File I/O

File I/O operations are fundamental for reading from and writing to files within an application. The sentry_file integration provides File support for Sentry thus providing insight into performance monitoring of file operations.

Behavior

  • The created spans will be attached to the transaction on the scope - if no transaction is on the scope the File I/O span will not be sent to Sentry.
  • The File I/O integration is only available for the dart:io:File class, not for the dart:html:File class.
  • The SDK sets the span operation to file.copy, file.write, file.delete, file.open, file.read or file.rename, and description to filename (for example, file.txt).
  • The span finishes once the operation has been executed. The span status is then set to SpanStatus.ok if successful, or SpanStatus.internalError if there was an error.
  • When the operation throws an Exception, Sentry's SDK associates it with the running span.

Prerequisites

  1. The Sentry Dart SDK is initialized.
  2. Performance Monitoring is set up. Learn more here.

Install

To use the SentryFile wrapper, add the sentry_file dependency.

pubspec.yaml
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dependencies:
  sentry: ^7.16.1
  sentry_file: ^7.16.1

Configure

Call the Sentry extension method to wrap the file:

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final sentryFile = file.sentryTrace();

Verify

1. Execute the Code

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import 'package:sentry/sentry.dart';
import 'package:sentry_file/sentry_file.dart';
import 'dart:io';

Future<void> main() async {
  await Sentry.init(
    (options) {
      options.dsn = 'https://example@sentry.io/example';
      // To set a uniform sample rate
      options.tracesSampleRate = 1.0;
    },
    appRunner: runApp, // Init your App.
  );
}

Future<void> runApp() async {
  final file = File('my_file.txt');
  // Call the Sentry extension method to wrap up the File
  final sentryFile = file.sentryTrace();

  // Start a transaction if there's no active transaction
  final transaction = Sentry.startTransaction(
    'MyFileExample',
    'file',
    bindToScope: true,
  );

  // create the File
  await sentryFile.create();
  // Write some content
  await sentryFile.writeAsString('Hello World');
  // Read the content
  final text = await sentryFile.readAsString();

  print(text);

  // Delete the file
  await sentryFile.delete();

  // Finish the transaction
  await transaction.finish(status: SpanStatus.ok());

  await Sentry.close();
}

2. View the Recorded Transaction on Sentry.io

To view the recorded transaction, log into sentry.io and open your project. Clicking Performance will open a page with transactions, where you can select the just recorded transaction with the name MyFileExample.

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