| 1 | package moves |
| 2 | |
| 3 | import ( |
| 4 | "errors" |
| 5 | "fmt" |
| 6 | "strings" |
| 7 | "time" |
| 8 | |
| 9 | "github.com/carlosframework/platform/internal/hostclaim" |
| 10 | ) |
| 11 | |
| 12 | // The park scopes a move's chores carry (claim rev 6.23 §2, INV-22; Plan 5 |
| 13 | // ruling K8). These helpers are the one place the box and the console build |
| 14 | // them. Each takes its genuine bound as an argument and never reads the |
| 15 | // clock: the scope is bound once, in the CAS that queues the chore, and a |
| 16 | // retry or a restart that computes a later bound is refused |
| 17 | // (hostclaim.QueueStagingPark and friends, park.Engine.Bind), so the |
| 18 | // horizon is the evidence's, never the cleanup's start. The bound is stored |
| 19 | // in UTC. |
| 20 | |
| 21 | // ParkRequestLimit is every moves park's request limit: the longest a |
| 22 | // staging request runs (lease's stagingRequestTimeout). |
| 23 | const ParkRequestLimit = 120 * time.Second |
| 24 | |
| 25 | // SourceLocationScope is the source region's location park a commit queues: |
| 26 | // holder.location, in the holder's form without a trailing slash, and the |
| 27 | // holder's incarnation. Its horizon starts at the flip (ruling H7): the flip |
| 28 | // comes after ExecToNone, after which the source never writes its location |
| 29 | // again. |
| 30 | func SourceLocationScope(holder hostclaim.Holder, flippedAt time.Time) hostclaim.ParkScope { |
| 31 | return locationScope(holder, flippedAt) |
| 32 | } |
| 33 | |
| 34 | // TargetLocationScope is a rolled-back target region's location park, queued |
| 35 | // when the target releases (hostclaim.TargetReleased): holder.location and |
| 36 | // the holder's incarnation. Its horizon is the target's stop report's |
| 37 | // CheckedAt, after which the target writes its location no more. |
| 38 | func TargetLocationScope(holder hostclaim.Holder, stopCheckedAt time.Time) hostclaim.ParkScope { |
| 39 | return locationScope(holder, stopCheckedAt) |
| 40 | } |
| 41 | |
| 42 | // ResidueScope is the location a landing's earlier-stay residue parks |
| 43 | // (hostclaim.QueueResidueParks) are scoped to: holder.location and the |
| 44 | // holder's incarnation. Its horizon starts at the flip, like the source's. |
| 45 | func ResidueScope(holder hostclaim.Holder, flippedAt time.Time) hostclaim.ParkScope { |
| 46 | return locationScope(holder, flippedAt) |
| 47 | } |
| 48 | |
| 49 | func locationScope(holder hostclaim.Holder, bound time.Time) hostclaim.ParkScope { |
| 50 | return hostclaim.ParkScope{Location: strings.TrimSuffix(holder.Location, "/"), Incarnation: holder.Incarnation, EvidenceAt: bound.UTC(), RequestLimit: ParkRequestLimit} |
| 51 | } |
| 52 | |
| 53 | // StagingScope is the park of a move's own staging lane, moves/<host>/<op>, |
| 54 | // after a seal: its horizon is the seal's bound (a staged seal's for a |
| 55 | // rollback's target, the journalled revert bound for a revert). |
| 56 | func StagingScope(host, op, inc string, sealBound time.Time) hostclaim.ParkScope { |
| 57 | return laneScope(host, op, inc, sealBound) |
| 58 | } |
| 59 | |
| 60 | // AbortScope is the park of an aborted move's staging lane. No seal exists |
| 61 | // before an abort, so its horizon is the journalled abort bound (Plan 5 |
| 62 | // ruling K5): the later of the decision's time plus a signature's life and |
| 63 | // the skew, and any seal's bound. |
| 64 | func AbortScope(host, op, inc string, abortBound time.Time) hostclaim.ParkScope { |
| 65 | return laneScope(host, op, inc, abortBound) |
| 66 | } |
| 67 | |
| 68 | // ReturnLaneScope is the park of a dirty rollback's return lane, |
| 69 | // moves/<host>/<rb>: its horizon is the return seal's bound. |
| 70 | func ReturnLaneScope(host, rbID, inc string, returnSealBound time.Time) hostclaim.ParkScope { |
| 71 | return laneScope(host, rbID, inc, returnSealBound) |
| 72 | } |
| 73 | |
| 74 | func laneScope(host, lane, inc string, bound time.Time) hostclaim.ParkScope { |
| 75 | return hostclaim.ParkScope{Location: ScopeLocation(host, lane), Incarnation: inc, EvidenceAt: bound.UTC(), RequestLimit: ParkRequestLimit} |
| 76 | } |
| 77 | |
| 78 | // CommitScopes are the two parks a commit queues (hostclaim.Commit), built |
| 79 | // from the claim and the record's flip time alone (Plan 5 Task 3, ruling |
| 80 | // K9): the source region's location from the flip (SourceLocationScope, |
| 81 | // ruling H7) and the move's own lane to the seal the claim journals |
| 82 | // (StagingScope with the seal's bound). The target box and the console's |
| 83 | // pass (Task 7a) both call it, so whichever commits first writes the |
| 84 | // obligations the other's replay finds; a scope built any other way would |
| 85 | // be refused as "another scope" by the queue helpers. It refuses without |
| 86 | // the flip's time, the holder or the journalled seal. |
| 87 | func CommitScopes(c *hostclaim.Claim, flippedAt *time.Time) (source, staging hostclaim.ParkScope, err error) { |
| 88 | if c == nil || c.Holder == nil { |
| 89 | return source, staging, errors.New("a commit's parks need the claim's holder") |
| 90 | } |
| 91 | if flippedAt == nil || flippedAt.IsZero() { |
| 92 | return source, staging, errors.New("the source's location park needs the flip's time") |
| 93 | } |
| 94 | raw, ok := c.Op.Journal[hostclaim.JournalSeal] |
| 95 | if !ok { |
| 96 | return source, staging, fmt.Errorf("%w: the claim carries no seal", ErrBadSeal) |
| 97 | } |
| 98 | seal, err := DecodeSeal(raw) |
| 99 | if err != nil { |
| 100 | return source, staging, err |
| 101 | } |
| 102 | return SourceLocationScope(*c.Holder, *flippedAt), StagingScope(c.Host, c.Op.ID, c.Holder.Incarnation, seal.Bound()), nil |
| 103 | } |
| 104 | |
amadan