Artifact [1285b3ddb4]

Artifact 1285b3ddb4adc3a8443ef98f9406b1dd608a387af6938ee7491a9b16ce1aab7e:

• File internal/sync/sparse.go — part of check-in [b5a64230b3] at 2026-10-21 14:43:59 on branch feat/submanifest-reader — feat(sparse): adopt sparse-cone at horizon-rfc a5741263ab

  The draft now settles zit #257 to #260, so the four rows that waited on it close against code:

  - Compaction and local filtering keep every manifest and sub-manifest node, interiors included (5.4, 6.3). RetainProvenance previously let an outside interior whose children were all held leaves go; the draft now requires it held, since it is the range proof that reaches the leaf. - A server answering a cone request acknowledges the reply with pragma cone-served in its leading pragma run (6.3). This server applies a request's whole cone or refuses it, and a refusal resets the reply, so the pragma is never sent for a refused or dense reply. SyncResult and CloneResult report ConeServed beside Elided, now public too. - An empty cone is refused (3.2); a new row and case pin it, locally and over the wire. - The per-round bound covers the tree walk only (6.2). A new row tests that a requester does not act on a dense inventory. It stays partial: an out-of-cone blob announced in the same reply as its check-in cannot be classified yet and is fetched, then filtered; zit #262 asks the draft to account for that cost. (user: [email protected], size: 1762) [annotate] [blame] [check-ins using] [more...]

package sync

import (
	"fmt"

	"github.com/danmestas/go-libfossil/internal/cone"
	"github.com/danmestas/go-libfossil/internal/deck"
	"github.com/danmestas/go-libfossil/internal/xfer"
)

// The draft defines request pragmas, but no capability advertisement spelling.
// Unknown pragmas remain ignored by peers that predate sparse transfer.
// coneServedPragma acknowledges a reply that applied the request's whole cone
// (draft-fossil-sparse-cone-00 §6.3). It travels only from server to client.
const coneServedPragma = "cone-served"

func conePragmas(c *cone.Cone) []xfer.Card {
	if c == nil {
		return nil
	}
	cards := make([]xfer.Card, 0, len(c.Include())+len(c.Exclude()))
	for _, m := range c.Include() {
		cards = append(cards, &xfer.PragmaCard{Name: "cone", Values: []string{deck.FossilEncode(m)}})
	}
	for _, m := range c.Exclude() {
		cards = append(cards, &xfer.PragmaCard{Name: "cone-not", Values: []string{deck.FossilEncode(m)}})
	}
	return cards
}

func requestCone(cards []xfer.Card) (*cone.Cone, error) {
	var include, exclude []string
	for _, card := range cards {
		p, ok := card.(*xfer.PragmaCard)
		if !ok || (p.Name != "cone" && p.Name != "cone-not") {
			continue
		}
		if len(p.Values) != 1 || len(p.Values[0]) > 2*cone.MaxMemberLen {
			return nil, fmt.Errorf("sparse cone: invalid member")
		}
		if len(include)+len(exclude) >= cone.MaxMembers {
			return nil, fmt.Errorf("sparse cone: too many members")
		}
		m := deck.FossilDecode(p.Values[0])
		if p.Name == "cone" {
			include = append(include, m)
		} else {
			exclude = append(exclude, m)
		}
	}
	if len(include)+len(exclude) == 0 {
		return nil, nil
	}
	c, err := cone.New(include, exclude)
	if err != nil {
		return nil, fmt.Errorf("sparse cone: %w", err)
	}
	return c, nil
}