grpcpool

Documentation

Index

• Variables
• type ClientConn
  • func (c *ClientConn) Close() error
  • func (c *ClientConn) Unhealthy()
• type Config
  • func (cfg *Config) NewPool(ctx context.Context, factory Factory) (*Pool, error)
• type Factory
• type Pool
  • func New(ctx context.Context, factory Factory, init, capacity int, ...) (*Pool, error)
  • func (p *Pool) Available() int
  • func (p *Pool) Capacity() int
  • func (p *Pool) Close()
  • func (p *Pool) Get(ctx context.Context) (*ClientConn, error)
  • func (p *Pool) IsClosed() bool

Variables

var (
	// ErrClosed is the error when the client pool is closed
	ErrClosed = errors.New("grpc pool: client pool is closed")
	// ErrTimeout is the error when the client pool timed out
	ErrTimeout = errors.New("grpc pool: client pool timed out")
	// ErrAlreadyClosed is the error when the client conn was already closed
	ErrAlreadyClosed = errors.New("grpc pool: the connection was already closed")
	// ErrFullPool is the error when the pool is already full
	ErrFullPool = errors.New("grpc pool: closing a ClientConn into a full pool")
)

Types

type ClientConn

type ClientConn struct {
	*grpc.ClientConn
	// contains filtered or unexported fields
}

ClientConn is the wrapper for a grpc client conn

func (*ClientConn) Close

func (c *ClientConn) Close() error

Close returns a ClientConn to the pool. It is safe to call multiple time, but will return an error after first time

func (*ClientConn) Unhealthy

func (c *ClientConn) Unhealthy()

Unhealthy marks the client conn as unhealthy, so that the connection gets reset when closed

type Config

type Config struct {
	Capacity struct {
		Initial uint `yaml:"initial" env-default:"2"`
		Max     uint `yaml:"max" env-default:"50"`
	} `yaml:"capacity"`
	Time struct {
		Idle    time.Duration `yaml:"idle" env-default:"5s"`
		MaxLife time.Duration `yaml:"max_life" env-default:"15m"`
	} `yaml:"time"`
}

func (*Config) NewPool

func (cfg *Config) NewPool(ctx context.Context, factory Factory) (*Pool, error)

type Factory

type Factory func(context.Context) (*grpc.ClientConn, error)

Factory is a function type creating a grpc client that accepts the context parameter that could be passed from Get or New method.

type Pool

type Pool struct {
	// contains filtered or unexported fields
}

Pool is the grpc client pool

func New

func New(ctx context.Context, factory Factory, init, capacity int, idleTimeout time.Duration,
	maxLifeDuration ...time.Duration) (*Pool, error)

New creates a new clients pool with the given initial and maximum capacity, and the timeout for the idle clients. The context parameter would be passed to the factory method during initialization. Returns an error if the initial clients could not be created.

func (*Pool) Available

func (p *Pool) Available() int

Available returns the number of currently unused clients

func (*Pool) Capacity

func (p *Pool) Capacity() int

Capacity returns the capacity

func (*Pool) Close

func (p *Pool) Close()

Close empties the pool calling Close on all its clients. You can call Close while there are outstanding clients. The pool channel is then closed, and Get will not be allowed anymore

func (*Pool) Get

func (p *Pool) Get(ctx context.Context) (*ClientConn, error)

Get will return the next available client. If capacity has not been reached, it will create a new one using the factory. Otherwise, it will wait till the next client becomes available or a timeout. A timeout of 0 is an indefinite wait

func (*Pool) IsClosed

func (p *Pool) IsClosed() bool

IsClosed returns true if the client pool is closed.