export type LogLevel = 'TRACE' | 'DEBUG' | 'INFO' | 'WARN' | 'ERROR';
export type LogMetadata = Record<string | symbol, any>;
/**
 * Implement this interface in order to customize worker logging
 */
export interface Logger {
    log(level: LogLevel, message: string, meta?: LogMetadata): any;
    trace(message: string, meta?: LogMetadata): any;
    debug(message: string, meta?: LogMetadata): any;
    info(message: string, meta?: LogMetadata): any;
    warn(message: string, meta?: LogMetadata): any;
    error(message: string, meta?: LogMetadata): any;
}
/**
 * Possible values of the `sdkComponent` meta attributes on log messages. This
 * attribute indicates which subsystem emitted the log message; this may for
 * example be used to implement fine-grained filtering of log messages.
 *
 * Note that there is no guarantee that this list will remain stable in the
 * future; values may be added or removed, and messages that are currently
 * emitted with some `sdkComponent` value may use a different value in the future.
 */
export declare enum SdkComponent {
    /**
     * Component name for messages emited from Workflow code, using the {@link Workflow context logger|workflow.log}.
     * The SDK itself never publishes messages with this component name.
     */
    workflow = "workflow",
    /**
     * Component name for messages emited from an activity, using the {@link activity context logger|Context.log}.
     * The SDK itself never publishes messages with this component name.
     */
    activity = "activity",
    /**
     * Component name for messages emited from a Nexus Operation Handler, using the Nexus context logger.
     * The SDK itself never publishes messages with this component name.
     */
    nexus = "nexus",
    /**
     * Component name for messages emited from a Temporal Worker instance.
     *
     * This notably includes:
     * - Issues with Worker or runtime configuration, or the JS execution environment;
     * - Worker's, Activity's, and Workflow's lifecycle events;
     * - Workflow Activation and Activity Task processing events;
     * - Workflow bundling messages;
     * - Sink processing issues.
     */
    worker = "worker",
    /**
     * Component name for all messages emitted by the Rust Core SDK library.
     */
    core = "core"
}
/**
 * @internal
 * @hidden
 */
export type LogMetaOrFunc = LogMetadata | (() => LogMetadata);
/**
 * A logger implementation that adds metadata before delegating calls to a parent logger.
 *
 * @internal
 * @hidden
 */
export declare class LoggerWithComposedMetadata implements Logger {
    private readonly parentLogger;
    private readonly contributors;
    /**
     * Return a {@link Logger} that adds metadata before delegating calls to a parent logger.
     *
     * New metadata may either be specified statically as a delta object, or as a function evaluated
     * every time a log is emitted that will return a delta object.
     *
     * Some optimizations are performed to avoid creating unnecessary objects and to keep runtime
     * overhead associated with resolving metadata as low as possible.
     */
    static compose(logger: Logger, metaOrFunc: LogMetaOrFunc): Logger;
    constructor(parentLogger: Logger, contributors: LogMetaOrFunc[]);
    log(level: LogLevel, message: string, extraMeta?: LogMetadata): void;
    trace(message: string, extraMeta?: LogMetadata): void;
    debug(message: string, extraMeta?: LogMetadata): void;
    info(message: string, extraMeta?: LogMetadata): void;
    warn(message: string, extraMeta?: LogMetadata): void;
    error(message: string, extraMeta?: LogMetadata): void;
}