lbcd/blockchain/notifications.go
Dave Collins b69a849114 Import btcchain repo into blockchain directory.
This commit contains the entire btcchain repository along with several
changes needed to move all of the files into the blockchain directory in
order to prepare it for merging.  This does NOT update btcd or any of the
other packages to use the new location as that will be done separately.

- All import paths in the old btcchain test files have been changed to
  the new location
- All references to btcchain as the package name have been changed to
  blockchain
2015-01-30 15:49:59 -06:00

73 lines
2.3 KiB
Go

// Copyright (c) 2013-2014 Conformal Systems LLC.
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package blockchain
import (
"fmt"
)
// NotificationType represents the type of a notification message.
type NotificationType int
// NotificationCallback is used for a caller to provide a callback for
// notifications about various chain events.
type NotificationCallback func(*Notification)
// Constants for the type of a notification message.
const (
// NTBlockAccepted indicates the associated block was accepted into
// the block chain. Note that this does not necessarily mean it was
// added to the main chain. For that, use NTBlockConnected.
NTBlockAccepted NotificationType = iota
// NTBlockConnected indicates the associated block was connected to the
// main chain.
NTBlockConnected
// NTBlockDisconnected indicates the associated block was disconnected
// from the main chain.
NTBlockDisconnected
)
// notificationTypeStrings is a map of notification types back to their constant
// names for pretty printing.
var notificationTypeStrings = map[NotificationType]string{
NTBlockAccepted: "NTBlockAccepted",
NTBlockConnected: "NTBlockConnected",
NTBlockDisconnected: "NTBlockDisconnected",
}
// String returns the NotificationType in human-readable form.
func (n NotificationType) String() string {
if s, ok := notificationTypeStrings[n]; ok {
return s
}
return fmt.Sprintf("Unknown Notification Type (%d)", int(n))
}
// Notification defines notification that is sent to the caller via the callback
// function provided during the call to New and consists of a notification type
// as well as associated data that depends on the type as follows:
// - NTBlockAccepted: *btcutil.Block
// - NTBlockConnected: *btcutil.Block
// - NTBlockDisconnected: *btcutil.Block
type Notification struct {
Type NotificationType
Data interface{}
}
// sendNotification sends a notification with the passed type and data if the
// caller requested notifications by providing a callback function in the call
// to New.
func (b *BlockChain) sendNotification(typ NotificationType, data interface{}) {
// Ignore it if the caller didn't request notifications.
if b.notifications == nil {
return
}
// Generate and send the notification.
n := Notification{Type: typ, Data: data}
b.notifications(&n)
}