Difficulties With Efficient Large File Parsing

[Michael_Ilseman]

@TellowKrinkle

I'm guessing it was this one:

let data = try Data(contentsOf: url)
_ = data.withUnsafeBytes {
	return $0.split(separator: UInt8(ascii: "\n")).map { String(decoding: UnsafeRawBufferPointer(rebasing: $0), as: UTF8.self) }
}

I wasn't sure if he was still calling a split() somewhere or if he did the logic himself.

@TellowKrinkle

If all the splitted strings are <15 characters

<= 15 UTF-8 code units

@TellowKrinkle

they get to be stack allocate

They're inlined directly into the struct's bits, i.e. Array.Element. They're "struct-allocated" .

@TellowKrinkle

I'm sure that saves a lot of allocation and reference counting time.

Correct, no allocations or reference counting.