Merge pull request #153 from ydb-platform/balancer.create

v3.14.1: balancers.CreateFromConfig + balancer.Balancer.Create

CHANGELOG.md

@@ -1,5 +1,9 @@
+## 3.14.1
+* Added `balacers.CreateFromConfig` balancer creator
+* Added `Create` method to interface `balancer.Balancer`
+
 ## 3.14.0
-* Added `balacers.FromConfig` balancers creator
+* Added `balacers.FromConfig` balancer creator
 
 ## 3.13.3
 * Fixed linter issues

balancers/config.go

@@ -48,23 +48,15 @@ func WithParseErrorHandler(errorHandler func(error)) fromConfigOption {
  }
 }
 
-func FromConfig(config string, opts ...fromConfigOption) (b balancer.Balancer) {
+func CreateFromConfig(config string) (balancer.Balancer, error) {
  var (
- h = fromConfigOptionsHolder{
- fallbackBalancer: Default(),
- }
- c balancersConfig
+ b balancer.Balancer
+ err error
+ c balancersConfig
  )
 
- for _, o := range opts {
- o(&h)
- }
-
- if err := json.Unmarshal([]byte(config), &c); err != nil {
- if h.errorHandler != nil {
- h.errorHandler(err)
- }
- return h.fallbackBalancer
+ if err = json.Unmarshal([]byte(config), &c); err != nil {
+ return nil, err
  }
 
  switch c.Type {
@@ -75,30 +67,47 @@ func FromConfig(config string, opts ...fromConfigOption) (b balancer.Balancer) {
  case typeRoundRobin:
  b = RoundRobin()
  default:
- if h.errorHandler != nil {
- h.errorHandler(errors.Errorf("unknown type of balancer: %s", c.Type))
- }
- return h.fallbackBalancer
+ return nil, errors.Errorf("unknown type of balancer: %s", c.Type)
  }
 
  switch c.Prefer {
  case preferLocalDC:
  if c.Fallback {
- return PreferLocalDCWithFallBack(b)
+ return PreferLocalDCWithFallBack(b), nil
  }
- return PreferLocalDC(b)
+ return PreferLocalDC(b), nil
  case preferLocations:
  if len(c.Locations) == 0 {
- if h.errorHandler != nil {
- h.errorHandler(errors.Errorf("empty locations list in balancer '%s' config", c.Type))
- }
- return h.fallbackBalancer
+ return nil, errors.Errorf("empty locations list in balancer '%s' config", c.Type)
  }
  if c.Fallback {
- return PreferLocationsWithFallback(b, c.Locations...)
+ return PreferLocationsWithFallback(b, c.Locations...), nil
  }
- return PreferLocations(b, c.Locations...)
+ return PreferLocations(b, c.Locations...), nil
  default:
- return b
+ return b, nil
  }
 }
+
+func FromConfig(config string, opts ...fromConfigOption) balancer.Balancer {
+ var (
+ h = fromConfigOptionsHolder{
+ fallbackBalancer: Default(),
+ }
+ b balancer.Balancer
+ err error
+ )
+ for _, o := range opts {
+ o(&h)
+ }
+
+ b, err = CreateFromConfig(config)
+ if err != nil {
+ if h.errorHandler != nil {
+ h.errorHandler(err)
+ }
+ return h.fallbackBalancer
+ }
+
+ return b
+}

balancers/config_test.go

@@ -10,6 +10,10 @@ import (
 
 type testBalancer struct{}
 
+func (t testBalancer) Create() balancer.Balancer {
+ panic("unexpected call")
+}
+
 func (t testBalancer) Next() conn.Conn {
  panic("unexpected call")
 }

internal/balancer/balancer.go

@@ -29,8 +29,7 @@ type Balancer interface {
 
  // Contains returns true if Balancer contains requested element.
  Contains(Element) bool
-}
 
-type Creator interface {
+ // Create makes empty balancer with same implementation
  Create() Balancer
 }

internal/balancer/multi/multi.go

@@ -26,7 +26,7 @@ type multi struct {
 func (m *multi) Create() balancer.Balancer {
  bb := make([]balancer.Balancer, len(m.balancer))
  for i, b := range m.balancer {
- bb[i] = b.(balancer.Creator).Create()
+ bb[i] = b.Create()
  }
  return &multi{
  balancer: bb,

internal/balancer/stub/stub.go

@@ -16,6 +16,7 @@ type stubBalancer struct {
  OnRemove func(balancer.Element) bool
  OnPessimize func(context.Context, balancer.Element) error
  OnContains func(balancer.Element) bool
+ OnCreate func() balancer.Balancer
 }
 
 func Balancer() (*list.List, balancer.Balancer) {
@@ -55,6 +56,13 @@ func Balancer() (*list.List, balancer.Balancer) {
  }
 }
 
+func (s stubBalancer) Create() balancer.Balancer {
+ if f := s.OnCreate; f != nil {
+ return f()
+ }
+ return nil
+}
+
 func (s stubBalancer) Next() conn.Conn {
  if f := s.OnNext; f != nil {
  return f()

internal/meta/version.go

@@ -1,5 +1,5 @@
 package meta
 
 const (
- Version = "ydb-go-sdk/3.14.0"
+ Version = "ydb-go-sdk/3.14.1"
 )

with.go

@@ -3,8 +3,6 @@ package ydb
 import (
  "context"
  "sync/atomic"
-
- "github.com/ydb-platform/ydb-go-sdk/v3/internal/balancer"
 )
 
 var nextID = uint64(0)
@@ -14,14 +12,12 @@ func (c *connection) With(ctx context.Context, opts ...Option) (Connection, erro
  return c, nil
  }
 
- if creator, ok := c.config.Balancer().(balancer.Creator); ok {
- opts = append(
- opts,
- WithBalancer(
- creator.Create(),
- ),
- )
- }
+ opts = append(
+ opts,
+ WithBalancer(
+ c.config.Balancer().Create(),
+ ),
+ )
 
  id := atomic.AddUint64(&nextID, 1)