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Re: SetLineKeyValue - in memory:update2 [message #47979 is a reply to message #47907]

Sun, 30 April 2017 14:33

luoganda
Messages: 215
Registered: November 2016

Experienced Member

Using SetLineKeyValue with StringStream:
-StringStream: a few funcs should be added to use this,chk down

If you read this, there was also original func update - chk original message

Usage:
-to speedup and data(lines) is/are known to be contignous,then;
   SetLineKeyValue(ss,"a key","a value");
   ss.GetLine(); //advance pos to next line,so next is found immediatelly
-when keys(data) is not known to be contignous(butAreSearchable),then;
   SetLineKeyValue(ss,"a key","a value"); //just this

bool SetLineKeyValue(StringStream& ss,const String& key,const String& val,bool chkForEqualSign,dword *chkForExistanceOnly,String *prevBack){
  if(ss.IsEof())return false;
  register char *p=(char*)ss.PeekPtr();
  int64 fpos=ss.GetPos();ss.Seek(0);
  char *pst,*porg=p,*ssSt=(char*)ss.PeekPtr();
  int pos,off,linenum;
  ss.Seek(fpos);
  if(prevBack)*prevBack="";
  while(*p){
    fpos=ss.GetPos(); linenum=0;pos=0;pst=p;
    while(*p){if(*p=='\r'&&*p=='\n'){linenum=p-pst/*p-~lines-fpos*/;break;}if(*p=='\r'||*p=='\n'){linenum=p-pst/*p-~lines-fpos*/;break;}if(*p=='=')pos=p-pst/*p-~lines-fpos*/; ++p;}
    if(*p!=0)++p;
    if(linenum==0 && 0==(linenum=p-(*p?1:0)-pst/*~lines-fpos*/))continue;
    if(linenum&&*pst==';'||linenum>=2&&pst[0]=='/'&&pst[1]=='/')continue;
    if(chkForEqualSign&&!pos)continue;
    if(linenum<key.GetCount()+(chkForEqualSign?1:0)||0!=memcmp(pst,~key,key.GetCount()))continue;if(chkForEqualSign&&pst[key.GetCount()]!='=')continue;
    if(prevBack&&linenum>fpos+/*key.GetCount()*/pos+1)*prevBack=String(pst+/*key.GetCount()*/pos+1/*lines.Mid(fpos+key.GetCount()+1*/,linenum-(/*key.GetCount()*/pos+1));
    if(chkForExistanceOnly){*chkForExistanceOnly=(dword)(int32)fpos;return true;}
    fpos+=/*key.GetCount()*/pos+1;
    off=(/*key.GetCount()*/pos+1+val.GetCount())-linenum; //speedup a litle - don't insert/remove twice
    if(off<0)ss.Remove(abs(off),fpos); else if(off)ss.Insert('R',off,fpos);
    *(char*)ss.GetIter(fpos-1)='='; memcpy((void*)ss.GetIter(fpos),~val,val.GetCount());
    //if(off<0)slns. lines.Remove(fpos,abs(off)); else if(off)lines.Insert(fpos," ",off);
    //*(char*)lines.GetIter(fpos-1)='='; memcpy((void*)lines.GetIter(fpos),~val,val.GetCount());
    return true;
    }
  return false;
}

StringStream added code for this - but should be revisited;
StringStream has Put methods but no Remove(Pos isTakenInConsideration), here they are - but are not yet 100% tested
optimally it should be added between SetSize and Open

	virtual  void  Insert(int ch,int num=1,int at=-1);
	virtual  void  Insert(const String& str,int at=-1);
	virtual  void  Remove(int num=1,int at=-1);
	virtual  const byte* GetIter(int at){ASSERT(at<GetSize());return buffer+at;}

//cpp files
void StringStream::Insert(int ch,int num,int at){
	Insert(String(ch,num),at);
}
void StringStream::Insert(const String& str,int at){
	if(at==-1)at=GetPos();
	ASSERT(at+str.GetCount()<=GetSize());
	SetReadMode(); //justToKnowWhichToUse...
	int64 npos=at<GetPos()?GetPos()+GetPos()-at:GetPos();
	data.Insert(at,str);
	buffer = (byte *) ~data;  //<=this should be checked,may point to another unknown buffer
	//ptr = wrlim = buffer;
	rdlim = buffer + data.GetCount();
	Seek(npos);
}
void StringStream::Remove(int num,int at){
	if(at==-1)at=GetPos();
	ASSERT(at+num<=GetSize());
	SetReadMode(); //justToKnowWhichToUse...
	int64 npos=at<=GetPos()?GetPos()-num/*+GetPos()-at*/:GetPos();
	data.Remove(at,num);
	//memmove(buffer+at,buffer+at+num,n);
	buffer = (byte *) ~data;
	rdlim = buffer + data.GetCount();
	Seek(npos);
}

[Updated on: Mon, 01 May 2017 20:33]

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