github.com/micro/go-micro/v2@v2.9.1/util/sync/sync.go (about)

     1  // Package syncs will sync multiple stores
     2  package sync
     3  
     4  import (
     5  	"fmt"
     6  	"sync"
     7  	"time"
     8  
     9  	"github.com/ef-ds/deque"
    10  	"github.com/micro/go-micro/v2/store"
    11  	"github.com/pkg/errors"
    12  )
    13  
    14  // Sync implements a sync in for stores
    15  type Sync interface {
    16  	// Implements the store interface
    17  	store.Store
    18  	// Force a full sync
    19  	Sync() error
    20  }
    21  
    22  type syncStore struct {
    23  	storeOpts           store.Options
    24  	syncOpts            Options
    25  	pendingWrites       []*deque.Deque
    26  	pendingWriteTickers []*time.Ticker
    27  	sync.RWMutex
    28  }
    29  
    30  // NewSync returns a new Sync
    31  func NewSync(opts ...Option) Sync {
    32  	c := &syncStore{}
    33  	for _, o := range opts {
    34  		o(&c.syncOpts)
    35  	}
    36  	if c.syncOpts.SyncInterval == 0 {
    37  		c.syncOpts.SyncInterval = 1 * time.Minute
    38  	}
    39  	if c.syncOpts.SyncMultiplier == 0 {
    40  		c.syncOpts.SyncMultiplier = 5
    41  	}
    42  	return c
    43  }
    44  
    45  func (c *syncStore) Close() error {
    46  	return nil
    47  }
    48  
    49  // Init initialises the storeOptions
    50  func (c *syncStore) Init(opts ...store.Option) error {
    51  	for _, o := range opts {
    52  		o(&c.storeOpts)
    53  	}
    54  	if len(c.syncOpts.Stores) == 0 {
    55  		return errors.New("the sync has no stores")
    56  	}
    57  	if c.storeOpts.Context == nil {
    58  		return errors.New("please provide a context to the sync. Cancelling the context signals that the sync is being disposed and syncs the sync")
    59  	}
    60  	for _, s := range c.syncOpts.Stores {
    61  		if err := s.Init(); err != nil {
    62  			return errors.Wrapf(err, "Store %s failed to Init()", s.String())
    63  		}
    64  	}
    65  	c.pendingWrites = make([]*deque.Deque, len(c.syncOpts.Stores)-1)
    66  	c.pendingWriteTickers = make([]*time.Ticker, len(c.syncOpts.Stores)-1)
    67  	for i := 0; i < len(c.pendingWrites); i++ {
    68  		c.pendingWrites[i] = deque.New()
    69  		c.pendingWrites[i].Init()
    70  		c.pendingWriteTickers[i] = time.NewTicker(c.syncOpts.SyncInterval * time.Duration(intpow(c.syncOpts.SyncMultiplier, int64(i))))
    71  	}
    72  	go c.syncManager()
    73  	return nil
    74  }
    75  
    76  // Options returns the sync's store options
    77  func (c *syncStore) Options() store.Options {
    78  	return c.storeOpts
    79  }
    80  
    81  // String returns a printable string describing the sync
    82  func (c *syncStore) String() string {
    83  	backends := make([]string, len(c.syncOpts.Stores))
    84  	for i, s := range c.syncOpts.Stores {
    85  		backends[i] = s.String()
    86  	}
    87  	return fmt.Sprintf("sync %v", backends)
    88  }
    89  
    90  func (c *syncStore) List(opts ...store.ListOption) ([]string, error) {
    91  	return c.syncOpts.Stores[0].List(opts...)
    92  }
    93  
    94  func (c *syncStore) Read(key string, opts ...store.ReadOption) ([]*store.Record, error) {
    95  	return c.syncOpts.Stores[0].Read(key, opts...)
    96  }
    97  
    98  func (c *syncStore) Write(r *store.Record, opts ...store.WriteOption) error {
    99  	return c.syncOpts.Stores[0].Write(r, opts...)
   100  }
   101  
   102  // Delete removes a key from the sync
   103  func (c *syncStore) Delete(key string, opts ...store.DeleteOption) error {
   104  	return c.syncOpts.Stores[0].Delete(key, opts...)
   105  }
   106  
   107  func (c *syncStore) Sync() error {
   108  	return nil
   109  }
   110  
   111  type internalRecord struct {
   112  	key       string
   113  	value     []byte
   114  	expiresAt time.Time
   115  }