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// 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
use inherent::inherent;
use super::{CommonMetricData, MetricId};
use glean::traits::StringList;
use crate::ipc::{need_ipc, with_ipc_payload};
/// A string list metric.
///
/// This allows appending a string value with arbitrary content to a list.
#[derive(Clone)]
pub enum StringListMetric {
Parent {
/// The metric's ID.
///
/// **TEST-ONLY** - Do not use unless gated with `#[cfg(test)]`.
id: MetricId,
inner: glean::private::StringListMetric,
},
Child(StringListMetricIpc),
}
#[derive(Clone, Debug)]
pub struct StringListMetricIpc(MetricId);
impl StringListMetric {
/// Create a new string list metric.
pub fn new(id: MetricId, meta: CommonMetricData) -> Self {
if need_ipc() {
StringListMetric::Child(StringListMetricIpc(id))
} else {
let inner = glean::private::StringListMetric::new(meta);
StringListMetric::Parent { id, inner }
}
}
#[cfg(test)]
pub(crate) fn child_metric(&self) -> Self {
match self {
StringListMetric::Parent { id, .. } => {
StringListMetric::Child(StringListMetricIpc(*id))
}
StringListMetric::Child(_) => panic!("Can't get a child metric from a child metric"),
}
}
}
#[inherent]
impl StringList for StringListMetric {
/// Add a new string to the list.
///
/// ## Arguments
///
/// * `value` - The string to add.
///
/// ## Notes
///
/// Truncates the value if it is longer than `MAX_STRING_LENGTH` bytes and logs an error.
/// See [String list metric limits](https://mozilla.github.io/glean/book/user/metrics/string_list.html#limits).
pub fn add<S: Into<String>>(&self, value: S) {
match self {
StringListMetric::Parent { inner, .. } => {
inner.add(value.into());
}
StringListMetric::Child(c) => {
with_ipc_payload(move |payload| {
if let Some(v) = payload.string_lists.get_mut(&c.0) {
v.push(value.into());
} else {
let v = vec![value.into()];
payload.string_lists.insert(c.0, v);
}
});
}
}
}
/// Set to a specific list of strings.
///
/// ## Arguments
///
/// * `value` - The list of string to set the metric to.
///
/// ## Notes
///
/// If passed an empty list, records an error and returns.
/// Truncates the list if it is longer than `MAX_LIST_LENGTH` and logs an error.
/// Truncates any value in the list if it is longer than `MAX_STRING_LENGTH` and logs an error.
pub fn set(&self, value: Vec<String>) {
match self {
StringListMetric::Parent { inner, .. } => {
inner.set(value);
}
StringListMetric::Child(c) => {
log::error!(
"Unable to set string list metric {:?} in non-main process. This operation will be ignored.",
c.0
);
// If we're in automation we can panic so the instrumentor knows they've gone wrong.
// This is a deliberate violation of Glean's "metric APIs must not throw" design.assert!(!crate::ipc::is_in_automation());
assert!(!crate::ipc::is_in_automation(), "Attempted to set string list metric in non-main process, which is forbidden. This panics in automation.");
// TODO: Record an error.
}
}
}
/// **Test-only API.**
///
/// Get the currently stored values.
/// This doesn't clear the stored value.
///
/// ## Arguments
///
/// * `storage_name` - the storage name to look into.
///
/// ## Return value
///
/// Returns the stored value or `None` if nothing stored.
pub fn test_get_value<'a, S: Into<Option<&'a str>>>(
&self,
ping_name: S,
) -> Option<Vec<String>> {
let ping_name = ping_name.into().map(|s| s.to_string());
match self {
StringListMetric::Parent { inner, .. } => inner.test_get_value(ping_name),
StringListMetric::Child(c) => {
panic!("Cannot get test value for {:?} in non-parent process!", c.0)
}
}
}
/// **Exported for test purposes.**
///
/// Gets the number of recorded errors for the given error type.
///
/// # Arguments
///
/// * `error` - The type of error
/// * `ping_name` - represents the optional name of the ping to retrieve the
/// metric for. Defaults to the first value in `send_in_pings`.
///
/// # Returns
///
/// The number of errors recorded.
pub fn test_get_num_recorded_errors(&self, error: glean::ErrorType) -> i32 {
match self {
StringListMetric::Parent { inner, .. } => inner.test_get_num_recorded_errors(error),
StringListMetric::Child(c) => panic!(
"Cannot get the number of recorded errors for {:?} in non-parent process!",
c.0
),
}
}
}
#[cfg(test)]
mod test {
use crate::{common_test::*, ipc, metrics};
#[test]
fn sets_string_list_value() {
let _lock = lock_test();
let metric = &metrics::test_only_ipc::a_string_list;
metric.set(vec!["test_string_value".to_string()]);
metric.add("another test value");
assert_eq!(
vec!["test_string_value", "another test value"],
metric.test_get_value("store1").unwrap()
);
}
#[test]
fn string_list_ipc() {
// StringListMetric supports IPC only for `add`, not `set`.
let _lock = lock_test();
let parent_metric = &metrics::test_only_ipc::a_string_list;
parent_metric.set(vec!["test_string_value".to_string()]);
parent_metric.add("another test value");
{
let child_metric = parent_metric.child_metric();
// scope for need_ipc RAII
let _raii = ipc::test_set_need_ipc(true);
// Recording APIs do not panic, even when they don't work.
child_metric.set(vec!["not gonna be set".to_string()]);
child_metric.add("child_value");
assert!(ipc::take_buf().unwrap().len() > 0);
}
// Then perform the replay and assert we have the values from both "processes".
assert!(ipc::replay_from_buf(&ipc::take_buf().unwrap()).is_ok());
assert_eq!(
vec!["test_string_value", "another test value"],
parent_metric.test_get_value("store1").unwrap()
);
}
}