| 1 | package hostclaim |
| 2 | |
| 3 | import ( |
| 4 | "fmt" |
| 5 | "time" |
| 6 | ) |
| 7 | |
| 8 | // WriteSet is where a delete parks: the touched set, plus the whole |
| 9 | // deployment while discovery is incomplete (§5.2 step 3, §9). |
| 10 | func WriteSet(c *Claim, allRegions, allBoxes []string) (regions, boxes []string) { |
| 11 | if c.Touched.Complete { |
| 12 | return c.Touched.Regions, c.Touched.Boxes |
| 13 | } |
| 14 | return union(c.Touched.Regions, allRegions), union(c.Touched.Boxes, allBoxes) |
| 15 | } |
| 16 | |
| 17 | func union(known, supplied []string) []string { |
| 18 | var result []string |
| 19 | seen := make(map[string]bool) |
| 20 | for _, locations := range [][]string{known, supplied} { |
| 21 | for _, location := range locations { |
| 22 | if !seen[location] { |
| 23 | result = append(result, location) |
| 24 | seen[location] = true |
| 25 | } |
| 26 | } |
| 27 | } |
| 28 | return result |
| 29 | } |
| 30 | |
| 31 | // BeginDelete starts a delete from serving. fencedCompletion is |
| 32 | // StartGuard's (ruling 86): the completion box whose termination fence the |
| 33 | // caller verified, or "". |
| 34 | func BeginDelete(opID, by, recordETag string, now time.Time, allRegions, allBoxes []string, fencedCompletion string) func(*Claim) error { |
| 35 | return func(c *Claim) error { |
| 36 | regions, boxes := WriteSet(c, allRegions, allBoxes) |
| 37 | if err := StartGuard(c, regions, boxes, fencedCompletion); err != nil { |
| 38 | return err |
| 39 | } |
| 40 | if opID == "" || recordETag == "" { |
| 41 | return fmt.Errorf("%w: delete needs an op id and the record's etag", ErrMalformed) |
| 42 | } |
| 43 | exec, parts := c.Op.Exec, c.Op.Participants // execution authority is kept (R6-4) |
| 44 | c.Op = Op{Kind: KindDeleting, ID: opID, By: by, StartedAt: now.UTC(), Exec: exec, Participants: parts, |
| 45 | Intent: map[string]string{"key": c.Holder.Key, "etag": recordETag}} |
| 46 | return nil |
| 47 | } |
| 48 | } |
| 49 | |
| 50 | func ToParking(opID string, allRegions, allBoxes []string, newID func() string) func(*Claim) error { |
| 51 | return func(c *Claim) error { |
| 52 | if err := RequireOp(opID)(c); err != nil { |
| 53 | return err |
| 54 | } |
| 55 | // purging: §5.3 step 4 retires records under the purge's own claim |
| 56 | // (R4-4); Plan 5 adds the purge journal's preconditions around it. |
| 57 | if c.Op.Kind != KindDeleting && c.Op.Kind != KindPurging { |
| 58 | return fmt.Errorf("%w: kind %q", ErrWrongState, c.Op.Kind) |
| 59 | } |
| 60 | if c.Holder == nil { // a holderless purge fence (CC21) has nothing to park |
| 61 | return fmt.Errorf("%w: no holder to park", ErrWrongState) |
| 62 | } |
| 63 | regions, boxes := WriteSet(c, allRegions, allBoxes) |
| 64 | appendParkObligations(c, opID, regions, boxes, newID) |
| 65 | retire(c, c.Holder.Incarnation) |
| 66 | if c.Op.Kind == KindDeleting && c.Op.Phase == "" { |
| 67 | c.Op.Phase = "park" |
| 68 | } |
| 69 | c.Op.Kind = KindParking |
| 70 | return nil |
| 71 | } |
| 72 | } |
| 73 | |
| 74 | func appendParkObligations(c *Claim, opID string, regions, boxes []string, newID func() string) { |
| 75 | target := "" |
| 76 | if c.Holder != nil { |
| 77 | target = c.Holder.Location |
| 78 | } |
| 79 | for _, r := range regions { |
| 80 | c.Obligations = append(c.Obligations, Obligation{ParkTarget: target, ID: newID(), Op: opID, Kind: "park-replica", Region: r, Retirement: newID(), Owner: "region:" + r}) |
| 81 | } |
| 82 | for _, b := range boxes { |
| 83 | c.Obligations = append(c.Obligations, Obligation{ID: newID(), Op: opID, Kind: "park-local", Box: b, Retirement: newID(), Owner: "box:" + b}) |
| 84 | } |
| 85 | } |
| 86 | |
| 87 | // CompleteObligation removes one chore, matched by its OWN op id and id. |
| 88 | // Discovery chores outlive the adoption that made them (§9). |
| 89 | func CompleteObligation(obligationOp, obligationID string) func(*Claim) error { |
| 90 | return func(c *Claim) error { |
| 91 | idx := -1 |
| 92 | for i, o := range c.Obligations { |
| 93 | if o.ID == obligationID && o.Op == obligationOp { |
| 94 | idx = i |
| 95 | break |
| 96 | } |
| 97 | } |
| 98 | if idx < 0 { |
| 99 | return fmt.Errorf("%w: no obligation %q of op %q", ErrWrongState, obligationID, obligationOp) |
| 100 | } |
| 101 | if c.Obligations[idx].Kind == "relocation-release" { |
| 102 | return ErrWrongState |
| 103 | } |
| 104 | c.Obligations = append(c.Obligations[:idx], c.Obligations[idx+1:]...) |
| 105 | if c.Touched.DiscoveryOp != "" && c.Touched.DiscoveryOp == obligationOp { |
| 106 | for _, o := range c.Obligations { |
| 107 | if o.Op == obligationOp { |
| 108 | return nil |
| 109 | } |
| 110 | } |
| 111 | c.Touched.Complete, c.Touched.DiscoveryOp = true, "" |
| 112 | } |
| 113 | return nil |
| 114 | } |
| 115 | } |
| 116 | |
| 117 | func FreeAfterPark(opID string) func(*Claim) error { |
| 118 | return func(c *Claim) error { |
| 119 | if err := RequireOp(opID)(c); err != nil { |
| 120 | return err |
| 121 | } |
| 122 | if c.Op.Kind != KindParking || len(c.Obligations) > 0 { |
| 123 | return fmt.Errorf("%w: kind %q, %d obligations left", ErrWrongState, c.Op.Kind, len(c.Obligations)) |
| 124 | } |
| 125 | if err := retainNativeAdmissionLosses(c); err != nil { |
| 126 | return err |
| 127 | } |
| 128 | c.Holder, c.Op, c.Touched, c.Inventory = nil, Op{}, Touched{}, nil |
| 129 | return nil |
| 130 | } |
| 131 | } |
| 132 | |
amadan