CronetEngine

const val ACTIVE_REQUEST_COUNT_UNKNOWN = -1: Int

The value of the active request count is unknown

const val CONNECTION_METRIC_UNKNOWN = -1: Int

The value of a connection metric is unknown.

const val EFFECTIVE_CONNECTION_TYPE_2G = 3: Int

The estimate of the effective connection type is 2G.

const val EFFECTIVE_CONNECTION_TYPE_3G = 4: Int

The estimate of the effective connection type is 3G.

const val EFFECTIVE_CONNECTION_TYPE_4G = 5: Int

The estimate of the effective connection type is 4G.

const val EFFECTIVE_CONNECTION_TYPE_OFFLINE = 1: Int

The device is offline.

const val EFFECTIVE_CONNECTION_TYPE_SLOW_2G = 2: Int

The estimate of the effective connection type is slow 2G.

const val EFFECTIVE_CONNECTION_TYPE_UNKNOWN = 0: Int

The estimate of the effective connection type is unknown.

const val UNBIND_NETWORK_HANDLE = -1: Long

The value to be used to undo any previous network binding.

fun addRequestFinishedListener(listener: RequestFinishedInfo.Listener!): Unit

Registers a listener that gets called after the end of each request with the request info.

The listener is called on an java.util.concurrent.Executor provided by the listener.

fun addRttListener(listener: NetworkQualityRttListener!): Unit

Registers a listener that gets called whenever the network quality estimator witnesses a sample round trip time. This must be called after enableNetworkQualityEstimator, and with throw an exception otherwise. Round trip times may be recorded at various layers of the network stack, including TCP, QUIC, and at the URL request layer. The listener is called on the java.util.concurrent.Executor that is passed to enableNetworkQualityEstimator.

fun addThroughputListener(listener: NetworkQualityThroughputListener!): Unit

Registers a listener that gets called whenever the network quality estimator witnesses a sample throughput measurement. This must be called after enableNetworkQualityEstimator. Throughput observations are computed by measuring bytes read over the active network interface at times when at least one URL response is being received. The listener is called on the java.util.concurrent.Executor that is passed to enableNetworkQualityEstimator.

fun bindToNetwork(networkHandle: Long): Unit

Binds the engine to the specified network handle. All requests created through this engine will use the network associated to this handle. If this network disconnects all requests will fail, the exact error will depend on the stage of request processing when the network disconnects. Network handles can be obtained through Network#getNetworkHandle. Only available starting from Android Marshmallow.

fun configureNetworkQualityEstimatorForTesting(
    useLocalHostRequests: Boolean,
    useSmallerResponses: Boolean,
    disableOfflineCheck: Boolean
): Unit

Configures the network quality estimator for testing. This must be called before round trip time and throughput listeners are added, and after the network quality estimator has been enabled.

abstract fun createURLStreamHandlerFactory(): URLStreamHandlerFactory!

Creates a URLStreamHandlerFactory to handle HTTP and HTTPS traffic. An instance of this class can be installed via setURLStreamHandlerFactory thus using this CronetEngine by default for all requests created via openConnection.

Cronet does not use certain HTTP features provided via the system:

• the HTTP cache installed via HttpResponseCache.install()
• the HTTP authentication method installed via setDefault
• the HTTP cookie storage installed via setDefault

While Cronet supports and encourages requests using the HTTPS protocol, Cronet does not provide support for the HttpsURLConnection API. This lack of support also includes not using certain HTTPS features provided via the system:

• the HTTPS hostname verifier installed via HttpsURLConnection.setDefaultHostnameVerifier()
• the HTTPS socket factory installed via HttpsURLConnection.setDefaultSSLSocketFactory()

fun getActiveRequestCount(): Int

Returns the number of active requests.

A request becomes "active" in UrlRequest.start(), assuming that method does not throw an exception. It becomes inactive when all callbacks have returned and no additional callbacks can be triggered in the future. In practice, that means the request is inactive once onSucceeded/onCanceled/onFailed has returned and all request finished listeners have returned. Cronet requests's lifecycle for more information.

fun getDownstreamThroughputKbps(): Int

Returns the downstream throughput estimate (in kilobits per second) computed by the network quality estimator. Set to CONNECTION_METRIC_UNKNOWN if the value is unavailable. This must be called after enableNetworkQualityEstimator, and will throw an exception otherwise.

fun getEffectiveConnectionType(): Int

Returns an estimate of the effective connection type computed by the network quality estimator. Call enableNetworkQualityEstimator to begin computing this value.

fun getHttpRttMs(): Int

Returns the HTTP RTT estimate (in milliseconds) computed by the network quality estimator. Set to CONNECTION_METRIC_UNKNOWN if the value is unavailable. This must be called after enableNetworkQualityEstimator, and will throw an exception otherwise.

fun getTransportRttMs(): Int

Returns the transport RTT estimate (in milliseconds) computed by the network quality estimator. Set to CONNECTION_METRIC_UNKNOWN if the value is unavailable. This must be called after enableNetworkQualityEstimator, and will throw an exception otherwise.

abstract fun newUrlRequestBuilder(
    url: String!,
    callback: UrlRequest.Callback!,
    executor: Executor!
): UrlRequest.Builder!

Creates a builder for UrlRequest. All callbacks for generated UrlRequest objects will be invoked on executor's threads. executor must not run tasks on the thread calling execute to prevent blocking networking operations and causing exceptions during shutdown.

abstract fun openConnection(url: URL!): URLConnection!

Establishes a new connection to the resource specified by the URLurl.

Note: Cronet's java.net.HttpURLConnection implementation is subject to certain limitations, see createURLStreamHandlerFactory for details.

fun removeRequestFinishedListener(listener: RequestFinishedInfo.Listener!): Unit

Removes a finished request listener.

fun removeRttListener(listener: NetworkQualityRttListener!): Unit

Removes a listener of round trip times if previously registered with addRttListener. This should be called after a NetworkQualityRttListener is added in order to stop receiving observations.

fun removeThroughputListener(listener: NetworkQualityThroughputListener!): Unit

Removes a listener of throughput. This should be called after a NetworkQualityThroughputListener is added with addThroughputListener in order to stop receiving observations.

abstract fun shutdown(): Unit

Shuts down the CronetEngine if there are no active requests, otherwise throws an exception.

Cannot be called on network thread - the thread Cronet calls into Executor on (which is different from the thread the Executor invokes callbacks on). May block until all the CronetEngine's resources have been cleaned up.

fun startNetLogToDisk(dirPath: String!, logAll: Boolean, maxSize: Int): Unit

Starts NetLog logging to a specified directory with a bounded size. The NetLog will contain events emitted by all live CronetEngines. The NetLog is useful for debugging. Once logging has stopped stopNetLog, the data will be written to netlog.json in dirPath. If logging is interrupted, you can stitch the files found in .inprogress subdirectory manually using: https://chromium.googlesource.com/chromium/src/+/main/net/tools/stitch_net_log_files.py. The log can be viewed using a Chrome browser navigated to chrome://net-internals/#import.

abstract fun startNetLogToFile(fileName: String!, logAll: Boolean): Unit

Starts NetLog logging to a file. The NetLog will contain events emitted by all live CronetEngines. The NetLog is useful for debugging. The file can be viewed using a Chrome browser navigated to chrome://net-internals/#import

abstract fun stopNetLog(): Unit

Stops NetLog logging and flushes file to disk. If a logging session is not in progress, this call is ignored.