ghost

A set of go tools with simple construction and powerful features.
As ghost is forced to be external depandency free, it is easy to run go codes with ghost without downloading varieties of extra libs. This implies that ghost might be a best solution for internal enterprise servers with internet cut off or some users who have harsh conditions to access abroad, especially CHN developers.

Connection Pool

Example

// Create a factory() to be used with the Pool
factory := func() (net.Conn, error) {
    return net.Dial("tcp", "127.0.0.1:4000")
}

// Create a new blocking pool with an init capacity of 5 and max capacity of 30.
// Currently no new connections would be made when the pool is busy, so
// the number of connections of the pool is kept no more than 5 and 30 does not
// make sense though the api is reserved. 
// The timeout to block Get() is set to 3 by default.
p, err := pool.NewBlockingPool(5, 30, factory)

// Get a connection from the pool, if there is no connection available
// it blocks for a recycled one is available til timeout.
conn, err := p.Get()

// Use net.Conn's Write() method
// This conn is marked as unusable automatically when an error counted,
// and will be later abandoned when you close the conn, which means
// the underlying connection will be closed.
// Yet a new net.Conn will be created through factory() and put back to the pool. 
lens, err := conn.Write(bytes)

// You can also use other net.Conn's methods
// The underlying connection is only wrapped with all features reserved.

// Put it back to the pool by closing the connection
conn.Close()

Shared File

Example

Retry

Delegate

type Operation func() error
type Transform func(ori time.Duration) (ret time.Duration)
type Recursion func(fir, pre time.Duration) (cur time.Duration)

Simple

//retry at most 3 times.
//sleeps for 1 second before first retry, and sleep time doubles after each time it retries
retries, errors := retry.Attempt(3, 1*time.Second, func() error{
	//on error counted return the error
	//on success return nil
})

Custom

r := retry.Retry{

	//time to sleep before first retry
	FirstSleep: 1 * time.Second,

	//sleep time increase or decline
	//---linear---
	//	n = nsub1 + 1
	//--exponent--
	//	n = nsub1 * 2
	//or you can use custom recursions besides predefines
	//example:
	//
	//Recursion: 
	//	func(nsub1 time.Duration) time.Duration {
	//		return nsub1+1 * time.Second
	//	},
	Recursion: retry.Double,

	//sleep time limitation or randomization
	//----max----
	//	if ori > 3 * time.Second {
	//		return 3 * time.Second
	//	} else {
	//		return ori
	//	}
	Transform: retry.Max(3 * time.Second),

	//max time to retry
	Retries: 5,
}
//return nil to announce success
//return a counted error to announce failure, requesting for retry
//see example/ for detail
r.Attempt(yourOperation)