gecko-dev/xpcom/string/obsolete/nsStr.h
1999-04-05 21:38:50 +00:00

368 lines
13 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.
*/
/***********************************************************************
MODULE NOTES:
1. There are two philosophies to building string classes:
A. Hide the underlying buffer & offer API's allow indirect iteration
B. Reveal underlying buffer, risk corruption, but gain performance
We chose the option B for performance reasons.
2 Our internal buffer always holds capacity+1 bytes.
3. Note that our internal format for this class makes our memory
layout compatible with BStrings.
The nsStr struct is a simple structure (no methods) that contains
the necessary info to be described as a string. This simple struct
is manipulated by the static methods provided in this class.
(Which effectively makes this a library that works on structs).
There are also object-based versions called nsString and nsAutoString
which use nsStr but makes it look at feel like an object.
***********************************************************************/
#ifndef _nsStr
#define _nsStr
#include "prtypes.h"
#include "nscore.h"
//----------------------------------------------------------------------------------------
enum eCharSize {eOneByte=0,eTwoByte=1};
#define kDefaultCharSize eTwoByte
union UStrPtr {
char* mCharBuf;
PRUnichar* mUnicharBuf;
};
/**************************************************************************
Here comes the nsBufDescriptor class which describes buffer properties.
**************************************************************************/
struct nsBufDescriptor {
nsBufDescriptor(char* aBuffer,PRUint32 aBufferSize,eCharSize aCharSize,PRBool aOwnsBuffer) {
mStr=aBuffer;
mMultibyte=aCharSize;
mCapacity=(aBufferSize>>mMultibyte)-1;
mOwnsBuffer=aOwnsBuffer;
}
PRUint32 mCapacity;
PRBool mOwnsBuffer;
eCharSize mMultibyte;
// UStrPtr mStr;
union {
char* mStr;
PRUnichar* mUStr;
};
};
class nsIMemoryAgent;
//----------------------------------------------------------------------------------------
struct nsStr {
/**
* This method initializes an nsStr for use
*
* @update gess 01/04/99
* @param aString is the nsStr to be initialized
* @param aCharSize tells us the requested char size (1 or 2 bytes)
*/
static void Initialize(nsStr& aDest,eCharSize aCharSize);
/**
* This method destroys the given nsStr, and *MAY*
* deallocate it's memory depending on the setting
* of the internal mOwnsBUffer flag.
*
* @update gess 01/04/99
* @param aString is the nsStr to be manipulated
* @param anAgent is the allocator to be used to the nsStr
*/
static void Destroy(nsStr& aDest,nsIMemoryAgent* anAgent=0);
/**
* These methods are where memory allocation/reallocation occur.
*
* @update gess 01/04/99
* @param aString is the nsStr to be manipulated
* @param anAgent is the allocator to be used on the nsStr
* @return
*/
static void EnsureCapacity(nsStr& aString,PRUint32 aNewLength,nsIMemoryAgent* anAgent=0);
static void GrowCapacity(nsStr& aString,PRUint32 aNewLength,nsIMemoryAgent* anAgent=0);
/**
* These methods are used to append content to the given nsStr
*
* @update gess 01/04/99
* @param aDest is the nsStr to be appended to
* @param aSource is the buffer to be copied from
* @param anOffset tells us where in source to start copying
* @param aCount tells us the (max) # of chars to copy
* @param anAgent is the allocator to be used for alloc/free operations
*/
static void Append(nsStr& aDest,const nsStr& aSource,PRUint32 anOffset,PRInt32 aCount,nsIMemoryAgent* anAgent=0);
/**
* These methods are used to assign contents of a source string to dest string
*
* @update gess 01/04/99
* @param aDest is the nsStr to be appended to
* @param aSource is the buffer to be copied from
* @param anOffset tells us where in source to start copying
* @param aCount tells us the (max) # of chars to copy
* @param anAgent is the allocator to be used for alloc/free operations
*/
static void Assign(nsStr& aDest,const nsStr& aSource,PRUint32 anOffset,PRInt32 aCount,nsIMemoryAgent* anAgent=0);
/**
* These methods are used to insert content from source string to the dest nsStr
*
* @update gess 01/04/99
* @param aDest is the nsStr to be appended to
* @param aDestOffset tells us where in dest to start insertion
* @param aSource is the buffer to be copied from
* @param aSrcOffset tells us where in source to start copying
* @param aCount tells us the (max) # of chars to insert
* @param anAgent is the allocator to be used for alloc/free operations
*/
static void Insert( nsStr& aDest,PRUint32 aDestOffset,const nsStr& aSource,PRUint32 aSrcOffset,PRInt32 aCount,nsIMemoryAgent* anAgent=0);
/**
* This method deletes chars from the given str.
* The given allocator may choose to resize the str as well.
*
* @update gess 01/04/99
* @param aDest is the nsStr to be deleted from
* @param aDestOffset tells us where in dest to start deleting
* @param aCount tells us the (max) # of chars to delete
* @param anAgent is the allocator to be used for alloc/free operations
*/
static void Delete(nsStr& aDest,PRUint32 aDestOffset,PRInt32 aCount,nsIMemoryAgent* anAgent=0);
/**
* This method is used to truncate the given string.
* The given allocator may choose to resize the str as well (but it's not likely).
*
* @update gess 01/04/99
* @param aDest is the nsStr to be appended to
* @param aDestOffset tells us where in dest to start insertion
* @param aSource is the buffer to be copied from
* @param aSrcOffset tells us where in source to start copying
* @param anAgent is the allocator to be used for alloc/free operations
*/
static void Truncate(nsStr& aDest,PRUint32 aDestOffset,nsIMemoryAgent* anAgent=0);
/**
* This method is used to perform a case conversion on the given string
*
* @update gess 01/04/99
* @param aDest is the nsStr to be case shifted
* @param toUpper tells us to go upper vs. lower
*/
static void ChangeCase(nsStr& aDest,PRBool aToUpper);
/**
* This method removes chars (given in aSet) from the given buffer
*
* @update gess 01/04/99
* @param aString is the buffer to be manipulated
* @param aDestOffset is starting pos in buffer for manipulation
* @param aCount is the number of chars to compare
* @param aSet tells us which chars to remove from given buffer
*/
static void StripChars(nsStr& aDest,PRUint32 aDestOffset,PRInt32 aCount,const char* aCharSet);
/**
* This method trims chars (given in aSet) from the edges of given buffer
*
* @update gess 01/04/99
* @param aDest is the buffer to be manipulated
* @param aSet tells us which chars to remove from given buffer
* @param aEliminateLeading tells us whether to strip chars from the start of the buffer
* @param aEliminateTrailing tells us whether to strip chars from the start of the buffer
*/
static void Trim(nsStr& aDest,const char* aSet,PRBool aEliminateLeading,PRBool aEliminateTrailing);
/**
* This method compresses duplicate runs of a given char from the given buffer
*
* @update gess 01/04/99
* @param aDest is the buffer to be manipulated
* @param aSet tells us which chars to compress from given buffer
* @param aChar is the replacement char
* @param aEliminateLeading tells us whether to strip chars from the start of the buffer
* @param aEliminateTrailing tells us whether to strip chars from the start of the buffer
*/
static void CompressSet(nsStr& aDest,const char* aSet,PRUint32 aChar,PRBool aEliminateLeading,PRBool aEliminateTrailing);
/**
* This method compares the data bewteen two nsStr's
*
* @update gess 01/04/99
* @param aStr1 is the first buffer to be compared
* @param aStr2 is the 2nd buffer to be compared
* @param aCount is the number of chars to compare
* @param aIgnorecase tells us whether to use a case-sensitive comparison
* @return -1,0,1 depending on <,==,>
*/
static PRInt32 Compare(const nsStr& aDest,const nsStr& aSource,PRInt32 aCount,PRBool aIgnoreCase);
/**
* These methods scan the given string for 1 or more chars in a given direction
*
* @update gess 01/04/99
* @param aDest is the nsStr to be searched to
* @param aSource (or aChar) is the substr we're looking to find
* @param aIgnoreCase tells us whether to search in a case-sensitive manner
* @param anOffset tells us where in the dest string to start searching
* @return the index of the source (substr) in dest, or -1 (kNotFound) if not found.
*/
static PRInt32 FindSubstr(const nsStr& aDest,const nsStr& aSource, PRBool aIgnoreCase,PRUint32 anOffset);
static PRInt32 FindChar(const nsStr& aDest,PRUnichar aChar, PRBool aIgnoreCase,PRUint32 anOffset);
static PRInt32 FindCharInSet(const nsStr& aDest,const nsStr& aSet,PRBool aIgnoreCase,PRUint32 anOffset);
static PRInt32 RFindSubstr(const nsStr& aDest,const nsStr& aSource, PRBool aIgnoreCase,PRUint32 anOffset);
static PRInt32 RFindChar(const nsStr& aDest,PRUnichar aChar, PRBool aIgnoreCase,PRUint32 anOffset);
static PRInt32 RFindCharInSet(const nsStr& aDest,const nsStr& aSet,PRBool aIgnoreCase,PRUint32 anOffset);
/**
* This method is used to access a given char in the given string
*
* @update gess 01/04/99
* @param aDest is the nsStr to be appended to
* @param anIndex tells us where in dest to get the char from
* @return the given char, or 0 if anIndex is out of range
*/
static PRUnichar GetCharAt(const nsStr& aDest,PRUint32 anIndex);
PRUint32 mLength : 30;
eCharSize mMultibyte : 2;
PRUint32 mCapacity: 30;
PRUint32 mOwnsBuffer: 1;
PRUint32 mUnused: 1;
union {
char* mStr;
PRUnichar* mUStr;
};
};
/**************************************************************
A couple of tiny helper methods used in the string classes.
**************************************************************/
inline PRInt32 MinInt(PRInt32 anInt1,PRInt32 anInt2){
return (anInt1<anInt2) ? anInt1 : anInt2;
}
inline PRInt32 MaxInt(PRInt32 anInt1,PRInt32 anInt2){
return (anInt1<anInt2) ? anInt2 : anInt1;
}
inline void ToRange(PRInt32& aValue,PRInt32 aMin,PRInt32 aMax){
if(aValue<aMin)
aValue=aMin;
else if(aValue>aMax)
aValue=aMax;
}
inline void ToRange(PRUint32& aValue,PRUint32 aMin,PRUint32 aMax){
if(aValue<aMin)
aValue=aMin;
else if(aValue>aMax)
aValue=aMax;
}
inline void AddNullTerminator(nsStr& aDest) {
if(eTwoByte==aDest.mMultibyte)
aDest.mUStr[aDest.mLength]=0;
else aDest.mStr[aDest.mLength]=0;
}
//----------------------------------------------------------------------------------------
class nsIMemoryAgent {
public:
virtual PRBool Alloc(nsStr& aString,PRInt32 aCount)=0;
virtual PRBool Realloc(nsStr& aString,PRInt32 aCount)=0;
virtual PRBool Free(nsStr& aString)=0;
};
class nsMemoryAgent : public nsIMemoryAgent {
enum eDelta{eGrowthDelta=8};
public:
virtual PRBool Alloc(nsStr& aDest,PRInt32 aCount) {
//we're given the acount value in charunits; we have to scale up by the charsize.
PRInt32 theNewCapacity;
if (aDest.mCapacity > 64) {
// When the string starts getting large, double the capacity as we grow.
theNewCapacity = aDest.mCapacity * 2;
if (theNewCapacity < aCount) {
theNewCapacity = aDest.mCapacity + aCount;
}
} else {
// When the string is small, keep it's capacity a multiple of kGrowthDelta
PRInt32 unitDelta=(aCount/eGrowthDelta)+1;
theNewCapacity=unitDelta*eGrowthDelta;
}
aDest.mCapacity=theNewCapacity++;
size_t theSize=(theNewCapacity<<aDest.mMultibyte);
aDest.mStr=new char[theSize];
aDest.mOwnsBuffer=1;
return PR_TRUE;
}
virtual PRBool Free(nsStr& aDest){
if(aDest.mStr){
if(aDest.mOwnsBuffer){
delete [] aDest.mStr;
}
aDest.mStr=0;
aDest.mOwnsBuffer=0;
return PR_TRUE;
}
return PR_FALSE;
}
virtual PRBool Realloc(nsStr& aDest,PRInt32 aCount){
Free(aDest);
return Alloc(aDest,aCount);
}
};
#endif