1 files changed, 86 insertions, 0 deletions
diff --git a/tools/profiler/rust-api/src/json_writer.rs b/tools/profiler/rust-api/src/json_writer.rs
new file mode 100644
index 0000000000..8ab6f2ed99
--- /dev/null
+++ b/tools/profiler/rust-api/src/json_writer.rs
@@ -0,0 +1,86 @@
+/* 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/. */
+
+//! Gecko JSON writer support for marker API.
+
+use crate::gecko_bindings::{bindings, structs::mozilla};
+use std::os::raw::c_char;
+
+/// Wrapper for the C++ SpliceableJSONWriter object. It exposes some methods to
+/// add various properties to the JSON.
+#[derive(Debug)]
+pub struct JSONWriter<'a>(&'a mut mozilla::baseprofiler::SpliceableJSONWriter);
+
+impl<'a> JSONWriter<'a> {
+    /// Constructor for the JSONWriter object. It takes a C++ SpliceableJSONWriter
+    /// reference as its argument and stores it for later accesses.
+    pub(crate) fn new(json_writer: &'a mut mozilla::baseprofiler::SpliceableJSONWriter) -> Self {
+        JSONWriter(json_writer)
+    }
+
+    /// Adds an int property to the JSON.
+    /// Prints: "<name>": <value>
+    pub fn int_property(&mut self, name: &str, value: i64) {
+        unsafe {
+            bindings::gecko_profiler_json_writer_int_property(
+                self.0,
+                name.as_ptr() as *const c_char,
+                name.len(),
+                value,
+            );
+        }
+    }
+
+    /// Adds a float property to the JSON.
+    /// Prints: "<name>": <value>
+    pub fn float_property(&mut self, name: &str, value: f64) {
+        unsafe {
+            bindings::gecko_profiler_json_writer_float_property(
+                self.0,
+                name.as_ptr() as *const c_char,
+                name.len(),
+                value,
+            );
+        }
+    }
+
+    /// Adds an bool property to the JSON.
+    /// Prints: "<name>": <value>
+    pub fn bool_property(&mut self, name: &str, value: bool) {
+        unsafe {
+            bindings::gecko_profiler_json_writer_bool_property(
+                self.0,
+                name.as_ptr() as *const c_char,
+                name.len(),
+                value,
+            );
+        }
+    }
+
+    /// Adds a string property to the JSON.
+    /// Prints: "<name>": "<value>"
+    pub fn string_property(&mut self, name: &str, value: &str) {
+        unsafe {
+            bindings::gecko_profiler_json_writer_string_property(
+                self.0,
+                name.as_ptr() as *const c_char,
+                name.len(),
+                value.as_ptr() as *const c_char,
+                value.len(),
+            );
+        }
+    }
+
+    /// Adds a null property to the JSON.
+    /// Prints: "<name>": null
+    pub fn null_property(&mut self, name: &str) {
+        unsafe {
+            bindings::gecko_profiler_json_writer_null_property(
+                self.0,
+                name.as_ptr() as *const c_char,
+                name.len(),
+            );
+        }
+    }
+}