| 1 | package hostbox |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "errors" |
| 6 | "sync" |
| 7 | |
| 8 | "github.com/carlosframework/platform/internal/lease" |
| 9 | "github.com/carlosframework/platform/internal/park" |
| 10 | ) |
| 11 | |
| 12 | type Renewable interface { |
| 13 | Err() error |
| 14 | Lost() <-chan struct{} |
| 15 | Release(context.Context) error |
| 16 | } |
| 17 | type RenewingLeases struct { |
| 18 | Region string |
| 19 | Open func(context.Context, string, string, string) (Renewable, error) |
| 20 | } |
| 21 | |
| 22 | func (l RenewingLeases) Acquire(ctx context.Context, bucket, scope string) (park.HeldLease, error) { |
| 23 | if ctx == nil || l.Region == "" || bucket == "" || scope == "" { |
| 24 | return nil, ErrUnsupported |
| 25 | } |
| 26 | open := l.Open |
| 27 | if open == nil { |
| 28 | open = func(ctx context.Context, b, p, r string) (Renewable, error) { return lease.Acquire(ctx, b, p, r) } |
| 29 | } |
| 30 | bounded, cancel := context.WithTimeout(ctx, RequestLimit) |
| 31 | h, err := open(bounded, bucket, scope, l.Region) |
| 32 | cancel() |
| 33 | if err != nil { |
| 34 | return nil, err |
| 35 | } |
| 36 | if h == nil { |
| 37 | return nil, ErrUnsupported |
| 38 | } |
| 39 | cctx, stop := context.WithCancel(ctx) |
| 40 | held := &renewingHeld{bucket: bucket, scope: scope, h: h, ctx: cctx, cancel: stop, done: make(chan struct{})} |
| 41 | go func() { |
| 42 | defer close(held.done) |
| 43 | select { |
| 44 | case <-h.Lost(): |
| 45 | stop() |
| 46 | case <-cctx.Done(): |
| 47 | } |
| 48 | }() |
| 49 | if err := held.Check(ctx); err != nil { |
| 50 | held.Close() |
| 51 | return nil, err |
| 52 | } |
| 53 | return held, nil |
| 54 | } |
| 55 | |
| 56 | type renewingHeld struct { |
| 57 | bucket, scope string |
| 58 | h Renewable |
| 59 | ctx context.Context |
| 60 | cancel context.CancelFunc |
| 61 | done chan struct{} |
| 62 | once sync.Once |
| 63 | releaseErr error |
| 64 | } |
| 65 | |
| 66 | func (h *renewingHeld) Check(ctx context.Context) error { |
| 67 | if err := ctx.Err(); err != nil { |
| 68 | return err |
| 69 | } |
| 70 | if err := h.ctx.Err(); err != nil { |
| 71 | return err |
| 72 | } |
| 73 | return h.h.Err() |
| 74 | } |
| 75 | func (h *renewingHeld) Context(ctx context.Context) context.Context { |
| 76 | c, cancel := context.WithCancel(ctx) |
| 77 | stop := context.AfterFunc(h.ctx, cancel) |
| 78 | context.AfterFunc(c, func() { stop() }) |
| 79 | return c |
| 80 | } |
| 81 | func (h *renewingHeld) Release(ctx context.Context) error { |
| 82 | h.once.Do(func() { |
| 83 | h.cancel() |
| 84 | <-h.done |
| 85 | bounded, cancel := context.WithTimeout(context.WithoutCancel(ctx), RequestLimit) |
| 86 | defer cancel() |
| 87 | h.releaseErr = h.h.Release(bounded) |
| 88 | }) |
| 89 | return h.releaseErr |
| 90 | } |
| 91 | func (h *renewingHeld) Close() { _ = h.Release(context.Background()) } |
| 92 | |
| 93 | // Context carries every constituent's cancellation into the engine's requests. |
| 94 | func (h *aggregateHeld) Context(ctx context.Context) context.Context { |
| 95 | for _, l := range h.leases { |
| 96 | if bound, ok := l.(interface { |
| 97 | Context(context.Context) context.Context |
| 98 | }); ok { |
| 99 | ctx = bound.Context(ctx) |
| 100 | } |
| 101 | } |
| 102 | return ctx |
| 103 | } |
| 104 | |
| 105 | // LeasedCheck is useful before requests that are issued by a wake's producer. |
| 106 | func LeasedCheck(ctx context.Context, health func() error, authority func(context.Context) error) error { |
| 107 | if health == nil || authority == nil { |
| 108 | return ErrUnsupported |
| 109 | } |
| 110 | return errors.Join(ctx.Err(), health(), authority(ctx)) |
| 111 | } |
| 112 | |
| 113 | func (h *renewingHeld) LeaseScope() (string, string) { return h.bucket, h.scope } |
| 114 | |
amadan