micro/register/memory.go

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package register
import (
"context"
"sync"
"time"
"go.unistack.org/micro/v4/logger"
"go.unistack.org/micro/v4/util/id"
)
var (
sendEventTime = 10 * time.Millisecond
ttlPruneTime = time.Second
)
type node struct {
LastSeen time.Time
*Node
TTL time.Duration
}
type record struct {
Name string
Version string
Metadata map[string]string
Nodes map[string]*node
Endpoints []*Endpoint
}
type memory struct {
sync.RWMutex
records map[string]services
watchers map[string]*watcher
opts Options
}
// services is a KV map with service name as the key and a map of records as the value
type services map[string]map[string]*record
// NewRegister returns an initialized in-memory register
func NewRegister(opts ...Option) Register {
r := &memory{
opts: NewOptions(opts...),
records: make(map[string]services),
watchers: make(map[string]*watcher),
}
go r.ttlPrune()
return r
}
func (m *memory) ttlPrune() {
prune := time.NewTicker(ttlPruneTime)
defer prune.Stop()
for range prune.C {
m.Lock()
for domain, services := range m.records {
for service, versions := range services {
for version, record := range versions {
for id, n := range record.Nodes {
if n.TTL != 0 && time.Since(n.LastSeen) > n.TTL {
if m.opts.Logger.V(logger.DebugLevel) {
m.opts.Logger.Debug(m.opts.Context, "RegisterTTL expired for node "+n.ID+" of service "+service)
}
delete(m.records[domain][service][version].Nodes, id)
}
}
}
}
}
m.Unlock()
}
}
func (m *memory) sendEvent(r *Result) {
m.RLock()
watchers := make([]*watcher, 0, len(m.watchers))
for _, w := range m.watchers {
watchers = append(watchers, w)
}
m.RUnlock()
for _, w := range watchers {
select {
case <-w.exit:
m.Lock()
delete(m.watchers, w.id)
m.Unlock()
default:
select {
case w.res <- r:
case <-time.After(sendEventTime):
}
}
}
}
func (m *memory) Connect(ctx context.Context) error {
return nil
}
func (m *memory) Disconnect(ctx context.Context) error {
return nil
}
func (m *memory) Init(opts ...Option) error {
for _, o := range opts {
o(&m.opts)
}
// add services
m.Lock()
defer m.Unlock()
return nil
}
func (m *memory) Options() Options {
return m.opts
}
func (m *memory) Register(ctx context.Context, s *Service, opts ...RegisterOption) error {
m.Lock()
defer m.Unlock()
options := NewRegisterOptions(opts...)
// get the services for this domain from the register
srvs, ok := m.records[options.Domain]
if !ok {
srvs = make(services)
}
// domain is set in metadata so it can be passed to watchers
if s.Metadata == nil {
s.Metadata = map[string]string{"domain": options.Domain}
} else {
s.Metadata["domain"] = options.Domain
}
// ensure the service name exists
r := serviceToRecord(s, options.TTL)
if _, ok := srvs[s.Name]; !ok {
srvs[s.Name] = make(map[string]*record)
}
if _, ok := srvs[s.Name][s.Version]; !ok {
srvs[s.Name][s.Version] = r
if m.opts.Logger.V(logger.DebugLevel) {
m.opts.Logger.Debug(m.opts.Context, "register added new service: "+s.Name+", version "+s.Version)
}
m.records[options.Domain] = srvs
go m.sendEvent(&Result{Action: "create", Service: s})
}
var addedNodes bool
for _, n := range s.Nodes {
// check if already exists
if _, ok := srvs[s.Name][s.Version].Nodes[n.ID]; ok {
continue
}
metadata := make(map[string]string, len(n.Metadata))
// make copy of metadata
for k, v := range n.Metadata {
metadata[k] = v
}
// set the domain
metadata["domain"] = options.Domain
// add the node
srvs[s.Name][s.Version].Nodes[n.ID] = &node{
Node: &Node{
ID: n.ID,
Address: n.Address,
Metadata: metadata,
},
TTL: options.TTL,
LastSeen: time.Now(),
}
addedNodes = true
}
if addedNodes {
if m.opts.Logger.V(logger.DebugLevel) {
m.opts.Logger.Debug(m.opts.Context, "register added new node to service: "+s.Name+", version "+s.Version)
}
go m.sendEvent(&Result{Action: "update", Service: s})
} else {
// refresh TTL and timestamp
for _, n := range s.Nodes {
if m.opts.Logger.V(logger.DebugLevel) {
m.opts.Logger.Debug(m.opts.Context, "updated registration for service: "+s.Name+", version "+s.Version)
}
srvs[s.Name][s.Version].Nodes[n.ID].TTL = options.TTL
srvs[s.Name][s.Version].Nodes[n.ID].LastSeen = time.Now()
}
}
m.records[options.Domain] = srvs
return nil
}
func (m *memory) Deregister(ctx context.Context, s *Service, opts ...DeregisterOption) error {
m.Lock()
defer m.Unlock()
options := NewDeregisterOptions(opts...)
// domain is set in metadata so it can be passed to watchers
if s.Metadata == nil {
s.Metadata = map[string]string{"domain": options.Domain}
} else {
s.Metadata["domain"] = options.Domain
}
// if the domain doesn't exist, there is nothing to deregister
services, ok := m.records[options.Domain]
if !ok {
return nil
}
// if no services with this name and version exist, there is nothing to deregister
versions, ok := services[s.Name]
if !ok {
return nil
}
version, ok := versions[s.Version]
if !ok {
return nil
}
// deregister all of the service nodes from this version
for _, n := range s.Nodes {
if _, ok := version.Nodes[n.ID]; ok {
if m.opts.Logger.V(logger.DebugLevel) {
m.opts.Logger.Debug(m.opts.Context, "register removed node from service: "+s.Name+", version "+s.Version)
}
delete(version.Nodes, n.ID)
}
}
// if the nodes not empty, we replace the version in the store and exist, the rest of the logic
// is cleanup
if len(version.Nodes) > 0 {
m.records[options.Domain][s.Name][s.Version] = version
go m.sendEvent(&Result{Action: "update", Service: s})
return nil
}
// if this version was the only version of the service, we can remove the whole service from the
// register and exit
if len(versions) == 1 {
delete(m.records[options.Domain], s.Name)
go m.sendEvent(&Result{Action: "delete", Service: s})
if m.opts.Logger.V(logger.DebugLevel) {
m.opts.Logger.Debug(m.opts.Context, "register removed service: "+s.Name)
}
return nil
}
// there are other versions of the service running, so only remove this version of it
delete(m.records[options.Domain][s.Name], s.Version)
go m.sendEvent(&Result{Action: "delete", Service: s})
if m.opts.Logger.V(logger.DebugLevel) {
m.opts.Logger.Debug(m.opts.Context, "register removed service: "+s.Name+", version "+s.Version)
}
return nil
}
func (m *memory) LookupService(ctx context.Context, name string, opts ...LookupOption) ([]*Service, error) {
options := NewLookupOptions(opts...)
// if it's a wildcard domain, return from all domains
if options.Domain == WildcardDomain {
m.RLock()
recs := m.records
m.RUnlock()
var services []*Service
for domain := range recs {
srvs, err := m.LookupService(ctx, name, append(opts, LookupDomain(domain))...)
if err == ErrNotFound {
continue
} else if err != nil {
return nil, err
}
services = append(services, srvs...)
}
if len(services) == 0 {
return nil, ErrNotFound
}
return services, nil
}
m.RLock()
defer m.RUnlock()
// check the domain exists
services, ok := m.records[options.Domain]
if !ok {
return nil, ErrNotFound
}
// check the service exists
versions, ok := services[name]
if !ok || len(versions) == 0 {
return nil, ErrNotFound
}
// serialize the response
result := make([]*Service, len(versions))
var i int
for _, r := range versions {
result[i] = recordToService(r, options.Domain)
i++
}
return result, nil
}
func (m *memory) ListServices(ctx context.Context, opts ...ListOption) ([]*Service, error) {
options := NewListOptions(opts...)
// if it's a wildcard domain, list from all domains
if options.Domain == WildcardDomain {
m.RLock()
recs := m.records
m.RUnlock()
var services []*Service
for domain := range recs {
srvs, err := m.ListServices(ctx, append(opts, ListDomain(domain))...)
if err != nil {
return nil, err
}
services = append(services, srvs...)
}
return services, nil
}
m.RLock()
defer m.RUnlock()
// ensure the domain exists
services, ok := m.records[options.Domain]
if !ok {
return make([]*Service, 0), nil
}
// serialize the result, each version counts as an individual service
var result []*Service
for _, service := range services {
for _, version := range service {
result = append(result, recordToService(version, options.Domain))
}
}
return result, nil
}
func (m *memory) Watch(ctx context.Context, opts ...WatchOption) (Watcher, error) {
id, err := id.New()
if err != nil {
return nil, err
}
wo := NewWatchOptions(opts...)
// construct the watcher
w := &watcher{
exit: make(chan bool),
res: make(chan *Result),
id: id,
wo: wo,
}
m.Lock()
m.watchers[w.id] = w
m.Unlock()
return w, nil
}
func (m *memory) Name() string {
return m.opts.Name
}
func (m *memory) String() string {
return "memory"
}
type watcher struct {
res chan *Result
exit chan bool
wo WatchOptions
id string
}
func (m *watcher) Next() (*Result, error) {
for {
select {
case r := <-m.res:
if r.Service == nil {
continue
}
if len(m.wo.Service) > 0 && m.wo.Service != r.Service.Name {
continue
}
// extract domain from service metadata
var domain string
if r.Service.Metadata != nil && len(r.Service.Metadata["domain"]) > 0 {
domain = r.Service.Metadata["domain"]
} else {
domain = DefaultDomain
}
// only send the event if watching the wildcard or this specific domain
if m.wo.Domain == WildcardDomain || m.wo.Domain == domain {
return r, nil
}
case <-m.exit:
return nil, ErrWatcherStopped
}
}
}
func (m *watcher) Stop() {
select {
case <-m.exit:
return
default:
close(m.exit)
}
}
func serviceToRecord(s *Service, ttl time.Duration) *record {
metadata := make(map[string]string, len(s.Metadata))
for k, v := range s.Metadata {
metadata[k] = v
}
nodes := make(map[string]*node, len(s.Nodes))
for _, n := range s.Nodes {
nodes[n.ID] = &node{
Node: n,
TTL: ttl,
LastSeen: time.Now(),
}
}
endpoints := make([]*Endpoint, len(s.Endpoints))
for i, e := range s.Endpoints { // TODO: vtolstov use copy
endpoints[i] = e
}
return &record{
Name: s.Name,
Version: s.Version,
Metadata: metadata,
Nodes: nodes,
Endpoints: endpoints,
}
}
func recordToService(r *record, domain string) *Service {
metadata := make(map[string]string, len(r.Metadata))
for k, v := range r.Metadata {
metadata[k] = v
}
// set the domain in metadata so it can be determined when a wildcard query is performed
metadata["domain"] = domain
endpoints := make([]*Endpoint, len(r.Endpoints))
for i, e := range r.Endpoints {
md := make(map[string]string, len(e.Metadata))
for k, v := range e.Metadata {
md[k] = v
}
endpoints[i] = &Endpoint{
Name: e.Name,
Request: e.Request,
Response: e.Response,
Metadata: md,
}
}
nodes := make([]*Node, len(r.Nodes))
i := 0
for _, n := range r.Nodes {
md := make(map[string]string, len(n.Metadata))
for k, v := range n.Metadata {
md[k] = v
}
nodes[i] = &Node{
ID: n.ID,
Address: n.Address,
Metadata: md,
}
i++
}
return &Service{
Name: r.Name,
Version: r.Version,
Metadata: metadata,
Endpoints: endpoints,
Nodes: nodes,
}
}