabled. To make sure that we're not deleted across
+ // the reenabling process, hold a reference to ourselves.
+ nsresult result = NS_OK;
+ nsCOMPtr<nsIParser> kungFuDeathGrip(this);
+ nsCOMPtr<nsIContentSink> sinkDeathGrip(mSink);
+
+#ifdef DEBUG
+ if (mBlocked) {
+ NS_WARNING("Don't call ContinueInterruptedParsing on a blocked parser.");
+ }
+#endif
+
+ bool isFinalChunk =
+ mParserContext && mParserContext->mStreamListenerState == eOnStop;
+
+ mProcessingNetworkData = true;
+ if (sinkDeathGrip) {
+ sinkDeathGrip->WillParse();
+ }
+ result = ResumeParse(true, isFinalChunk); // Ref. bug 57999
+ mProcessingNetworkData = false;
+
+ if (result != NS_OK) {
+ result = mInternalState;
+ }
+
+ return result;
+}
+
+/**
+ * Stops parsing temporarily. That is, it will prevent the
+ * parser from building up content model while scripts
+ * are being loaded (either an external script from a web
+ * page, or any number of extension content scripts).
+ */
+NS_IMETHODIMP_(void)
+nsParser::BlockParser() { mBlocked++; }
+
+/**
+ * Open up the parser for tokenization, building up content
+ * model..etc. However, this method does not resume parsing
+ * automatically. It's the callers' responsibility to restart
+ * the parsing engine.
+ */
+NS_IMETHODIMP_(void)
+nsParser::UnblockParser() {
+ MOZ_DIAGNOSTIC_ASSERT(mBlocked > 0);
+ if (MOZ_LIKELY(mBlocked > 0)) {
+ mBlocked--;
+ }
+}
+
+NS_IMETHODIMP_(void)
+nsParser::ContinueInterruptedParsingAsync() {
+ MOZ_ASSERT(mSink);
+ if (MOZ_LIKELY(mSink)) {
+ mSink->ContinueInterruptedParsingAsync();
+ }
+}
+
+/**
+ * Call this to query whether the parser is enabled or not.
+ */
+NS_IMETHODIMP_(bool)
+nsParser::IsParserEnabled() { return !mBlocked; }
+
+/**
+ * Call this to query whether the parser thinks it's done with parsing.
+ */
+NS_IMETHODIMP_(bool)
+nsParser::IsComplete() {
+ return !(mFlags & NS_PARSER_FLAG_PENDING_CONTINUE_EVENT);
+}
+
+void nsParser::HandleParserContinueEvent(nsParserContinueEvent* ev) {
+ // Ignore any revoked continue events...
+ if (mContinueEvent != ev) return;
+
+ mFlags &= ~NS_PARSER_FLAG_PENDING_CONTINUE_EVENT;
+ mContinueEvent = nullptr;
+
+ NS_ASSERTION(IsOkToProcessNetworkData(),
+ "Interrupted in the middle of a script?");
+ ContinueInterruptedParsing();
+}
+
+bool nsParser::IsInsertionPointDefined() { return false; }
+
+void nsParser::IncrementScriptNestingLevel() {}
+
+void nsParser::DecrementScriptNestingLevel() {}
+
+bool nsParser::HasNonzeroScriptNestingLevel() const { return false; }
+
+bool nsParser::IsScriptCreated() { return false; }
+
+/**
+ * This is the main controlling routine in the parsing process.
+ * Note that it may get called multiple times for the same scanner,
+ * since this is a pushed based system, and all the tokens may
+ * not have been consumed by the scanner during a given invocation
+ * of this method.
+ */
+NS_IMETHODIMP
+nsParser::Parse(nsIURI* aURL) {
+ MOZ_ASSERT(aURL, "Error: Null URL given");
+
+ if (mInternalState == NS_ERROR_OUT_OF_MEMORY) {
+ // Checking NS_ERROR_OUT_OF_MEMORY instead of NS_FAILED
+ // to avoid introducing unintentional changes to behavior.
+ return mInternalState;
+ }
+
+ if (!aURL) {
+ return NS_ERROR_HTMLPARSER_BADURL;
+ }
+
+ MOZ_ASSERT(!mParserContext, "We expect mParserContext to be null.");
+
+ mParserContext = MakeUnique<CParserContext>(aURL, mCommand);
+
+ return NS_OK;
+}
+
+/**
+ * Used by XML fragment parsing below.
+ *
+ * @param aSourceBuffer contains a string-full of real content
+ */
+nsresult nsParser::Parse(const nsAString& aSourceBuffer, bool aLastCall) {
+ if (mInternalState == NS_ERROR_OUT_OF_MEMORY) {
+ // Checking NS_ERROR_OUT_OF_MEMORY instead of NS_FAILED
+ // to avoid introducing unintentional changes to behavior.
+ return mInternalState;
+ }
+
+ // Don't bother if we're never going to parse this.
+ if (mInternalState == NS_ERROR_HTMLPARSER_STOPPARSING) {
+ return NS_OK;
+ }
+
+ if (!aLastCall && aSourceBuffer.IsEmpty()) {
+ // Nothing is being passed to the parser so return
+ // immediately. mUnusedInput will get processed when
+ // some data is actually passed in.
+ // But if this is the last call, make sure to finish up
+ // stuff correctly.
+ return NS_OK;
+ }
+
+ // Maintain a reference to ourselves so we don't go away
+ // till we're completely done.
+ nsCOMPtr<nsIParser> kungFuDeathGrip(this);
+
+ if (!mParserContext) {
+ // Only make a new context if we don't have one.
+ mParserContext =
+ MakeUnique<CParserContext>(mUnusedInput, mCommand, aLastCall);
+
+ mUnusedInput.Truncate();
+ } else if (aLastCall) {
+ // Set stream listener state to eOnStop, on the final context - Fix
+ // 68160, to guarantee DidBuildModel() call - Fix 36148
+ mParserContext->mStreamListenerState = eOnStop;
+ mParserContext->mScanner.SetIncremental(false);
+ }
+
+ mParserContext->mScanner.Append(aSourceBuffer);
+ return ResumeParse(false, false, false);
+}
+
+nsresult nsParser::ParseFragment(const nsAString& aSourceBuffer,
+ nsTArray<nsString>& aTagStack) {
+ if (mInternalState == NS_ERROR_OUT_OF_MEMORY) {
+ // Checking NS_ERROR_OUT_OF_MEMORY instead of NS_FAILED
+ // to avoid introducing unintentional changes to behavior.
+ return mInternalState;
+ }
+
+ nsresult result = NS_OK;
+ nsAutoString theContext;
+ uint32_t theCount = aTagStack.Length();
+ uint32_t theIndex = 0;
+
+ for (theIndex = 0; theIndex < theCount; theIndex++) {
+ theContext.Append('<');
+ theContext.Append(aTagStack[theCount - theIndex - 1]);
+ theContext.Append('>');
+ }
+
+ if (theCount == 0) {
+ // Ensure that the buffer is not empty. Because none of the DTDs care
+ // about leading whitespace, this doesn't change the result.
+ theContext.Assign(' ');
+ }
+
+ // First, parse the context to build up the DTD's tag stack. Note that we
+ // pass false for the aLastCall parameter.
+ result = Parse(theContext, false);
+ if (NS_FAILED(result)) {
+ return result;
+ }
+
+ if (!mSink) {
+ // Parse must have failed in the XML case and so the sink was killed.
+ return NS_ERROR_HTMLPARSER_STOPPARSING;
+ }
+
+ nsCOMPtr<nsIFragmentContentSink> fragSink = do_QueryInterface(mSink);
+ NS_ASSERTION(fragSink, "ParseFragment requires a fragment content sink");
+
+ fragSink->WillBuildContent();
+ // Now, parse the actual content. Note that this is the last call
+ // for HTML content, but for XML, we will want to build and parse
+ // the end tags. However, if tagStack is empty, it's the last call
+ // for XML as well.
+ if (theCount == 0) {
+ result = Parse(aSourceBuffer, true);
+ fragSink->DidBuildContent();
+ } else {
+ // Add an end tag chunk, so expat will read the whole source buffer,
+ // and not worry about ']]' etc.
+ result = Parse(aSourceBuffer + u"</"_ns, false);
+ fragSink->DidBuildContent();
+
+ if (NS_SUCCEEDED(result)) {
+ nsAutoString endContext;
+ for (theIndex = 0; theIndex < theCount; theIndex++) {
+ // we already added an end tag chunk above
+ if (theIndex > 0) {
+ endContext.AppendLiteral("</");
+ }
+
+ nsString& thisTag = aTagStack[theIndex];
+ // was there an xmlns=?
+ int32_t endOfTag = thisTag.FindChar(char16_t(' '));
+ if (endOfTag == -1) {
+ endContext.Append(thisTag);
+ } else {
+ endContext.Append(Substring(thisTag, 0, endOfTag));
+ }
+
+ endContext.Append('>');
+ }
+
+ result = Parse(endContext, true);
+ }
+ }
+
+ mParserContext.reset();
+
+ return result;
+}
+
+/**
+ * This routine is called to cause the parser to continue parsing its
+ * underlying stream. This call allows the parse process to happen in
+ * chunks, such as when the content is push based, and we need to parse in
+ * pieces.
+ *
+ * An interesting change in how the parser gets used has led us to add extra
+ * processing to this method. The case occurs when the parser is blocked in
+ * one context, and gets a parse(string) call in another context. In this
+ * case, the parserContexts are linked. No problem.
+ *
+ * The problem is that Parse(string) assumes that it can proceed unabated,
+ * but if the parser is already blocked that assumption is false. So we
+ * needed to add a mechanism here to allow the parser to continue to process
+ * (the pop and free) contexts until 1) it get's blocked again; 2) it runs
+ * out of contexts.
+ *
+ *
+ * @param allowItertion : set to true if non-script resumption is requested
+ * @param aIsFinalChunk : tells us when the last chunk of data is provided.
+ * @return error code -- 0 if ok, non-zero if error.
+ */
+nsresult nsParser::ResumeParse(bool allowIteration, bool aIsFinalChunk,
+ bool aCanInterrupt) {
+ if (mInternalState == NS_ERROR_OUT_OF_MEMORY) {
+ // Checking NS_ERROR_OUT_OF_MEMORY instead of NS_FAILED
+ // to avoid introducing unintentional changes to behavior.
+ return mInternalState;
+ }
+
+ nsresult result = NS_OK;
+
+ if (!mBlocked && mInternalState != NS_ERROR_HTMLPARSER_STOPPARSING) {
+ result = WillBuildModel();
+ if (NS_FAILED(result)) {
+ mFlags &= ~NS_PARSER_FLAG_CAN_TOKENIZE;
+ return result;
+ }
+
+ if (mDTD) {
+ mSink->WillResume();
+ bool theIterationIsOk = true;
+
+ while (result == NS_OK && theIterationIsOk) {
+ if (!mUnusedInput.IsEmpty()) {
+ // -- Ref: Bug# 22485 --
+ // Insert the unused input into the source buffer
+ // as if it was read from the input stream.
+ // Adding UngetReadable() per vidur!!
+ mParserContext->mScanner.UngetReadable(mUnusedInput);
+ mUnusedInput.Truncate(0);
+ }
+
+ // Only allow parsing to be interrupted in the subsequent call to
+ // build model.
+ nsresult theTokenizerResult;
+ if (mFlags & NS_PARSER_FLAG_CAN_TOKENIZE) {
+ mParserContext->mScanner.Mark();
+ if (mParserContext->mDocType == eXML &&
+ mParserContext->mParserCommand != eViewSource) {
+ nsExpatDriver* expat = static_cast<nsExpatDriver*>(mDTD.get());
+ theTokenizerResult =
+ expat->ResumeParse(mParserContext->mScanner, aIsFinalChunk);
+ if (NS_FAILED(theTokenizerResult)) {
+ mParserContext->mScanner.RewindToMark();
+ if (NS_ERROR_HTMLPARSER_STOPPARSING == theTokenizerResult) {
+ theTokenizerResult = Terminate();
+ mSink = nullptr;
+ }
+ }
+ } else {
+ // Nothing to do for non-XML. Note that this should only be
+ // about:blank at this point, we're also checking for view-source
+ // above, but that shouldn't end up here anymore.
+ theTokenizerResult = NS_ERROR_HTMLPARSER_EOF;
+ }
+ } else {
+ theTokenizerResult = NS_OK;
+ }
+
+ result = mDTD->BuildModel(mSink);
+ if (result == NS_ERROR_HTMLPARSER_INTERRUPTED && aIsFinalChunk) {
+ PostContinueEvent();
+ }
+
+ theIterationIsOk = theTokenizerResult != NS_ERROR_HTMLPARSER_EOF &&
+ result != NS_ERROR_HTMLPARSER_INTERRUPTED;
+
+ // Make sure not to stop parsing too early. Therefore, before shutting
+ // down the parser, it's important to check whether the input buffer
+ // has been scanned to completion (theTokenizerResult should be kEOF).
+ // kEOF -> End of buffer.
+
+ // If we're told the parser has been blocked, we disable all further
+ // parsing (and cache any data coming in) until the parser is
+ // re-enabled.
+ if (NS_ERROR_HTMLPARSER_BLOCK == result) {
+ mSink->WillInterrupt();
+ return NS_OK;
+ }
+ if (NS_ERROR_HTMLPARSER_STOPPARSING == result) {
+ // Note: Parser Terminate() calls DidBuildModel.
+ if (mInternalState != NS_ERROR_HTMLPARSER_STOPPARSING) {
+ DidBuildModel();
+ mInternalState = result;
+ }
+
+ return NS_OK;
+ }
+ if (((NS_OK == result &&
+ theTokenizerResult == NS_ERROR_HTMLPARSER_EOF) ||
+ result == NS_ERROR_HTMLPARSER_INTERRUPTED) &&
+ mParserContext->mStreamListenerState == eOnStop) {
+ DidBuildModel();
+ return NS_OK;
+ }
+
+ if (theTokenizerResult == NS_ERROR_HTMLPARSER_EOF ||
+ result == NS_ERROR_HTMLPARSER_INTERRUPTED) {
+ result = (result == NS_ERROR_HTMLPARSER_INTERRUPTED) ? NS_OK : result;
+ mSink->WillInterrupt();
+ }
+ }
+ } else {
+ mInternalState = result = NS_ERROR_HTMLPARSER_UNRESOLVEDDTD;
+ }
+ }
+
+ return (result == NS_ERROR_HTMLPARSER_INTERRUPTED) ? NS_OK : result;
+}
+
+/*******************************************************************
+ These methods are used to talk to the netlib system...
+ *******************************************************************/
+
+nsresult nsParser::OnStartRequest(nsIRequest* request) {
+ if (mInternalState == NS_ERROR_OUT_OF_MEMORY) {
+ // Checking NS_ERROR_OUT_OF_MEMORY instead of NS_FAILED
+ // to avoid introducing unintentional changes to behavior.
+ return mInternalState;
+ }
+
+ MOZ_ASSERT(eNone == mParserContext->mStreamListenerState,
+ "Parser's nsIStreamListener API was not setup "
+ "correctly in constructor.");
+
+ mParserContext->mStreamListenerState = eOnStart;
+ mParserContext->mAutoDetectStatus = eUnknownDetect;
+ mParserContext->mRequest = request;
+
+ mDTD = nullptr;
+
+ nsresult rv;
+ nsAutoCString contentType;
+ nsCOMPtr<nsIChannel> channel = do_QueryInterface(request);
+ if (channel) {
+ rv = channel->GetContentType(contentType);
+ if (NS_SUCCEEDED(rv)) {
+ mParserContext->SetMimeType(contentType);
+ }
+ }
+
+ rv = NS_OK;
+
+ return rv;
+}
+
+static bool ExtractCharsetFromXmlDeclaration(const unsigned char* aBytes,
+ int32_t aLen,
+ nsCString& oCharset) {
+ // This code is rather pointless to have. Might as well reuse expat as
+ // seen in nsHtml5StreamParser. -- hsivonen
+ oCharset.Truncate();
+ if ((aLen >= 5) && ('<' == aBytes[0]) && ('?' == aBytes[1]) &&
+ ('x' == aBytes[2]) && ('m' == aBytes[3]) && ('l' == aBytes[4])) {
+ int32_t i;
+ bool versionFound = false, encodingFound = false;
+ for (i = 6; i < aLen && !encodingFound; ++i) {
+ // end of XML declaration?
+ if ((((char*)aBytes)[i] == '?') && ((i + 1) < aLen) &&
+ (((char*)aBytes)[i + 1] == '>')) {
+ break;
+ }
+ // Version is required.
+ if (!versionFound) {
+ // Want to avoid string comparisons, hence looking for 'n'
+ // and only if found check the string leading to it. Not
+ // foolproof, but fast.
+ // The shortest string allowed before this is (strlen==13):
+ // <?xml version
+ if ((((char*)aBytes)[i] == 'n') && (i >= 12) &&
+ (0 == strncmp("versio", (char*)(aBytes + i - 6), 6))) {
+ // Fast forward through version
+ char q = 0;
+ for (++i; i < aLen; ++i) {
+ char qi = ((char*)aBytes)[i];
+ if (qi == '\'' || qi == '"') {
+ if (q && q == qi) {
+ // ending quote
+ versionFound = true;
+ break;
+ } else {
+ // Starting quote
+ q = qi;
+ }
+ }
+ }
+ }
+ } else {
+ // encoding must follow version
+ // Want to avoid string comparisons, hence looking for 'g'
+ // and only if found check the string leading to it. Not
+ // foolproof, but fast.
+ // The shortest allowed string before this (strlen==26):
+ // <?xml version="1" encoding
+ if ((((char*)aBytes)[i] == 'g') && (i >= 25) &&
+ (0 == strncmp("encodin", (char*)(aBytes + i - 7), 7))) {
+ int32_t encStart = 0;
+ char q = 0;
+ for (++i; i < aLen; ++i) {
+ char qi = ((char*)aBytes)[i];
+ if (qi == '\'' || qi == '"') {
+ if (q && q == qi) {
+ int32_t count = i - encStart;
+ // encoding value is invalid if it is UTF-16
+ if (count > 0 &&
+ PL_strncasecmp("UTF-16", (char*)(aBytes + encStart),
+ count)) {
+ oCharset.Assign((char*)(aBytes + encStart), count);
+ }
+ encodingFound = true;
+ break;
+ } else {
+ encStart = i + 1;
+ q = qi;
+ }
+ }
+ }
+ }
+ } // if (!versionFound)
+ } // for
+ }
+ return !oCharset.IsEmpty();
+}
+
+inline char GetNextChar(nsACString::const_iterator& aStart,
+ nsACString::const_iterator& aEnd) {
+ NS_ASSERTION(aStart != aEnd, "end of buffer");
+ return (++aStart != aEnd) ? *aStart : '\0';
+}
+
+static nsresult NoOpParserWriteFunc(nsIInputStream* in, void* closure,
+ const char* fromRawSegment,
+ uint32_t toOffset, uint32_t count,
+ uint32_t* writeCount) {
+ *writeCount = count;
+ return NS_OK;
+}
+
+typedef struct {
+ bool mNeedCharsetCheck;
+ nsParser* mParser;
+ nsScanner* mScanner;
+ nsIRequest* mRequest;
+} ParserWriteStruct;
+
+/*
+ * This function is invoked as a result of a call to a stream's
+ * ReadSegments() method. It is called for each contiguous buffer
+ * of data in the underlying stream or pipe. Using ReadSegments
+ * allows us to avoid copying data to read out of the stream.
+ */
+static nsresult ParserWriteFunc(nsIInputStream* in, void* closure,
+ const char* fromRawSegment, uint32_t toOffset,
+ uint32_t count, uint32_t* writeCount) {
+ nsresult result;
+ ParserWriteStruct* pws = static_cast<ParserWriteStruct*>(closure);
+ const unsigned char* buf =
+ reinterpret_cast<const unsigned char*>(fromRawSegment);
+ uint32_t theNumRead = count;
+
+ if (!pws) {
+ return NS_ERROR_FAILURE;
+ }
+
+ if (pws->mNeedCharsetCheck) {
+ pws->mNeedCharsetCheck = false;
+ int32_t source;
+ auto preferred = pws->mParser->GetDocumentCharset(source);
+
+ // This code was bogus when I found it. It expects the BOM or the XML
+ // declaration to be entirely in the first network buffer. -- hsivonen
+ const Encoding* encoding;
+ std::tie(encoding, std::ignore) = Encoding::ForBOM(Span(buf, count));
+ if (encoding) {
+ // The decoder will swallow the BOM. The UTF-16 will re-sniff for
+ // endianness. The value of preferred is now "UTF-8", "UTF-16LE"
+ // or "UTF-16BE".
+ preferred = WrapNotNull(encoding);
+ source = kCharsetFromByteOrderMark;
+ } else if (source < kCharsetFromChannel) {
+ nsAutoCString declCharset;
+
+ if (ExtractCharsetFromXmlDeclaration(buf, count, declCharset)) {
+ encoding = Encoding::ForLabel(declCharset);
+ if (encoding) {
+ preferred = WrapNotNull(encoding);
+ source = kCharsetFromMetaTag;
+ }
+ }
+ }
+
+ pws->mParser->SetDocumentCharset(preferred, source, false);
+ pws->mParser->SetSinkCharset(preferred);
+ }
+
+ result = pws->mScanner->Append(fromRawSegment, theNumRead);
+ if (NS_SUCCEEDED(result)) {
+ *writeCount = count;
+ }
+
+ return result;
+}
+
+nsresult nsParser::OnDataAvailable(nsIRequest* request,
+ nsIInputStream* pIStream,
+ uint64_t sourceOffset, uint32_t aLength) {
+ if (mInternalState == NS_ERROR_OUT_OF_MEMORY) {
+ // Checking NS_ERROR_OUT_OF_MEMORY instead of NS_FAILED
+ // to avoid introducing unintentional changes to behavior.
+ return mInternalState;
+ }
+
+ MOZ_ASSERT((eOnStart == mParserContext->mStreamListenerState ||
+ eOnDataAvail == mParserContext->mStreamListenerState),
+ "Error: OnStartRequest() must be called before OnDataAvailable()");
+ MOZ_ASSERT(NS_InputStreamIsBuffered(pIStream),
+ "Must have a buffered input stream");
+
+ nsresult rv = NS_OK;
+
+ if (mIsAboutBlank) {
+ MOZ_ASSERT(false, "Must not get OnDataAvailable for about:blank");
+ // ... but if an extension tries to feed us data for about:blank in a
+ // release build, silently ignore the data.
+ uint32_t totalRead;
+ rv = pIStream->ReadSegments(NoOpParserWriteFunc, nullptr, aLength,
+ &totalRead);
+ return rv;
+ }
+
+ if (mParserContext->mRequest == request) {
+ mParserContext->mStreamListenerState = eOnDataAvail;
+
+ uint32_t totalRead;
+ ParserWriteStruct pws;
+ pws.mNeedCharsetCheck = true;
+ pws.mParser = this;
+ pws.mScanner = &mParserContext->mScanner;
+ pws.mRequest = request;
+
+ rv = pIStream->ReadSegments(ParserWriteFunc, &pws, aLength, &totalRead);
+ if (NS_FAILED(rv)) {
+ return rv;
+ }
+
+ if (IsOkToProcessNetworkData()) {
+ nsCOMPtr<nsIParser> kungFuDeathGrip(this);
+ nsCOMPtr<nsIContentSink> sinkDeathGrip(mSink);
+ mProcessingNetworkData = true;
+ if (sinkDeathGrip) {
+ sinkDeathGrip->WillParse();
+ }
+ rv = ResumeParse();
+ mProcessingNetworkData = false;
+ }
+ } else {
+ rv = NS_ERROR_UNEXPECTED;
+ }
+
+ return rv;
+}
+
+/**
+ * This is called by the networking library once the last block of data
+ * has been collected from the net.
+ */
+nsresult nsParser::OnStopRequest(nsIRequest* request, nsresult status) {
+ if (mInternalState == NS_ERROR_OUT_OF_MEMORY) {
+ // Checking NS_ERROR_OUT_OF_MEMORY instead of NS_FAILED
+ // to avoid introducing unintentional changes to behavior.
+ return mInternalState;
+ }
+
+ nsresult rv = NS_OK;
+
+ if (mParserContext->mRequest == request) {
+ mParserContext->mStreamListenerState = eOnStop;
+ mParserContext->mScanner.SetIncremental(false);
+ }
+
+ mStreamStatus = status;
+
+ if (IsOkToProcessNetworkData() && NS_SUCCEEDED(rv)) {
+ mProcessingNetworkData = true;
+ if (mSink) {
+ mSink->WillParse();
+ }
+ rv = ResumeParse(true, true);
+ mProcessingNetworkData = false;
+ }
+
+ // If the parser isn't enabled, we don't finish parsing till
+ // it is reenabled.
+
+ return rv;
+}
+
+/**
+ * Get this as nsIStreamListener
+ */
+nsIStreamListener* nsParser::GetStreamListener() { return this; }