README
¶
Fader
In-Memory storage that distributes items via UDP multicast.
Documentation is available at godoc.org
Interface
type Item interface {
Key() string
Time() time.Time
}
type Fader interface {
Open() error
Close() error
Store(Item) error
Earliest() Item
Select(string) []Item
Detect(string) Item
Size() int
}
A remove function is missing, because every stored item is supposed to expire after a defined period of time. See the memory fader implementation for details.
Memory Fader
An implementation of the Fader interface, that stores all items in memory using container/heap. The
constructor function takes a time.Duration that specifies the period after which a stored item is removed.
memoryFader := fader.NewMemory(1*time.Second)
memoryFader.Open()
defer memoryFader.Close()
memoryFader.Store(item)
memoryFader.Size() // => 1
time.Sleep(2*time.Second)
memoryFader.Size() // => 0
Multicast Fader
Another implementation of the Fader interface. It does not store item directly, but delegates them to a given
parent instance. Additionally, every Store operation is converted into an UDP packet which is sent to the
given multicast group. The packet is encrypted using the given key.
multicastFaderOne := fader.NewMulticast(memoryFaderOne, "224.0.0.1:1888", fader.DefaultKey)
multicastFaderOne.Open()
defer multicastFaderOne.Close()
multicastFaderTwo := fader.NewMulticast(memoryFaderTwo, "224.0.0.1:1888", fader.DefaultKey)
multicastFaderTwo.Open()
defer multicastFaderTwo.Close()
multicastFaderOne.Store(item)
multicastFaderOne.Size() // => 1
time.Sleep(10*time.Millisecond)
multicastFaderTwo.Size() // => 1
Contribution
Any contribution is welcome! Feel free to open an issue or do a pull request.
Documentation
¶
Overview ¶
This package provides an interface to store and fetch items. The implementation is responsible for the removal after a expiry period.
Example for a memory fader, that expires items after 2 seconds
memoryFader := fader.NewMemory(2*time.Second) memoryFader.Open() defer memoryFader.Close() memoryFader.Store(item) memoryFader.Size() // => 1 time.Sleep(3*time.Second) memoryFader.Size() // => 0
The multicast fader can be used to distribute `Store` operations via a multicast group. Other instances that listen to the same group, will perform that operation on thier own, so that each instance end up with the same data.
multicastFaderOne := fader.NewMulticast(memoryFaderOne, "224.0.0.1:1888", fader.DefaultKey) multicastFaderOne.Open() defer multicastFaderOne.Close() multicastFaderTwo := fader.NewMulticast(memoryFaderTwo, "224.0.0.1:1888", fader.DefaultKey) multicastFaderTwo.Open() defer multicastFaderTwo.Close() multicastFaderOne.Store(item) multicastFaderOne.Size() // => 1 time.Sleep(10*time.Millisecond) multicastFaderTwo.Size() // => 1
Index ¶
Constants ¶
const (
IDSize = 10
)
Variables ¶
var (
DefaultKey = []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
)
Functions ¶
This section is empty.
Types ¶
type Fader ¶
type Fader interface {
Open() error
Close() error
Store(Item) error
Earliest() Item
Select(string) []Item
Detect(string) Item
Size() int
}
func NewMemory ¶
Creates a Fader instance that stores all data in the memory. The expiresIn parameter defines after which period a stored item will be removed.
func NewMulticast ¶
func NewMulticast( parent Fader, address string, key []byte, id []byte, itemReceivedHandler func(Item) bool, ) Fader
Creates a Fader instance that delegates all calls to a parent Fader instance. Additional to that, all store-operations are published to a multicast group which is specified by the given address. All packets will encrypted with AES-GCM using the given key. The length of the key's byte-slice, can be 16, 24 or 32 and will define if AES-128, AES-192 or AES-256 is used. For testing purposes, a 10-byte long id can be set. If no id is nil, a random id will be generated. The argument can take a function that is called every time an item is received. If the function is nil or returns true, the received item will be stored in the parent fader. Otherwise, the item will be dismissed.
Source Files
Directories