import { type PerformanceObserverOptions } from '../performance-observer.js';
import type { ActionTrackEntryPayload } from '../user-timing-extensibility-api.type.js';
import { type WalRecord } from '../wal.js';
import { Profiler, type ProfilerOptions } from './profiler.js';
/**
 * Options for configuring a NodejsProfiler instance.
 *
 * Extends ProfilerOptions with a required sink parameter.
 *
 * @template Tracks - Record type defining available track names and their configurations
 */
export type NodejsProfilerOptions<DomainEvents extends string | object, Tracks extends Record<string, ActionTrackEntryPayload>> = ProfilerOptions<Tracks> & Omit<PerformanceObserverOptions<DomainEvents>, 'sink'> & {
    /**
     * File path for the WriteAheadLogFile sink.
     * If not provided, defaults to `trace.json` in the current working directory.
     *
     * @default path.join(process.cwd(), 'trace.json')
     */
    filename?: string;
    /**
     * Name of the environment variable to check for debug mode.
     * When the env var is set to 'true', profiler state transitions create performance marks for debugging.
     *
     * @default 'CP_PROFILER_DEBUG'
     */
    debugEnvVar?: string;
};
/**
 * Performance profiler with automatic process exit handling for buffered performance data.
 *
 * This class extends the base {@link Profiler} with automatic flushing of performance data
 * when the process exits. It automatically creates a {@link WriteAheadLogFile} sink that buffers
 * performance entries and ensures they are written out during process termination, even for unexpected exits.
 *
 * The sink uses a default codec for serializing performance data to JSON format,
 * enabling compatibility with Chrome DevTools trace file format.
 *
 * The profiler automatically subscribes to the performance observer when enabled and installs
 * exit handlers that flush buffered data on process termination (signals, fatal errors, or normal exit).
 *
 * @template DomainEvents - The type of domain-specific events encoded by the performance observer sink
 * @template Tracks - Record type defining available track names and their configurations
 */
export declare class NodejsProfiler<DomainEvents extends WalRecord, Tracks extends Record<string, ActionTrackEntryPayload> = Record<string, ActionTrackEntryPayload>> extends Profiler<Tracks> {
    #private;
    /**
     * Creates a NodejsProfiler instance.
     * A WriteAheadLogFile sink is automatically created for buffering performance data.
     * @param options - Configuration options
     */
    constructor(options: NodejsProfilerOptions<DomainEvents, Tracks>);
    /**
     * Returns whether debug mode is enabled for profiler state transitions.
     *
     * Debug mode is initially determined by the environment variable specified by `debugEnvVar`
     * (defaults to 'CP_PROFILER_DEBUG') during construction, but can be changed at runtime
     * using {@link setDebugMode}. When enabled, profiler state transitions create
     * performance marks for debugging.
     *
     * @returns true if debug mode is enabled, false otherwise
     */
    get debug(): boolean;
    /**
     * Sets debug mode for profiler state transitions.
     *
     * When debug mode is enabled, profiler state transitions create performance marks
     * for debugging. This allows runtime control of debug mode without needing to
     * restart the application or change environment variables.
     *
     * @param enabled - Whether to enable debug mode
     */
    setDebugMode(enabled: boolean): void;
    /**
     * Closes profiler and releases resources. Idempotent, safe for exit handlers.
     * **Exit Handler Usage**: Call only this method from process exit handlers.
     */
    close(): void;
    /** @returns Current profiler state */
    get state(): 'idle' | 'running' | 'closed';
    /** @returns Whether profiler is in 'running' state */
    isEnabled(): boolean;
    /** Enables profiling (start/stop) */
    setEnabled(enabled: boolean): void;
    /** @returns Queue statistics and profiling state for monitoring */
    get stats(): {
        debug: boolean;
        state: "idle" | "running" | "closed";
        walOpen: boolean;
        isSubscribed: boolean;
        queued: number;
        dropped: number;
        written: number;
        maxQueueSize: number;
        flushThreshold: number;
        addedSinceLastFlush: number;
        buffered: boolean;
    };
    /** Flushes buffered performance data to sink. */
    flush(): void;
    /** @returns The file path of the WriteAheadLogFile sink */
    get filePath(): string;
}