Code Smell 20 - Premature Optimization

Planning ahead of time needs a crystal ball no developer has.

TL;DR: Don't guess things that might not happen.

Problems

Coupling
Testability
Readability
YAGNI

Solutions

Create great models and bijections first.
Create a conclusive benchmark once the model is working.
Programmers waste enormous amounts of time worrying about, the speed of noncritical parts of their programs, and these attempts at efficiency actually have a strong negative impact when debugging and maintenance are considered. Donald Knuth
Design for Performance.
Use Test Driven Development technique. It always favors the simplest solution.

Examples

Weird data structures
Caches
Singletons

Sample Code

Wrong

class Person {
    ancestors() {
        cachedResults = GlobalPeopleSingletonCache.getInstance().relativesCache(this.id);
        if (cachedResults != null) {
            return (cachedResults.hashFor(this.id)).getAllParents();
        }
        return database().getAllParents(this.id);
    }
}

Right

class Person {   
  ancestors(){
     return this.mother.meAndAncerstors().concat(this.father.meAndAncerstors());      
  }
  meAndAncerstors(){
     return this.ancestors().push(this);
  }
}

Detection

This is a design smell so it can not be detected by mechanical tools (yet).

Conclusion

Defer performance decisions until functional models are mature enough.

Donald Knuth created/compiled the best/fastest algorithms and data structures. With great wisdom he warned us of abuse. Why do we think we are smarter than him?

Relations

Code Smell 06 - Too Clever Programmer

Maxi Contieri ・ Oct 25 '20

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More info

Singleton: The Root of all Evil

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Credits

Photo by Markus Spiske on Unsplash

Premature optimization is the root of all evil.

Donald Knuth

Software Engineering Great Quotes

Maxi Contieri ・ Dec 28 '20

#codenewbie #programming #quotes #software

This article is part of the CodeSmell Series.

How to Find the Stinky parts of your Code

Maxi Contieri ・ May 21 '21

#codenewbie #tutorial #codequality #beginners

Last update: 2021/07/02