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- /**
- * The `node:trace_events` module provides a mechanism to centralize tracing information
- * generated by V8, Node.js core, and userspace code.
- *
- * Tracing can be enabled with the `--trace-event-categories` command-line flag
- * or by using the `trace_events` module. The `--trace-event-categories` flag
- * accepts a list of comma-separated category names.
- *
- * The available categories are:
- *
- * * `node`: An empty placeholder.
- * * `node.async_hooks`: Enables capture of detailed [`async_hooks`](https://nodejs.org/docs/latest-v22.x/api/async_hooks.html) trace data.
- * The [`async_hooks`](https://nodejs.org/docs/latest-v22.x/api/async_hooks.html) events have a unique `asyncId` and a special `triggerId` `triggerAsyncId` property.
- * * `node.bootstrap`: Enables capture of Node.js bootstrap milestones.
- * * `node.console`: Enables capture of `console.time()` and `console.count()` output.
- * * `node.threadpoolwork.sync`: Enables capture of trace data for threadpool synchronous operations, such as `blob`, `zlib`, `crypto` and `node_api`.
- * * `node.threadpoolwork.async`: Enables capture of trace data for threadpool asynchronous operations, such as `blob`, `zlib`, `crypto` and `node_api`.
- * * `node.dns.native`: Enables capture of trace data for DNS queries.
- * * `node.net.native`: Enables capture of trace data for network.
- * * `node.environment`: Enables capture of Node.js Environment milestones.
- * * `node.fs.sync`: Enables capture of trace data for file system sync methods.
- * * `node.fs_dir.sync`: Enables capture of trace data for file system sync directory methods.
- * * `node.fs.async`: Enables capture of trace data for file system async methods.
- * * `node.fs_dir.async`: Enables capture of trace data for file system async directory methods.
- * * `node.perf`: Enables capture of [Performance API](https://nodejs.org/docs/latest-v22.x/api/perf_hooks.html) measurements.
- * * `node.perf.usertiming`: Enables capture of only Performance API User Timing
- * measures and marks.
- * * `node.perf.timerify`: Enables capture of only Performance API timerify
- * measurements.
- * * `node.promises.rejections`: Enables capture of trace data tracking the number
- * of unhandled Promise rejections and handled-after-rejections.
- * * `node.vm.script`: Enables capture of trace data for the `node:vm` module's `runInNewContext()`, `runInContext()`, and `runInThisContext()` methods.
- * * `v8`: The [V8](https://nodejs.org/docs/latest-v22.x/api/v8.html) events are GC, compiling, and execution related.
- * * `node.http`: Enables capture of trace data for http request / response.
- *
- * By default the `node`, `node.async_hooks`, and `v8` categories are enabled.
- *
- * ```bash
- * node --trace-event-categories v8,node,node.async_hooks server.js
- * ```
- *
- * Prior versions of Node.js required the use of the `--trace-events-enabled` flag to enable trace events. This requirement has been removed. However, the `--trace-events-enabled` flag _may_ still be
- * used and will enable the `node`, `node.async_hooks`, and `v8` trace event categories by default.
- *
- * ```bash
- * node --trace-events-enabled
- *
- * # is equivalent to
- *
- * node --trace-event-categories v8,node,node.async_hooks
- * ```
- *
- * Alternatively, trace events may be enabled using the `node:trace_events` module:
- *
- * ```js
- * import trace_events from 'node:trace_events';
- * const tracing = trace_events.createTracing({ categories: ['node.perf'] });
- * tracing.enable(); // Enable trace event capture for the 'node.perf' category
- *
- * // do work
- *
- * tracing.disable(); // Disable trace event capture for the 'node.perf' category
- * ```
- *
- * Running Node.js with tracing enabled will produce log files that can be opened
- * in the [`chrome://tracing`](https://www.chromium.org/developers/how-tos/trace-event-profiling-tool) tab of Chrome.
- *
- * The logging file is by default called `node_trace.${rotation}.log`, where `${rotation}` is an incrementing log-rotation id. The filepath pattern can
- * be specified with `--trace-event-file-pattern` that accepts a template
- * string that supports `${rotation}` and `${pid}`:
- *
- * ```bash
- * node --trace-event-categories v8 --trace-event-file-pattern '${pid}-${rotation}.log' server.js
- * ```
- *
- * To guarantee that the log file is properly generated after signal events like `SIGINT`, `SIGTERM`, or `SIGBREAK`, make sure to have the appropriate handlers
- * in your code, such as:
- *
- * ```js
- * process.on('SIGINT', function onSigint() {
- * console.info('Received SIGINT.');
- * process.exit(130); // Or applicable exit code depending on OS and signal
- * });
- * ```
- *
- * The tracing system uses the same time source
- * as the one used by `process.hrtime()`.
- * However the trace-event timestamps are expressed in microseconds,
- * unlike `process.hrtime()` which returns nanoseconds.
- *
- * The features from this module are not available in [`Worker`](https://nodejs.org/docs/latest-v22.x/api/worker_threads.html#class-worker) threads.
- * @experimental
- * @see [source](https://github.com/nodejs/node/blob/v22.x/lib/trace_events.js)
- */
- declare module "trace_events" {
- /**
- * The `Tracing` object is used to enable or disable tracing for sets of
- * categories. Instances are created using the
- * `trace_events.createTracing()` method.
- *
- * When created, the `Tracing` object is disabled. Calling the
- * `tracing.enable()` method adds the categories to the set of enabled trace
- * event categories. Calling `tracing.disable()` will remove the categories
- * from the set of enabled trace event categories.
- */
- interface Tracing {
- /**
- * A comma-separated list of the trace event categories covered by this
- * `Tracing` object.
- * @since v10.0.0
- */
- readonly categories: string;
- /**
- * Disables this `Tracing` object.
- *
- * Only trace event categories _not_ covered by other enabled `Tracing`
- * objects and _not_ specified by the `--trace-event-categories` flag
- * will be disabled.
- *
- * ```js
- * import trace_events from 'node:trace_events';
- * const t1 = trace_events.createTracing({ categories: ['node', 'v8'] });
- * const t2 = trace_events.createTracing({ categories: ['node.perf', 'node'] });
- * t1.enable();
- * t2.enable();
- *
- * // Prints 'node,node.perf,v8'
- * console.log(trace_events.getEnabledCategories());
- *
- * t2.disable(); // Will only disable emission of the 'node.perf' category
- *
- * // Prints 'node,v8'
- * console.log(trace_events.getEnabledCategories());
- * ```
- * @since v10.0.0
- */
- disable(): void;
- /**
- * Enables this `Tracing` object for the set of categories covered by
- * the `Tracing` object.
- * @since v10.0.0
- */
- enable(): void;
- /**
- * `true` only if the `Tracing` object has been enabled.
- * @since v10.0.0
- */
- readonly enabled: boolean;
- }
- interface CreateTracingOptions {
- /**
- * An array of trace category names. Values included in the array are
- * coerced to a string when possible. An error will be thrown if the
- * value cannot be coerced.
- */
- categories: string[];
- }
- /**
- * Creates and returns a `Tracing` object for the given set of `categories`.
- *
- * ```js
- * import trace_events from 'node:trace_events';
- * const categories = ['node.perf', 'node.async_hooks'];
- * const tracing = trace_events.createTracing({ categories });
- * tracing.enable();
- * // do stuff
- * tracing.disable();
- * ```
- * @since v10.0.0
- */
- function createTracing(options: CreateTracingOptions): Tracing;
- /**
- * Returns a comma-separated list of all currently-enabled trace event
- * categories. The current set of enabled trace event categories is determined
- * by the _union_ of all currently-enabled `Tracing` objects and any categories
- * enabled using the `--trace-event-categories` flag.
- *
- * Given the file `test.js` below, the command `node --trace-event-categories node.perf test.js` will print `'node.async_hooks,node.perf'` to the console.
- *
- * ```js
- * import trace_events from 'node:trace_events';
- * const t1 = trace_events.createTracing({ categories: ['node.async_hooks'] });
- * const t2 = trace_events.createTracing({ categories: ['node.perf'] });
- * const t3 = trace_events.createTracing({ categories: ['v8'] });
- *
- * t1.enable();
- * t2.enable();
- *
- * console.log(trace_events.getEnabledCategories());
- * ```
- * @since v10.0.0
- */
- function getEnabledCategories(): string | undefined;
- }
- declare module "node:trace_events" {
- export * from "trace_events";
- }
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