output_state.go RawHistoryFolder

1package client
2
3import "github.com/bnema/vev/internal/ports"
4
5// outputApplyState is the client-side dependency chain for one attachment.
6// State-bearing frames are accepted only when their epoch, base, and view
7// revision continue the last frame; a new epoch must carry a full reset.
8type outputApplyState struct {
9	epoch        uint64
10	state        uint64
11	viewRevision uint64
12	initialized  bool
13}
14
15func (s outputApplyState) next(output ports.Output) (outputApplyState, bool) {
16	if output.Epoch == 0 {
17		return outputApplyState{}, false
18	}
19	if !s.initialized {
20		if output.New == 0 {
21			return s, true
22		}
23		if output.Base != 0 || !output.Full {
24			return outputApplyState{}, false
25		}
26		return outputApplyState{epoch: output.Epoch, state: output.New, viewRevision: output.ViewRevision, initialized: true}, true
27	}
28	if output.Epoch < s.epoch {
29		return outputApplyState{}, false
30	}
31	if output.Epoch == s.epoch {
32		if output.ViewRevision != s.viewRevision {
33			return outputApplyState{}, false
34		}
35		if output.New == 0 {
36			if output.Base != 0 || output.Full {
37				return outputApplyState{}, false
38			}
39			return s, true
40		}
41		if output.Full || output.Base != s.state || output.New != output.Base+1 {
42			return outputApplyState{}, false
43		}
44		return outputApplyState{epoch: s.epoch, state: output.New, viewRevision: s.viewRevision, initialized: true}, true
45	}
46	if !output.Full || output.Base != 0 {
47		return outputApplyState{}, false
48	}
49	return outputApplyState{epoch: output.Epoch, state: output.New, viewRevision: output.ViewRevision, initialized: true}, true
50}