gecko-dev/xpcom/ds/nsStringImpl.h

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/*****************************************************************************************************************
*
* This template provides the basic implementation for all the original
* nsString classes (nsString, nsCString) and serve as the basis for
* thier autostring forms.
*
* DEVELOPMENT NOTES:
*
* 0. Note that I've explictly created interfaces for both the nsString(s),
* and for the nsReadableString (ABT). This will allow the nsString
* form to be optimized (as in the original), while the nsReadable
* interfaces can use a new, more generic approach (including iterators).
* SEE Append() as an example.
*
* 1. Flesh out more of the nsReadableString and nsReadableStringIterator interfaces.
* Note the use of the readableStringIterator in the version of Append() that
* accepts an nsReadableString&. This is because the readableString may have
* almost any form (e.g. segmentString), and we can't rely upon a linear
* layout of buffer memory as we can with nsString class deriviates.
*
* I fully expect this pattern to get replaced with a legitimate form.
*
*
* 2. I don't really think it's necessary to go crazy with virtual methods
* but I've done so for now as a matter of consistency. Once this file
* gets further along, and I have a workable nsAutoString, then I'll start
* backing off from virtual methods whereever possible. Please be patient.
*
* 3. I'm being lazy for the time being, and NOT encoding the buffer-ownership
* flag into the high-order bit of the length field. This needs to be done
* "real soon" but it's not worth doing (today) while I'm still designing.
*
* 4. I explictly implemented the orthodox canonical form.
*
* 5. Before anyone get's too critical of this design, note that I'm using
* the dual-class template form to make interoperability between char*
* and prunichar* obvious. I recognize that it's better to switch to
* an nsReadableString interface, but I've done this for now ONLY to
* make the conversion from our existing nsString class easier. Once
* I get over a few hurdles there, I'll re-examine this approach.
* Once again: please be patient (I'm only 5 hours into this effort).
*
* 6. I've quickly hooked up some of the low level routines (in the
* file nsBufferManager.h). Don't expect it all to work just yet --
* they're mostly placeholders. You CAN already construct and copy
* construct an nsString, nsCString and the autostring forms.
*
* 7. Note that the basic nsString interfaces (append, assign, etc) are not
* perfectly equivalent to the originals. All I tried to do was capture
* the gist of the originals to flesh out these interfaces.
*
* 8. Next Up: Mapping of more nsString functions (insert, delete, the
* boolean operators, the searching methods, etc.
*
* *** NOTE: I've begun to map the existing nsString functions --
* most are empty covers, to be used as a placeholder.
*
* 9. After I'm done with #8, I'll split this implementation into 2 files.
*
* FILE NOTES:
*
* 02.29.2000: Original files (rickg)
* 03.02.2000: Expand the API's to be a bit more realistic (rickg):
* 1. Flesh out the interface to be compatible with old library
* 2. Enable both nsString-based interfaces and nsReadableString interfaces
* 3. Build enough infrastructure to test nsString(s) and nsImmutableString constructions.
*
*****************************************************************************************************************/
#ifndef NS_STRINGIMPL_
#define NS_STRINGIMPL_
#include "nsStringValue.h"
#include "nsBufferManager.h"
/***************************************************************************
*
* The following is the basic interface nsString searching...
*
* We will merge this into nsReadableString very soon, but I've kept it
* seperate until I can map and factor the original nsString methods.
*
***************************************************************************/
class nsSearchableString {
public:
//We need to decide how deep (and generic) this API can go...
};
/***************************************************************************
*
* This isn't intended as a real class, but only to illustrate that for
* nsReadableString, we want a common access pattern to get at the underlying
* buffer. Iterators make perfect sense, but it will take a real implementation.
*
* Note: This class is intended to replace direct calls to GetBuffer()
* in cases where iteration on an nsReadableString is taking place.
*
***************************************************************************/
class nsReadableStringIterator {
public:
nsReadableStringIterator() { }
};
/***************************************************************************
*
* The following is the basic interface anyone who wants to be passed
* as a string should define.
*
***************************************************************************/
class nsReadableString : public nsSearchableString {
public:
virtual PRUint32 Length() =0;
virtual size_t GetCharSize() =0;
virtual PRUnichar operator[](PRUint32) = 0;
virtual nsReadableStringIterator* First() = 0; //These are here so that nsReadable strings can offer a standard mechanism for
virtual nsReadableStringIterator* Last() = 0; //callers to access underlying data. Feel free to replace with a better pattern.
//by moving to iterators, we can support segmented content models...
//virtual nsStringIterator GetIterator() = 0;
//virtual PRBool IsEmpty(void) = 0;
//etc.
};
/***************************************************************************
*
* Now the basic nsStringImpl implementation, that becomes the functional
* base for genericized strings storing a given chartype.for nsString,
nsCStirng and the autoString pairs.
*
***************************************************************************/
template <class CharType>
class nsStringImpl: public nsReadableString {
public:
nsStringImpl() : mStringValue() {
}
//call this version for nsString,nsCString and the autostrings
nsStringImpl(const nsStringImpl& aString,PRInt32 aLength=-1) : mStringValue() {
Assign(aString,aLength);
}
//call this version for nsString,nsCString and the autostrings
nsStringImpl(const CharType* aString,PRInt32 aLength=-1) : mStringValue() {
Assign(aString,aLength);
}
//call this version for all other ABT versions of readable strings
nsStringImpl(const nsReadableString &aString) : mStringValue() {
Assign(aString);
}
virtual ~nsStringImpl() { }
nsStringImpl& operator=(const nsStringImpl<CharType>& aString) {
if(aString.mStringValue.mBuffer!=mStringValue.mBuffer) {
Assign(aString);
}
return *this;
}
//******************************************
// Here are the accessor methods...
//******************************************
virtual nsresult SetLength(PRUint32 aLength) {
return NS_OK;
}
virtual nsresult SetCapacity(PRUint32 aCapacity) {
return NS_OK;
}
operator CharType*() {return mStringValue.mBuffer;}
PRUint32 Length() {return mStringValue.mLength;}
size_t GetCharSize() {return sizeof(CharType);}
PRBool IsEmpty(void) {return PRBool(mStringValue.mLength==0);}
PRUnichar operator[](PRUint32 aOffset) {return mStringValue[aOffset];}
PRBool SetCharAt(PRUnichar aChar,PRUint32 anIndex) {return PR_FALSE;}
PRUnichar CharAt(PRUint32 anIndex) const {return mStringValue[aOffset];}
PRUnichar First(void) const {return mStringValue[0];}
PRUnichar Last(void) const {return mStringValue[mStringValue.mLength];}
//these aren't the real deal, but serve as a placeholder for us to implement iterators.
virtual nsReadableStringIterator* First() {return new nsReadableStringIterator(); }
virtual nsReadableStringIterator* Last() {return new nsReadableStringIterator(); }
PRInt32 CountChar(PRUnichar aChar) { return 0; }
void DebugDump(void) const { }
//******************************************
// Here are the mutation methods...
//******************************************
virtual nsresult Truncate(PRUint32 offset=0) {
if(mStringValue) {
mStringValue[0]=0;
mStringValue.mLength=0;
}
return NS_OK;
}
//assign from a stringimpl
nsresult Assign(const nsStringImpl& aString) {
nsresult result=NS_OK;
if(mStringValue.mBuffer!=aString.mStringValue.mBuffer){
Truncate();
result=Append(aString);
}
return result;
}
//assign from a compatible string pointer
virtual nsresult Assign(const CharType* aString,PRInt32 aLength=-1) {
nsresult result=NS_OK;
if(mStringValue.mBuffer!=aString){
Truncate();
result=Append(aString,aLength);
}
return result;
}
//assign from an nsReadableString (the ABT)
virtual nsresult Assign(const nsReadableString &aString,PRInt32 aLength=-1) {
nsresult result=NS_OK;
Truncate();
SVAppendReadable<CharType>(mStringValue,aString,0,aLength);
return result;
}
//append from a stringimpl
virtual nsresult Append(const nsStringImpl<CharType> &aString,PRInt32 aLength=-1) {
SVAppend< CharType, CharType > (mStringValue,aString.mStringValue,0,aString.mStringValue.mLength);
return NS_OK;
}
//append from a type compatible string pointer
virtual nsresult Append(const CharType* aString,PRInt32 aLength=-1) {
nsresult result=NS_OK;
if(aString) {
nsStringValueImpl<CharType> theStringValue(const_cast<CharType*>(aString),aLength);
SVAppend< CharType, CharType > (mStringValue,theStringValue,0,aLength);
}
return result;
}
//append from an nsReadableString (the ABT)
virtual nsresult Append(const nsReadableString &aString,PRInt32 aLength=-1) {
SVAppendReadable<CharType> (mStringValue,aString,0,aLength);
return NS_OK;
}
//append an integer
virtual nsresult Append(PRInt32 aInteger,PRInt32 aRadix=10) {
nsresult result=NS_OK;
return result;
}
//Append a float
virtual nsresult Append(float aFloat) {
nsresult result=NS_OK;
return result;
}
//***************************************
// Here come a few deletion methods...
//***************************************
nsStringImpl<CharType>& Cut(PRUint32 anOffset,PRInt32 aCount) {
return *this;
}
nsStringImpl<CharType>& Trim(const char* aSet,PRBool aEliminateLeading=PR_TRUE,PRBool aEliminateTrailing=PR_TRUE,PRBool aIgnoreQuotes=PR_FALSE) {
return *this;
}
nsStringImpl<CharType>& CompressSet(const char* aSet, PRUnichar aChar,PRBool aEliminateLeading=PR_TRUE,PRBool aEliminateTrailing=PR_TRUE){
return *this;
}
nsStringImpl<CharType>& CompressWhitespace( PRBool aEliminateLeading=PR_TRUE,PRBool aEliminateTrailing=PR_TRUE){
return *this;
}
//***************************************
// Here come a wad of insert methods...
//***************************************
nsStringImpl<CharType>& Insert(const nsStringImpl<CharType>& aCopy,PRUint32 anOffset,PRInt32 aCount=-1) {
return *this;
}
nsStringImpl<CharType>& Insert(const CharType* aChar,PRUint32 anOffset,PRInt32 aCount=-1){
return *this;
}
nsStringImpl<CharType>& Insert(CharType aChar,PRUint32 anOffset){
return *this;
}
//*******************************************
// Here come inplace replacement methods...
//*******************************************
nsStringImpl<CharType>& ReplaceChar(PRUnichar anOldChar,PRUnichar aNewChar){
return *this;
}
nsStringImpl<CharType>& ReplaceChar(const char* aSet,PRUnichar aNewChar){
return *this;
}
nsStringImpl<CharType>& ReplaceSubstring( const nsStringImpl<CharType>& aTarget,
const nsStringImpl<CharType>& aNewValue){
return *this;
}
nsStringImpl<CharType>& ReplaceSubstring(const CharType* aTarget,const CharType* aNewValue) {
return *this;
}
//*******************************************
// Here come the stripchar methods...
//*******************************************
nsStringImpl<CharType>& StripChars(const char* aSet){
return *this;
}
nsStringImpl<CharType>& StripChar(CharType aChar,PRInt32 anOffset=0){
return *this;
}
nsStringImpl<CharType>& StripChar(PRInt32 anInt,PRInt32 anOffset=0) {return StripChar((PRUnichar)anInt,anOffset); }
nsStringImpl<CharType>& StripWhitespace() {
return *this;
}
//**************************************************
// Here are some methods that extract substrings...
//**************************************************
PRUint32 Left(nsStringImpl<CharType>& aCopy,PRInt32 aCount) const {
}
PRUint32 Mid(nsStringImpl<CharType>& aCopy,PRUint32 anOffset,PRInt32 aCount) const {
}
PRUint32 Right(nsStringImpl<CharType>& aCopy,PRInt32 aCount) const {
}
//*******************************************
// Here come the operator+=() methods...
//*******************************************
nsStringImpl<CharType>& operator+=(const nsStringImpl<CharType>& aString){
Append(aString,aString.mStringValue.mLength);
return *this;
}
nsStringImpl<CharType>& operator+=(const CharType* aString) {
Append(aString);
return *this;
}
nsStringImpl<CharType>& operator+=(const CharType aChar) {
return *this;
}
nsStringImpl<CharType>& operator+=(const int anInt){
Append(anInt,10);
return *this;
}
void ToLowerCase() {
}
void ToLowerCase(nsStringImpl<CharType> &aString) const {
}
void ToUpperCase() {
}
void ToUpperCase(nsStringImpl<CharType> &aString) const {
}
/***********************************
Comparison methods...
***********************************/
PRBool operator==(const nsStringImpl<CharType>& aString) const {return Equals(aString);}
PRBool operator==(const CharType* aString) const {return Equals(aString);}
PRBool operator!=(const nsStringImpl<CharType>& aString) const {return PRBool(Compare(aString)!=0);}
PRBool operator!=(const CharType* aString) const {return PRBool(Compare(aString)!=0);}
PRBool operator<(const nsStringImpl<CharType>& aString) const {return PRBool(Compare(aString)<0);}
PRBool operator<(const CharType* aString) const {return PRBool(Compare(aString)<0);}
PRBool operator>(const nsStringImpl<CharType>& aString) const {return PRBool(Compare(aString)>0);}
PRBool operator>(const CharType* aString) const {return PRBool(Compare(aString)>0);}
PRBool operator<=(const nsStringImpl<CharType>& aString) const {return PRBool(Compare(aString)<=0);}
PRBool operator<=(const CharType* aString) const {return PRBool(Compare(aString)<=0);}
PRBool operator>=(const nsStringImpl<CharType>& aString) const {return PRBool(Compare(aString)>=0);}
PRBool operator>=(const CharType* aString) const {return PRBool(Compare(aString)>=0);}
PRInt32 Compare(const nsStringImpl<CharType>& aString,PRBool aIgnoreCase=PR_FALSE,PRInt32 aCount=-1) const;
PRInt32 Compare(const CharType* aString,PRBool aIgnoreCase=PR_FALSE,PRInt32 aCount=-1) const;
PRBool Equals(const nsStringImpl<CharType> &aString,PRBool aIgnoreCase=PR_FALSE,PRInt32 aCount=-1) const;
PRBool Equals(const CharType* aString,PRBool aIgnoreCase=PR_FALSE,PRInt32 aCount=-1) const;
// PRBool Equals(/*FIX: const */nsIAtom* anAtom,PRBool aIgnoreCase) const;
/***************************************
These are string searching methods...
***************************************/
PRInt32 FindChar(PRUnichar aChar) {
return -1;
}
PRInt32 Find(const nsStringImpl<CharType>& aString,PRBool aIgnoreCase=PR_FALSE,PRInt32 anOffset=-1,PRInt32 aCount=-1) const {
return -1;
}
PRInt32 Find(const CharType* aString,PRBool aIgnoreCase=PR_FALSE,PRInt32 anOffset=-1,PRInt32 aCount=-1) const {
return -1;
}
PRInt32 FindCharInSet(const nsStringImpl<CharType>& aString,PRInt32 anOffset=-1) const{
return -1;
}
PRInt32 FindCharInSet(const CharType* aString,PRInt32 anOffset=-1) const{
return -1;
}
PRInt32 FindChar(CharType aChar,PRBool aIgnoreCase=PR_FALSE,PRInt32 anOffset=-1,PRInt32 aCount=-1) const {
return -1;
}
PRInt32 RFindChar(CharType aChar,PRBool aIgnoreCase=PR_FALSE,PRInt32 anOffset=-1,PRInt32 aCount=-1) const{
return -1;
}
PRInt32 RFind(const nsStringImpl<CharType>& aString,PRBool aIgnoreCase=PR_FALSE,PRInt32 anOffset=-1,PRInt32 aCount=-1) const{
return -1;
}
PRInt32 RFind(const CharType* aCString,PRBool aIgnoreCase=PR_FALSE,PRInt32 anOffset=-1,PRInt32 aCount=-1) const{
return -1;
}
PRInt32 RFindCharInSet(const nsStringImpl<CharType>& aString,PRInt32 anOffset=-1) const {
return -1;
}
PRInt32 RFindCharInSet(const CharType* aString,PRInt32 anOffset=-1) const{
return -1;
}
/***************************************
These convert to a different type
***************************************/
char* ToNewCString() const {
}
char* ToNewUTF8String() const {
}
PRUnichar* ToNewUnicode() const {
}
char* ToCString(char* aBuf,PRUint32 aBufLength,PRUint32 anOffset=0) const {
}
float ToFloat(PRInt32* aErrorCode) const {
}
PRInt32 ToInteger(PRInt32* aErrorCode,PRUint32 aRadix=kRadix10) const{
}
nsStringValueImpl<CharType> mStringValue;
};
#endif