bitswap: better wantlist allocation patterns

License: MIT
Signed-off-by: Steven Allen <steven@stebalien.com>

exchange/bitswap/bitswap.go

@@ -451,8 +451,9 @@ func (bs *Bitswap) Close() error {
 }
 
 func (bs *Bitswap) GetWantlist() []*cid.Cid {
-	var out []*cid.Cid
-	for _, e := range bs.wm.wl.Entries() {
+	entries := bs.wm.wl.Entries()
+	out := make([]*cid.Cid, 0, len(entries))
+	for _, e := range entries {
 		out = append(out, e.Cid)
 	}
 	return out

exchange/bitswap/wantlist/wantlist.go

@@ -126,7 +126,7 @@ func (w *ThreadSafe) Contains(k *cid.Cid) (*Entry, bool) {
 func (w *ThreadSafe) Entries() []*Entry {
 	w.lk.RLock()
 	defer w.lk.RUnlock()
-	var es entrySlice
+	es := make([]*Entry, 0, len(w.set))
 	for _, e := range w.set {
 		es = append(es, e)
 	}
@@ -134,13 +134,8 @@ func (w *ThreadSafe) Entries() []*Entry {
 }
 
 func (w *ThreadSafe) SortedEntries() []*Entry {
-	w.lk.RLock()
-	defer w.lk.RUnlock()
-	var es entrySlice
-	for _, e := range w.set {
-		es = append(es, e)
-	}
-	sort.Sort(es)
+	es := w.Entries()
+	sort.Sort(entrySlice(es))
 	return es
 }
 
@@ -194,7 +189,7 @@ func (w *Wantlist) Contains(k *cid.Cid) (*Entry, bool) {
 }
 
 func (w *Wantlist) Entries() []*Entry {
-	var es entrySlice
+	es := make([]*Entry, 0, len(w.set))
 	for _, e := range w.set {
 		es = append(es, e)
 	}
@@ -202,10 +197,7 @@ func (w *Wantlist) Entries() []*Entry {
 }
 
 func (w *Wantlist) SortedEntries() []*Entry {
-	var es entrySlice
-	for _, e := range w.set {
-		es = append(es, e)
-	}
-	sort.Sort(es)
+	es := w.Entries()
+	sort.Sort(entrySlice(es))
 	return es
 }