MemcachedLock

Implements: Lock

Description

The MemcachedLock class allows you to create a lock that is implemented based on the Memcached’s caching service.

Important points

• The current implementation does not support authentication.

Configuration parameters

• connection(s):
  • discovery_key: (optional) key to retrieve the connection from IDiscovery
  • host: host name or IP address
  • port: port number
  • uri: resource URI or connection string with all parameters in it
• options:
  • max_size: maximum number of values stored in this cache (default: 1000)
  • max_key_size: maximum key length (default: 250)
  • max_expiration: maximum expiration duration in milliseconds (default: 2592000)
  • max_value: maximum value length (default: 1048576)
  • pool_size: pool size (default: 5)
  • reconnect: reconnection timeout in milliseconds (default: 10 sec)
  • retries: number of retries (default: 3)
  • timeout: default caching timeout in milliseconds (default: 1 minute)
  • failures: number of failures before stop retrying (default: 5)
  • retry: retry timeout in milliseconds (default: 30 sec)
  • idle: idle timeout (milliseconds) before disconnecting (default: 5 sec)

References

• *:discovery:*:*:1.0 - (optional) IDiscovery services to resolve connection

Methods

Close

Closes a component and frees used resources.

(c *MemcachedLock) Close(ctx context.Context, correlationId string) error

• ctx: context.Context - operation context.
• correlationId: string - (optional) transaction id used to trace execution through the call chain.
• returns: error - error or nil if no errors occurred

Configure

Configures a component by passing its configuration parameters.

(c *MemcachedLock) Configure(ctx context.Context, config *ConfigParams)

• ctx: context.Context - operation context.
• config: *ConfigParams - configuration parameters to be set.

IsOpen

Checks if the component is open.

(c *MemcachedLock) IsOpen() bool

• returns: bool - true if the component is open and false otherwise.

Open

Opens the component.

(c *MemcachedLock) Open(ctx context.Context, correlationId string) error

• ctx: context.Context - operation context.
• correlationId: string - (optional) transaction id used to trace execution through the call chain.
• returns: error - error or nil if no errors occurred

ReleaseLock

Releases a prevously acquired lock by its key.

(c *MemcachedLock) ReleaseLock(ctx context.Context, correlationId string, key string) error

• ctx: context.Context - operation context.
• correlationId: string - (optional) transaction id used to trace execution through the call chain.
• key: string - unique lock key to release.
• returns: error - error or nil if no errors occurred

SetReferences

Sets references to dependent components.

(c *MemcachedLock) SetReferences(references IReferences)

• references: IReferences - references to locate the component’s dependencies.

TryAcquireLock

Makes a single attempt to acquire a lock by its key. It returns immediately a positive or negative result.

(c *MemcachedLock) TryAcquireLock(ctx context.Context, correlationId string, key string, ttl int64) (result bool, err error)

• ctx: context.Context - operation context.
• correlationId: string - (optional) transaction id used to trace execution through the call chain.
• key: string - unique lock key to acquire.
• ttl: int64 - lock timeout (time to live) in milliseconds.
• returns: (result bool, err error) - true if lock was successfull and false otherwise.

Examples

ctx := context.Background()

lock := NewMemcachedLock[string]()
lock.Configure(ctx, cconf.NewConfigParamsFromTuples(
  "host", "localhost",
  "port", 11211,
))

err := lock.Open(ctx, "123")
if err != nil {
  ...
}

result, err := lock.TryAcquireLock(ctx, "123", "key1", 3000)
if result {
	// Processing...
}
err = lock.ReleaseLock(ctx, "123", "key1")
// Continue...