pool

README

NSQPool

NSQPool is a thread safe connection pool for nsq producer. It can be used to manage and reuse nsq producer connection.

Install and Usage

Install the package with:

github.com/qgymje/nsqpool

Import it with:

import (
    "github.com/qgymje/nsqpool"
    nsq "github.com/nsqio/go-nsq"
)

and use pool as the package name inside the code.

Example

// create a factory() to be used with channel based pool
factory := func() (*nsq.Producer, error) { 
    config := nsq.NewConfig()
    return nsq.NewProducer(":4150", config)
}

nsqPool, err := pool.NewChannelPool(5, 30, factory)

producer, err := nsqPool.Get()

producer.Publish("topic", "some data")
// do something with producer and put it back to the pool by closing the connection
// (this doesn't close the underlying connection instead it's putting it back
// to the pool).
producer.Close()

// close pool any time you want, this closes all the connections inside a pool
nsqPool.Close()

// currently available connections in the pool
current := nsqPool.Len()

License

The MIT License (MIT) - see LICENSE for more details

Documentation

Overview

Package pool implements a pool of net.Conn interfaces to manage and reuse them.

Index

• Variables
• type Factory
• type Pool
  • func NewChannelPool(initialCap, maxCap int, factory Factory) (Pool, error)
• type PoolConn
  • func (p *PoolConn) Close() error
  • func (p *PoolConn) MarkUnusable()

Variables

var (
	// ErrClosed is the error resulting if the pool is closed via pool.Close().
	ErrClosed = errors.New("pool is closed")
)

Types

type Factory

type Factory func() (*nsq.Producer, error)

Factory is a function to create new connections.

type Pool

type Pool interface {
	// Get returns a new connection from the pool. Closing the connections puts
	// it back to the Pool. Closing it when the pool is destroyed or full will
	// be counted as an error.
	Get() (*PoolConn, error)

	// Close closes the pool and all its connections. After Close() the pool is
	// no longer usable.
	Close()

	// Len returns the current number of connections of the pool.
	Len() int
}

Pool interface describes a pool implementation. A pool should have maximum capacity. An ideal pool is threadsafe and easy to use.

func NewChannelPool

func NewChannelPool(initialCap, maxCap int, factory Factory) (Pool, error)

NewChannelPool returns a new pool based on buffered channels with an initial capacity and maximum capacity. Factory is used when initial capacity is greater than zero to fill the pool. A zero initialCap doesn't fill the Pool until a new Get() is called. During a Get(), If there is no new connection available in the pool, a new connection will be created via the Factory() method.

type PoolConn

type PoolConn struct {
	*nsq.Producer
	// contains filtered or unexported fields
}

PoolConn is a wrapper around net.Conn to modify the the behavior of net.Conn's Close() method.

func (*PoolConn) Close

func (p *PoolConn) Close() error

Close puts the given connects back to the pool instead of closing it.

func (*PoolConn) MarkUnusable

func (p *PoolConn) MarkUnusable()

MarkUnusable marks the connection not usable any more, to let the pool close it instead of returning it to pool.