pkg/_fe_analyzer_shared/lib/src/exhaustiveness/profile.dart

// Copyright (c) 2022, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'dart:math';

bool enabled = false;

final _counts = <String, int>{};

void count(String name, [String? subname]) {
  if (!enabled) return;
  _counts.putIfAbsent(name, () => 0);
  _counts[name] = _counts[name]! + 1;

  if (subname != null) {
    count('$name/$subname');
  }
}

void log() {
  List<String> names = _counts.keys.toList();
  names.sort();
  int nameLength = names.fold<int>(
    0,
    (length, name) => max(length, name.length),
  );
  int countLength = _counts.values.fold<int>(
    0,
    (length, count) => max(length, count.toString().length),
  );

  for (String name in names) {
    print(
      '${name.padRight(nameLength)} = '
      '${_counts[name].toString().padLeft(countLength)}',
    );
  }
}

void reset() {
  _counts.clear();
}

void run(void Function() callback) {
  reset();
  try {
    callback();
  } finally {
    log();
    reset();
  }
}