1 files changed, 124 insertions, 0 deletions
diff --git a/toolkit/components/glean/api/src/private/url.rs b/toolkit/components/glean/api/src/private/url.rs
new file mode 100644
index 0000000000..1ad49c3a7d
--- /dev/null
+++ b/toolkit/components/glean/api/src/private/url.rs
@@ -0,0 +1,124 @@
+// 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 https://mozilla.org/MPL/2.0/.
+
+use inherent::inherent;
+
+use super::{CommonMetricData, MetricId};
+
+use crate::ipc::need_ipc;
+
+/// Developer-facing API for recording URL metrics.
+///
+/// Instances of this class type are automatically generated by the parsers
+/// at build time, allowing developers to record values that were previously
+/// registered in the metrics.yaml file.
+#[derive(Clone)]
+pub enum UrlMetric {
+    Parent(glean::private::UrlMetric),
+    Child(UrlMetricIpc),
+}
+#[derive(Clone, Debug)]
+pub struct UrlMetricIpc;
+
+impl UrlMetric {
+    /// Create a new Url metric.
+    pub fn new(_id: MetricId, meta: CommonMetricData) -> Self {
+        if need_ipc() {
+            UrlMetric::Child(UrlMetricIpc)
+        } else {
+            UrlMetric::Parent(glean::private::UrlMetric::new(meta))
+        }
+    }
+
+    #[cfg(test)]
+    pub(crate) fn child_metric(&self) -> Self {
+        match self {
+            UrlMetric::Parent(_) => UrlMetric::Child(UrlMetricIpc),
+            UrlMetric::Child(_) => panic!("Can't get a child metric from a child metric"),
+        }
+    }
+}
+
+#[inherent]
+impl glean::traits::Url for UrlMetric {
+    pub fn set<S: Into<std::string::String>>(&self, value: S) {
+        match self {
+            UrlMetric::Parent(p) => p.set(value),
+            UrlMetric::Child(_) => {
+                log::error!("Unable to set Url metric in non-main process. Ignoring.");
+                // TODO: Record an error.
+            }
+        };
+    }
+
+    pub fn test_get_value<'a, S: Into<Option<&'a str>>>(
+        &self,
+        ping_name: S,
+    ) -> Option<std::string::String> {
+        let ping_name = ping_name.into().map(|s| s.to_string());
+        match self {
+            UrlMetric::Parent(p) => p.test_get_value(ping_name),
+            UrlMetric::Child(_) => {
+                panic!("Cannot get test value for Url metric in non-parent process!")
+            }
+        }
+    }
+
+    pub fn test_get_num_recorded_errors(&self, error: glean::ErrorType) -> i32 {
+        match self {
+            UrlMetric::Parent(p) => p.test_get_num_recorded_errors(error),
+            UrlMetric::Child(_) => panic!(
+                "Cannot get the number of recorded errors for Url metric in non-parent process!"
+            ),
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use crate::{common_test::*, ipc, metrics};
+
+    #[test]
+    fn sets_url_value() {
+        let _lock = lock_test();
+
+        let metric = &metrics::test_only_ipc::a_url;
+
+        metric.set("https://example.com");
+
+        assert_eq!(
+            "https://example.com",
+            metric.test_get_value("store1").unwrap()
+        );
+    }
+
+    #[test]
+    fn url_ipc() {
+        // UrlMetric doesn't support IPC.
+        let _lock = lock_test();
+
+        let parent_metric = &metrics::test_only_ipc::a_url;
+
+        parent_metric.set("https://example.com/parent");
+
+        {
+            let child_metric = parent_metric.child_metric();
+
+            let _raii = ipc::test_set_need_ipc(true);
+
+            // Instrumentation calls do not panic.
+            child_metric.set("https://example.com/child");
+
+            // (They also shouldn't do anything,
+            // but that's not something we can inspect in this test)
+        }
+
+        assert!(ipc::replay_from_buf(&ipc::take_buf().unwrap()).is_ok());
+
+        assert!(
+            "https://example.com/parent" == parent_metric.test_get_value("store1").unwrap(),
+            "Url metrics should only work in the parent process"
+        );
+    }
+}