Allow skipping validation when Matching

[wingsofovnia]

doMatchWithSeparator does support turning off validation

doublestar/match.go

Line 74 in 180028b

func doMatchWithSeparator(pattern, name string, separator rune, validate bool, doublestarPatternBacktrack, doublestarNameBacktrack, starPatternBacktrack, starNameBacktrack, patIdx, nameIdx int) (matched bool, err error) {

However, it's public counter part doesn't and always enables validation:

doublestar/match.go

Lines 52 to 53 in 180028b

	func Match(pattern, name string) (bool, error) {
	return matchWithSeparator(pattern, name, '/', true)

Allowing matching without validation can save some cycles in the use cases where glob patterns have been already validated at an earlier point. A suggested (public) func may look like:

func MatchUnvalidated(pattern, name string) (bool, error) {
	return matchWithSeparator(pattern, name, '/', false)
}

[jbedard]

I've been having the same performance concerns for a while, also from a bazel gazelle extension where the same globs are invoked a significant number of times.

[bmatcuk]

Sorry I haven't replied to this in so long - life is busy 😢

So, the validate flag to doMatchWithSeparator only affects one case: when matching reaches the end of name before reaching the end of pattern, ie, in something like Match("a/b/c", "a").

doublestar/match.go

Lines 286 to 288 in 424062b

	if validate && patIdx < patLen && !doValidatePattern(pattern[patIdx:], separator) {
	return false, ErrBadPattern
	}

That's the only case Match runs validation. So, I wouldn't expect a huge performance improvement from a MatchUnvalidated. But, I suppose if matching is run many, many times, it would add up.

I cut a v4.7.0 which includes a MatchUnvalidated. It only returns a bool instead of bool, error.