github.com/iWdGo/GoCompilerEfficiency

Benchmarking good practices

Go is strong typed and object oriented by definition. To distinguish bad habits, benchmarking against the compiler performance is often convincing.

Logic

• The most efficient loop is using a locally defined variable
• Don't bother to use anything but the len() to get the size of an array
• Don't duplicate code to handle the first item of a list
• Don't try to keep a single exit
• Always use shadowing inside a for loop even for a boolean.
• Don't bother about irrelevant cases in a switch.
• Use bit masking instead of a second if.
• Get the bits representation of a byte using bits package is simple and efficient.

Math

• math.Log2() is the most efficient to check that 2 is the sole divisor.

Arrays

• Array of struct is as efficient as multiple arrays.
• Array initialization using append is costly.
• Using a method is marginally more efficient to add an element to an array.

Templates

• Use implicit parsing for forms
• Keep a global var to hold a template read from file

Buffers

• No difference when writing to file
• Returning a buffer as a string is marginally more expensive.
• Package io is much more efficient than fmt which offers many more possibilities:
  • write a simple string.
  • write a buffer to a buffer.
• When handling every byte of a buffer, use ReadByte.

Builder

• No difference for a url builder between returning the string or the url.URL.