diff options
Diffstat (limited to 'vendor/github.com/sourcegraph/conc/iter/iter.go')
-rw-r--r-- | vendor/github.com/sourcegraph/conc/iter/iter.go | 85 |
1 files changed, 0 insertions, 85 deletions
diff --git a/vendor/github.com/sourcegraph/conc/iter/iter.go b/vendor/github.com/sourcegraph/conc/iter/iter.go deleted file mode 100644 index 124b4f940..000000000 --- a/vendor/github.com/sourcegraph/conc/iter/iter.go +++ /dev/null @@ -1,85 +0,0 @@ -package iter - -import ( - "runtime" - "sync/atomic" - - "github.com/sourcegraph/conc" -) - -// defaultMaxGoroutines returns the default maximum number of -// goroutines to use within this package. -func defaultMaxGoroutines() int { return runtime.GOMAXPROCS(0) } - -// Iterator can be used to configure the behaviour of ForEach -// and ForEachIdx. The zero value is safe to use with reasonable -// defaults. -// -// Iterator is also safe for reuse and concurrent use. -type Iterator[T any] struct { - // MaxGoroutines controls the maximum number of goroutines - // to use on this Iterator's methods. - // - // If unset, MaxGoroutines defaults to runtime.GOMAXPROCS(0). - MaxGoroutines int -} - -// ForEach executes f in parallel over each element in input. -// -// It is safe to mutate the input parameter, which makes it -// possible to map in place. -// -// ForEach always uses at most runtime.GOMAXPROCS goroutines. -// It takes roughly 2µs to start up the goroutines and adds -// an overhead of roughly 50ns per element of input. For -// a configurable goroutine limit, use a custom Iterator. -func ForEach[T any](input []T, f func(*T)) { Iterator[T]{}.ForEach(input, f) } - -// ForEach executes f in parallel over each element in input, -// using up to the Iterator's configured maximum number of -// goroutines. -// -// It is safe to mutate the input parameter, which makes it -// possible to map in place. -// -// It takes roughly 2µs to start up the goroutines and adds -// an overhead of roughly 50ns per element of input. -func (iter Iterator[T]) ForEach(input []T, f func(*T)) { - iter.ForEachIdx(input, func(_ int, t *T) { - f(t) - }) -} - -// ForEachIdx is the same as ForEach except it also provides the -// index of the element to the callback. -func ForEachIdx[T any](input []T, f func(int, *T)) { Iterator[T]{}.ForEachIdx(input, f) } - -// ForEachIdx is the same as ForEach except it also provides the -// index of the element to the callback. -func (iter Iterator[T]) ForEachIdx(input []T, f func(int, *T)) { - if iter.MaxGoroutines == 0 { - // iter is a value receiver and is hence safe to mutate - iter.MaxGoroutines = defaultMaxGoroutines() - } - - numInput := len(input) - if iter.MaxGoroutines > numInput { - // No more concurrent tasks than the number of input items. - iter.MaxGoroutines = numInput - } - - var idx atomic.Int64 - // Create the task outside the loop to avoid extra closure allocations. - task := func() { - i := int(idx.Add(1) - 1) - for ; i < numInput; i = int(idx.Add(1) - 1) { - f(i, &input[i]) - } - } - - var wg conc.WaitGroup - for i := 0; i < iter.MaxGoroutines; i++ { - wg.Go(task) - } - wg.Wait() -} |