1 files changed, 70 insertions, 0 deletions
diff --git a/toolkit/components/glean/bindings/private/Counter.h b/toolkit/components/glean/bindings/private/Counter.h
new file mode 100644
index 0000000000..e1e7190e4e
--- /dev/null
+++ b/toolkit/components/glean/bindings/private/Counter.h
@@ -0,0 +1,70 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_glean_GleanCounter_h
+#define mozilla_glean_GleanCounter_h
+
+#include "mozilla/Maybe.h"
+#include "mozilla/Result.h"
+#include "nsIGleanMetrics.h"
+#include "nsString.h"
+
+namespace mozilla::glean {
+
+namespace impl {
+
+class CounterMetric {
+ public:
+  constexpr explicit CounterMetric(uint32_t aId) : mId(aId) {}
+
+  /*
+   * Increases the counter by `amount`.
+   *
+   * @param aAmount The amount to increase by. Should be positive.
+   */
+  void Add(int32_t aAmount = 1) const;
+
+  /**
+   * **Test-only API**
+   *
+   * Gets the currently stored value as an integer.
+   *
+   * This function will attempt to await the last parent-process task (if any)
+   * writing to the the metric's storage engine before returning a value.
+   * This function will not wait for data from child processes.
+   *
+   * This doesn't clear the stored value.
+   * Parent process only. Panics in child processes.
+   *
+   * @param aPingName The (optional) name of the ping to retrieve the metric
+   *        for. Defaults to the first value in `send_in_pings`.
+   *
+   * @return value of the stored metric, or Nothing() if there is no value.
+   */
+  Result<Maybe<int32_t>, nsCString> TestGetValue(
+      const nsACString& aPingName = nsCString()) const;
+
+ private:
+  const uint32_t mId;
+};
+}  // namespace impl
+
+class GleanCounter final : public nsIGleanCounter {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIGLEANCOUNTER
+
+  explicit GleanCounter(uint32_t id) : mCounter(id){};
+
+ private:
+  virtual ~GleanCounter() = default;
+
+  const impl::CounterMetric mCounter;
+};
+
+}  // namespace mozilla::glean
+
+#endif /* mozilla_glean_GleanCounter_h */