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gecko-dev/parser/html/nsHtml5StreamParser.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* 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/. */
#ifndef nsHtml5StreamParser_h
#define nsHtml5StreamParser_h
#include "nsAutoPtr.h"
#include "nsCOMPtr.h"
#include "nsICharsetDetectionObserver.h"
#include "nsHtml5MetaScanner.h"
#include "nsIUnicodeDecoder.h"
#include "nsHtml5TreeOpExecutor.h"
#include "nsHtml5OwningUTF16Buffer.h"
#include "nsIInputStream.h"
#include "mozilla/Mutex.h"
#include "mozilla/UniquePtr.h"
#include "nsHtml5AtomTable.h"
#include "nsHtml5Speculation.h"
#include "nsITimer.h"
#include "nsICharsetDetector.h"
class nsHtml5Parser;
#define NS_HTML5_STREAM_PARSER_READ_BUFFER_SIZE 1024
#define NS_HTML5_STREAM_PARSER_SNIFFING_BUFFER_SIZE 1024
enum eParserMode {
/**
* Parse a document normally as HTML.
*/
NORMAL,
/**
* View document as HTML source.
*/
VIEW_SOURCE_HTML,
/**
* View document as XML source
*/
VIEW_SOURCE_XML,
/**
* View document as plain text source
*/
VIEW_SOURCE_PLAIN,
/**
* View document as plain text
*/
PLAIN_TEXT,
/**
* Load as data (XHR)
*/
LOAD_AS_DATA
};
enum eBomState {
/**
* BOM sniffing hasn't started.
*/
BOM_SNIFFING_NOT_STARTED = 0,
/**
* BOM sniffing is ongoing, and the first byte of an UTF-16LE BOM has been
* seen.
*/
SEEN_UTF_16_LE_FIRST_BYTE = 1,
/**
* BOM sniffing is ongoing, and the first byte of an UTF-16BE BOM has been
* seen.
*/
SEEN_UTF_16_BE_FIRST_BYTE = 2,
/**
* BOM sniffing is ongoing, and the first byte of an UTF-8 BOM has been
* seen.
*/
SEEN_UTF_8_FIRST_BYTE = 3,
/**
* BOM sniffing is ongoing, and the first and second bytes of an UTF-8 BOM
* have been seen.
*/
SEEN_UTF_8_SECOND_BYTE = 4,
/**
* BOM sniffing was started but is now over for whatever reason.
*/
BOM_SNIFFING_OVER = 5
};
enum eHtml5StreamState {
STREAM_NOT_STARTED = 0,
STREAM_BEING_READ = 1,
STREAM_ENDED = 2
};
class nsHtml5StreamParser : public nsICharsetDetectionObserver {
friend class nsHtml5RequestStopper;
friend class nsHtml5DataAvailable;
friend class nsHtml5StreamParserContinuation;
friend class nsHtml5TimerKungFu;
public:
NS_DECL_AND_IMPL_ZEROING_OPERATOR_NEW
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(nsHtml5StreamParser,
nsICharsetDetectionObserver)
static void InitializeStatics();
nsHtml5StreamParser(nsHtml5TreeOpExecutor* aExecutor,
nsHtml5Parser* aOwner,
eParserMode aMode);
// Methods that nsHtml5StreamListener calls
nsresult CheckListenerChain();
nsresult OnStartRequest(nsIRequest* aRequest, nsISupports* aContext);
nsresult OnDataAvailable(nsIRequest* aRequest,
nsISupports* aContext,
nsIInputStream* aInStream,
uint64_t aSourceOffset,
uint32_t aLength);
nsresult OnStopRequest(nsIRequest* aRequest,
nsISupports* aContext,
nsresult status);
// nsICharsetDetectionObserver
/**
* Chardet calls this to report the detection result
*/
NS_IMETHOD Notify(const char* aCharset, nsDetectionConfident aConf) override;
// EncodingDeclarationHandler
// http://hg.mozilla.org/projects/htmlparser/file/tip/src/nu/validator/htmlparser/common/EncodingDeclarationHandler.java
/**
* Tree builder uses this to report a late <meta charset>
*/
bool internalEncodingDeclaration(nsString* aEncoding);
// Not from an external interface
/**
* 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
*/
inline void SetDocumentCharset(const nsACString& aCharset, int32_t aSource) {
NS_PRECONDITION(mStreamState == STREAM_NOT_STARTED,
"SetDocumentCharset called too late.");
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
mCharset = aCharset;
mCharsetSource = aSource;
}
inline void SetObserver(nsIRequestObserver* aObserver) {
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
mObserver = aObserver;
}
nsresult GetChannel(nsIChannel** aChannel);
/**
* The owner parser must call this after script execution
* when no scripts are executing and the document.written
* buffer has been exhausted.
*/
void ContinueAfterScripts(nsHtml5Tokenizer* aTokenizer,
nsHtml5TreeBuilder* aTreeBuilder,
bool aLastWasCR);
/**
* Continues the stream parser if the charset switch failed.
*/
void ContinueAfterFailedCharsetSwitch();
void Terminate()
{
mozilla::MutexAutoLock autoLock(mTerminatedMutex);
mTerminated = true;
}
void DropTimer();
/**
* Sets mCharset and mCharsetSource appropriately for the XML View Source
* case if aEncoding names a supported rough ASCII superset and sets
* the mCharset and mCharsetSource to the UTF-8 default otherwise.
*/
void SetEncodingFromExpat(const char16_t* aEncoding);
/**
* Sets the URL for View Source title in case this parser ends up being
* used for View Source. If aURL is a view-source: URL, takes the inner
* URL. data: URLs are shown with an ellipsis instead of the actual data.
*/
void SetViewSourceTitle(nsIURI* aURL);
private:
virtual ~nsHtml5StreamParser();
#ifdef DEBUG
bool IsParserThread() {
bool ret;
mThread->IsOnCurrentThread(&ret);
return ret;
}
#endif
void MarkAsBroken(nsresult aRv);
/**
* Marks the stream parser as interrupted. If you ever add calls to this
* method, be sure to review Uninterrupt usage very, very carefully to
* avoid having a previous in-flight runnable cancel your Interrupt()
* call on the other thread too soon.
*/
void Interrupt()
{
mozilla::MutexAutoLock autoLock(mTerminatedMutex);
mInterrupted = true;
}
void Uninterrupt()
{
NS_ASSERTION(IsParserThread(), "Wrong thread!");
mTokenizerMutex.AssertCurrentThreadOwns();
// Not acquiring mTerminatedMutex because mTokenizerMutex is already
// held at this point and is already stronger.
mInterrupted = false;
}
/**
* Flushes the tree ops from the tree builder and disarms the flush
* timer.
*/
void FlushTreeOpsAndDisarmTimer();
void ParseAvailableData();
void DoStopRequest();
void DoDataAvailable(const uint8_t* aBuffer, uint32_t aLength);
static NS_METHOD CopySegmentsToParser(nsIInputStream *aInStream,
void *aClosure,
const char *aFromSegment,
uint32_t aToOffset,
uint32_t aCount,
uint32_t *aWriteCount);
bool IsTerminatedOrInterrupted()
{
mozilla::MutexAutoLock autoLock(mTerminatedMutex);
return mTerminated || mInterrupted;
}
bool IsTerminated()
{
mozilla::MutexAutoLock autoLock(mTerminatedMutex);
return mTerminated;
}
/**
* True when there is a Unicode decoder already
*/
inline bool HasDecoder()
{
return !!mUnicodeDecoder;
}
/**
* Push bytes from network when there is no Unicode decoder yet
*/
nsresult SniffStreamBytes(const uint8_t* aFromSegment,
uint32_t aCount,
uint32_t* aWriteCount);
/**
* Push bytes from network when there is a Unicode decoder already
*/
nsresult WriteStreamBytes(const uint8_t* aFromSegment,
uint32_t aCount,
uint32_t* aWriteCount);
/**
* Check whether every other byte in the sniffing buffer is zero.
*/
void SniffBOMlessUTF16BasicLatin(const uint8_t* aFromSegment,
uint32_t aCountToSniffingLimit);
/**
* <meta charset> scan failed. Try chardet if applicable. After this, the
* the parser will have some encoding even if a last resolt fallback.
*
* @param aFromSegment The current network buffer or null if the sniffing
* buffer is being flushed due to network stream ending.
* @param aCount The number of bytes in aFromSegment (ignored if
* aFromSegment is null)
* @param aWriteCount Return value for how many bytes got read from the
* buffer.
* @param aCountToSniffingLimit The number of unfilled slots in
* mSniffingBuffer
*/
nsresult FinalizeSniffing(const uint8_t* aFromSegment,
uint32_t aCount,
uint32_t* aWriteCount,
uint32_t aCountToSniffingLimit);
/**
* Set up the Unicode decoder and write the sniffing buffer into it
* followed by the current network buffer.
*
* @param aFromSegment The current network buffer or null if the sniffing
* buffer is being flushed due to network stream ending.
* @param aCount The number of bytes in aFromSegment (ignored if
* aFromSegment is null)
* @param aWriteCount Return value for how many bytes got read from the
* buffer.
*/
nsresult SetupDecodingAndWriteSniffingBufferAndCurrentSegment(const uint8_t* aFromSegment,
uint32_t aCount,
uint32_t* aWriteCount);
/**
* Initialize the Unicode decoder, mark the BOM as the source and
* drop the sniffer.
*
* @param aDecoderCharsetName The name for the decoder's charset
* (UTF-16BE, UTF-16LE or UTF-8; the BOM has
* been swallowed)
*/
nsresult SetupDecodingFromBom(const char* aDecoderCharsetName);
/**
* Become confident or resolve and encoding name to its preferred form.
* @param aEncoding the value of an internal encoding decl. Acts as an
* out param, too, when the method returns true.
* @return true if the parser needs to start using the new value of
* aEncoding and false if the parser became confident or if
* the encoding name did not specify a usable encoding
*/
bool PreferredForInternalEncodingDecl(nsACString& aEncoding);
/**
* Callback for mFlushTimer.
*/
static void TimerCallback(nsITimer* aTimer, void* aClosure);
/**
* Parser thread entry point for (maybe) flushing the ops and posting
* a flush runnable back on the main thread.
*/
void TimerFlush();
/**
* Called when speculation fails.
*/
void MaybeDisableFutureSpeculation()
{
mSpeculationFailureCount++;
}
/**
* Used to check whether we're getting too many speculation failures and
* should just stop trying. The 100 is picked pretty randomly to be not too
* small (so most pages are not affected) but small enough that we don't end
* up with failed speculations over and over in pathological cases.
*/
bool IsSpeculationEnabled()
{
return mSpeculationFailureCount < 100;
}
nsCOMPtr<nsIRequest> mRequest;
nsCOMPtr<nsIRequestObserver> mObserver;
/**
* The document title to use if this turns out to be a View Source parser.
*/
nsCString mViewSourceTitle;
/**
* The Unicode decoder
*/
nsCOMPtr<nsIUnicodeDecoder> mUnicodeDecoder;
/**
* The buffer for sniffing the character encoding
*/
mozilla::UniquePtr<uint8_t[]> mSniffingBuffer;
/**
* The number of meaningful bytes in mSniffingBuffer
*/
uint32_t mSniffingLength;
/**
* BOM sniffing state
*/
eBomState mBomState;
/**
* <meta> prescan implementation
*/
nsAutoPtr<nsHtml5MetaScanner> mMetaScanner;
// encoding-related stuff
/**
* The source (confidence) of the character encoding in use
*/
int32_t mCharsetSource;
/**
* The character encoding in use
*/
nsCString mCharset;
/**
* Whether reparse is forbidden
*/
bool mReparseForbidden;
// Portable parser objects
/**
* The first buffer in the pending UTF-16 buffer queue
*/
RefPtr<nsHtml5OwningUTF16Buffer> mFirstBuffer;
/**
* The last buffer in the pending UTF-16 buffer queue
*/
nsHtml5OwningUTF16Buffer* mLastBuffer; // weak ref; always points to
// a buffer of the size NS_HTML5_STREAM_PARSER_READ_BUFFER_SIZE
/**
* The tree operation executor
*/
nsHtml5TreeOpExecutor* mExecutor;
/**
* The HTML5 tree builder
*/
nsAutoPtr<nsHtml5TreeBuilder> mTreeBuilder;
/**
* The HTML5 tokenizer
*/
nsAutoPtr<nsHtml5Tokenizer> mTokenizer;
/**
* Makes sure the main thread can't mess the tokenizer state while it's
* tokenizing. This mutex also protects the current speculation.
*/
mozilla::Mutex mTokenizerMutex;
/**
* The scoped atom table
*/
nsHtml5AtomTable mAtomTable;
/**
* The owner parser.
*/
RefPtr<nsHtml5Parser> mOwner;
/**
* Whether the last character tokenized was a carriage return (for CRLF)
*/
bool mLastWasCR;
/**
* For tracking stream life cycle
*/
eHtml5StreamState mStreamState;
/**
* Whether we are speculating.
*/
bool mSpeculating;
/**
* Whether the tokenizer has reached EOF. (Reset when stream rewinded.)
*/
bool mAtEOF;
/**
* The speculations. The mutex protects the nsTArray itself.
* To access the queue of current speculation, mTokenizerMutex must be
* obtained.
* The current speculation is the last element
*/
nsTArray<nsAutoPtr<nsHtml5Speculation> > mSpeculations;
mozilla::Mutex mSpeculationMutex;
/**
* Number of times speculation has failed for this parser.
*/
uint32_t mSpeculationFailureCount;
/**
* True to terminate early; protected by mTerminatedMutex
*/
bool mTerminated;
bool mInterrupted;
mozilla::Mutex mTerminatedMutex;
/**
* The thread this stream parser runs on.
*/
nsCOMPtr<nsIThread> mThread;
nsCOMPtr<nsIRunnable> mExecutorFlusher;
nsCOMPtr<nsIRunnable> mLoadFlusher;
/**
* The chardet instance if chardet is enabled.
*/
nsCOMPtr<nsICharsetDetector> mChardet;
/**
* If false, don't push data to chardet.
*/
bool mFeedChardet;
/**
* Whether the initial charset source was kCharsetFromParentFrame
*/
bool mInitialEncodingWasFromParentFrame;
/**
* Timer for flushing tree ops once in a while when not speculating.
*/
nsCOMPtr<nsITimer> mFlushTimer;
/**
* Keeps track whether mFlushTimer has been armed. Unfortunately,
* nsITimer doesn't enable querying this from the timer itself.
*/
bool mFlushTimerArmed;
/**
* False initially and true after the timer has fired at least once.
*/
bool mFlushTimerEverFired;
/**
* Whether the parser is doing a normal parse, view source or plain text.
*/
eParserMode mMode;
/**
* The pref html5.flushtimer.initialdelay: Time in milliseconds between
* the time a network buffer is seen and the timer firing when the
* timer hasn't fired previously in this parse.
*/
static int32_t sTimerInitialDelay;
/**
* The pref html5.flushtimer.subsequentdelay: Time in milliseconds between
* the time a network buffer is seen and the timer firing when the
* timer has already fired previously in this parse.
*/
static int32_t sTimerSubsequentDelay;
};
#endif // nsHtml5StreamParser_h
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