Method pullerRoutine

lib/model/folder_sendrecv.go:1525–1562

(ctx context.Context, in <-chan pullBlockState, out chan<- *sharedPullerState)

}

func (f *sendReceiveFolder) pullerRoutine(ctx context.Context, in <-chan pullBlockState, out chan<- *sharedPullerState) {
	requestLimiter := semaphore.New(f.PullerMaxPendingKiB * 1024)
	var wg sync.WaitGroup

	for state := range in {
		if state.failed() != nil {
			out <- state.sharedPullerState
			continue
		}

		f.setState(FolderSyncing) // Does nothing if already FolderSyncing

		// The requestLimiter limits how many pending block requests we have
		// ongoing at any given time, based on the size of the blocks
		// themselves.

		bytes := state.block.Size

		if bytes == 0 {
			// Pulling zero bytes is a no-op.
			state.pullDone(state.block)
			out <- state.sharedPullerState
			continue
		}

		if err := requestLimiter.TakeWithContext(ctx, bytes); err != nil {
			state.fail(err)
			out <- state.sharedPullerState
			continue
		}

		wg.Go(func() {
			defer requestLimiter.Give(bytes)
			f.pullBlock(ctx, state, out)
		})
	}
	wg.Wait()
}

func (f *sendReceiveFolder) pullBlock(ctx context.Context, state pullBlockState, out chan<- *sharedPullerState) {
	// Get an fd to the temporary file. Technically we don't need it until