1 files changed, 58 insertions, 0 deletions
diff --git a/go/src/lib/statusline/ratelimit.go b/go/src/lib/statusline/ratelimit.go
new file mode 100644
index 0000000..970f8e5
--- /dev/null
+++ b/go/src/lib/statusline/ratelimit.go
@@ -0,0 +1,58 @@
+package statusline
+
+import (
+	"time"
+)
+
+type rateLimiter struct {
+	lines chan string
+	end1  chan bool
+	end2  chan struct{}
+}
+
+func RateLimit(sl StatusLine, d time.Duration) StatusLine {
+	ret := &rateLimiter{
+		lines: make(chan string),
+		end1:  make(chan bool),
+		end2:  make(chan struct{}),
+	}
+	go func() {
+		ticker := time.NewTicker(d)
+		var oldLine string
+		var newLine string
+		dirty := false
+		for {
+			select {
+			case <-ticker.C:
+				if dirty && newLine != oldLine {
+					sl.Put(newLine)
+				}
+				dirty = false
+			case line := <-ret.lines:
+				newLine = line
+				dirty = true
+			case keep := <-ret.end1:
+				if keep && dirty && newLine != oldLine {
+					sl.Put(newLine)
+				}
+				sl.End(keep)
+				ticker.Stop()
+				ret.end2 <- struct{}{}
+				close(ret.end2)
+				return
+			}
+		}
+	}()
+	return ret
+}
+
+func (sl *rateLimiter) Put(line string) {
+	sl.lines <- line
+}
+
+func (sl *rateLimiter) End(keep bool) {
+	sl.end1 <- keep
+	close(sl.lines)
+	close(sl.end1)
+	<-sl.end2
+}