| 1 | package provision |
| 2 | |
| 3 | import ( |
| 4 | "encoding/json" |
| 5 | "fmt" |
| 6 | "time" |
| 7 | ) |
| 8 | |
| 9 | // MoveRelocating is the record state of a move whose source was terminated |
| 10 | // before the flip (claim Plan 5, C7). Every forward and abort transition |
| 11 | // lists its legal states, so none of them accepts it: the decision is |
| 12 | // terminal for the move. |
| 13 | const MoveRelocating = "relocating" |
| 14 | |
| 15 | // ValidMoveID reports a Phase 1 move id (moveIDShape). A claim-mode move's |
| 16 | // admission registration is minted under this id. |
| 17 | func ValidMoveID(id string) bool { return moveIDShape.MatchString(id) } |
| 18 | |
| 19 | // MoveRelocationDecision is a durable record decision, not an installation. |
| 20 | // Every other MoveState field is preserved so a crash can reconstruct the |
| 21 | // move. |
| 22 | type MoveRelocationDecision struct { |
| 23 | MovingIdentity string `json:"moving_identity"` |
| 24 | HolderIdentity string `json:"holder_identity"` |
| 25 | ClaimGen uint64 `json:"claim_gen"` |
| 26 | ClaimETag string `json:"claim_etag"` |
| 27 | SourceBox string `json:"source_box"` |
| 28 | Enrollment string `json:"enrollment"` |
| 29 | Region string `json:"region"` |
| 30 | Fence string `json:"fence"` |
| 31 | PreviousState string `json:"previous_state"` |
| 32 | PreviousCutPhase string `json:"previous_cut_phase,omitempty"` |
| 33 | DecidedAt time.Time `json:"decided_at"` |
| 34 | } |
| 35 | |
| 36 | // MoveRelocatingDecision competes with the flip under the same record CAS: |
| 37 | // only one of them can win. region must be the record's own region and the |
| 38 | // move's origin; the caller has also bound it to the fence's roster region. |
| 39 | // A replay with the same identities is a no-op that keeps the original |
| 40 | // decision time. |
| 41 | func MoveRelocatingDecision(g MoveGuard, box, enrollment, region, fence string, claimGen uint64, claimETag, movingIdentity, holderIdentity string, now time.Time) func(*Record) error { |
| 42 | return func(rec *Record) error { |
| 43 | if err := g.check(rec); err != nil { |
| 44 | return err |
| 45 | } |
| 46 | var ref struct{ Enrollment, Key, SHA256 string } |
| 47 | if len(movingIdentity) != 64 || len(holderIdentity) != 64 || claimGen == 0 || claimETag == "" || box == "" || enrollment == "" || !ValidRegion(region) || now.IsZero() || |
| 48 | json.Unmarshal([]byte(fence), &ref) != nil || ref.Enrollment != enrollment || ref.Key != "control/box-fences/"+enrollment+".json" || len(ref.SHA256) != 64 || |
| 49 | rec.Region != region || rec.Move.From != region { |
| 50 | return fmt.Errorf("%w: the relocation decision does not match this move", ErrMoveConflict) |
| 51 | } |
| 52 | if rec.Move.State == MoveRelocating { |
| 53 | d := rec.Move.Relocation |
| 54 | if d == nil || d.SourceBox != box || d.Enrollment != enrollment || d.Region != region || d.Fence != fence || d.MovingIdentity != movingIdentity || d.HolderIdentity != holderIdentity { |
| 55 | return fmt.Errorf("%w: another relocation decision is recorded", ErrMoveConflict) |
| 56 | } |
| 57 | return nil |
| 58 | } |
| 59 | switch rec.Move.State { |
| 60 | case MovePreparing, MoveReady, MoveCutting: |
| 61 | default: |
| 62 | return fmt.Errorf("%w: a move in state %q cannot relocate", ErrMoveConflict, rec.Move.State) |
| 63 | } |
| 64 | if rec.Move.CutPhase == CutFlipped || rec.Move.FlippedAt != nil || rec.Move.CommittedAt != nil || rec.Move.Rollback != nil || rec.Move.Relocation != nil { |
| 65 | return fmt.Errorf("%w: the move is past its flip", ErrMoveConflict) |
| 66 | } |
| 67 | rec.Move.Relocation = &MoveRelocationDecision{MovingIdentity: movingIdentity, HolderIdentity: holderIdentity, ClaimGen: claimGen, ClaimETag: claimETag, SourceBox: box, Enrollment: enrollment, Region: region, Fence: fence, PreviousState: rec.Move.State, PreviousCutPhase: rec.Move.CutPhase, DecidedAt: now.UTC()} |
| 68 | rec.Move.State = MoveRelocating |
| 69 | return nil |
| 70 | } |
| 71 | } |
| 72 | |
| 73 | // MoveLostTargetParked is separate from the ordinary forward phase table: |
| 74 | // a permanently lost target cannot run returning/cleaning itself. The caller |
| 75 | // must freshly prove the claim's lost binding and drained target obligations. |
| 76 | func MoveLostTargetParked(g MoveGuard, rollbackID string, now time.Time) func(*Record) error { |
| 77 | return func(rec *Record) error { |
| 78 | if err := g.check(rec); err != nil { |
| 79 | return err |
| 80 | } |
| 81 | rb := rec.Move.Rollback |
| 82 | if now.IsZero() || rec.Move.State != MoveRollingBack || rb == nil || rollbackID == "" || rb.ID != rollbackID { |
| 83 | return fmt.Errorf("%w: no matching rollback", ErrMoveConflict) |
| 84 | } |
| 85 | if rb.TargetPhase == RbTargetCleaned && rb.TargetParkedAt != nil { |
| 86 | return nil |
| 87 | } |
| 88 | if rb.TargetPhase != RbTargetReleased || rb.Dirty || rb.TargetParkedAt != nil { |
| 89 | return fmt.Errorf("%w: the lost target is not cleanly released", ErrMoveConflict) |
| 90 | } |
| 91 | at := now.UTC() |
| 92 | rb.TargetPhase, rb.TargetParkedAt = RbTargetCleaned, &at |
| 93 | return nil |
| 94 | } |
| 95 | } |
| 96 | |
amadan