Bug 1654413 - Add JSONWriter struct for marker schema r=emilio,gerald

JSON writer will be used for the third and last marker API. This is needed
because we need to describe a marker payload struct on how to serialize it.

Differential Revision: https://phabricator.services.mozilla.com/D124024

tools/profiler/core/ProfilerBindings.cpp

@@ -111,6 +111,46 @@ void gecko_profiler_destruct_marker_timing(
 #endif
 }
 
+void gecko_profiler_json_writer_int_property(
+    mozilla::baseprofiler::SpliceableJSONWriter* aWriter, const char* aName,
+    size_t aNameLength, int64_t aValue) {
+#ifdef MOZ_GECKO_PROFILER
+  aWriter->IntProperty(mozilla::Span(aName, aNameLength), aValue);
+#endif
+}
+
+void gecko_profiler_json_writer_float_property(
+    mozilla::baseprofiler::SpliceableJSONWriter* aWriter, const char* aName,
+    size_t aNameLength, double aValue) {
+#ifdef MOZ_GECKO_PROFILER
+  aWriter->DoubleProperty(mozilla::Span(aName, aNameLength), aValue);
+#endif
+}
+
+void gecko_profiler_json_writer_bool_property(
+    mozilla::baseprofiler::SpliceableJSONWriter* aWriter, const char* aName,
+    size_t aNameLength, bool aValue) {
+#ifdef MOZ_GECKO_PROFILER
+  aWriter->BoolProperty(mozilla::Span(aName, aNameLength), aValue);
+#endif
+}
+void gecko_profiler_json_writer_string_property(
+    mozilla::baseprofiler::SpliceableJSONWriter* aWriter, const char* aName,
+    size_t aNameLength, const char* aValue, size_t aValueLength) {
+#ifdef MOZ_GECKO_PROFILER
+  aWriter->StringProperty(mozilla::Span(aName, aNameLength),
+                          mozilla::Span(aValue, aValueLength));
+#endif
+}
+
+void gecko_profiler_json_writer_null_property(
+    mozilla::baseprofiler::SpliceableJSONWriter* aWriter, const char* aName,
+    size_t aNameLength) {
+#ifdef MOZ_GECKO_PROFILER
+  aWriter->NullProperty(mozilla::Span(aName, aNameLength));
+#endif
+}
+
 void gecko_profiler_add_marker_untyped(
     const char* aName, size_t aNameLength,
     mozilla::baseprofiler::ProfilingCategoryPair aCategoryPair,

tools/profiler/public/ProfilerBindings.h

@@ -20,6 +20,7 @@ enum class StackCaptureOptions;
 
 namespace baseprofiler {
 enum class ProfilingCategoryPair : uint32_t;
+class SpliceableJSONWriter;
 }  // namespace baseprofiler
 
 }  // namespace mozilla
@@ -60,6 +61,23 @@ void gecko_profiler_construct_marker_timing_interval_end(
 void gecko_profiler_destruct_marker_timing(
     mozilla::MarkerTiming* aMarkerTiming);
 
+// Various SpliceableJSONWriter methods to add properties.
+void gecko_profiler_json_writer_int_property(
+    mozilla::baseprofiler::SpliceableJSONWriter* aWriter, const char* aName,
+    size_t aNameLength, int64_t aValue);
+void gecko_profiler_json_writer_float_property(
+    mozilla::baseprofiler::SpliceableJSONWriter* aWriter, const char* aName,
+    size_t aNameLength, double aValue);
+void gecko_profiler_json_writer_bool_property(
+    mozilla::baseprofiler::SpliceableJSONWriter* aWriter, const char* aName,
+    size_t aNameLength, bool aValue);
+void gecko_profiler_json_writer_string_property(
+    mozilla::baseprofiler::SpliceableJSONWriter* aWriter, const char* aName,
+    size_t aNameLength, const char* aValue, size_t aValueLength);
+void gecko_profiler_json_writer_null_property(
+    mozilla::baseprofiler::SpliceableJSONWriter* aWriter, const char* aName,
+    size_t aNameLength);
+
 // Marker APIs.
 void gecko_profiler_add_marker_untyped(
     const char* aName, size_t aNameLength,

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(),
+            );
+        }
+    }
+}

tools/profiler/rust-api/src/lib.rs

@@ -4,6 +4,7 @@
 
 ///! Profiler Rust API
 pub mod gecko_bindings;
+mod json_writer;
 mod label;
 mod marker;
 mod profiler_state;
@@ -11,6 +12,7 @@ mod thread;
 mod time;
 
 pub use gecko_bindings::profiling_categories::*;
+pub use json_writer::*;
 pub use label::*;
 pub use marker::options::*;
 pub use marker::schema::MarkerSchema;