Function createEventHandler

lib/hooks.ts:293–375

(state: SessionState, logger: Logger)

}

export function createEventHandler(state: SessionState, logger: Logger) {
    return async (input: { event: any }) => {
        const eventTime =
            typeof input.event?.time === "number" && Number.isFinite(input.event.time)
                ? input.event.time
                : typeof input.event?.properties?.time === "number" &&
                    Number.isFinite(input.event.properties.time)
                  ? input.event.properties.time
                  : undefined

        if (input.event.type !== "message.part.updated") {
            return
        }

        const part = input.event.properties?.part
        if (part?.type !== "tool" || part.tool !== "compress") {
            return
        }

        if (part.state.status === "pending") {
            if (typeof part.callID !== "string" || typeof part.messageID !== "string") {
                return
            }

            const startedAt = eventTime ?? Date.now()
            const key = buildCompressionTimingKey(part.messageID, part.callID)
            if (state.compressionTiming.startsByCallId.has(key)) {
                return
            }
            state.compressionTiming.startsByCallId.set(key, startedAt)
            logger.debug("Recorded compression start", {
                messageID: part.messageID,
                callID: part.callID,
                startedAt,
            })
            return
        }

        if (part.state.status === "completed") {
            if (typeof part.callID !== "string" || typeof part.messageID !== "string") {
                return
            }

            const key = buildCompressionTimingKey(part.messageID, part.callID)
            const start = consumeCompressionStart(state, part.messageID, part.callID)
            const durationMs = resolveCompressionDuration(start, eventTime, part.state.time)
            if (typeof durationMs !== "number") {
                return
            }

            state.compressionTiming.pendingByCallId.set(key, {
                messageId: part.messageID,
                callId: part.callID,
                durationMs,
            })

            const updates = applyPendingCompressionDurations(state)
            if (updates === 0) {