use doublejump to replace google jump algorithm

gandalf1024 · Nov 19, 2018 · 7682139 · 7682139
1 parent e4c779c
commit 7682139
Show file tree

Hide file tree

Showing 4 changed files with 30 additions and 7 deletions.
diff --git a/client/hash_utils.go b/client/hash_utils.go
@@ -36,14 +36,18 @@ type HashServiceAndArgs func(len int, options ...interface{}) int
 // Return service address, like "[email protected]:8970"
 type ConsistentAddrStrFunction func(options ...interface{}) string
 
-// JumpConsistentHash selects a server by serviceMethod and args
-func JumpConsistentHash(len int, options ...interface{}) int {
+func genKey(options ...interface{}) uint64 {
 	keyString := ""
 	for _, opt := range options {
 		keyString = keyString + "/" + toString(opt)
 	}
-	key := HashString(keyString)
-	return int(Hash(key, int32(len)))
+
+	return HashString(keyString)
+}
+
+// JumpConsistentHash selects a server by serviceMethod and args
+func JumpConsistentHash(len int, options ...interface{}) int {
+	return int(Hash(genKey(options...), int32(len)))
 }
 
 func toString(obj interface{}) string {

diff --git a/client/selector.go b/client/selector.go
@@ -9,6 +9,8 @@ import (
 	"strconv"
 	"time"
 
+	"github.com/edwingeng/doublejump"
+
 	"github.com/valyala/fastrand"
 )
 
@@ -233,6 +235,7 @@ func createGeoServer(servers map[string]string) []*geoServer {
 
 // consistentHashSelector selects based on JumpConsistentHash.
 type consistentHashSelector struct {
+	h       *doublejump.Hash
 	servers []string
 }
 
@@ -243,26 +246,35 @@ func newConsistentHashSelector(servers map[string]string) Selector {
 	}
 
 	sort.Slice(ss, func(i, j int) bool { return ss[i] < ss[j] })
-	return &consistentHashSelector{servers: ss}
+	return &consistentHashSelector{servers: ss, h: doublejump.NewHash()}
 }
 
 func (s consistentHashSelector) Select(ctx context.Context, servicePath, serviceMethod string, args interface{}) string {
 	ss := s.servers
 	if len(ss) == 0 {
 		return ""
 	}
-	i := JumpConsistentHash(len(ss), servicePath, serviceMethod, args)
-	return ss[i]
+
+	key := genKey(servicePath, serviceMethod, args)
+	return s.h.Get(key).(string)
 }
 
 func (s *consistentHashSelector) UpdateServer(servers map[string]string) {
 	var ss = make([]string, 0, len(servers))
 	for k := range servers {
+		s.h.Add(k)
 		ss = append(ss, k)
 	}
 
 	sort.Slice(ss, func(i, j int) bool { return ss[i] < ss[j] })
+
+	for _, k := range s.servers {
+		if servers[k] == "" { //remove
+			s.h.Remove(k)
+		}
+	}
 	s.servers = ss
+
 }
 
 // weightedICMPSelector selects servers with ping result.

diff --git a/go.mod b/go.mod
@@ -22,6 +22,7 @@ require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/dgrijalva/jwt-go v3.2.0+incompatible // indirect
 	github.com/docker/libkv v0.2.1
+	github.com/edwingeng/doublejump v0.0.0-20181118175321-74c86884ec85
 	github.com/facebookgo/clock v0.0.0-20150410010913-600d898af40a // indirect
 	github.com/fatih/color v1.7.0
 	github.com/fsnotify/fsnotify v1.4.7 // indirect

diff --git a/go.sum b/go.sum
@@ -46,10 +46,14 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dgrijalva/jwt-go v3.2.0+incompatible h1:7qlOGliEKZXTDg6OTjfoBKDXWrumCAMpl/TFQ4/5kLM=
 github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
+github.com/dgryski/go-jump v0.0.0-20170409065014-e1f439676b57 h1:qZNIK8jjHgLFHAW2wzCWPEv0ZIgcBhU7X3oDt/p3Sv0=
+github.com/dgryski/go-jump v0.0.0-20170409065014-e1f439676b57/go.mod h1:4hKCXuwrJoYvHZxJ86+bRVTOMyJ0Ej+RqfSm8mHi6KA=
 github.com/docker/libkv v0.2.1 h1:PNXYaftMVCFS5CmnDtDWTg3wbBO61Q/cEo3KX1oKxto=
 github.com/docker/libkv v0.2.1/go.mod h1:r5hEwHwW8dr0TFBYGCarMNbrQOiwL1xoqDYZ/JqoTK0=
 github.com/docopt/docopt-go v0.0.0-20180111231733-ee0de3bc6815/go.mod h1:WwZ+bS3ebgob9U8Nd0kOddGdZWjyMGR8Wziv+TBNwSE=
 github.com/dustin/go-humanize v0.0.0-20180421182945-02af3965c54e/go.mod h1:HtrtbFcZ19U5GC7JDqmcUSB87Iq5E25KnS6fMYU6eOk=
+github.com/edwingeng/doublejump v0.0.0-20181118175321-74c86884ec85 h1:RWBKPjhoGko+4x/ohPudSgzw/p8N8Yunr0bzVXf6ksE=
+github.com/edwingeng/doublejump v0.0.0-20181118175321-74c86884ec85/go.mod h1:HQjgsCnC5Rku4T9y5KM6q2mIA1TZPVWKI2acMB2VQcw=
 github.com/facebookgo/clock v0.0.0-20150410010913-600d898af40a h1:yDWHCSQ40h88yih2JAcL6Ls/kVkSE8GFACTGVnMPruw=
 github.com/facebookgo/clock v0.0.0-20150410010913-600d898af40a/go.mod h1:7Ga40egUymuWXxAe151lTNnCv97MddSOVsjpPPkityA=
 github.com/fatih/color v1.7.0 h1:DkWD4oS2D8LGGgTQ6IvwJJXSL5Vp2ffcQg58nFV38Ys=
@@ -198,6 +202,7 @@ github.com/samuel/go-zookeeper v0.0.0-20180130194729-c4fab1ac1bec h1:6ncX5ko6B9L
 github.com/samuel/go-zookeeper v0.0.0-20180130194729-c4fab1ac1bec/go.mod h1:gi+0XIa01GRL2eRQVjQkKGqKF3SF9vZR/HnPullcV2E=
 github.com/sean-/seed v0.0.0-20170313163322-e2103e2c3529 h1:nn5Wsu0esKSJiIVhscUtVbo7ada43DJhG55ua/hjS5I=
 github.com/sean-/seed v0.0.0-20170313163322-e2103e2c3529/go.mod h1:DxrIzT+xaE7yg65j358z/aeFdxmN0P9QXhEzd20vsDc=
+github.com/serialx/hashring v0.0.0-20180504054112-49a4782e9908/go.mod h1:/yeG0My1xr/u+HZrFQ1tOQQQQrOawfyMUH13ai5brBc=
 github.com/sirupsen/logrus v1.0.6 h1:hcP1GmhGigz/O7h1WVUM5KklBp1JoNS9FggWKdj/j3s=
 github.com/sirupsen/logrus v1.0.6/go.mod h1:pMByvHTf9Beacp5x1UXfOR9xyW/9antXMhjMPG0dEzc=
 github.com/soheilhy/cmux v0.1.4 h1:0HKaf1o97UwFjHH9o5XsHUOF+tqmdA7KEzXLpiyaw0E=
@@ -257,3 +262,4 @@ gopkg.in/vmihailenco/msgpack.v2 v2.9.1 h1:kb0VV7NuIojvRfzwslQeP3yArBqJHW9tOl4t38
 gopkg.in/vmihailenco/msgpack.v2 v2.9.1/go.mod h1:/3Dn1Npt9+MYyLpYYXjInO/5jvMLamn+AEGwNEOatn8=
 gopkg.in/yaml.v2 v2.2.1 h1:mUhvW9EsL+naU5Q3cakzfE91YhliOondGd6ZrsDBHQE=
 gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+stathat.com/c/consistent v1.0.0/go.mod h1:QkzMWzcbB+yQBL2AttO6sgsQS/JSTapcDISJalmCDS0=