Jake Smith

Fun fact: you can reduce the memory usage of a Golang program by rearranging your structs. For example, this struct takes up 24 bytes of memory: type Example struct { A int8 B int64 C int8 } This struct, with optimized members takes up 16 bytes: type Example struct { B int64 A int8 C int8 } The reason for this drop in memory usage is because in the optimized struct, we've gotten rid of unnecessary "padding". Struct padding in Go (and in many other programming languages) is a technique to align data in memory according to the CPU's architecture requirements. This is essential for efficient memory access and performance optimization. Different data types have different alignment requirements. Example: int32 is 4 bytes and must be aligned to a 4-byte boundary. When you define a struct with fields of different types, the Go compiler may insert extra space (padding) between the fields to ensure each field starts at an address that satisfies its alignment requirements. There is also padding added at the end to ensure the size of the struct is a multiple of the largest alignment requirement within the struct. Going back up to the above, this struct takes up 24 bytes of memory: type Example struct { A int8 // 1 byte + 7 bytes of padding because B has to be aligned to a 8-byte boundary B int64 // 8 bytes C int8 // 1 byte // 7 bytes of padding at the end (platform dependent) } And this optimized struct takes 16 bytes of memory: type Example struct { B int64 // 8 bytes, aligned to 8-byte boundary A int8 // 1 byte C int8 // 1 byte // 6 bytes of padding (to align struct size to 8-byte boundary) } Most of your programs will not need to care about reducing memory usage. For those that do, hope you like Tetris! One obvious caveat of rearranging structs is that you give up human readability of grouping related fields together to instead favor the compiler.