#### 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.
Title Page
Packt Upsell
Contributors
Preface
Free Chapter
Fixing the Algorithm
Fine-Tuning the Code
Memory Management
Getting Started with the Parallel World
Working with Parallel Tools
Exploring Parallel Practices
Using External Libraries
Best Practices
Other Books You May Enjoy
Index

## Caching

Our good friend Mr. Smith has improved his programming skills considerably. Currently, he is learning about recursive functions and he programmed his first recursive piece of code. He wrote a simple seven-liner which calculates the nth element in the Fibonacci sequence:

```function TfrmFibonacci.FibonacciRecursive(element: int64): int64;
begin
if element < 3 then
Result := 1
else
Result := FibonacciRecursive(element - 1) +
FibonacciRecursive(element - 2);
end;```

I will not argue with him—if you look up the definition of a Fibonacci sequence it really looks like it could be perfectly solved with a recursive function.

A sequence of Fibonacci numbers, F, is defined with two simple rules:

• First two numbers in the sequence are both 1 (F1 = 1, F2 = 1),

• Every other number in the sequence is the sum of the preceding two (Fn = Fn-1 + Fn-2).

You will also find a different definition of the Fibonacci sequence in the literature, starting with values 0 and 1, but it only differs...