PCP: /api/v1/regions optimization

server/api/region.go

@@ -50,22 +50,32 @@ func NewRegionInfo(r *core.RegionInfo) *RegionInfo {
 	if r == nil {
 		return nil
 	}
-	return &RegionInfo{
-		ID:              r.GetID(),
-		StartKey:        string(core.HexRegionKey(r.GetStartKey())),
-		EndKey:          string(core.HexRegionKey(r.GetEndKey())),
-		RegionEpoch:     r.GetRegionEpoch(),
-		Peers:           r.GetPeers(),
-		Leader:          r.GetLeader(),
-		DownPeers:       r.GetDownPeers(),
-		PendingPeers:    r.GetPendingPeers(),
-		WrittenBytes:    r.GetBytesWritten(),
-		WrittenKeys:     r.GetKeysWritten(),
-		ReadBytes:       r.GetBytesRead(),
-		ReadKeys:        r.GetKeysRead(),
-		ApproximateSize: r.GetApproximateSize(),
-		ApproximateKeys: r.GetApproximateKeys(),
+	ri := &RegionInfo{}
+	return InitRegion(r, ri)
+}
+
+// InitRegion init a new api RegionInfo from the core.RegionInfo.
+func InitRegion(r *core.RegionInfo, s *RegionInfo) *RegionInfo {
+	if r == nil {
+		return nil
 	}
+
+	s.ID = r.GetID()
+	s.StartKey = core.HexRegionKeyStr(r.GetStartKey())
+	s.EndKey = core.HexRegionKeyStr(r.GetEndKey())
+	s.RegionEpoch = r.GetRegionEpoch()
+	s.Peers = r.GetPeers()
+	s.Leader = r.GetLeader()
+	s.DownPeers = r.GetDownPeers()
+	s.PendingPeers = r.GetPendingPeers()
+	s.WrittenBytes = r.GetBytesWritten()
+	s.WrittenKeys = r.GetKeysWritten()
+	s.ReadBytes = r.GetBytesRead()
+	s.ReadKeys = r.GetKeysRead()
+	s.ApproximateSize = r.GetApproximateSize()
+	s.ApproximateKeys = r.GetApproximateKeys()
+
+	return s
 }
 
 // RegionsInfo contains some regions with the detailed region info.
@@ -122,13 +132,18 @@ func newRegionsHandler(svr *server.Server, rd *render.Render) *regionsHandler {
 }
 
 func convertToAPIRegions(regions []*core.RegionInfo) *RegionsInfo {
-	regionInfos := make([]*RegionInfo, len(regions))
+	regionInfos := make([]RegionInfo, len(regions))
+	regionInfosRefs := make([]*RegionInfo, len(regions))
+
+	for i := 0; i < len(regions); i++ {
+		regionInfosRefs[i] = &regionInfos[i]
+	}
 	for i, r := range regions {
-		regionInfos[i] = NewRegionInfo(r)
+		regionInfosRefs[i] = InitRegion(r, regionInfosRefs[i])
 	}
 	return &RegionsInfo{
 		Count:   len(regions),
-		Regions: regionInfos,
+		Regions: regionInfosRefs,
 	}
 }
 

server/api/region_test.go

@@ -14,10 +14,12 @@
 package api
 
 import (
+	"bytes"
 	"fmt"
 	"math/rand"
 	"net/url"
 	"sort"
+	"testing"
 
 	. "github.com/pingcap/check"
 	"github.com/pingcap/kvproto/pkg/metapb"
@@ -331,3 +333,72 @@ func (s *testGetRegionSuite) TestScanRegionByKey(c *C) {
 		c.Assert(v, Equals, regions.Regions[i].ID)
 	}
 }
+
+// Create n regions (0..n) of n stores (0..n).
+// Each region contains np peers, the first peer is the leader.
+// (copied from server/cluster_test.go)
+func newTestRegions(n, np uint64) []*core.RegionInfo {
+	regions := make([]*core.RegionInfo, 0, n)
+	for i := uint64(0); i < n; i++ {
+		peers := make([]*metapb.Peer, 0, np)
+		for j := uint64(0); j < np; j++ {
+			peer := &metapb.Peer{
+				Id: i*np + j,
+			}
+			peer.StoreId = (i + j) % n
+			peers = append(peers, peer)
+		}
+		region := &metapb.Region{
+			Id:          i,
+			Peers:       peers,
+			StartKey:    []byte{byte(i)},
+			EndKey:      []byte{byte(i + 1)},
+			RegionEpoch: &metapb.RegionEpoch{ConfVer: 2, Version: 2},
+		}
+		regions = append(regions, core.NewRegionInfo(region, peers[0]))
+	}
+	return regions
+}
+
+func BenchmarkRenderJSON(b *testing.B) {
+	regionsCount := uint64(10000)
+	storeCount := uint64(100)
+	regionInfos := newTestRegions(regionsCount, storeCount)
+
+	rd := createRender()
+	regions := convertToAPIRegions(regionInfos)
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		var buffer bytes.Buffer
+		rd.JSON(&buffer, 200, regions)
+	}
+}
+
+func BenchmarkConvertToAPIRegions(b *testing.B) {
+	regionsCount := uint64(10000)
+	storeCount := uint64(100)
+	regionInfos := newTestRegions(regionsCount, storeCount)
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		regions := convertToAPIRegions(regionInfos)
+		_ = regions.Count
+	}
+}
+
+func BenchmarkHexRegionKey(b *testing.B) {
+	key := []byte("region_number_infinity")
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_ = string(core.HexRegionKey(key))
+	}
+}
+
+func BenchmarkHexRegionKeyStr(b *testing.B) {
+	key := []byte("region_number_infinity")
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_ = core.HexRegionKeyStr(key)
+	}
+}

server/api/router.go

@@ -22,10 +22,14 @@ import (
 	"github.com/unrolled/render"
 )
 
-func createRouter(prefix string, svr *server.Server) *mux.Router {
-	rd := render.New(render.Options{
-		IndentJSON: true,
+func createRender() *render.Render {
+	return render.New(render.Options{
+		StreamingJSON: true,
 	})
+}
+
+func createRouter(prefix string, svr *server.Server) *mux.Router {
+	rd := createRender()
 
 	rootRouter := mux.NewRouter().PathPrefix(prefix).Subrouter()
 	handler := svr.GetHandler()

server/core/region.go

@@ -891,7 +891,13 @@ func isInvolved(region *RegionInfo, startKey, endKey []byte) bool {
 // HexRegionKey converts region key to hex format. Used for formating region in
 // logs.
 func HexRegionKey(key []byte) []byte {
-	return []byte(strings.ToUpper(hex.EncodeToString(key)))
+	return []byte(HexRegionKeyStr(key))
+}
+
+// HexRegionKeyStr converts region key to hex format. Used for formating region in
+// logs.
+func HexRegionKeyStr(key []byte) string {
+	return strings.ToUpper(hex.EncodeToString(key))
 }
 
 // RegionToHexMeta converts a region meta's keys to hex format. Used for formating