Abstracts throttle, response cache and network implementation details.\n *\n *
Modeled after the native {@link GlobalFetch} interface, which is relatively modern and\n * convenient, but simplified for Remote Config's use case.\n *\n * Disambiguation: {@link GlobalFetch} interface and the Remote Config service define \"fetch\"\n * methods. The RestClient uses the former to make HTTP calls. This interface abstracts the latter.\n */\nexport interface RemoteConfigFetchClient {\n /**\n * @throws if response status is not 200 or 304.\n */\n fetch(request: FetchRequest): Promise
AbortController's AbortSignal conveniently decouples fetch timeout logic from other aspects\n * of networking, such as retries. Firebase doesn't use AbortController enough to justify a\n * polyfill recommendation, like we do with the Fetch API, but this minimal shim can easily be\n * swapped out if/when we do.\n */\nexport class RemoteConfigAbortSignal {\n listeners: Array<() => void> = [];\n addEventListener(listener: () => void): void {\n this.listeners.push(listener);\n }\n abort(): void {\n this.listeners.forEach(listener => listener());\n }\n}\n\n/**\n * Defines per-request inputs for the Remote Config fetch request.\n *\n *
Modeled after the native {@link Request} interface, but simplified for Remote Config's\n * use case.\n */\nexport interface FetchRequest {\n /**\n * Uses cached config if it is younger than this age.\n *\n *
Required because it's defined by settings, which always have a value.\n *\n *
Comparable to passing `headers = { 'Cache-Control': max-age
Required because all requests should be abortable.\n *\n *
Comparable to the native\n * Fetch API's \"signal\" field on its request configuration object\n * https://fetch.spec.whatwg.org/#dom-requestinit-signal.\n *\n *
Disambiguation: Remote Config commonly refers to API inputs as\n * \"signals\". See the private ConfigFetchRequestBody interface for those:\n * http://google3/firebase/remote_config/web/src/core/rest_client.ts?l=14&rcl=255515243.\n */\n signal: RemoteConfigAbortSignal;\n\n /**\n * The ETag header value from the last response.\n *\n *
Optional in case this is the first request.\n *\n *
Comparable to passing `headers = { 'If-None-Match':
Optional in case no custom signals are set for the instance.\n */\n customSignals?: CustomSignals;\n}\n","/**\n * @license\n * Copyright 2020 Google LLC\n *\n * Licensed under the Apache License, Version 2.0 (the \"License\");\n * you may not use this file except in compliance with the License.\n * You may obtain a copy of the License at\n *\n * http://www.apache.org/licenses/LICENSE-2.0\n *\n * Unless required by applicable law or agreed to in writing, software\n * distributed under the License is distributed on an \"AS IS\" BASIS,\n * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n * See the License for the specific language governing permissions and\n * limitations under the License.\n */\n\nexport const RC_COMPONENT_NAME = 'remote-config';\nexport const RC_CUSTOM_SIGNAL_MAX_ALLOWED_SIGNALS = 100;\nexport const RC_CUSTOM_SIGNAL_KEY_MAX_LENGTH = 250;\nexport const RC_CUSTOM_SIGNAL_VALUE_MAX_LENGTH = 500;\n","/**\n * @license\n * Copyright 2019 Google LLC\n *\n * Licensed under the Apache License, Version 2.0 (the \"License\");\n * you may not use this file except in compliance with the License.\n * You may obtain a copy of the License at\n *\n * http://www.apache.org/licenses/LICENSE-2.0\n *\n * Unless required by applicable law or agreed to in writing, software\n * distributed under the License is distributed on an \"AS IS\" BASIS,\n * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n * See the License for the specific language governing permissions and\n * limitations under the License.\n */\n\nimport { ErrorFactory, FirebaseError } from '@firebase/util';\n\nexport const enum ErrorCode {\n ALREADY_INITIALIZED = 'already-initialized',\n REGISTRATION_WINDOW = 'registration-window',\n REGISTRATION_PROJECT_ID = 'registration-project-id',\n REGISTRATION_API_KEY = 'registration-api-key',\n REGISTRATION_APP_ID = 'registration-app-id',\n STORAGE_OPEN = 'storage-open',\n STORAGE_GET = 'storage-get',\n STORAGE_SET = 'storage-set',\n STORAGE_DELETE = 'storage-delete',\n FETCH_NETWORK = 'fetch-client-network',\n FETCH_TIMEOUT = 'fetch-timeout',\n FETCH_THROTTLE = 'fetch-throttle',\n FETCH_PARSE = 'fetch-client-parse',\n FETCH_STATUS = 'fetch-status',\n INDEXED_DB_UNAVAILABLE = 'indexed-db-unavailable',\n CUSTOM_SIGNAL_MAX_ALLOWED_SIGNALS = 'custom-signal-max-allowed-signals'\n}\n\nconst ERROR_DESCRIPTION_MAP: { readonly [key in ErrorCode]: string } = {\n [ErrorCode.ALREADY_INITIALIZED]: 'Remote Config already initialized',\n [ErrorCode.REGISTRATION_WINDOW]:\n 'Undefined window object. This SDK only supports usage in a browser environment.',\n [ErrorCode.REGISTRATION_PROJECT_ID]:\n 'Undefined project identifier. Check Firebase app initialization.',\n [ErrorCode.REGISTRATION_API_KEY]:\n 'Undefined API key. Check Firebase app initialization.',\n [ErrorCode.REGISTRATION_APP_ID]:\n 'Undefined app identifier. Check Firebase app initialization.',\n [ErrorCode.STORAGE_OPEN]:\n 'Error thrown when opening storage. Original error: {$originalErrorMessage}.',\n [ErrorCode.STORAGE_GET]:\n 'Error thrown when reading from storage. Original error: {$originalErrorMessage}.',\n [ErrorCode.STORAGE_SET]:\n 'Error thrown when writing to storage. Original error: {$originalErrorMessage}.',\n [ErrorCode.STORAGE_DELETE]:\n 'Error thrown when deleting from storage. Original error: {$originalErrorMessage}.',\n [ErrorCode.FETCH_NETWORK]:\n 'Fetch client failed to connect to a network. Check Internet connection.' +\n ' Original error: {$originalErrorMessage}.',\n [ErrorCode.FETCH_TIMEOUT]:\n 'The config fetch request timed out. ' +\n ' Configure timeout using \"fetchTimeoutMillis\" SDK setting.',\n [ErrorCode.FETCH_THROTTLE]:\n 'The config fetch request timed out while in an exponential backoff state.' +\n ' Configure timeout using \"fetchTimeoutMillis\" SDK setting.' +\n ' Unix timestamp in milliseconds when fetch request throttling ends: {$throttleEndTimeMillis}.',\n [ErrorCode.FETCH_PARSE]:\n 'Fetch client could not parse response.' +\n ' Original error: {$originalErrorMessage}.',\n [ErrorCode.FETCH_STATUS]:\n 'Fetch server returned an HTTP error status. HTTP status: {$httpStatus}.',\n [ErrorCode.INDEXED_DB_UNAVAILABLE]:\n 'Indexed DB is not supported by current browser',\n [ErrorCode.CUSTOM_SIGNAL_MAX_ALLOWED_SIGNALS]:\n 'Setting more than {$maxSignals} custom signals is not supported.'\n};\n\n// Note this is effectively a type system binding a code to params. This approach overlaps with the\n// role of TS interfaces, but works well for a few reasons:\n// 1) JS is unaware of TS interfaces, eg we can't test for interface implementation in JS\n// 2) callers should have access to a human-readable summary of the error and this interpolates\n// params into an error message;\n// 3) callers should be able to programmatically access data associated with an error, which\n// ErrorData provides.\ninterface ErrorParams {\n [ErrorCode.STORAGE_OPEN]: { originalErrorMessage: string | undefined };\n [ErrorCode.STORAGE_GET]: { originalErrorMessage: string | undefined };\n [ErrorCode.STORAGE_SET]: { originalErrorMessage: string | undefined };\n [ErrorCode.STORAGE_DELETE]: { originalErrorMessage: string | undefined };\n [ErrorCode.FETCH_NETWORK]: { originalErrorMessage: string };\n [ErrorCode.FETCH_THROTTLE]: { throttleEndTimeMillis: number };\n [ErrorCode.FETCH_PARSE]: { originalErrorMessage: string };\n [ErrorCode.FETCH_STATUS]: { httpStatus: number };\n [ErrorCode.CUSTOM_SIGNAL_MAX_ALLOWED_SIGNALS]: { maxSignals: number };\n}\n\nexport const ERROR_FACTORY = new ErrorFactory
Aborting after the request completes is a no-op, so we don't need a\n // corresponding `clearTimeout`.\n //\n // Locating abort logic here because:\n // * it uses a developer setting (timeout)\n // * it applies to all retries (like curl's max-time arg)\n // * it is consistent with the Fetch API's signal input\n const abortSignal = new RemoteConfigAbortSignal();\n\n setTimeout(async () => {\n // Note a very low delay, eg < 10ms, can elapse before listeners are initialized.\n abortSignal.abort();\n }, rc.settings.fetchTimeoutMillis);\n\n const customSignals = rc._storageCache.getCustomSignals();\n if (customSignals) {\n rc._logger.debug(\n `Fetching config with custom signals: ${JSON.stringify(customSignals)}`\n );\n }\n // Catches *all* errors thrown by client so status can be set consistently.\n try {\n await rc._client.fetch({\n cacheMaxAgeMillis: rc.settings.minimumFetchIntervalMillis,\n signal: abortSignal,\n customSignals\n });\n\n await rc._storageCache.setLastFetchStatus('success');\n } catch (e) {\n const lastFetchStatus = hasErrorCode(e as Error, ErrorCode.FETCH_THROTTLE)\n ? 'throttle'\n : 'failure';\n await rc._storageCache.setLastFetchStatus(lastFetchStatus);\n throw e;\n }\n}\n\n/**\n * Gets all config.\n *\n * @param remoteConfig - The {@link RemoteConfig} instance.\n * @returns All config.\n *\n * @public\n */\nexport function getAll(remoteConfig: RemoteConfig): RecordremoteConfig.getValue(key).asBoolean()
.\n *\n * @param remoteConfig - The {@link RemoteConfig} instance.\n * @param key - The name of the parameter.\n *\n * @returns The value for the given key as a boolean.\n * @public\n */\nexport function getBoolean(remoteConfig: RemoteConfig, key: string): boolean {\n return getValue(getModularInstance(remoteConfig), key).asBoolean();\n}\n\n/**\n * Gets the value for the given key as a number.\n *\n * Convenience method for calling remoteConfig.getValue(key).asNumber()
.\n *\n * @param remoteConfig - The {@link RemoteConfig} instance.\n * @param key - The name of the parameter.\n *\n * @returns The value for the given key as a number.\n *\n * @public\n */\nexport function getNumber(remoteConfig: RemoteConfig, key: string): number {\n return getValue(getModularInstance(remoteConfig), key).asNumber();\n}\n\n/**\n * Gets the value for the given key as a string.\n * Convenience method for calling remoteConfig.getValue(key).asString()
.\n *\n * @param remoteConfig - The {@link RemoteConfig} instance.\n * @param key - The name of the parameter.\n *\n * @returns The value for the given key as a string.\n *\n * @public\n */\nexport function getString(remoteConfig: RemoteConfig, key: string): string {\n return getValue(getModularInstance(remoteConfig), key).asString();\n}\n\n/**\n * Gets the {@link Value} for the given key.\n *\n * @param remoteConfig - The {@link RemoteConfig} instance.\n * @param key - The name of the parameter.\n *\n * @returns The value for the given key.\n *\n * @public\n */\nexport function getValue(remoteConfig: RemoteConfig, key: string): Value {\n const rc = getModularInstance(remoteConfig) as RemoteConfigImpl;\n if (!rc._isInitializationComplete) {\n rc._logger.debug(\n `A value was requested for key \"${key}\" before SDK initialization completed.` +\n ' Await on ensureInitialized if the intent was to get a previously activated value.'\n );\n }\n const activeConfig = rc._storageCache.getActiveConfig();\n if (activeConfig && activeConfig[key] !== undefined) {\n return new ValueImpl('remote', activeConfig[key]);\n } else if (rc.defaultConfig && rc.defaultConfig[key] !== undefined) {\n return new ValueImpl('default', String(rc.defaultConfig[key]));\n }\n rc._logger.debug(\n `Returning static value for key \"${key}\".` +\n ' Define a default or remote value if this is unintentional.'\n );\n return new ValueImpl('static');\n}\n\n/**\n * Defines the log level to use.\n *\n * @param remoteConfig - The {@link RemoteConfig} instance.\n * @param logLevel - The log level to set.\n *\n * @public\n */\nexport function setLogLevel(\n remoteConfig: RemoteConfig,\n logLevel: RemoteConfigLogLevel\n): void {\n const rc = getModularInstance(remoteConfig) as RemoteConfigImpl;\n switch (logLevel) {\n case 'debug':\n rc._logger.logLevel = FirebaseLogLevel.DEBUG;\n break;\n case 'silent':\n rc._logger.logLevel = FirebaseLogLevel.SILENT;\n break;\n default:\n rc._logger.logLevel = FirebaseLogLevel.ERROR;\n }\n}\n\n/**\n * Dedupes and returns an array of all the keys of the received objects.\n */\nfunction getAllKeys(obj1: {} = {}, obj2: {} = {}): string[] {\n return Object.keys({ ...obj1, ...obj2 });\n}\n\n/**\n * Sets the custom signals for the app instance.\n *\n * @param remoteConfig - The {@link RemoteConfig} instance.\n * @param customSignals - Map (key, value) of the custom signals to be set for the app instance. If\n * a key already exists, the value is overwritten. Setting the value of a custom signal to null\n * unsets the signal. The signals will be persisted locally on the client.\n *\n * @public\n */\nexport async function setCustomSignals(\n remoteConfig: RemoteConfig,\n customSignals: CustomSignals\n): Promise
Comparable to the browser's Cache API for responses, but the Cache API requires a Service\n * Worker, which requires HTTPS, which would significantly complicate SDK installation. Also, the\n * Cache API doesn't support matching entries by time.\n */\nexport class CachingClient implements RemoteConfigFetchClient {\n constructor(\n private readonly client: RemoteConfigFetchClient,\n private readonly storage: Storage,\n private readonly storageCache: StorageCache,\n private readonly logger: Logger\n ) {}\n\n /**\n * Returns true if the age of the cached fetched configs is less than or equal to\n * {@link Settings#minimumFetchIntervalInSeconds}.\n *\n *
This is comparable to passing `headers = { 'Cache-Control': max-age
Visible for testing.\n */\n isCachedDataFresh(\n cacheMaxAgeMillis: number,\n lastSuccessfulFetchTimestampMillis: number | undefined\n ): boolean {\n // Cache can only be fresh if it's populated.\n if (!lastSuccessfulFetchTimestampMillis) {\n this.logger.debug('Config fetch cache check. Cache unpopulated.');\n return false;\n }\n\n // Calculates age of cache entry.\n const cacheAgeMillis = Date.now() - lastSuccessfulFetchTimestampMillis;\n\n const isCachedDataFresh = cacheAgeMillis <= cacheMaxAgeMillis;\n\n this.logger.debug(\n 'Config fetch cache check.' +\n ` Cache age millis: ${cacheAgeMillis}.` +\n ` Cache max age millis (minimumFetchIntervalMillis setting): ${cacheMaxAgeMillis}.` +\n ` Is cache hit: ${isCachedDataFresh}.`\n );\n\n return isCachedDataFresh;\n }\n\n async fetch(request: FetchRequest): Promise
Not exported because this file encapsulates REST API specifics.\n *\n *
Not passing User Properties because Analytics' source of truth on Web is server-side.\n */\ninterface FetchRequestBody {\n // Disables camelcase linting for request body params.\n /* eslint-disable camelcase*/\n sdk_version: string;\n app_instance_id: string;\n app_instance_id_token: string;\n app_id: string;\n language_code: string;\n custom_signals?: CustomSignals;\n /* eslint-enable camelcase */\n}\n\n/**\n * Implements the Client abstraction for the Remote Config REST API.\n */\nexport class RestClient implements RemoteConfigFetchClient {\n constructor(\n private readonly firebaseInstallations: _FirebaseInstallationsInternal,\n private readonly sdkVersion: string,\n private readonly namespace: string,\n private readonly projectId: string,\n private readonly apiKey: string,\n private readonly appId: string\n ) {}\n\n /**\n * Fetches from the Remote Config REST API.\n *\n * @throws a {@link ErrorCode.FETCH_NETWORK} error if {@link GlobalFetch#fetch} can't\n * connect to the network.\n * @throws a {@link ErrorCode.FETCH_PARSE} error if {@link Response#json} can't parse the\n * fetch response.\n * @throws a {@link ErrorCode.FETCH_STATUS} error if the service returns an HTTP error status.\n */\n async fetch(request: FetchRequest): Promise
Adapted from getUserLanguage in packages/auth/src/utils.js for TypeScript.\n *\n *
Defers default language specification to server logic for consistency.\n *\n * @param navigatorLanguage Enables tests to override read-only {@link NavigatorLanguage}.\n */\nexport function getUserLanguage(\n navigatorLanguage: NavigatorLanguage = navigator\n): string {\n return (\n // Most reliable, but only supported in Chrome/Firefox.\n (navigatorLanguage.languages && navigatorLanguage.languages[0]) ||\n // Supported in most browsers, but returns the language of the browser\n // UI, not the language set in browser settings.\n navigatorLanguage.language\n // Polyfill otherwise.\n );\n}\n","/**\n * @license\n * Copyright 2019 Google LLC\n *\n * Licensed under the Apache License, Version 2.0 (the \"License\");\n * you may not use this file except in compliance with the License.\n * You may obtain a copy of the License at\n *\n * http://www.apache.org/licenses/LICENSE-2.0\n *\n * Unless required by applicable law or agreed to in writing, software\n * distributed under the License is distributed on an \"AS IS\" BASIS,\n * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n * See the License for the specific language governing permissions and\n * limitations under the License.\n */\n\nimport { FetchResponse } from '../public_types';\nimport {\n RemoteConfigAbortSignal,\n RemoteConfigFetchClient,\n FetchRequest\n} from './remote_config_fetch_client';\nimport { ThrottleMetadata, Storage } from '../storage/storage';\nimport { ErrorCode, ERROR_FACTORY } from '../errors';\nimport { FirebaseError, calculateBackoffMillis } from '@firebase/util';\n\n/**\n * Supports waiting on a backoff by:\n *\n *
Visible for testing.\n */\nexport function setAbortableTimeout(\n signal: RemoteConfigAbortSignal,\n throttleEndTimeMillis: number\n): Promise
Comparable to CachingClient, but uses backoff logic instead of cache max age and doesn't cache\n * responses (because the SDK has no use for error responses).\n */\nexport class RetryingClient implements RemoteConfigFetchClient {\n constructor(\n private readonly client: RemoteConfigFetchClient,\n private readonly storage: Storage\n ) {}\n\n async fetch(request: FetchRequest): Promise
Visible for testing\n */\nexport const MAX_VALUE_MILLIS = 4 * 60 * 60 * 1000; // Four hours, like iOS and Android.\n\n/**\n * The percentage of backoff time to randomize by.\n * See\n * http://go/safe-client-behavior#step-1-determine-the-appropriate-retry-interval-to-handle-spike-traffic\n * for context.\n *\n *
Visible for testing\n */\nexport const RANDOM_FACTOR = 0.5;\n\n/**\n * Based on the backoff method from\n * https://github.com/google/closure-library/blob/master/closure/goog/math/exponentialbackoff.js.\n * Extracted here so we don't need to pass metadata and a stateful ExponentialBackoff object around.\n */\nexport function calculateBackoffMillis(\n backoffCount: number,\n intervalMillis: number = DEFAULT_INTERVAL_MILLIS,\n backoffFactor: number = DEFAULT_BACKOFF_FACTOR\n): number {\n // Calculates an exponentially increasing value.\n // Deviation: calculates value from count and a constant interval, so we only need to save value\n // and count to restore state.\n const currBaseValue = intervalMillis * Math.pow(backoffFactor, backoffCount);\n\n // A random \"fuzz\" to avoid waves of retries.\n // Deviation: randomFactor is required.\n const randomWait = Math.round(\n // A fraction of the backoff value to add/subtract.\n // Deviation: changes multiplication order to improve readability.\n RANDOM_FACTOR *\n currBaseValue *\n // A random float (rounded to int by Math.round above) in the range [-1, 1]. Determines\n // if we add or subtract.\n (Math.random() - 0.5) *\n 2\n );\n\n // Limits backoff to max to avoid effectively permanent backoff.\n return Math.min(MAX_VALUE_MILLIS, currBaseValue + randomWait);\n}\n","/**\n * @license\n * Copyright 2019 Google LLC\n *\n * Licensed under the Apache License, Version 2.0 (the \"License\");\n * you may not use this file except in compliance with the License.\n * You may obtain a copy of the License at\n *\n * http://www.apache.org/licenses/LICENSE-2.0\n *\n * Unless required by applicable law or agreed to in writing, software\n * distributed under the License is distributed on an \"AS IS\" BASIS,\n * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n * See the License for the specific language governing permissions and\n * limitations under the License.\n */\n\nimport { FirebaseApp } from '@firebase/app';\nimport {\n RemoteConfig as RemoteConfigType,\n FetchStatus,\n RemoteConfigSettings\n} from './public_types';\nimport { StorageCache } from './storage/storage_cache';\nimport { RemoteConfigFetchClient } from './client/remote_config_fetch_client';\nimport { Storage } from './storage/storage';\nimport { Logger } from '@firebase/logger';\n\nconst DEFAULT_FETCH_TIMEOUT_MILLIS = 60 * 1000; // One minute\nconst DEFAULT_CACHE_MAX_AGE_MILLIS = 12 * 60 * 60 * 1000; // Twelve hours.\n\n/**\n * Encapsulates business logic mapping network and storage dependencies to the public SDK API.\n *\n * See {@link https://github.com/firebase/firebase-js-sdk/blob/main/packages/firebase/compat/index.d.ts|interface documentation} for method descriptions.\n */\nexport class RemoteConfig implements RemoteConfigType {\n /**\n * Tracks completion of initialization promise.\n * @internal\n */\n _isInitializationComplete = false;\n\n /**\n * De-duplicates initialization calls.\n * @internal\n */\n _initializePromise?: Promise
The Remote Config SDK can be used with multiple app installations, and each app can interact\n * with multiple namespaces, so this store uses app (ID + name) and namespace as common parent keys\n * for a set of key-value pairs. See {@link Storage#createCompositeKey}.\n *\n *
Visible for testing.\n */\nexport const APP_NAMESPACE_STORE = 'app_namespace_store';\n\nconst DB_NAME = 'firebase_remote_config';\nconst DB_VERSION = 1;\n\n/**\n * Encapsulates metadata concerning throttled fetch requests.\n */\nexport interface ThrottleMetadata {\n // The number of times fetch has backed off. Used for resuming backoff after a timeout.\n backoffCount: number;\n // The Unix timestamp in milliseconds when callers can retry a request.\n throttleEndTimeMillis: number;\n}\n\n/**\n * Provides type-safety for the \"key\" field used by {@link APP_NAMESPACE_STORE}.\n *\n *
This seems like a small price to avoid potentially subtle bugs caused by a typo.\n */\ntype ProjectNamespaceKeyFieldValue =\n | 'active_config'\n | 'active_config_etag'\n | 'last_fetch_status'\n | 'last_successful_fetch_timestamp_millis'\n | 'last_successful_fetch_response'\n | 'settings'\n | 'throttle_metadata'\n | 'custom_signals';\n\n// Visible for testing.\nexport function openDatabase(): Promise