gocp

Go connection pool.

Description

Go connection pool provides a pool of network connections to a single remote endpoint.

The connection pool uses go persistent connections for each network connection, which attempts to reconnect to the remote end when the connection has an error.

Usage Example

Basic Example

Only the Address of the remote host is required. All other parameters have reasonalbe defaults and may be elided.

    package main

    import (
        "log"
        "github.com/karrick/gocp"
    )

    func main() {
        pool, err := gocp.New(gocp.Address("echo-server.example.com:7"))

        // later ...

        conn := pool.Get()
        defer pool.Put(conn)

        _, err = conn.Write([]byte("hello, world"))
        if err != nil {
            log.Fatal(err)
        }

        buf := make([]byte, 512)
        _, err = conn.Read(buf)
        if err != nil {
            log.Fatal(err)
        }
    }

Logger

If there are connection errors, or an error that takes place during an I/O operation, and you want to be notified of the error, you may pass an object that has a Print(...interface{}) method, and it will be called with the error message.

    package main

    import (
        "log"
        "github.com/karrick/gocp"
    )

    func main() {

        printer := log.New(os.Stderr, "WARNING: ", 0)

        pool, err := gocp.New(gocp.Address("echo-server.example.com:7"),
            gocp.Logger(printer))

        // later ...

        conn := pool.Get()
        defer pool.Put(conn)

        _, err = conn.Write([]byte("hello, world"))
        if err != nil {
            log.Fatal(err)
        }

        buf := make([]byte, 512)
        _, err = conn.Read(buf)
        if err != nil {
            log.Fatal(err)
        }
    }

Size

If the desired pool size is different than the default, DefaultSize, it can be changed by using the Size function.

    package main

    import (
        "log"
        "github.com/karrick/gocp"
    )

    func main() {

        pool, err := gocp.New(gocp.Address("echo-server.example.com:7"),
            gocp.Size(10))

        // later ...

        conn := pool.Get()
        defer pool.Put(conn)

        _, err = conn.Write([]byte("hello, world"))
        if err != nil {
            log.Fatal(err)
        }

        buf := make([]byte, 512)
        _, err = conn.Read(buf)
        if err != nil {
            log.Fatal(err)
        }
    }

Implementation Notes

If you close the pool, only the connections in the pool at the time it is closed will be closed. Connections which have been acquired and not yet released will remain open.