micro/util/sync/sync.go
2020-04-11 12:00:34 +01:00

116 lines
2.8 KiB
Go

// Package syncs will sync multiple stores
package sync
import (
"fmt"
"sync"
"time"
"github.com/ef-ds/deque"
"github.com/micro/go-micro/v2/store"
"github.com/pkg/errors"
)
// Sync implements a sync in for stores
type Sync interface {
// Implements the store interface
store.Store
// Force a full sync
Sync() error
}
type syncStore struct {
storeOpts store.Options
syncOpts Options
pendingWrites []*deque.Deque
pendingWriteTickers []*time.Ticker
sync.RWMutex
}
// NewSync returns a new Sync
func NewSync(opts ...Option) Sync {
c := &syncStore{}
for _, o := range opts {
o(&c.syncOpts)
}
if c.syncOpts.SyncInterval == 0 {
c.syncOpts.SyncInterval = 1 * time.Minute
}
if c.syncOpts.SyncMultiplier == 0 {
c.syncOpts.SyncMultiplier = 5
}
return c
}
func (c *syncStore) Close() error {
return nil
}
// Init initialises the storeOptions
func (c *syncStore) Init(opts ...store.Option) error {
for _, o := range opts {
o(&c.storeOpts)
}
if len(c.syncOpts.Stores) == 0 {
return errors.New("the sync has no stores")
}
if c.storeOpts.Context == nil {
return errors.New("please provide a context to the sync. Cancelling the context signals that the sync is being disposed and syncs the sync")
}
for _, s := range c.syncOpts.Stores {
if err := s.Init(); err != nil {
return errors.Wrapf(err, "Store %s failed to Init()", s.String())
}
}
c.pendingWrites = make([]*deque.Deque, len(c.syncOpts.Stores)-1)
c.pendingWriteTickers = make([]*time.Ticker, len(c.syncOpts.Stores)-1)
for i := 0; i < len(c.pendingWrites); i++ {
c.pendingWrites[i] = deque.New()
c.pendingWrites[i].Init()
c.pendingWriteTickers[i] = time.NewTicker(c.syncOpts.SyncInterval * time.Duration(intpow(c.syncOpts.SyncMultiplier, int64(i))))
}
go c.syncManager()
return nil
}
// Options returns the sync's store options
func (c *syncStore) Options() store.Options {
return c.storeOpts
}
// String returns a printable string describing the sync
func (c *syncStore) String() string {
backends := make([]string, len(c.syncOpts.Stores))
for i, s := range c.syncOpts.Stores {
backends[i] = s.String()
}
return fmt.Sprintf("sync %v", backends)
}
func (c *syncStore) List(opts ...store.ListOption) ([]string, error) {
return c.syncOpts.Stores[0].List(opts...)
}
func (c *syncStore) Read(key string, opts ...store.ReadOption) ([]*store.Record, error) {
return c.syncOpts.Stores[0].Read(key, opts...)
}
func (c *syncStore) Write(r *store.Record, opts ...store.WriteOption) error {
return c.syncOpts.Stores[0].Write(r, opts...)
}
// Delete removes a key from the sync
func (c *syncStore) Delete(key string, opts ...store.DeleteOption) error {
return c.syncOpts.Stores[0].Delete(key, opts...)
}
func (c *syncStore) Sync() error {
return nil
}
type internalRecord struct {
key string
value []byte
expiresAt time.Time
}