source: cpp/gdk/sstring.cpp @ 50

// This file is a part of Framsticks GDK library.
// Copyright (C) 2002-2006  Szymon Ulatowski.  See LICENSE.txt for details.
// Refer to http://www.frams.alife.pl/ for further information.


#include "sstring.h"
#include "nonstd.h"


static int guessMemSize(int request, int memhint)
{
if (memhint>=0)
        return request+memhint;
else
        return request+min(request/2,10000)+8;
}

SBuf::SBuf()
{
txt="";
size=used=0;
refcount=1;
}

SBuf::SBuf(int initsize, int memhint)
{
size=guessMemSize(initsize,memhint);
if (size>0)     { txt=(char*)malloc(size+1); txt[0]=0; }
        else    txt="";
used=0;
refcount=1;
}

SBuf::~SBuf()
{
freeBuf();
}

void SBuf::initEmpty()
{
txt="";
used=size=0;
refcount=1;
}

void SBuf::freeBuf()
{
if (!size) return;
free(txt); used=0;
}

void SBuf::copyFrom(const char *ch,int chlen,int memhint)
{
if (chlen==-1) chlen=strlen(ch);
if (chlen>0)
{
if (chlen<size)
        {
        memcpy(txt,ch,chlen);
        }
else
        {
        size=guessMemSize(chlen,memhint);
        char *newtxt=(char*)malloc(size+1);
        memcpy(newtxt,ch,chlen);
        free(txt);
        txt=newtxt;
        }
}
txt[chlen]=0;
used=chlen;
}

void SBuf::append(const char *ch,int chlen)
{ // doesn't check anything!
memcpy(txt+used,ch,chlen);
used+=chlen;
txt[used]=0;
}

void SBuf::ensureSize(int needed, int memhint)
{
if (size>=needed) return;
needed=guessMemSize(needed,memhint);
txt=(char*)realloc(txt,needed+1);
size=needed;
}

/////////////////////////////////////////////

SString::SString()
{
initEmpty();
}

SString::~SString()
{
detach();
}

SString::SString(int x)
{
buf=new SBuf(x);
}

SString::SString(const char *t,int t_len)
{
initEmpty();
if (!t) return;
copyFrom(t,t_len);
}

SString::SString(const SString &from)
{
buf=from.buf;
if (buf->size) buf->refcount++;
memhint=-1;
}

void SString::initEmpty()
{
buf=&SBuf::empty;
memhint=-1;
}

void SString::memoryHint(int howbig)
{
memhint=howbig;
}
        
void SString::detachEmpty(int ensuresize)
{
if (buf==&SBuf::empty) { buf=new SBuf(ensuresize,memhint); return; }
if (buf->refcount<2) buf->ensureSize(ensuresize,memhint);
else
        {
        buf->refcount--;
        buf=new SBuf(ensuresize,memhint);
        }
}

void SString::detach()
{
if (buf==&SBuf::empty) return;
if (!--buf->refcount) delete buf;
}

void SString::detachCopy(int ensuresize)
{
if (buf==&SBuf::empty) { buf=new SBuf(ensuresize,memhint); return; }
if (buf->refcount<2)
        {
        buf->ensureSize(ensuresize,memhint);
        return;
        }
buf->refcount--;
SBuf *newbuf=new SBuf(ensuresize,memhint);
newbuf->copyFrom(buf->txt,min(ensuresize,buf->used),memhint);
buf=newbuf;
}

char *SString::directWrite(int ensuresize)
{
if (ensuresize<0) ensuresize=len();
detachCopy(ensuresize);
appending=buf->used;
return buf->txt;
}

/*
char *SString::directWrite()
{
return directWrite(buf->used);
}
*/
char *SString::directAppend(int maxappend)
{
detachCopy(buf->used+maxappend);
appending=buf->used;
return buf->txt+appending;
}

void SString::endWrite(int newlength)
{
if (newlength<0) newlength=strlen(buf->txt);
else buf->txt[newlength]=0;
buf->used=newlength;
}

void SString::endAppend(int newappend)
{
if (newappend<0) newappend=strlen(buf->txt+appending);
else buf->txt[appending+newappend]=0;
buf->used=appending+newappend;
}

////////////// append /////////////////

void SString::operator+=(const char *s)
{
if (!s) return;
int x=strlen(s);
if (!x) return;
append(s,x);
}

void SString::append(const char *txt,int count)
{
if (!count) return;
detachCopy(buf->used+count);
buf->append(txt,count);
}

void SString::operator+=(const SString&s)
{
append((const char*)s,s.len());
}

SString SString::operator+(const SString& s) const
{
SString ret(*this);
ret+=s;
return ret;
}

/////////////////////////////

void SString::copyFrom(const char *ch,int chlen)
{
if (!ch) chlen=0;
else if (chlen<0) chlen=strlen(ch);
detachEmpty(chlen);
memcpy(buf->txt,ch,chlen);
buf->txt[chlen]=0; buf->used=chlen;
}

void SString::operator=(const char *ch)
{
copyFrom(ch);
}

void SString::operator=(const SString&s)
{
if (s.buf==buf) return;
detach();
buf=s.buf;
if (buf->size) buf->refcount++;
}
///////////////////////////////////////

SString SString::substr(int begin, int length) const
{
if (begin<0) { length+=begin; begin=0; }
if (length>=(len()-begin)) length=len()-begin;
if (length<=0) return SString();
if (length==len()) return *this;
return SString((*this)(begin),length);
}

///////////////////////////////////////

int SString::equals(const SString& s) const
{
if (s.buf==buf) return 1;
return !strcmp(buf->txt,s.buf->txt);
}

///////////////////////////////////////

int SString::indexOf(int character,int start) const
{
const char *found=strchr(buf->txt+start,character);
return found?found-buf->txt:-1;
}

int SString::indexOf(const char *substring,int start) const
{
char *found=strstr(buf->txt+start,substring);
return found?found-buf->txt:-1;
}

int SString::indexOf(const SString & substring,int start) const
{
char *found=strstr(buf->txt+start,((const char*)substring));
return found?found-buf->txt:-1;
}

int SString::getNextToken (int& pos,SString &token,char separator) const
{
if (pos>=len()) {token=0;return 0;}
int p1=pos,p2;
const char *t1=buf->txt+pos;
const char *t2=strchr(t1,separator);
if (t2) pos=(p2=(t2-buf->txt))+1; else p2=pos=len();
strncpy(token.directWrite(p2-p1),t1,p2-p1);
token.endWrite(p2-p1);
return 1;
}

int SString::startsWith(const char *pattern) const
{
const char *t=(const char*)(*this);
for (;*pattern;pattern++,t++)
        if (*t != *pattern) return 0;
return 1;
}

const SString& SString::valueOf(int i)
{
static SString t;
sprintf(t.directWrite(20),"%d",i); t.endWrite();
return t;
}
const SString& SString::valueOf(double d)
{
static SString t;
sprintf(t.directWrite(20),"%g",d); t.endWrite();
return t;
}


SString SString::empty;
SBuf SBuf::empty;