Add refcode to select P3A Constellation metrics

components/p3a/BUILD.gn

@@ -81,6 +81,7 @@ static_library("p3a") {
     deps += [ "//ios/web/public/thread" ]
   } else {
     deps += [
+      "//brave/components/brave_referrals/common",
       "//content/public/browser",
       "//content/public/common",
     ]
@@ -117,6 +118,9 @@ source_set("unit_tests") {
     "//testing/gtest",
   ]
   if (!is_ios) {
-    deps += [ "//content/test:test_support" ]
+    deps += [
+      "//brave/components/brave_referrals/common",
+      "//content/test:test_support",
+    ]
   }
 }

components/p3a/constellation_helper_unittest.cc

@@ -21,6 +21,7 @@
 #include "brave/components/p3a/p3a_message.h"
 #include "brave/components/p3a/star_randomness_test_util.h"
 #include "brave/components/p3a/uploader.h"
+#include "components/prefs/pref_registry_simple.h"
 #include "components/prefs/testing_pref_service.h"
 #include "content/public/test/browser_task_environment.h"
 #include "services/network/public/cpp/resource_request.h"
@@ -29,6 +30,10 @@
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/googletest/src/googletest/include/gtest/gtest.h"
 
+#if !BUILDFLAG(IS_IOS)
+#include "brave/components/brave_referrals/common/pref_names.h"
+#endif  // !BUILDFLAG(IS_IOS)
+
 namespace p3a {
 
 namespace {
@@ -59,6 +64,10 @@ class P3AConstellationHelperTest : public testing::Test {
 
     ConstellationHelper::RegisterPrefs(local_state_.registry());
 
+#if !BUILDFLAG(IS_IOS)
+    local_state_.registry()->RegisterStringPref(kReferralPromoCode, {});
+#endif  // !BUILDFLAG(IS_IOS)
+
     url_loader_factory_.SetInterceptor(base::BindLambdaForTesting(
         [&](const network::ResourceRequest& request) {
           url_loader_factory_.ClearResponses();
@@ -244,7 +253,7 @@ TEST_F(P3AConstellationHelperTest, GenerateBasicMessage) {
     helper_->StartMessagePreparation(
         kTestHistogramName, log_type,
         GenerateP3AConstellationMessage(kTestHistogramName, test_epoch,
-                                        meta_info, kP3AUploadType));
+                                        meta_info, kP3AUploadType, false));
     task_environment_.RunUntilIdle();
 
     CheckPointsRequestMade(log_type);
@@ -258,4 +267,57 @@ TEST_F(P3AConstellationHelperTest, GenerateBasicMessage) {
   }
 }
 
+TEST_F(P3AConstellationHelperTest, IncludeRefcode) {
+  MessageMetainfo meta_info;
+  meta_info.Init(&local_state_, "release", "2022-01-01");
+
+  std::string message_with_no_refcode = GenerateP3AConstellationMessage(
+      kTestHistogramName, 0, meta_info, kP3AUploadType, false);
+  std::vector<std::string> no_refcode_layers = base::SplitString(
+      message_with_no_refcode, kP3AMessageConstellationLayerSeparator,
+      base::WhitespaceHandling::TRIM_WHITESPACE,
+      base::SplitResult::SPLIT_WANT_NONEMPTY);
+
+  EXPECT_EQ(no_refcode_layers.size(), 8U);
+  EXPECT_FALSE(base::StartsWith(no_refcode_layers.at(7), "ref"));
+
+  std::string message_with_refcode = GenerateP3AConstellationMessage(
+      kTestHistogramName, 0, meta_info, kP3AUploadType, true);
+  std::vector<std::string> refcode_layers = base::SplitString(
+      message_with_refcode, kP3AMessageConstellationLayerSeparator,
+      base::WhitespaceHandling::TRIM_WHITESPACE,
+      base::SplitResult::SPLIT_WANT_NONEMPTY);
+
+  EXPECT_EQ(refcode_layers.size(), 9U);
+  EXPECT_EQ(refcode_layers.at(8), "ref|none");
+
+#if !BUILDFLAG(IS_IOS)
+  local_state_.SetString(kReferralPromoCode, "BRV003");
+  meta_info.Init(&local_state_, "release", "2022-01-01");
+
+  message_with_refcode = GenerateP3AConstellationMessage(
+      kTestHistogramName, 0, meta_info, kP3AUploadType, true);
+  refcode_layers = base::SplitString(message_with_refcode,
+                                     kP3AMessageConstellationLayerSeparator,
+                                     base::WhitespaceHandling::TRIM_WHITESPACE,
+                                     base::SplitResult::SPLIT_WANT_NONEMPTY);
+
+  EXPECT_EQ(refcode_layers.size(), 9U);
+  EXPECT_EQ(refcode_layers.at(8), "ref|BRV003");
+
+  local_state_.SetString(kReferralPromoCode, "ZRK009");
+  meta_info.Init(&local_state_, "release", "2022-01-01");
+
+  message_with_refcode = GenerateP3AConstellationMessage(
+      kTestHistogramName, 0, meta_info, kP3AUploadType, true);
+  refcode_layers = base::SplitString(message_with_refcode,
+                                     kP3AMessageConstellationLayerSeparator,
+                                     base::WhitespaceHandling::TRIM_WHITESPACE,
+                                     base::SplitResult::SPLIT_WANT_NONEMPTY);
+
+  EXPECT_EQ(refcode_layers.size(), 9U);
+  EXPECT_EQ(refcode_layers.at(8), "ref|other");
+#endif  // !BUILDFLAG(IS_IOS)
+}
+
 }  // namespace p3a

components/p3a/message_manager.cc

@@ -368,8 +368,10 @@ std::string MessageManager::SerializeLog(std::string_view histogram_name,
   message_meta_.Update();
 
   if (is_constellation) {
+    bool include_refcode =
+        p3a::kHistogramsWithRefcodeIncluded.contains(histogram_name);
     return GenerateP3AConstellationMessage(histogram_name, value, message_meta_,
-                                           upload_type);
+                                           upload_type, include_refcode);
   } else {
     base::Value::Dict p3a_json_value = GenerateP3AMessageDict(
         histogram_name, value, log_type, message_meta_, upload_type);

components/p3a/metric_names.h

@@ -315,6 +315,15 @@ inline constexpr auto kConstellationOnlyHistograms =
     "Brave.Core.PrimaryLang",
 });
 
+// List of metrics which will include the stored refcode when transmitted
+// via the STAR/Constellation protocol.
+inline constexpr auto kHistogramsWithRefcodeIncluded =
+  base::MakeFixedFlatSet<std::string_view>(base::sorted_unique,{
+    // TODO(djandries): Replace this metric with the first metric
+    // to include a refcode.
+    "Brave.ExampleMetric"
+});
+
 // clang-format on
 
 }  // namespace p3a

components/p3a/p3a_message.cc

@@ -24,25 +24,34 @@
 #include "brave/components/version_info/version_info.h"
 #include "components/prefs/pref_service.h"
 
+#if !BUILDFLAG(IS_IOS)
+#include "brave/components/brave_referrals/common/pref_names.h"
+#endif  // !BUILDFLAG(IS_IOS)
+
 namespace p3a {
 
 namespace {
-const char kMetricNameAttributeName[] = "metric_name";
-const char kMetricValueAttributeName[] = "metric_value";
-const char kPlatformAttributeName[] = "platform";
-const char kChannelAttributeName[] = "channel";
-const char kYosAttributeName[] = "yos";
-const char kWosAttributeName[] = "wos";
-const char kMosAttributeName[] = "mos";
-const char kWoiAttributeName[] = "woi";
-const char kYoiAttributeName[] = "yoi";
-const char kCountryCodeAttributeName[] = "country_code";
-const char kVersionAttributeName[] = "version";
-const char kCadenceAttributeName[] = "cadence";
-
-const char kSlowCadence[] = "slow";
-const char kTypicalCadence[] = "typical";
-const char kExpressCadence[] = "express";
+constexpr char kMetricNameAttributeName[] = "metric_name";
+constexpr char kMetricValueAttributeName[] = "metric_value";
+constexpr char kPlatformAttributeName[] = "platform";
+constexpr char kChannelAttributeName[] = "channel";
+constexpr char kYosAttributeName[] = "yos";
+constexpr char kWosAttributeName[] = "wos";
+constexpr char kMosAttributeName[] = "mos";
+constexpr char kWoiAttributeName[] = "woi";
+constexpr char kYoiAttributeName[] = "yoi";
+constexpr char kCountryCodeAttributeName[] = "country_code";
+constexpr char kVersionAttributeName[] = "version";
+constexpr char kCadenceAttributeName[] = "cadence";
+constexpr char kRefAttributeName[] = "ref";
+
+constexpr char kSlowCadence[] = "slow";
+constexpr char kTypicalCadence[] = "typical";
+constexpr char kExpressCadence[] = "express";
+
+constexpr char kOrganicRefPrefix[] = "BRV";
+constexpr char kRefNone[] = "none";
+constexpr char kRefOther[] = "other";
 
 }  // namespace
 
@@ -123,7 +132,8 @@ base::Value::Dict GenerateP3AMessageDict(std::string_view metric_name,
 std::string GenerateP3AConstellationMessage(std::string_view metric_name,
                                             uint64_t metric_value,
                                             const MessageMetainfo& meta,
-                                            const std::string& upload_type) {
+                                            const std::string& upload_type,
+                                            bool include_refcode) {
   base::Time::Exploded exploded;
   meta.date_of_install.LocalExplode(&exploded);
   DCHECK_GE(exploded.year, 999);
@@ -151,6 +161,10 @@ std::string GenerateP3AConstellationMessage(std::string_view metric_name,
     }};
   }
 
+  if (include_refcode) {
+    attributes.push_back({kRefAttributeName, meta.ref});
+  }
+
   std::vector<std::string> serialized_attributes(attributes.size());
 
   std::transform(attributes.begin(), attributes.end(),
@@ -166,9 +180,11 @@ std::string GenerateP3AConstellationMessage(std::string_view metric_name,
 void MessageMetainfo::Init(PrefService* local_state,
                            std::string brave_channel,
                            std::string week_of_install) {
+  local_state_ = local_state;
   platform = brave_stats::GetPlatformIdentifier();
   channel = brave_channel;
   InitVersion();
+  InitRef();
 
   if (!week_of_install.empty()) {
     date_of_install = brave_stats::GetYMDAsDate(week_of_install);
@@ -190,11 +206,12 @@ void MessageMetainfo::Init(PrefService* local_state,
 
   VLOG(2) << "Message meta: " << platform << " " << channel << " " << version
           << " " << woi << " " << country_code_from_timezone << " "
-          << country_code_from_locale;
+          << country_code_from_locale << " " << ref;
 }
 
 void MessageMetainfo::Update() {
   date_of_survey = base::Time::Now();
+  InitRef();
 }
 
 void MessageMetainfo::InitVersion() {
@@ -210,6 +227,22 @@ void MessageMetainfo::InitVersion() {
   }
 }
 
+void MessageMetainfo::InitRef() {
+  std::string referral_code;
+#if !BUILDFLAG(IS_IOS)
+  if (local_state_ && local_state_->HasPrefPath(kReferralPromoCode)) {
+    referral_code = local_state_->GetString(kReferralPromoCode);
+  }
+#endif  // !BUILDFLAG(IS_IOS)
+  if (referral_code.empty()) {
+    ref = kRefNone;
+  } else if (base::StartsWith(referral_code, kOrganicRefPrefix)) {
+    ref = referral_code;
+  } else {
+    ref = kRefOther;
+  }
+}
+
 void MessageMetainfo::MaybeStripCountry() {
   constexpr char kCountryOther[] = "other";
 

components/p3a/p3a_message.h

@@ -40,15 +40,21 @@ class MessageMetainfo {
   int woi;  // Week of install. Remove this occasionally and extract from above.
   std::string country_code_from_timezone;
   std::string country_code_from_locale;
+  // May contain 'none', a 'BRV'-prefixed refcode, or 'other'.
+  std::string ref;
 
  private:
   // Used to report major/minor version numbers to reduce amount of
   // Constellation tags
   void InitVersion();
 
+  void InitRef();
+
   // Ensures that country represent the big enough cohort that will not
   // let anybody identify the sender.
   void MaybeStripCountry();
+
+  raw_ptr<PrefService> local_state_ = nullptr;
 };
 
 base::Value::Dict GenerateP3AMessageDict(std::string_view metric_name,
@@ -60,7 +66,8 @@ base::Value::Dict GenerateP3AMessageDict(std::string_view metric_name,
 std::string GenerateP3AConstellationMessage(std::string_view metric_name,
                                             uint64_t metric_value,
                                             const MessageMetainfo& meta,
-                                            const std::string& upload_type);
+                                            const std::string& upload_type,
+                                            bool include_refcode);
 
 }  // namespace p3a