Book Image

Delphi High Performance

By : Primož Gabrijelčič
Book Image

Delphi High Performance

By: Primož Gabrijelčič

Overview of this book

Delphi is a cross-platform Integrated Development Environment (IDE) that supports rapid application development for Microsoft Windows, Apple Mac OS X, Google Android, iOS, and now Linux with RAD Studio 10.2. This book will be your guide to build efficient high performance applications with Delphi. The book begins by explaining how to find performance bottlenecks and apply the correct algorithm to fix them. It will teach you how to improve your algorithms before taking you through parallel programming. You’ll then explore various tools to build highly concurrent applications. After that, you’ll delve into improving the performance of your code and master cross-platform RTL improvements. Finally, we’ll go through memory management with Delphi and you’ll see how to leverage several external libraries to write better performing programs. By the end of the book, you’ll have the knowledge to create high performance applications with Delphi.
Table of Contents (16 chapters)
Title Page
Copyright and Credits
Packt Upsell

Optimizing strings and array allocations

When you create a string, the code allocates memory for its content, copies the content into that memory, and stores the address of this memory in the string variable. Of course, you all know that by now as this was the topic of the previous chapter.

If you append a character to this string, it must be stored somewhere in that memory. However, there is no place to store the string. The original memory block was just big enough to store the original content. The code must therefore enlarge that memory block, and only then can the appended character be stored in the newly acquired space.

As we'll see further on in the chapter, FastMM tries to make sure that the memory can be expanded in place, that is, without copying the original data into a new, larger block of memory. Still, this is not always possible and sometimes data must be copied around.

A very similar scenario plays out when you extend a dynamic array. Memory that contains the array data can...