rickg%netscape.com cf891caa2b fixed serious parser bug from earlier today
git-svn-id: svn://10.0.0.236/trunk@7237 18797224-902f-48f8-a5cc-f745e15eee43
1998-08-04 10:16:09 +00:00

525 lines
11 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/*
* The contents of this file are subject to the Netscape Public License
* Version 1.0 (the "NPL"); you may not use this file except in
* compliance with the NPL. You may obtain a copy of the NPL at
* http://www.mozilla.org/NPL/
*
* Software distributed under the NPL is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
* for the specific language governing rights and limitations under the
* NPL.
*
* The Initial Developer of this code under the NPL is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All Rights
* Reserved.
*/
//#define __INCREMENTAL 1
#include "nsScanner.h"
#include "nsDebug.h"
const char* kBadHTMLText="<H3>Oops...</H3>You just tried to read a non-existent document: <BR>";
#ifdef __INCREMENTAL
const int kBufsize=1;
#else
const int kBufsize=64;
#endif
/**
* Use this constructor if you want i/o to be based on
* a single string you hand in during construction.
* This short cut was added for Javascript.
*
* @update gess 5/12/98
* @param aMode represents the parser mode (nav, other)
* @return
*/
CScanner::CScanner(nsString& anHTMLString) :
mBuffer(anHTMLString), mFilename("")
{
mTotalRead=mBuffer.Length();
mIncremental=PR_FALSE;
mOwnsStream=PR_FALSE;
mOffset=0;
mMarkPos=-1;
mFileStream=0;
}
/**
* Use this constructor if you want i/o to be based on strings
* the scanner receives. If you pass a null filename, you
* can still provide data to the scanner via append.
*
* @update gess 5/12/98
* @param aFilename --
* @return
*/
CScanner::CScanner(nsString& aFilename,PRBool aCreateStream) :
mBuffer(""), mFilename(aFilename)
{
mIncremental=PR_TRUE;
mOffset=0;
mMarkPos=-1;
mTotalRead=0;
mOwnsStream=aCreateStream;
mFileStream=0;
if(aCreateStream) {
char buffer[513];
aFilename.ToCString(buffer,sizeof(buffer)-1);
#if defined(XP_UNIX) && (defined(IRIX) || defined(MKLINUX))
/* XXX: IRIX does not support ios::binary */
mFileStream=new fstream(buffer,ios::in);
#else
mFileStream=new fstream(buffer,ios::in|ios::binary);
#endif
} //if
}
/**
* Use this constructor if you want i/o to be stream based.
*
* @update gess 5/12/98
* @param aStream --
* @param assumeOwnership --
* @param aFilename --
* @return
*/
CScanner::CScanner(nsString& aFilename,fstream& aStream,PRBool assumeOwnership) :
mBuffer(""), mFilename(aFilename)
{
mIncremental=PR_TRUE;
mOffset=0;
mMarkPos=-1;
mTotalRead=0;
mOwnsStream=assumeOwnership;
mFileStream=&aStream;
}
/**
* default destructor
*
* @update gess 3/25/98
* @param
* @return
*/
CScanner::~CScanner() {
if(mFileStream) {
mFileStream->close();
if(mOwnsStream)
delete mFileStream;
}
mFileStream=0;
}
/**
* 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
*/
PRInt32 CScanner::RewindToMark(void){
mOffset=mMarkPos;
return mOffset;
}
/**
* 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 7/29/98
* @param
* @return
*/
PRInt32 CScanner::Mark(void){
mMarkPos=mOffset;
if((mMarkPos>0) && (mMarkPos>eBufferSizeThreshold)) {
mBuffer.Cut(0,mMarkPos); //delete chars up to mark position
mOffset-=mMarkPos;
}
return 0;
}
/**
* Append data to our underlying input buffer as
* if it were read from an input stream.
*
* @update gess4/3/98
* @return error code
*/
PRBool CScanner::Append(nsString& aBuffer) {
mBuffer.Append(aBuffer);
mTotalRead+=aBuffer.Length();
return PR_TRUE;
}
/**
*
*
* @update gess 5/21/98
* @param
* @return
*/
PRBool CScanner::Append(const char* aBuffer, PRInt32 aLen){
mBuffer.Append(aBuffer,aLen);
mTotalRead+=aLen;
return PR_TRUE;
}
/**
* Grab data from underlying stream.
*
* @update gess4/3/98
* @return error code
*/
nsresult CScanner::FillBuffer(void) {
nsresult anError=NS_OK;
if(!mFileStream) {
//This is DEBUG code!!!!!! XXX DEBUG XXX
//If you're here, it means someone tried to load a
//non-existent document. So as a favor, we emit a
//little bit of HTML explaining the error.
if(0==mTotalRead) {
mBuffer.Append((const char*)kBadHTMLText);
mBuffer.Append(mFilename);
}
else anError=(mIncremental) ? kInterrupted : kEOF;
}
else {
PRInt32 numread=0;
char buf[kBufsize+1];
buf[kBufsize]=0;
if(mFileStream) {
mFileStream->read(buf,kBufsize);
numread=mFileStream->gcount();
}
mOffset=mBuffer.Length();
if((0<numread) && (0==anError))
mBuffer.Append((const char*)buf,numread);
mTotalRead+=mBuffer.Length();
}
return anError;
}
/**
* determine if the scanner has reached EOF
*
* @update gess 5/12/98
* @param
* @return 0=!eof 1=eof kInterrupted=interrupted
*/
nsresult CScanner::Eof() {
nsresult theError=NS_OK;
if(mOffset>=mBuffer.Length()) {
theError=FillBuffer();
}
if(NS_OK==theError) {
if (0==mBuffer.Length()) {
return kEOF;
}
}
return theError;
}
/**
* retrieve next char from scanners internal input stream
*
* @update gess 3/25/98
* @param
* @return error code reflecting read status
*/
nsresult CScanner::GetChar(PRUnichar& aChar) {
nsresult result=NS_OK;
if(mOffset>=mBuffer.Length())
result=Eof();
if(NS_OK == result) {
aChar=mBuffer[mOffset++];
}
return result;
}
/**
* peek ahead to consume next char from scanner's internal
* input buffer
*
* @update gess 3/25/98
* @param
* @return
*/
nsresult CScanner::Peek(PRUnichar& aChar) {
nsresult result=NS_OK;
if(mOffset>=mBuffer.Length())
result=Eof();
if(NS_OK == result) {
aChar=mBuffer[mOffset];
}
return result;
}
/**
* Push the given char back onto the scanner
*
* @update gess 3/25/98
* @param
* @return error code
*/
nsresult CScanner::PutBack(PRUnichar aChar) {
if(mOffset>0)
mOffset--;
else mBuffer.Insert(aChar,0);
return NS_OK;
}
/**
* Skip whitespace on scanner input stream
*
* @update gess 3/25/98
* @param
* @return error status
*/
nsresult CScanner::SkipWhitespace(void) {
static nsAutoString chars(" \n\r\t");
return SkipOver(chars);
}
/**
* Skip over chars as long as they equal given char
*
* @update gess 3/25/98
* @param
* @return error code
*/
nsresult CScanner::SkipOver(PRUnichar aSkipChar){
PRUnichar ch=0;
nsresult result=NS_OK;
while(NS_OK==result) {
result=GetChar(ch);
if(NS_OK == result) {
if(ch!=aSkipChar) {
PutBack(ch);
break;
}
}
else break;
} //while
return result;
}
/**
* Skip over chars as long as they're in aSkipSet
*
* @update gess 3/25/98
* @param
* @return error code
*/
nsresult CScanner::SkipOver(nsString& aSkipSet){
PRUnichar ch=0;
nsresult result=NS_OK;
while(NS_OK==result) {
result=GetChar(ch);
if(NS_OK == result) {
PRInt32 pos=aSkipSet.Find(ch);
if(kNotFound==pos) {
PutBack(ch);
break;
}
}
else break;
} //while
return result;
}
/**
* Skip over chars until they're in aValidSet
*
* @update gess 3/25/98
* @param aValid set contains chars you're looking for
* @return error code
*/
nsresult CScanner::SkipTo(nsString& aValidSet){
PRUnichar ch=0;
nsresult result=NS_OK;
while(NS_OK==result) {
result=GetChar(ch);
if(NS_OK == result) {
PRInt32 pos=aValidSet.Find(ch);
if(kNotFound!=pos) {
PutBack(ch);
break;
}
}
else break;
} //while
return result;
}
/**
* Skip over chars as long as they're in aValidSet
*
* @update gess 3/25/98
* @param
* @return error code
*/
nsresult CScanner::SkipPast(nsString& aValidSet){
NS_NOTYETIMPLEMENTED("Error: SkipPast not yet implemented.");
return NS_OK;
}
/**
* Consume chars as long as they are <i>in</i> the
* given validSet of input chars.
*
* @update gess 3/25/98
* @param
* @return error code
*/
nsresult CScanner::ReadWhile(nsString& aString,
nsString& aValidSet,
PRBool addTerminal){
PRUnichar theChar=0;
nsresult result=NS_OK;
while(NS_OK==result) {
result=GetChar(theChar);
if(NS_OK==result) {
PRInt32 pos=aValidSet.Find(theChar);
if(kNotFound==pos) {
if(addTerminal)
aString+=theChar;
else PutBack(theChar);
break;
}
else aString+=theChar;
}
}
return result;
}
/**
* Consume characters until you find one contained in given
* input set.
*
* @update gess 3/25/98
* @param
* @return error code
*/
nsresult CScanner::ReadUntil(nsString& aString,
nsString& aTerminalSet,
PRBool addTerminal){
PRUnichar ch=0;
nsresult result=NS_OK;
while(NS_OK == result) {
result=GetChar(ch);
if(NS_OK==result) {
PRInt32 pos=aTerminalSet.Find(ch);
if(kNotFound!=pos) {
if(addTerminal)
aString+=ch;
else PutBack(ch);
break;
}
else aString+=ch;
}
}
return result;
}
/**
* Consumes chars until you see the given terminalChar
*
* @update gess 3/25/98
* @param
* @return error code
*/
nsresult CScanner::ReadUntil(nsString& aString,
PRUnichar aTerminalChar,
PRBool addTerminal){
PRUnichar ch=0;
nsresult result=NS_OK;
while(NS_OK==result) {
result=GetChar(ch);
if(ch==aTerminalChar) {
if(addTerminal)
aString+=ch;
else PutBack(ch);
break;
}
else aString+=ch;
}
return result;
}
/**
*
* @update gess 3/25/98
* @param
* @return
*/
nsString& CScanner::GetBuffer(void) {
return mBuffer;
}
/**
* 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& CScanner::GetFilename(void) {
return mFilename;
}
/**
* Conduct self test. Actually, selftesting for this class
* occurs in the parser selftest.
*
* @update gess 3/25/98
* @param
* @return
*/
void CScanner::SelfTest(void) {
#ifdef _DEBUG
#endif
}