Adds struct parameters parser/encoder.
This is similar to the field trial parser but it uses a normal struct
with normal fields as underlying storage. This makes it easier to
understand and use as only the encoding and parsing uses non-
standard constructs. Additionally, it makes it easier to use the
struct as a regular config struct when the values are not set
using field trials.
Bug: webrtc:9883
Change-Id: I5b16c2a71875b6f478383decff18fbaa62bc404a
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/145203
Reviewed-by: Jonas Olsson <jonasolsson@webrtc.org>
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28810}
diff --git a/rtc_base/experiments/struct_parameters_parser_unittest.cc b/rtc_base/experiments/struct_parameters_parser_unittest.cc
new file mode 100644
index 0000000..1e88f8c
--- /dev/null
+++ b/rtc_base/experiments/struct_parameters_parser_unittest.cc
@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2019 The WebRTC project authors. All Rights Reserved.
+ *
+ * Use of this source code is governed by a BSD-style license
+ * that can be found in the LICENSE file in the root of the source
+ * tree. An additional intellectual property rights grant can be found
+ * in the file PATENTS. All contributing project authors may
+ * be found in the AUTHORS file in the root of the source tree.
+ */
+#include "rtc_base/experiments/struct_parameters_parser.h"
+#include "rtc_base/gunit.h"
+
+namespace webrtc {
+namespace {
+struct DummyConfig {
+ bool enabled = false;
+ double factor = 0.5;
+ int retries = 5;
+ bool ping = 0;
+ std::string hash = "a80";
+ absl::optional<TimeDelta> duration;
+ absl::optional<TimeDelta> latency = TimeDelta::ms(100);
+ static StructParametersParser<DummyConfig>* Parser();
+};
+
+StructParametersParser<DummyConfig>* DummyConfig::Parser() {
+ using C = DummyConfig;
+ // The empty comments ensures that each pair is on a separate line.
+ static auto parser = CreateStructParametersParser(
+ "e", [](C* c) { return &c->enabled; }, //
+ "f", [](C* c) { return &c->factor; }, //
+ "r", [](C* c) { return &c->retries; }, //
+ "p", [](C* c) { return &c->ping; }, //
+ "h", [](C* c) { return &c->hash; }, //
+ "d", [](C* c) { return &c->duration; }, //
+ "l", [](C* c) { return &c->latency; }); //
+ return parser.get();
+}
+} // namespace
+
+TEST(StructParametersParserTest, ParsesValidParameters) {
+ DummyConfig exp =
+ DummyConfig::Parser()->Parse("e:1,f:-1.7,r:2,p:1,h:x7c,d:8,l:,");
+ EXPECT_TRUE(exp.enabled);
+ EXPECT_EQ(exp.factor, -1.7);
+ EXPECT_EQ(exp.retries, 2);
+ EXPECT_EQ(exp.ping, true);
+ EXPECT_EQ(exp.duration.value().ms(), 8);
+ EXPECT_FALSE(exp.latency);
+}
+
+TEST(StructParametersParserTest, UsesDefaults) {
+ DummyConfig exp = DummyConfig::Parser()->Parse("");
+ EXPECT_FALSE(exp.enabled);
+ EXPECT_EQ(exp.factor, 0.5);
+ EXPECT_EQ(exp.retries, 5);
+ EXPECT_EQ(exp.ping, false);
+ EXPECT_EQ(exp.hash, "a80");
+}
+
+TEST(StructParametersParserTest, EmptyDefaults) {
+ DummyConfig exp;
+ auto encoded = DummyConfig::Parser()->EncodeChanged(exp);
+ // Unchanged parameters are not encoded.
+ EXPECT_EQ(encoded, "");
+}
+
+TEST(StructParametersParserTest, EncodeAll) {
+ DummyConfig exp;
+ auto encoded = DummyConfig::Parser()->EncodeAll(exp);
+ // All parameters are encoded.
+ EXPECT_EQ(encoded, "d:,e:false,f:0.5,h:a80,l:100 ms,p:false,r:5");
+}
+
+TEST(StructParametersParserTest, EncodeChanged) {
+ DummyConfig exp;
+ exp.ping = true;
+ exp.retries = 4;
+ auto encoded = DummyConfig::Parser()->EncodeChanged(exp);
+ // We expect the changed parameters to be encoded in alphabetical order.
+ EXPECT_EQ(encoded, "p:true,r:4");
+}
+
+} // namespace webrtc