Profiling the code
Even if you know how fast or slow the algorithms that your program uses are, you should never just assume that you know which parts of the program are slowing you down. You should always measure the execution speed.
Note
Don’t guess, measure!
The simplest way to time parts of a program is to use Delphi’s TStopwatch
. It is useful when you think you know where the problem lies, and just want to confirm your suspicions and (later) verify that the improved solution is indeed faster than the original.
If you don’t know exactly which parts of the program are slow, you need to measure with a special tool, a profiler. They come in two varieties—sampling and instrumentation. As always, it is a question of balance. Sampling profilers are fast but will give you approximate results, while instrumenting profilers are very precise and can generate a call graph to show you exactly what goes on inside the program, but make the program run...