From 2a2af3f72f1841a67d06120d0be5553fddda71d7 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Thu, 13 Mar 2025 18:23:00 +0100
Subject: [PATCH] Logger::result(): Support logging arbitrary JSON objects

---
 src/libstore/unix/build/local-derivation-goal.cc |  8 ++++----
 src/libutil/logging.cc                           | 10 ++++++++++
 src/libutil/logging.hh                           |  7 +++++++
 src/libutil/tee-logger.cc                        |  6 ++++++
 4 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/src/libstore/unix/build/local-derivation-goal.cc b/src/libstore/unix/build/local-derivation-goal.cc
index 9ab0da32b..ec06c2044 100644
--- a/src/libstore/unix/build/local-derivation-goal.cc
+++ b/src/libstore/unix/build/local-derivation-goal.cc
@@ -2656,11 +2656,11 @@ SingleDrvOutputs LocalDerivationGoal::registerOutputs()
                             worker.store.printStorePath(drvPath),
                             wanted.to_string(HashFormat::SRI, true),
                             got.to_string(HashFormat::SRI, true)));
-                    // FIXME: put this in BuildResult and log that as JSON.
                     act->result(resHashMismatch,
-                        {worker.store.printStorePath(drvPath),
-                         wanted.to_string(HashFormat::SRI, true),
-                         got.to_string(HashFormat::SRI, true)
+                        {
+                            {"storePath", worker.store.printStorePath(drvPath)},
+                            {"wanted", wanted.to_string(HashFormat::SRI, true)},
+                            {"got", got.to_string(HashFormat::SRI, true)},
                         });
                 }
                 if (!newInfo0.references.empty()) {
diff --git a/src/libutil/logging.cc b/src/libutil/logging.cc
index 94683cca5..c7b859bd5 100644
--- a/src/libutil/logging.cc
+++ b/src/libutil/logging.cc
@@ -279,6 +279,16 @@ struct JSONLogger : Logger {
         addFields(json, fields);
         write(json);
     }
+
+    void result(ActivityId act, ResultType type, const nlohmann::json & j) override
+    {
+        nlohmann::json json;
+        json["action"] = "result";
+        json["id"] = act;
+        json["type"] = type;
+        json["payload"] = j;
+        write(json);
+    }
 };
 
 Logger * makeJSONLogger(Descriptor fd, bool includeNixPrefix)
diff --git a/src/libutil/logging.hh b/src/libutil/logging.hh
index ef449d03e..9d655f735 100644
--- a/src/libutil/logging.hh
+++ b/src/libutil/logging.hh
@@ -108,6 +108,8 @@ public:
 
     virtual void result(ActivityId act, ResultType type, const Fields & fields) { };
 
+    virtual void result(ActivityId act, ResultType type, const nlohmann::json & json) { };
+
     virtual void writeToStdout(std::string_view s);
 
     template<typename... Args>
@@ -160,6 +162,11 @@ struct Activity
     void setExpected(ActivityType type2, uint64_t expected) const
     { result(resSetExpected, type2, expected); }
 
+    void result(ResultType type, const nlohmann::json & json) const
+    {
+        logger.result(id, type, json);
+    }
+
     template<typename... Args>
     void result(ResultType type, const Args & ... args) const
     {
diff --git a/src/libutil/tee-logger.cc b/src/libutil/tee-logger.cc
index 7a5115ea7..c9873a53a 100644
--- a/src/libutil/tee-logger.cc
+++ b/src/libutil/tee-logger.cc
@@ -65,6 +65,12 @@ struct TeeLogger : Logger
             logger->result(act, type, fields);
     }
 
+    void result(ActivityId act, ResultType type, const nlohmann::json & json) override
+    {
+        for (auto & logger : loggers)
+            logger->result(act, type, json);
+    }
+
     void writeToStdout(std::string_view s) override
     {
         for (auto & logger : loggers) {