[build] add benchmark target

benchmark/parse/filter.cpp

@@ -0,0 +1,65 @@
+#include <benchmark/benchmark.h>
+
+#include <mbgl/style/filter.hpp>
+#include <mbgl/style/filter_evaluator.hpp>
+#include <mbgl/style/parser.hpp>
+#include <mbgl/tile/geometry_tile.hpp>
+
+#include <rapidjson/document.h>
+
+#include <map>
+
+using namespace mbgl;
+
+typedef std::multimap<std::string, Value> Properties;
+
+class StubFeature : public GeometryTileFeature {
+public:
+    inline StubFeature(const Properties& properties_, FeatureType type_)
+        : properties(properties_), type(type_) {
+    }
+
+    optional<Value> getValue(const std::string& key) const override {
+        auto it = properties.find(key);
+        if (it == properties.end())
+            return optional<Value>();
+        return it->second;
+    }
+
+    FeatureType getType() const override {
+        return type;
+    }
+
+    GeometryCollection getGeometries() const override {
+        return GeometryCollection();
+    }
+
+private:
+    const Properties properties;
+    FeatureType type;
+};
+
+style::Filter parse(const char* expression) {
+    rapidjson::GenericDocument<rapidjson::UTF8<>, rapidjson::CrtAllocator> doc;
+    doc.Parse<0>(expression);
+    return style::parseFilter(doc);
+}
+
+static void Parse_Filter(benchmark::State& state) {
+    while (state.KeepRunning()) {
+        parse(R"FILTER(["==", "foo", "bar"])FILTER");
+    }
+}
+
+static void Parse_EvaluateFilter(benchmark::State& state) {
+    const style::Filter filter = parse(R"FILTER(["==", "foo", "bar"])FILTER");
+    const Properties properties = { { "foo", std::string("bar") } };
+    const StubFeature feature(properties, FeatureType::Unknown);
+
+    while (state.KeepRunning()) {
+        style::Filter::visit(filter, style::FilterEvaluator{ feature });
+    }
+}
+
+BENCHMARK(Parse_Filter);
+BENCHMARK(Parse_EvaluateFilter);