jschoubben
5e67b548a0
distribution's two windows and the builder's old-form window each closed for good on a read that named no node (an empty node_haves, an unread placement): the second of a kind (security-upgrade review F3). delivery.StepWindow over delivery.WindowHeld is the one rule both call; a read naming no node judges nothing, as a first view's empty answer at revision 0 (ADR 0615). Claude-Session: https://claude.ai/code/session_01JG73KJNrH5EgFXMKKYSrig
65 lines
2.6 KiB
Go
65 lines
2.6 KiB
Go
package delivery
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import (
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"slices"
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"sort"
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"time"
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)
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// WindowHeld is the part of a window every window keeper shares (design 51: distribution's old seat name and direct
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// writes, the builder's old reference form): whether it is open, the nodes holding it and since when, and when it last
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// closed and who held it then. A keeper embeds it in its own record, so its JSON is the record's.
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type WindowHeld struct {
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Open bool `json:"open"`
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Holding []string `json:"holding,omitempty"`
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Since map[string]time.Time `json:"since,omitempty"`
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Closed time.Time `json:"closed,omitzero"`
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// LastHolding are the nodes that held it last, said when it closes.
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LastHolding []string `json:"last_holding,omitempty"`
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}
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// StepWindow is the one rule every window keeper steps its window by (security-upgrade review F3, the second of a
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// kind): named is every node the read named, dropped ones included, and holding those of them that hold the window at
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// now. A read that names no node judges nothing, as a first view's empty answer at revision 0 is no empty state (ADR
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// 0615): an empty node_haves or a placement not yet read never closes a window, and the window stays as it was. A read
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// naming nodes, none holding, closes an open window (closed true, once); one naming a holder opens it, each holder's
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// since kept from w. overdue are the holders whose since is at least findingAfter before now (the keeper's finding,
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// cleared for every other node); a read naming no node keeps w's holders' overdue as they stand at now.
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func StepWindow(w WindowHeld, named, holding []string, now time.Time, findingAfter time.Duration) (next WindowHeld, closed bool, overdue []string) {
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now = now.UTC()
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if len(named) == 0 {
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next = w
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for _, n := range w.Holding {
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if since, ok := w.Since[n]; ok && now.Sub(since) >= findingAfter {
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overdue = append(overdue, n)
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}
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}
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return next, false, overdue
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}
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if len(holding) == 0 {
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next = WindowHeld{Closed: w.Closed, LastHolding: w.LastHolding}
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if w.Open {
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next.Closed, next.LastHolding = now, slices.Clone(w.Holding)
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if next.LastHolding == nil {
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next.LastHolding = []string{}
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}
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return next, true, nil
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}
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return next, false, nil
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}
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held := slices.Clone(holding)
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sort.Strings(held)
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next = WindowHeld{Open: true, Holding: held, Since: map[string]time.Time{}, Closed: w.Closed, LastHolding: w.LastHolding}
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for _, n := range held {
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since, had := w.Since[n]
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if !had {
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since = now
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}
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next.Since[n] = since
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if now.Sub(since) >= findingAfter {
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overdue = append(overdue, n)
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}
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}
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return next, false, overdue
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}
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