gecko-dev/parser/htmlparser/nsScanner.h
2016-02-09 12:45:59 +02:00

231 lines
7.1 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/. */
/**
* MODULE NOTES:
* @update gess 4/1/98
*
* The scanner is a low-level service class that knows
* how to consume characters out of an (internal) stream.
* This class also offers a series of utility methods
* that most tokenizers want, such as readUntil()
* and SkipWhitespace().
*/
#ifndef SCANNER
#define SCANNER
#include "nsCOMPtr.h"
#include "nsString.h"
#include "nsIParser.h"
#include "nsIUnicodeDecoder.h"
#include "nsScannerString.h"
class nsReadEndCondition {
public:
const char16_t *mChars;
char16_t mFilter;
explicit nsReadEndCondition(const char16_t* aTerminateChars);
private:
nsReadEndCondition(const nsReadEndCondition& aOther); // No copying
void operator=(const nsReadEndCondition& aOther); // No assigning
};
class nsScanner {
public:
/**
* Use this constructor for the XML fragment parsing case
*/
explicit nsScanner(const nsAString& anHTMLString);
/**
* Use this constructor if you want i/o to be based on
* a file (therefore a stream) or just data you provide via Append().
*/
nsScanner(nsString& aFilename, bool aCreateStream);
~nsScanner();
/**
* retrieve next char from internal input stream
*
* @update gess 3/25/98
* @param ch is the char to accept new value
* @return error code reflecting read status
*/
nsresult GetChar(char16_t& ch);
/**
* peek ahead to consume next char from scanner's internal
* input buffer
*
* @update gess 3/25/98
* @param ch is the char to accept new value
* @return error code reflecting read status
*/
nsresult Peek(char16_t& ch, uint32_t aOffset=0);
nsresult Peek(nsAString& aStr, int32_t aNumChars, int32_t aOffset = 0);
/**
* Records current offset position in input stream. This allows us
* to back up to this point if the need should arise, such as when
* tokenization gets interrupted.
*
* @update gess 5/12/98
* @param
* @return
*/
int32_t Mark(void);
/**
* Resets current offset position of input stream to marked position.
* This allows us to back up to this point if the need should arise,
* such as when tokenization gets interrupted.
* NOTE: IT IS REALLY BAD FORM TO CALL RELEASE WITHOUT CALLING MARK FIRST!
*
* @update gess 5/12/98
* @param
* @return
*/
void RewindToMark(void);
/**
*
*
* @update harishd 01/12/99
* @param
* @return
*/
bool UngetReadable(const nsAString& aBuffer);
/**
*
*
* @update gess 5/13/98
* @param
* @return
*/
nsresult Append(const nsAString& aBuffer);
/**
*
*
* @update gess 5/21/98
* @param
* @return
*/
nsresult Append(const char* aBuffer, uint32_t aLen,
nsIRequest *aRequest);
/**
* Call this to copy bytes out of the scanner that have not yet been consumed
* by the tokenization process.
*
* @update gess 5/12/98
* @param aCopyBuffer is where the scanner buffer will be copied to
* @return true if OK or false on OOM
*/
bool CopyUnusedData(nsString& aCopyBuffer);
/**
* Retrieve the name of the file that the scanner is reading from.
* In some cases, it's just a given name, because the scanner isn't
* really reading from a file.
*
* @update gess 5/12/98
* @return
*/
nsString& GetFilename(void);
static void SelfTest();
/**
* Use this setter to change the scanner's unicode decoder
*
* @update ftang 3/02/99
* @param aCharset a normalized (alias resolved) charset name
* @param aCharsetSource- where the charset info came from
* @return
*/
nsresult SetDocumentCharset(const nsACString& aCharset, int32_t aSource);
void BindSubstring(nsScannerSubstring& aSubstring, const nsScannerIterator& aStart, const nsScannerIterator& aEnd);
void CurrentPosition(nsScannerIterator& aPosition);
void EndReading(nsScannerIterator& aPosition);
void SetPosition(nsScannerIterator& aPosition,
bool aTruncate = false,
bool aReverse = false);
void ReplaceCharacter(nsScannerIterator& aPosition,
char16_t aChar);
/**
* Internal method used to cause the internal buffer to
* be filled with data.
*
* @update gess4/3/98
*/
bool IsIncremental(void) {return mIncremental;}
void SetIncremental(bool anIncrValue) {mIncremental=anIncrValue;}
/**
* Return the position of the first non-whitespace
* character. This is only reliable before consumers start
* reading from this scanner.
*/
int32_t FirstNonWhitespacePosition()
{
return mFirstNonWhitespacePosition;
}
/**
* Override replacement character used by nsIUnicodeDecoder.
* Default behavior is that it uses nsIUnicodeDecoder's mapping.
*
* @param aReplacementCharacter the replacement character
* XML (expat) parser uses 0xffff
*/
void OverrideReplacementCharacter(char16_t aReplacementCharacter);
protected:
bool AppendToBuffer(nsScannerString::Buffer *, nsIRequest *aRequest, int32_t aErrorPos = -1);
bool AppendToBuffer(const nsAString& aStr)
{
nsScannerString::Buffer* buf = nsScannerString::AllocBufferFromString(aStr);
if (!buf)
return false;
AppendToBuffer(buf, nullptr);
return true;
}
nsScannerString* mSlidingBuffer;
nsScannerIterator mCurrentPosition; // The position we will next read from in the scanner buffer
nsScannerIterator mMarkPosition; // The position last marked (we may rewind to here)
nsScannerIterator mEndPosition; // The current end of the scanner buffer
nsScannerIterator mFirstInvalidPosition; // The position of the first invalid character that was detected
nsString mFilename;
uint32_t mCountRemaining; // The number of bytes still to be read
// from the scanner buffer
bool mIncremental;
bool mHasInvalidCharacter;
char16_t mReplacementCharacter;
int32_t mFirstNonWhitespacePosition;
int32_t mCharsetSource;
nsCString mCharset;
nsCOMPtr<nsIUnicodeDecoder> mUnicodeDecoder;
private:
nsScanner &operator =(const nsScanner &); // Not implemented.
};
#endif