impl.gno

 1// Package impl is version 0 of the implementation realm of the
 2// "self-registering implementation" upgrade pattern (pattern E; see
 3// ../../README.md).
 4//
 5// Deploying this realm is the whole upgrade: init registers it with the facade.
 6package impl
 7
 8import (
 9	facade "gno.land/r/moul/x/upgrade/selfreg/facade/v0"
10)
11
12type greeter struct{}
13
14func (greeter) Greet(name string) string { return "hello, " + name }
15func (greeter) Version() string          { return "impl/v0" }
16
17// Instance exposes the singleton so a test (or a rollback) can re-register it
18// without redeploying.
19func Instance() facade.Impl { return greeter{} }
20
21func init(cur realm) {
22	facade.Register(cross(cur), Instance())
23}
24
25// Register re-registers this implementation with the facade. init does it once
26// at deploy; exposing it as a transaction is what makes a rollback to an
27// already-deployed version a single call.
28func Register(cur realm) {
29	facade.Register(cross(cur), Instance())
30}
31
32// Seal asks the facade to end its upgradeability, forever. It only succeeds
33// while this implementation is the live one: the facade reads the caller off
34// the crossing frame, so this cannot be used to seal somebody else's tenure.
35func Seal(cur realm) {
36	facade.Seal(cross(cur))
37}