| 1 | import { noteSessionObservation } from "./sessionObservationDiagnostics"; |
| 2 | import { app } from "./bridge"; |
| 3 | import { bindNativeTranscriptHistory, nativeSnapshotWindow } from "./nativeTranscriptHistory"; |
| 4 | import { entriesFor, registerTranscriptContentRecovery } from "./canonicalTranscriptBackend"; |
| 5 | import { TranscriptFollowClient } from "./transcriptFollowClient"; |
| 6 | import { getTranscriptStore } from "./transcriptStore"; |
| 7 | import type { Action, State } from "./useController"; |
| 8 | import type { HistoryEntry, HistoryMessage, WireEvent } from "./types"; |
| 9 | import type { TranscriptSnapshot } from "./transcriptProtocol"; |
| 10 | import type { Message, TranscriptFollowResponse } from "../generated/desktopContract.generated"; |
| 11 | import { canonicalUserConfirmations } from "./localSubmissionState"; |
| 12 | import { snapshotRecords } from "./transcriptSnapshotState"; |
| 13 | import { signalOutline } from "./transcriptOutlineSignals"; |
| 14 | import { historyMessageIdentity } from "./historyItemIds"; |
| 15 | |
| 16 | /** Canonical positions and projection indexes count different record sets. |
| 17 | * Join the two ordered windows by shared message identity before assigning |
| 18 | * positions to projection-only rows. */ |
| 19 | function mergeFollowEntries(canonical: HistoryEntry[], snapshot: HistoryEntry[], merged: Map<string, HistoryEntry>): HistoryEntry[] { |
| 20 | const canonicalIds = new Set(canonical.map(entry => entry.entryId)); |
| 21 | const ordered = [...canonical].sort((a, b) => a.order - b.order).map(entry => merged.get(entry.entryId)!); |
| 22 | const present = new Set(canonicalIds); |
| 23 | for (let snapshotIndex = 0; snapshotIndex < snapshot.length; snapshotIndex++) { |
| 24 | // Multiple projection aliases can normalize to one durable identity. The |
| 25 | // merge map owns its body/ref precedence; this pass only places that owner. |
| 26 | const entry = merged.get(snapshot[snapshotIndex].entryId)!; |
| 27 | if (present.has(entry.entryId)) continue; |
| 28 | let at = -1; |
| 29 | for (let index = snapshotIndex - 1; index >= 0; index--) { |
| 30 | const anchor = snapshot[index].entryId; |
| 31 | if (!present.has(anchor)) continue; |
| 32 | at = ordered.findIndex(candidate => candidate.entryId === anchor) + 1; |
| 33 | break; |
| 34 | } |
| 35 | if (at < 0) { |
| 36 | for (let index = snapshotIndex + 1; index < snapshot.length; index++) { |
| 37 | const anchor = snapshot[index].entryId; |
| 38 | if (!present.has(anchor)) continue; |
| 39 | at = ordered.findIndex(candidate => candidate.entryId === anchor); |
| 40 | break; |
| 41 | } |
| 42 | } |
| 43 | if (at < 0) { |
| 44 | at = ordered.findIndex(candidate => candidate.turn > entry.turn); |
| 45 | if (at < 0) at = ordered.length; |
| 46 | } |
| 47 | ordered.splice(at, 0, entry); |
| 48 | present.add(entry.entryId); |
| 49 | } |
| 50 | for (let start = 0; start < ordered.length;) { |
| 51 | if (canonicalIds.has(ordered[start].entryId)) { start++; continue; } |
| 52 | let end = start; |
| 53 | while (end < ordered.length && !canonicalIds.has(ordered[end].entryId)) end++; |
| 54 | const left = start > 0 ? ordered[start - 1].order : undefined; |
| 55 | const right = end < ordered.length ? ordered[end].order : undefined; |
| 56 | for (let index = start; index < end; index++) { |
| 57 | const fraction = (index - start + 1) / (end - start + 1); |
| 58 | let order = ordered[index].order; |
| 59 | if (left !== undefined && right !== undefined) order = left + (right - left) * fraction; |
| 60 | else if (left !== undefined) order = left + fraction; |
| 61 | else if (right !== undefined) order = right - 1 + fraction; |
| 62 | ordered[index] = { ...ordered[index], order }; |
| 63 | } |
| 64 | start = end; |
| 65 | } |
| 66 | return ordered; |
| 67 | } |
| 68 | |
| 69 | export class TranscriptSessionFollowerRuntime { |
| 70 | private readonly client: TranscriptFollowClient; |
| 71 | private readonly orders = new Map<string, number>(); |
| 72 | private nextOrder = 0; |
| 73 | private turn = 0; |
| 74 | private generation = 0; |
| 75 | private releaseContentRecovery?: () => void; |
| 76 | private releaseNativeHistory?: () => void; |
| 77 | private recoveringContent = false; |
| 78 | private coverage = 0; |
| 79 | private recoveryScheduled = false; |
| 80 | private readonly confirmationReads = new Map<string, { coverage: number; pending: boolean }>(); |
| 81 | private readonly submissionCoverage = new Map<string, number>(); |
| 82 | metrics = { entries: 0, inlineBytes: 0 }; |
| 83 | |
| 84 | constructor(private readonly tabId: string, private readonly path: string, private readonly remote: boolean, |
| 85 | private readonly dispatch: (action: Action) => void, |
| 86 | private readonly state: () => State | undefined = () => getTranscriptStore().states.get(tabId)) { |
| 87 | this.client = new TranscriptFollowClient(request => { |
| 88 | const read = remote ? app.RemoteTranscriptFollowForTab : app.TranscriptFollowForTab; |
| 89 | if (!read) return Promise.reject(new Error("Transcript v2 is required. Upgrade Desktop and Serve together.")); |
| 90 | return read(tabId, request); |
| 91 | }, { transport: remote ? "remote" : "local" }); |
| 92 | } |
| 93 | |
| 94 | async start(): Promise<void> { |
| 95 | this.generation++; |
| 96 | this.releaseNativeHistory?.(); |
| 97 | this.releaseNativeHistory = undefined; |
| 98 | noteSessionObservation(this.path, { action: "subscribe", tabId: this.tabId, generation: this.generation, sequence: this.coverage }); |
| 99 | this.recoveryScheduled = false; |
| 100 | this.coverage = 0; |
| 101 | this.confirmationReads.clear(); |
| 102 | this.submissionCoverage.clear(); |
| 103 | this.observeSubmissions(); |
| 104 | this.releaseContentRecovery?.(); |
| 105 | this.releaseContentRecovery = registerTranscriptContentRecovery(this.tabId, () => { |
| 106 | if (this.recoveringContent) return; |
| 107 | this.recoveringContent = true; |
| 108 | void this.start().catch(() => undefined).finally(() => { this.recoveringContent = false; }); |
| 109 | }); |
| 110 | await this.client.start({ |
| 111 | install: response => this.install(response), |
| 112 | changes: changes => { |
| 113 | if (changes.some(change => change.records?.some(record => record.role === "user" || record.role === "assistant") || change.durableSeq > this.coverage)) signalOutline(this.tabId); |
| 114 | this.observeSubmissions(); |
| 115 | for (const change of changes) { |
| 116 | if (change.records?.length) { |
| 117 | const entries = change.records.map(message => this.entry(message)); |
| 118 | const projection = getTranscriptStore().upsertEntries(this.tabId, this.path, entries, change.commitSeq); |
| 119 | if (!projection) throw new Error("Transcript window is unavailable; synchronize again"); |
| 120 | this.dispatch({ type: "transcript_records", projection, |
| 121 | confirmedUsers: canonicalUserConfirmations(entries.map(entry => ({ ...entry.message, kind: entry.message.role }))) }); |
| 122 | this.coverage = Math.max(this.coverage, change.commitSeq); |
| 123 | } |
| 124 | if (change.event) this.dispatch({ type: "event", e: { ...change.event, tabId: this.tabId } as unknown as WireEvent, remote: this.remote }); |
| 125 | if (change.runtime) this.dispatch({ type: "transcript_runtime", runtime: change.runtime }); |
| 126 | } |
| 127 | this.scheduleConfirmationRecovery(); |
| 128 | }, |
| 129 | connection: (status, error) => { noteSessionObservation(this.path, { action: "connection", tabId: this.tabId, generation: this.generation, sequence: this.coverage, status }); this.dispatch({ type: "transcript_connection", status, error }); }, |
| 130 | }); |
| 131 | } |
| 132 | |
| 133 | stop(closeSubscription = true, reason?: "service_stopping"): void { noteSessionObservation(this.path, { action: "unsubscribe", tabId: this.tabId, generation: this.generation, sequence: this.coverage }); this.generation++; this.confirmationReads.clear(); this.submissionCoverage.clear(); this.releaseContentRecovery?.(); this.releaseContentRecovery = undefined; this.releaseNativeHistory?.(); this.releaseNativeHistory = undefined; this.client.stop(closeSubscription, reason); } |
| 134 | |
| 135 | private observeSubmissions(): void { |
| 136 | const pending = new Set(this.state()?.localSubmissionOrder ?? []); |
| 137 | for (const id of this.submissionCoverage.keys()) if (!pending.has(id)) this.submissionCoverage.delete(id); |
| 138 | for (const id of pending) if (!this.submissionCoverage.has(id)) this.submissionCoverage.set(id, this.coverage); |
| 139 | } |
| 140 | |
| 141 | private scheduleConfirmationRecovery(): void { |
| 142 | if (this.recoveryScheduled) return; |
| 143 | this.recoveryScheduled = true; |
| 144 | const generation = this.generation; |
| 145 | queueMicrotask(() => { |
| 146 | this.recoveryScheduled = false; |
| 147 | if (generation !== this.generation) return; |
| 148 | const state = this.state(); |
| 149 | if (!state) return; |
| 150 | this.observeSubmissions(); |
| 151 | const unresolved = new Set(state.localSubmissionOrder); |
| 152 | for (const key of this.confirmationReads.keys()) if (!unresolved.has(key)) this.confirmationReads.delete(key); |
| 153 | for (const local of Object.values(state.localSubmissions)) { |
| 154 | // Identity events alone do not justify a history read. Only recover |
| 155 | // after a committed cut could have hidden an earlier formal record. |
| 156 | if (!local.messageId || this.coverage <= (this.submissionCoverage.get(local.submissionId) ?? this.coverage)) continue; |
| 157 | const previous = this.confirmationReads.get(local.submissionId); |
| 158 | if (previous?.pending || previous?.coverage === this.coverage) continue; |
| 159 | const read = this.remote ? app.RemoteSessionHistoryWindowForTab : app.SessionHistoryWindowForTab; |
| 160 | if (!read) continue; |
| 161 | const ticket = { coverage: this.coverage, pending: true }; |
| 162 | this.confirmationReads.set(local.submissionId, ticket); |
| 163 | const current = () => generation === this.generation && this.state()?.sessionGen === state.sessionGen |
| 164 | && this.state()?.localSubmissions[local.submissionId]?.messageId === local.messageId; |
| 165 | void read(this.tabId, { anchor: "message", messageId: local.messageId, limit: 1 }).then(page => { |
| 166 | if (!current() || page.status !== "ready") return; |
| 167 | const message = page.messages.find(message => message.messageId === local.messageId && message.role === "user"); |
| 168 | if (message) this.dispatch({ type: "submission_verified", submissionId: local.submissionId, messageId: local.messageId! }); |
| 169 | }).catch(() => { /* An inconclusive read retains the echo until the next committed cut. */ }).finally(() => { |
| 170 | if (this.confirmationReads.get(local.submissionId) !== ticket) return; |
| 171 | ticket.pending = false; |
| 172 | if (!current()) this.confirmationReads.delete(local.submissionId); |
| 173 | else if (ticket.coverage !== this.coverage) this.scheduleConfirmationRecovery(); |
| 174 | }); |
| 175 | } |
| 176 | }); |
| 177 | } |
| 178 | |
| 179 | private entry(message: Message | HistoryMessage, outerRecordId?: string, snapshotOrder?: number): HistoryEntry { |
| 180 | // Canonical history addresses every persisted message as m:<messageId>, |
| 181 | // including tool results. A snapshot may instead carry its projection |
| 182 | // identity (for example tool:<toolCallId>); that explicit identity is |
| 183 | // valid metadata, while messageId remains the merge key used by history. |
| 184 | const messageId = historyMessageIdentity(message, outerRecordId); |
| 185 | const derived = messageId ? `m:${messageId}` |
| 186 | : message.role === "tool" && message.toolCallId ? `tool:${message.toolCallId}` : undefined; |
| 187 | if (outerRecordId && message.recordId && outerRecordId !== message.recordId) { |
| 188 | throw new Error("transcript snapshot record identity mismatch"); |
| 189 | } |
| 190 | const entryId = derived ?? message.recordId ?? outerRecordId; |
| 191 | if (!entryId) throw new Error("invalid transcript snapshot record identity"); |
| 192 | const normalized = message.recordId === entryId && message.messageId === messageId ? message : { ...message, messageId, recordId: entryId }; |
| 193 | let order = this.orders.get(entryId); |
| 194 | if (order === undefined) { |
| 195 | order = snapshotOrder ?? this.nextOrder; |
| 196 | this.nextOrder = Math.max(this.nextOrder, order + 1); |
| 197 | this.orders.set(entryId, order); |
| 198 | // A snapshot's total already includes users outside its history page. |
| 199 | // Only newly followed user records advance the turn counter. |
| 200 | if (message.role === "user" && snapshotOrder === undefined) this.turn++; |
| 201 | // Only the resident tail needs an order index. Older pages carry their |
| 202 | // canonical positions and are owned by the bounded transcript store. |
| 203 | while (this.orders.size > 192) this.orders.delete(this.orders.keys().next().value!); |
| 204 | } |
| 205 | return { entryId, order, turn: message.historyTurn || this.turn, message: normalized as unknown as HistoryMessage, refs: [] }; |
| 206 | } |
| 207 | |
| 208 | private async install(response: TranscriptFollowResponse): Promise<void> { |
| 209 | const generation = this.generation; |
| 210 | const snapshot = response.snapshot!; |
| 211 | // Validate the untrusted bridge cut before resolving refs, merging rows or |
| 212 | // changing the resident store. The outer record id is authoritative for |
| 213 | // older peers that did not repeat it inside the message. |
| 214 | const records = snapshotRecords(snapshot as unknown as TranscriptSnapshot); |
| 215 | // A suffix must never be applied to a truncated prefix. Resolve active |
| 216 | // snapshot references before publishing any part of this recovery cut. |
| 217 | const activeIds = new Set(snapshot.activeAttempts.map(attempt => attempt.messageId)); |
| 218 | for (const record of records) { |
| 219 | if (!record.message.messageId || !activeIds.has(record.message.messageId)) continue; |
| 220 | for (const ref of record.refs) { |
| 221 | const read = this.remote ? app.RemoteTranscriptContentForTab : app.TranscriptContentForTab; |
| 222 | if (!read) throw new Error("Transcript v2 content is unavailable"); |
| 223 | let offset = 0, text = ""; |
| 224 | while (true) { |
| 225 | const chunk = await read(this.tabId, { ...ref, offset }); |
| 226 | if (generation !== this.generation) return; |
| 227 | if (chunk.stale) throw new Error("Active transcript snapshot expired; synchronize again"); |
| 228 | text += chunk.data; |
| 229 | if (chunk.done) break; |
| 230 | if (chunk.nextOffset <= offset) throw new Error("Active transcript content did not advance"); |
| 231 | offset = chunk.nextOffset; |
| 232 | } |
| 233 | let target = record.message as unknown as Record<string, unknown>; |
| 234 | for (const key of ref.path.slice(0, -1)) target = target[key] as Record<string, unknown>; |
| 235 | target[ref.path[ref.path.length - 1]] = text; |
| 236 | } |
| 237 | record.refs = []; |
| 238 | } |
| 239 | if (generation !== this.generation) return; |
| 240 | this.observeSubmissions(); |
| 241 | const page = response.history; |
| 242 | this.releaseNativeHistory?.(); |
| 243 | this.releaseNativeHistory = response.storageBackend === "legacy" |
| 244 | ? bindNativeTranscriptHistory(this.tabId, snapshot as unknown as TranscriptSnapshot, this.remote) : undefined; |
| 245 | const nativeWindow = response.storageBackend === "legacy" ? nativeSnapshotWindow(snapshot as unknown as TranscriptSnapshot) : undefined; |
| 246 | this.turn = page?.totalTurns ?? snapshot.totalTurns; |
| 247 | this.orders.clear(); |
| 248 | const entries = nativeWindow?.entries ?? entriesFor(page?.messages ?? [], page?.snapshotSequence ?? snapshot.coveredThroughSeq); |
| 249 | for (const entry of entries) this.orders.set(entry.entryId, entry.order); |
| 250 | this.nextOrder = Math.max(0, ...entries.map(entry => entry.order + 1)); |
| 251 | const merged = new Map(entries.map(entry => [entry.entryId, entry])); |
| 252 | const snapshotEntries: HistoryEntry[] = []; |
| 253 | for (const record of records) { |
| 254 | const entry = this.entry(record.message, record.id, record.order); |
| 255 | snapshotEntries.push(entry); |
| 256 | // Durable canonical refs remain loadable after a view snapshot expires. |
| 257 | const canonical = merged.get(entry.entryId); |
| 258 | if (canonical && !snapshot.activeAttempts.some(attempt => attempt.messageId === record.message.messageId)) continue; |
| 259 | entry.refs = record.refs.map(ref => ({ entryId: entry.entryId, field: ref.path[0], size: ref.bytes, chunks: 1, |
| 260 | revision: snapshot.coveredThroughSeq, revKnown: true, digest: snapshot.snapshotId, transcriptRef: ref })); |
| 261 | merged.set(entry.entryId, entry); |
| 262 | } |
| 263 | // Native pages and activeRecords share the frozen snapshot's order space. |
| 264 | // Keep those positions so pages fetched into an active-prefix gap can sort |
| 265 | // between its original neighbors. |
| 266 | const all = nativeWindow ? [...merged.values()].sort((a, b) => a.order - b.order) |
| 267 | : mergeFollowEntries(entries, snapshotEntries, merged); |
| 268 | this.orders.clear(); |
| 269 | for (const entry of all.slice(-192)) this.orders.set(entry.entryId, entry.order); |
| 270 | this.nextOrder = Math.max(this.nextOrder, ...all.map(entry => entry.order + 1)); |
| 271 | this.metrics = { entries: all.length, inlineBytes: all.reduce((bytes, entry) => bytes + entry.message.content.length + (entry.message.reasoning?.length ?? 0), 0) }; |
| 272 | const prepared = getTranscriptStore().prepareInstallSlice(this.tabId, this.path, { |
| 273 | entries: all, nextCursor: page?.olderCursor ?? nativeWindow?.olderCursor ?? "", newerCursor: page?.newerCursor ?? nativeWindow?.newerCursor ?? "", |
| 274 | hasOlder: Boolean(page?.hasOlder ?? nativeWindow?.hasOlder), hasNewer: Boolean(page?.hasNewer ?? nativeWindow?.hasNewer), totalTurns: this.turn, |
| 275 | startTurn: Math.min(this.turn, ...all.map(entry => entry.turn)), endTurn: this.turn, |
| 276 | revision: page?.snapshotSequence ?? snapshot.coveredThroughSeq, revisionKnown: true, digest: page?.generation ?? nativeWindow?.digest ?? "", stale: false, |
| 277 | }); |
| 278 | const combined: TranscriptSnapshot = { |
| 279 | ...snapshot as unknown as TranscriptSnapshot, |
| 280 | records: all.map((entry, order) => ({ id: entry.entryId, order, message: entry.message, refs: [] })), |
| 281 | activeRecords: [], totalRecords: all.length, totalTurns: this.turn, |
| 282 | }; |
| 283 | this.dispatch({ type: "transcript_v2_snapshot", snapshot: combined, projection: prepared.projection, remote: this.remote }); |
| 284 | prepared.commit(); |
| 285 | signalOutline(this.tabId); |
| 286 | this.dispatch({ type: "transcript_runtime", runtime: snapshot.runtime }); |
| 287 | this.coverage = snapshot.coveredThroughSeq; |
| 288 | noteSessionObservation(this.path, { action: "snapshot_installed", tabId: this.tabId, generation: this.generation, sequence: this.coverage, status: snapshot.runtime.status }); |
| 289 | this.scheduleConfirmationRecovery(); |
| 290 | } |
| 291 | } |
| 292 |