@braze/web-sdk/src/DUST/dust-shared-worker-code.js

Braze SDK for web sites and other JS platforms.

export const DUST_SHARED_WORKER_CODE =
  '\n"use strict";\nconst workerSelf = self;\nlet eventSource = null;\nlet currentConfig = null;\nlet retryCount = 0;\nlet retryTimeoutId = null;\nlet connectionInProgress = false;\nconst maxRetries = 5;\nconst connectedPorts = new Map();\nlet lastSleepMs = null;\nlet currentRcs = null;\nlet ttlTimeoutId = null;\nlet leaderPortId = null;\nlet ddrTimeoutId = null;\nconst fn = {\n    startConnection: null,\n    handleMessage: null,\n};\nfunction broadcast(message) {\n    connectedPorts.forEach((portInfo, portId) => {\n        try {\n            portInfo.port.postMessage(message);\n        }\n        catch (_a) {\n            connectedPorts.delete(portId);\n        }\n    });\n}\nfunction randomInclusive(min, max) {\n    return Math.floor(Math.random() * (max - min + 1)) + min;\n}\nfunction electLeader() {\n    if (leaderPortId && connectedPorts.has(leaderPortId)) {\n        return;\n    }\n    const firstPortId = connectedPorts.keys().next().value;\n    leaderPortId = firstPortId || null;\n    if (leaderPortId) {\n        console.log("[Braze Real-Time] Elected leader port:", leaderPortId);\n    }\n}\nfunction promoteToLeader(portId) {\n    if (connectedPorts.has(portId) && leaderPortId !== portId) {\n        leaderPortId = portId;\n        console.log("[Braze Real-Time] Promoted to leader (tab became active):", portId);\n    }\n}\nfunction sendToLeader(message) {\n    electLeader();\n    if (!leaderPortId) {\n        console.warn("[Braze Real-Time] No leader to send message to");\n        return;\n    }\n    const leader = connectedPorts.get(leaderPortId);\n    if (leader) {\n        try {\n            leader.port.postMessage(message);\n        }\n        catch (_a) {\n            connectedPorts.delete(leaderPortId);\n            leaderPortId = null;\n            sendToLeader(message);\n        }\n    }\n}\nfunction closeConnection() {\n    connectionInProgress = false;\n    if (retryTimeoutId !== null) {\n        clearTimeout(retryTimeoutId);\n        retryTimeoutId = null;\n    }\n    if (ttlTimeoutId !== null) {\n        clearTimeout(ttlTimeoutId);\n        ttlTimeoutId = null;\n    }\n    if (ddrTimeoutId !== null) {\n        clearTimeout(ddrTimeoutId);\n        ddrTimeoutId = null;\n    }\n    if (eventSource) {\n        eventSource.close();\n        eventSource = null;\n        broadcast({ type: "disconnected" });\n    }\n}\nfunction retryWithBackoff() {\n    if (!currentConfig) {\n        return;\n    }\n    retryCount++;\n    const { minSleepMs, maxSleepMs, scaleFactor } = currentConfig.backoff;\n    let previousSleepMs = lastSleepMs;\n    if (previousSleepMs == null || previousSleepMs < minSleepMs) {\n        previousSleepMs = minSleepMs;\n    }\n    const backoffMs = Math.min(maxSleepMs, randomInclusive(minSleepMs, previousSleepMs * scaleFactor));\n    lastSleepMs = backoffMs;\n    console.log("[Braze Real-Time] Retrying in " + backoffMs + "ms (attempt " + retryCount + "/" + maxRetries + ")");\n    retryTimeoutId = setTimeout(function () {\n        retryTimeoutId = null;\n        fn.startConnection();\n    }, backoffMs);\n}\nfunction startConnection(oldEventSourceToClose) {\n    if (!currentConfig) {\n        return;\n    }\n    if (eventSource && !oldEventSourceToClose) {\n        console.warn("[Braze Real-Time] Connection already exists");\n        return;\n    }\n    if (connectionInProgress && !oldEventSourceToClose) {\n        console.warn("[Braze Real-Time] Connection attempt already in progress");\n        return;\n    }\n    connectionInProgress = true;\n    const { dustHost, mite, auth } = currentConfig;\n    const dustHostWithScheme = /^https?:\\/\\//i.test(dustHost) ? dustHost : "https://" + dustHost;\n    let queryString = "mite=" + encodeURIComponent(mite) + "&attempts=" + retryCount;\n    if (auth) {\n        queryString += "&auth=" + encodeURIComponent(auth);\n    }\n    if (currentRcs) {\n        queryString += "&rcs=" + encodeURIComponent(currentRcs);\n    }\n    const subscribeUrl = dustHostWithScheme + "/sse?" + queryString;\n    try {\n        const newEventSource = new EventSource(subscribeUrl);\n        newEventSource.onopen = function () {\n            if (oldEventSourceToClose) {\n                console.log("[Braze Real-Time] Gapless reconnection: new connection established, closing old connection");\n                oldEventSourceToClose.close();\n            }\n            else {\n                console.log("[Braze Real-Time] Connection established");\n            }\n            eventSource = newEventSource;\n            connectionInProgress = false;\n            retryCount = 0;\n            lastSleepMs = null;\n            broadcast({ type: "connected" });\n        };\n        newEventSource.addEventListener("msg", function (event) {\n            fn.handleMessage(event.data);\n        });\n        newEventSource.onerror = function () {\n            const readyState = newEventSource ? newEventSource.readyState : -1;\n            if (readyState === 0) {\n                console.log("[Braze Real-Time] Failed to connect");\n            }\n            else {\n                console.log("[Braze Real-Time] Connection lost");\n            }\n            if (oldEventSourceToClose && eventSource !== newEventSource) {\n                console.log("[Braze Real-Time] Gapless reconnection failed, keeping old connection");\n                newEventSource.close();\n                connectionInProgress = false;\n                if (retryCount < maxRetries) {\n                    retryWithBackoff();\n                }\n                return;\n            }\n            closeConnection();\n            if (retryCount < maxRetries) {\n                retryWithBackoff();\n            }\n            else {\n                console.error("[Braze Real-Time] Max retries reached");\n                broadcast({ type: "error", error: "Max retry attempts reached" });\n            }\n        };\n    }\n    catch (error) {\n        connectionInProgress = false;\n        console.error("[Braze Real-Time] Failed to create EventSource:", error);\n        broadcast({ type: "error", error: String(error) });\n    }\n}\nfunction handleTtlMessage(tMs, rcs) {\n    if (typeof tMs !== "number") {\n        return;\n    }\n    if (typeof rcs === "string") {\n        currentRcs = rcs;\n    }\n    console.log("[Braze Real-Time] TTL set to " + tMs + "ms, will perform gapless reconnection when expired");\n    if (ttlTimeoutId !== null) {\n        clearTimeout(ttlTimeoutId);\n    }\n    ttlTimeoutId = setTimeout(function () {\n        ttlTimeoutId = null;\n        console.log("[Braze Real-Time] TTL expired, performing gapless reconnection");\n        startConnection(eventSource || undefined);\n    }, tMs);\n}\nfunction handleDdrMessage(rMs, reason) {\n    if (typeof rMs !== "number") {\n        return;\n    }\n    const jitter = Math.random() * rMs * 0.3;\n    const waitMs = Math.round(rMs + jitter);\n    const reasonStr = reason ? " (" + reason + ")" : "";\n    console.log("[Braze Real-Time] Admin requested disconnect" + reasonStr + ", reconnecting in " + waitMs + "ms");\n    if (ddrTimeoutId !== null) {\n        clearTimeout(ddrTimeoutId);\n    }\n    closeConnection();\n    ddrTimeoutId = setTimeout(function () {\n        ddrTimeoutId = null;\n        fn.startConnection();\n    }, waitMs);\n}\nfunction handleMessage(data) {\n    try {\n        const message = JSON.parse(data);\n        if (!message.type) {\n            console.warn("[Braze Real-Time] Message without type:", message);\n            return;\n        }\n        if (message.type === "ttl" && message.body) {\n            handleTtlMessage(message.body.t_ms, message.body.rcs);\n            return;\n        }\n        if (message.type === "ddr" && message.body) {\n            handleDdrMessage(message.body.r_ms, message.body.e);\n            return;\n        }\n        console.log("[Braze Real-Time] Routing \'" + message.type + "\' message to leader");\n        sendToLeader({ type: "message", data: message });\n    }\n    catch (error) {\n        console.warn("[Braze Real-Time] Failed to parse message:", error);\n    }\n}\nfn.startConnection = startConnection;\nfn.handleMessage = handleMessage;\nfunction handlePortMessage(port, portId, message) {\n    switch (message.type) {\n        case "connect":\n            if (currentConfig &&\n                (currentConfig.mite !== message.config.mite || currentConfig.dustHost !== message.config.dustHost)) {\n                console.log("[Braze Real-Time] Config changed, reconnecting");\n                closeConnection();\n                retryCount = 0;\n                lastSleepMs = null;\n                currentRcs = null;\n            }\n            currentConfig = message.config;\n            electLeader();\n            if (!eventSource && !connectionInProgress) {\n                startConnection();\n            }\n            else if (eventSource) {\n                port.postMessage({ type: "connected" });\n            }\n            break;\n        case "disconnect":\n            connectedPorts.delete(portId);\n            if (portId === leaderPortId) {\n                leaderPortId = null;\n                electLeader();\n            }\n            if (connectedPorts.size === 0) {\n                console.log("[Braze Real-Time] No more ports, closing connection");\n                closeConnection();\n                currentConfig = null;\n                currentRcs = null;\n                leaderPortId = null;\n            }\n            break;\n        case "tab_active":\n            promoteToLeader(portId);\n            break;\n        case "ping":\n            port.postMessage({ type: "pong" });\n            break;\n        default:\n            console.warn("[Braze Real-Time] Unknown message type:", message.type);\n    }\n}\nworkerSelf.onconnect = function (event) {\n    const port = event.ports[0];\n    const portId = "port-" + Date.now() + "-" + Math.random().toString(36).substr(2, 9);\n    connectedPorts.set(portId, { port: port });\n    port.onmessage = function (messageEvent) {\n        try {\n            handlePortMessage(port, portId, messageEvent.data);\n        }\n        catch (error) {\n            console.error("[Braze Real-Time] Error handling message:", error);\n        }\n    };\n    port.onmessageerror = function () {\n        console.warn("[Braze Real-Time] Message error from port:", portId);\n        connectedPorts.delete(portId);\n    };\n    port.start();\n};\n';