| 1 | package hostops |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "errors" |
| 6 | "os" |
| 7 | |
| 8 | "github.com/carlosframework/platform/internal/release" |
| 9 | ) |
| 10 | |
| 11 | // ProjectionGrant is positive bucket evidence that lets one console replay |
| 12 | // a per-console SQL projection of a settled app operation. It is minted |
| 13 | // only here; it cannot create an operation, reopen admission or write app |
| 14 | // content. The SQL view accepts exactly the statement family Kind names, |
| 15 | // with the app_id predicate fixed to AppID. |
| 16 | type ProjectionGrant struct { |
| 17 | kind, account, app, appID, operation string |
| 18 | epoch uint64 |
| 19 | deletedAt int64 |
| 20 | } |
| 21 | |
| 22 | const ( |
| 23 | ProjectionPurge = "purge" |
| 24 | ProjectionRestore = "restore" |
| 25 | ProjectionTrash = "trash" |
| 26 | ) |
| 27 | |
| 28 | func (g ProjectionGrant) Kind() string { return g.kind } |
| 29 | func (g ProjectionGrant) Account() string { return g.account } |
| 30 | func (g ProjectionGrant) App() string { return g.app } |
| 31 | func (g ProjectionGrant) AppID() string { return g.appID } |
| 32 | func (g ProjectionGrant) Operation() string { return g.operation } |
| 33 | func (g ProjectionGrant) Epoch() uint64 { return g.epoch } |
| 34 | func (g ProjectionGrant) DeletedAt() int64 { return g.deletedAt } |
| 35 | func (g ProjectionGrant) Valid() bool { return g.kind != "" && g.appID != "" } |
| 36 | |
| 37 | func (w *ControlWriter) canonical(ctx context.Context, account, app, appID string) (AdmissionObserved, error) { |
| 38 | if err := w.ready(); err != nil { |
| 39 | return AdmissionObserved{}, err |
| 40 | } |
| 41 | a, err := ReadCanonicalAdmission(ctx, w.raw, account, app) |
| 42 | if err != nil { |
| 43 | return AdmissionObserved{}, err |
| 44 | } |
| 45 | if a.Value.AppID != appID { |
| 46 | return AdmissionObserved{}, ErrIdentity |
| 47 | } |
| 48 | return a, nil |
| 49 | } |
| 50 | |
| 51 | // PurgeProjection: the incarnation is retired and its journal is gone. |
| 52 | func (w *ControlWriter) PurgeProjection(ctx context.Context, account, app, appID string) (ProjectionGrant, error) { |
| 53 | a, err := ReadCanonicalAdmission(ctx, w.raw, account, app) |
| 54 | if err != nil { |
| 55 | return ProjectionGrant{}, err |
| 56 | } |
| 57 | if !CompletedAdmission(a.Value) || a.Value.LastPurge.AppID != appID { |
| 58 | return ProjectionGrant{}, ErrPending |
| 59 | } |
| 60 | if err = w.purgeAbsent(ctx, account, app); err != nil { |
| 61 | return ProjectionGrant{}, err |
| 62 | } |
| 63 | return ProjectionGrant{kind: ProjectionPurge, account: account, app: app, appID: appID, operation: a.Value.LastPurge.ID, epoch: a.Value.Epoch}, nil |
| 64 | } |
| 65 | |
| 66 | // RestoreProjection: the exact receipt for this incarnation is complete, no |
| 67 | // tombstone and no purge journal exist, and ctx holds a live permit for the |
| 68 | // app. The open-admission projections (restore, trash) run inside their own |
| 69 | // short exclusive app-mutation ("projection"), so no purge can start between |
| 70 | // this evidence read and the SQL write. Epochs only grow after the receipt. |
| 71 | func (w *ControlWriter) RestoreProjection(ctx context.Context, account, app, appID string) (ProjectionGrant, error) { |
| 72 | a, err := w.canonical(ctx, account, app, appID) |
| 73 | if err != nil { |
| 74 | return ProjectionGrant{}, err |
| 75 | } |
| 76 | if err = RequireAppMutation(ctx, w.raw, account, app, appID); err != nil { |
| 77 | return ProjectionGrant{}, err |
| 78 | } |
| 79 | if err = w.purgeAbsent(ctx, account, app); err != nil { |
| 80 | return ProjectionGrant{}, err |
| 81 | } |
| 82 | r := a.Value.LastRestore |
| 83 | if CompletedAdmission(a.Value) || r == nil || r.State != "complete" || r.AppID != appID || r.Epoch > a.Value.Epoch || r.DeletedAt <= 0 { |
| 84 | return ProjectionGrant{}, ErrPending |
| 85 | } |
| 86 | if _, _, err = w.raw.Get(ctx, release.AppTombstoneKey(account, app)); !errors.Is(err, os.ErrNotExist) { |
| 87 | if err != nil { |
| 88 | return ProjectionGrant{}, err |
| 89 | } |
| 90 | return ProjectionGrant{}, ErrPending |
| 91 | } |
| 92 | return ProjectionGrant{kind: ProjectionRestore, account: account, app: app, appID: appID, operation: r.ID, epoch: a.Value.Epoch, deletedAt: r.DeletedAt}, nil |
| 93 | } |
| 94 | |
| 95 | // TrashProjection: a valid tombstone is present for the live incarnation. |
| 96 | func (w *ControlWriter) TrashProjection(ctx context.Context, account, app, appID string) (ProjectionGrant, error) { |
| 97 | a, err := w.canonical(ctx, account, app, appID) |
| 98 | if err != nil { |
| 99 | return ProjectionGrant{}, err |
| 100 | } |
| 101 | if CompletedAdmission(a.Value) { |
| 102 | return ProjectionGrant{}, ErrPending |
| 103 | } |
| 104 | if err = RequireAppMutation(ctx, w.raw, account, app, appID); err != nil { |
| 105 | return ProjectionGrant{}, err |
| 106 | } |
| 107 | tomb, err := release.ReadAppTombstone(ctx, w.raw, account, app) |
| 108 | if err != nil { |
| 109 | return ProjectionGrant{}, err |
| 110 | } |
| 111 | if tomb == nil || tomb.DeletedAt.IsZero() { |
| 112 | return ProjectionGrant{}, ErrPending |
| 113 | } |
| 114 | return ProjectionGrant{kind: ProjectionTrash, account: account, app: app, appID: appID, epoch: a.Value.Epoch, deletedAt: tomb.DeletedAt.Unix()}, nil |
| 115 | } |
| 116 | |
amadan