1 files changed, 71 insertions, 0 deletions
diff --git a/third_party/rust/error-support/src/reporting.rs b/third_party/rust/error-support/src/reporting.rs
new file mode 100644
index 0000000000..cf0f1ebd0b
--- /dev/null
+++ b/third_party/rust/error-support/src/reporting.rs
@@ -0,0 +1,71 @@
+/* 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/. */
+
+use parking_lot::RwLock;
+use std::sync::atomic::{AtomicU32, Ordering};
+
+/// Counter for breadcrumb messages
+///
+/// We are currently seeing breadcrumbs that may indicate that the reporting is unreliable.  In
+/// some reports, the breadcrumbs seem like they may be duplicated and/or out of order.  This
+/// counter is a temporary measure to check out that theory.
+static BREADCRUMB_COUNTER: AtomicU32 = AtomicU32::new(0);
+
+fn get_breadcrumb_counter_value() -> u32 {
+    // Notes:
+    //   - fetch_add is specified to wrap around in case of overflow, which seems okay.
+    //   - By itself, this does not guarentee that breadcrumb logs will be ordered the same way as
+    //     the counter values.  If two threads are running at the same time, it's very possible
+    //     that thread A gets the lower breadcrumb value, but thread B wins the race to report its
+    //     breadcrumb. However, if we expect operations to be synchronized, like with places DB,
+    //     then the breadcrumb counter values should always increase by 1.
+    BREADCRUMB_COUNTER.fetch_add(1, Ordering::Relaxed)
+}
+
+/// Application error reporting trait
+///
+/// The application that's consuming application-services implements this via a UniFFI callback
+/// interface, then calls `set_application_error_reporter()` to setup a global
+/// ApplicationErrorReporter.
+pub trait ApplicationErrorReporter: Sync + Send {
+    /// Send an error report to a Sentry-like error reporting system
+    ///
+    /// type_name should be used to group errors together
+    fn report_error(&self, type_name: String, message: String);
+    /// Send a breadcrumb to a Sentry-like error reporting system
+    fn report_breadcrumb(&self, message: String, module: String, line: u32, column: u32);
+}
+
+// ApplicationErrorReporter to use if the app doesn't set one
+struct DefaultApplicationErrorReporter;
+impl ApplicationErrorReporter for DefaultApplicationErrorReporter {
+    fn report_error(&self, _type_name: String, _message: String) {}
+    fn report_breadcrumb(&self, _message: String, _module: String, _line: u32, _column: u32) {}
+}
+
+lazy_static::lazy_static! {
+    // RwLock rather than a Mutex, since we only expect to set this once.
+    pub(crate) static ref APPLICATION_ERROR_REPORTER: RwLock<Box<dyn ApplicationErrorReporter>> = RwLock::new(Box::new(DefaultApplicationErrorReporter));
+}
+
+pub fn set_application_error_reporter(reporter: Box<dyn ApplicationErrorReporter>) {
+    *APPLICATION_ERROR_REPORTER.write() = reporter;
+}
+
+pub fn unset_application_error_reporter() {
+    *APPLICATION_ERROR_REPORTER.write() = Box::new(DefaultApplicationErrorReporter)
+}
+
+pub fn report_error_to_app(type_name: String, message: String) {
+    APPLICATION_ERROR_REPORTER
+        .read()
+        .report_error(type_name, message);
+}
+
+pub fn report_breadcrumb(message: String, module: String, line: u32, column: u32) {
+    let message = format!("{} ({})", message, get_breadcrumb_counter_value());
+    APPLICATION_ERROR_REPORTER
+        .read()
+        .report_breadcrumb(message, module, line, column);
+}