On Tue, 25 Jul 2017, Bo Berglund wrote:
I am working on moving away from using AnsiString as communications buffer in an old application, so I need to write efficient replacements for certain string functions (Delete, Insert, Copy etc). Now I am wondering if there is a better way to do the Insert() command than this: procedure InsertBytes(var Dest: TBytes; Src: TBytes; Index: integer); var Len, LenA: integer; begin Len := Length(Dest); LenA := Length(Src); if LenA = 0 then exit; //Do nothing if Index > Len then Index := Len; //Make an append instead SetLength(Dest, Len + LenA); Move(Dest[Index], Dest[Index + LenA], LenA); //Create space Move(Src[0], Dest[Index], LenA); //Insert data end; Ideally the function should be portable between FPC and Delphi XE5...
There is no better way if you only want to use TBytes. If you want less reallocations, you must reserve more memory for the array from the start (so length is a "capacity"), and keep a second count, the count of the number of bytes actually used.
Then you're maybe better off working with a TMemory stream, which does all this for you. Or write a TBuffer class. Michael. _______________________________________________ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
