Optimisation

register is a C keyword to hint on the compiler in order to store the variable in processor register instead of in memory. However, this can only happen in the function scope, that is within the function itself. It is advised to use it on frequently used variable in order to optimise# the performance.

Refactoring is rewriting, reworking and re-architecting. Do it when there is a duplication (violate the DRY principle), non-orthogonal design, outdated code (change of requirements, better understanding) or 202203011139 opportunities (improve performance).

Code profilers# can be useful to count the number of times the different steps in the algorithm get executed. Some might even provide a graphical plot with the information against the input size.

Although refactoring come at a cost of performance penalty due to indirection, it opens opportunities for fine-tuning since the code is more readable than ever. With refactoring, components tend to be small and easier to test. This means that it is easier to find out which part of code needs to be optimised which is measured by profiler since they are rather decoupled.

It is similar to Optimisation, however with a different purpose. Optimisation is to speed up the program but might end up with less comprehensibility of the codes whereas Refactoring wants to make the software easier to understand and extendible.

Refactoring is a process of rewriting, reworking and re-architecting of the program’s codebase without changing its observable behaviour. It is often used to prevent or correct code duplication#, preserve the orthogonality# of the software, update the code base on the changes of requirements or better understanding on the underlying technology, or optimise. The ultimate goal of Refactoring is to make the software easy to read, have all logic specified in one and only one place (no duplications#), doesn’t allow changes to alter existing behaviour, and allow only simple conditional logic.

Refactoring speeds up the software development by making the process of understanding a codebase easier. The code should be readable so the next guy who picks up the codebase will not waste much time on comprehending the code before becoming productive. This is with extra benefit where we can spot bugs more easily as we tend to spend more time in debugging#. Make the code speaks its purpose with more clarity. But it might drag the performance due to indirection.

A function with the identifier inline in C is called an Inline Function. Inline Function makes no function call, instead they are like macros where the place that the function called will be replaced by the function definition or the code that is inside the function. Since inline function doesn’t introduce #overhead, it is great to inline short functions especially 202202081524#. Always prefer Inline Function over function-like macro.

The default 202205161742# for containers are new and delete. You could change it in order to optimise the memory usage.

Aliasing is when different symbolic names can access to the same object that is stored in the memory. This could be a hassle for 202203011139#.