From: Matt Joiner <anacrolix@gmail.com>
Date: Fri, 22 Aug 2014 07:37:18 +0000 (+1000)
Subject: Avoid allocations in shuffledPendingChunkSpecs
X-Git-Tag: v1.0.0~1618
X-Git-Url: http://www.git.stargrave.org/?a=commitdiff_plain;h=063e02cbfd2ecaf5ac732180676214353761c0e1;p=btrtrc.git

Avoid allocations in shuffledPendingChunkSpecs
---

diff --git a/misc.go b/misc.go
index 784ecf4d..26bf7916 100644
--- a/misc.go
+++ b/misc.go
@@ -36,10 +36,16 @@ type piece struct {
 }
 
 func (p *piece) shuffledPendingChunkSpecs() (css []chunkSpec) {
+	if len(p.PendingChunkSpecs) == 0 {
+		return
+	}
 	css = make([]chunkSpec, 0, len(p.PendingChunkSpecs))
 	for cs := range p.PendingChunkSpecs {
 		css = append(css, cs)
 	}
+	if len(css) <= 1 {
+		return
+	}
 	for i := range css {
 		j := rand.Intn(i + 1)
 		css[i], css[j] = css[j], css[i]