add a helper class for runtime-derived uint32 (#16398)

Adding runtime helper protobuf messages for RuntimeUInt32. TODO(WeavingGao): use for Risk Level: Low Testing: Unit Test Docs Changes: N/A Release Notes: N/A part of #16392 Signed-off-by: gaoweiwen <[email protected]>
envoyproxy · May 20, 2021 · 2174fd0 · 2174fd0
1 parent 2b9fb47
commit 2174fd0
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diff --git a/source/common/runtime/runtime_protos.h b/source/common/runtime/runtime_protos.h
@@ -11,6 +11,34 @@
 namespace Envoy {
 namespace Runtime {
 
+// TODO(WeavingGao): use for #16392
+// Helper class for runtime-derived uint32.
+class UInt32 : Logger::Loggable<Logger::Id::runtime> {
+public:
+  UInt32(const envoy::config::core::v3::RuntimeUInt32& uint32_proto, Runtime::Loader& runtime)
+      : runtime_key_(uint32_proto.runtime_key()), default_value_(uint32_proto.default_value()),
+        runtime_(runtime) {}
+
+  const std::string& runtimeKey() const { return runtime_key_; }
+
+  uint32_t value() const {
+    uint64_t raw_value = runtime_.snapshot().getInteger(runtime_key_, default_value_);
+    if (raw_value > std::numeric_limits<uint32_t>::max()) {
+      ENVOY_LOG_EVERY_POW_2(
+          warn,
+          "parsed runtime value:{} of {} is larger than uint32 max, returning default instead",
+          raw_value, runtime_key_);
+      return default_value_;
+    }
+    return static_cast<uint32_t>(raw_value);
+  }
+
+private:
+  const std::string runtime_key_;
+  const uint32_t default_value_;
+  Runtime::Loader& runtime_;
+};
+
 // Helper class for runtime-derived boolean feature flags.
 class FeatureFlag {
 public:

diff --git a/test/common/runtime/runtime_protos_test.cc b/test/common/runtime/runtime_protos_test.cc
@@ -24,6 +24,27 @@ class RuntimeProtosTest : public testing::Test {
   NiceMock<MockLoader> runtime_;
 };
 
+TEST_F(RuntimeProtosTest, UInt32Test) {
+  envoy::config::core::v3::RuntimeUInt32 uint32_proto;
+  std::string yaml(R"EOF(
+runtime_key: "foo.bar"
+default_value: 99
+)EOF");
+  TestUtility::loadFromYamlAndValidate(yaml, uint32_proto);
+  UInt32 test_uint32(uint32_proto, runtime_);
+
+  EXPECT_EQ("foo.bar", test_uint32.runtimeKey());
+
+  EXPECT_CALL(runtime_.snapshot_, getInteger("foo.bar", 99));
+  EXPECT_EQ(99, test_uint32.value());
+
+  EXPECT_CALL(runtime_.snapshot_, getInteger("foo.bar", 99)).WillOnce(Return(1024));
+  EXPECT_EQ(1024, test_uint32.value());
+
+  EXPECT_CALL(runtime_.snapshot_, getInteger("foo.bar", 99)).WillOnce(Return(1ull << 33));
+  EXPECT_EQ(99, test_uint32.value());
+}
+
 TEST_F(RuntimeProtosTest, PercentBasicTest) {
   envoy::config::core::v3::RuntimePercent percent_proto;
   std::string yaml(R"EOF(