impl.gno

 1// Package impl is version 1 of the implementation realm of the
 2// "self-registering implementation" upgrade pattern (pattern E; see
 3// ../../README.md).
 4//
 5// Identical wiring to v0, different behaviour. Deploying it takes the facade
 6// over on the spot, with no transaction from anybody.
 7package impl
 8
 9import (
10	facade "gno.land/r/moul/x/upgrade/selfreg/facade/v0"
11)
12
13type greeter struct{}
14
15func (greeter) Greet(name string) string { return "HELLO, " + name + "!" }
16func (greeter) Version() string          { return "impl/v1" }
17
18// Instance exposes the singleton so a test (or a rollback) can re-register it
19// without redeploying.
20func Instance() facade.Impl { return greeter{} }
21
22func init(cur realm) {
23	facade.Register(cross(cur), Instance())
24}
25
26// Register re-registers this implementation with the facade. init does it once
27// at deploy; exposing it as a transaction is what makes a rollback to an
28// already-deployed version a single call.
29func Register(cur realm) {
30	facade.Register(cross(cur), Instance())
31}
32
33// Seal asks the facade to end its upgradeability, forever. It only succeeds
34// while this implementation is the live one: the facade reads the caller off
35// the crossing frame, so this cannot be used to seal somebody else's tenure.
36func Seal(cur realm) {
37	facade.Seal(cross(cur))
38}