| 1 | export type OperationTarget = |
| 2 | | { kind: "session"; tabId: string; sessionKey: string } |
| 3 | | { kind: "workspace"; workspaceKey: string } |
| 4 | | { kind: "application" }; |
| 5 | |
| 6 | export type OperationIdentity = { |
| 7 | ownerEpoch: number; |
| 8 | requestId: number; |
| 9 | target: OperationTarget; |
| 10 | navigationIntent?: number; |
| 11 | channel: string; |
| 12 | }; |
| 13 | |
| 14 | export type OperationTerminalStatus = "completed" | "failed" | "cancelled"; |
| 15 | |
| 16 | export function operationTargetsEqual(left: OperationTarget, right: OperationTarget): boolean { |
| 17 | if (left.kind !== right.kind) return false; |
| 18 | if (left.kind === "application") return true; |
| 19 | if (left.kind === "workspace" && right.kind === "workspace") { |
| 20 | return left.workspaceKey === right.workspaceKey; |
| 21 | } |
| 22 | return left.kind === "session" |
| 23 | && right.kind === "session" |
| 24 | && left.tabId === right.tabId |
| 25 | && left.sessionKey === right.sessionKey; |
| 26 | } |
| 27 | |
| 28 | function freezeIdentity(identity: OperationIdentity): OperationIdentity { |
| 29 | return Object.freeze({ ...identity, target: Object.freeze({ ...identity.target }) }); |
| 30 | } |
| 31 | |
| 32 | export type OperationOwner = ReturnType<typeof createOperationOwner>; |
| 33 | |
| 34 | /** |
| 35 | * Owns a last-request-wins interaction without retaining request payloads. |
| 36 | * Resource data may complete independently; `owns` governs current UI rights. |
| 37 | */ |
| 38 | export function createOperationOwner(trackOperation: (delta: 1 | -1) => void = () => {}) { |
| 39 | let ownerEpoch = 0; |
| 40 | let requestId = 0; |
| 41 | let mounted = false; |
| 42 | const active = new Map<string, OperationIdentity>(); |
| 43 | const terminalCounts: Record<OperationTerminalStatus, number> = { |
| 44 | completed: 0, |
| 45 | failed: 0, |
| 46 | cancelled: 0, |
| 47 | }; |
| 48 | |
| 49 | return { |
| 50 | mount(): number { |
| 51 | if (mounted) return ownerEpoch; |
| 52 | ownerEpoch += 1; |
| 53 | mounted = true; |
| 54 | active.clear(); |
| 55 | return ownerEpoch; |
| 56 | }, |
| 57 | |
| 58 | unmount(epoch: number): void { |
| 59 | if (!mounted || epoch !== ownerEpoch) return; |
| 60 | for (const _identity of active.values()) { |
| 61 | terminalCounts.cancelled += 1; |
| 62 | trackOperation(-1); |
| 63 | } |
| 64 | active.clear(); |
| 65 | mounted = false; |
| 66 | }, |
| 67 | |
| 68 | begin(target: OperationTarget, navigationIntent?: number, channel = "navigation"): OperationIdentity { |
| 69 | if (!mounted) throw new Error("operation owner is not mounted"); |
| 70 | if (active.has(channel)) terminalCounts.cancelled += 1; |
| 71 | else trackOperation(1); |
| 72 | const identity = freezeIdentity({ |
| 73 | ownerEpoch, |
| 74 | requestId: ++requestId, |
| 75 | target, |
| 76 | channel, |
| 77 | ...(navigationIntent === undefined ? {} : { navigationIntent }), |
| 78 | }); |
| 79 | active.set(channel, identity); |
| 80 | return identity; |
| 81 | }, |
| 82 | |
| 83 | owns(identity: OperationIdentity): boolean { |
| 84 | const current = active.get(identity.channel); |
| 85 | return Boolean( |
| 86 | mounted |
| 87 | && current |
| 88 | && identity.ownerEpoch === ownerEpoch |
| 89 | && identity === current |
| 90 | && operationTargetsEqual(identity.target, current.target) |
| 91 | && identity.navigationIntent === current.navigationIntent, |
| 92 | ); |
| 93 | }, |
| 94 | |
| 95 | finish(identity: OperationIdentity, status: OperationTerminalStatus = "completed"): boolean { |
| 96 | if (!this.owns(identity)) return false; |
| 97 | active.delete(identity.channel); |
| 98 | trackOperation(-1); |
| 99 | terminalCounts[status] += 1; |
| 100 | return true; |
| 101 | }, |
| 102 | |
| 103 | cancel(identity: OperationIdentity): boolean { |
| 104 | return this.finish(identity, "cancelled"); |
| 105 | }, |
| 106 | |
| 107 | get activeCount(): number { |
| 108 | return active.size; |
| 109 | }, |
| 110 | |
| 111 | get diagnostics(): Readonly<Record<OperationTerminalStatus, number>> { |
| 112 | return { ...terminalCounts }; |
| 113 | }, |
| 114 | }; |
| 115 | } |
| 116 |