From ae8a48590c00a1ed9e051960e6f2dba403f3b71a Mon Sep 17 00:00:00 2001
From: Vadim Sadokhov <v.sadokhov@vk.team>
Date: Mon, 7 Jul 2025 14:17:14 +0300
Subject: [PATCH 01/22] add trace tag

---
 .idea/misc.xml                                |  3 ++
 runtime-light/k2-platform/k2-header.h         |  7 ++++
 runtime-light/stdlib/diagnostics/backtrace.h  | 19 ---------
 runtime-light/utils/logs.h                    | 36 ++++++++++-------
 tests/python/lib/web_server.py                | 39 +++++++++++++++++++
 tests/python/tests/json_logs/test_warnings.py | 25 +++++++++++-
 6 files changed, 96 insertions(+), 33 deletions(-)

diff --git a/.idea/misc.xml b/.idea/misc.xml
index 9f883b3c5b..307dd609cd 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,5 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="Black">
+    <option name="sdkName" value="Python 3.10" />
+  </component>
   <component name="CMakePythonSetting">
     <option name="pythonIntegrationState" value="YES" />
   </component>
diff --git a/runtime-light/k2-platform/k2-header.h b/runtime-light/k2-platform/k2-header.h
index 6b32163045..c9beb0c8dc 100644
--- a/runtime-light/k2-platform/k2-header.h
+++ b/runtime-light/k2-platform/k2-header.h
@@ -313,6 +313,13 @@ void k2_free_descriptor(uint64_t descriptor);
  */
 uint8_t k2_take_update(uint64_t* update_d);
 
+struct LogKeyValuePair {
+  const char * key;
+  const char * value;
+  size_t key_len;
+  size_t value_len;
+};
+
 /**
  * Represents a key-value pair that can be added to a log.
  * Each instance of this struct must contain valid, non-null pointers for both the key and the value.
diff --git a/runtime-light/stdlib/diagnostics/backtrace.h b/runtime-light/stdlib/diagnostics/backtrace.h
index 712002318f..4ab690f72c 100644
--- a/runtime-light/stdlib/diagnostics/backtrace.h
+++ b/runtime-light/stdlib/diagnostics/backtrace.h
@@ -57,25 +57,6 @@ inline auto backtrace_symbols(std::span<void* const> addresses) noexcept {
 
 } // namespace kphp::diagnostic
 
-template<>
-struct std::formatter<std::invoke_result_t<decltype(kphp::diagnostic::backtrace_addresses), std::span<void* const>>> {
-  using addresses_t = std::invoke_result_t<decltype(kphp::diagnostic::backtrace_addresses), std::span<void* const>>;
-  template<typename ParseContext>
-  constexpr auto parse(ParseContext& ctx) const noexcept {
-    return ctx.begin();
-  }
-
-  template<typename FmtContext>
-  auto format(const addresses_t& addresses, FmtContext& ctx) const noexcept {
-    size_t level{};
-    for (const auto* addr : addresses) {
-      format_to(ctx.out(), "# {} : {:p}\n", level++, addr);
-    }
-
-    return ctx.out();
-  }
-};
-
 template<>
 struct std::formatter<std::invoke_result_t<decltype(kphp::diagnostic::backtrace_symbols), std::span<void* const>>> {
   using symbols_info_t = std::invoke_result_t<decltype(kphp::diagnostic::backtrace_symbols), std::span<void* const>>;
diff --git a/runtime-light/utils/logs.h b/runtime-light/utils/logs.h
index 3aa69143f3..b8983c37af 100644
--- a/runtime-light/utils/logs.h
+++ b/runtime-light/utils/logs.h
@@ -10,6 +10,7 @@
 #include <optional>
 #include <source_location>
 #include <span>
+#include <string_view>
 #include <type_traits>
 #include <utility>
 
@@ -42,28 +43,37 @@ enum class level : size_t { error = 1, warn, info, debug, trace };
 
 template<typename... Args>
 void log(level level, std::optional<std::span<void* const>> trace, std::format_string<impl::wrapped_arg_t<Args>...> fmt, Args&&... args) noexcept {
-  static constexpr size_t LOG_BUFFER_SIZE = 1024UZ * 4UZ;
   if (std::to_underlying(level) > k2::log_level_enabled()) {
     return;
   }
 
+  static constexpr size_t LOG_BUFFER_SIZE = 512;
   std::array<char, LOG_BUFFER_SIZE> log_buffer;
   auto [out, size]{std::format_to_n<decltype(log_buffer.data()), impl::wrapped_arg_t<Args>...>(log_buffer.data(), log_buffer.size() - 1, fmt,
                                                                                                impl::wrap_log_argument(std::forward<Args>(args))...)};
-  if (trace.has_value()) {
-    if (auto backtrace_symbols{kphp::diagnostic::backtrace_symbols(*trace)}; !backtrace_symbols.empty()) {
-      const auto [trace_out, trace_size]{std::format_to_n(out, std::distance(out, log_buffer.end()) - 1, "\nBacktrace\n{}", backtrace_symbols)};
-      out = trace_out;
-      size += trace_size;
-    } else if (auto backtrace_addresses{kphp::diagnostic::backtrace_addresses(*trace)}; !backtrace_addresses.empty()) {
-      const auto [trace_out, trace_size]{std::format_to_n(out, std::distance(out, log_buffer.end()) - 1, "\nBacktrace\n{}", backtrace_addresses)};
-      out = trace_out;
-      size += trace_size;
-    }
+  *out = '\0';
+  auto message{std::span(log_buffer.data(), size + 1)};
+  if (!trace.has_value()) {
+    k2::log(std::to_underlying(level), message, std::nullopt);
+    return;
   }
 
-  *out = '\0';
-  k2::log(std::to_underlying(level), std::string_view{log_buffer.data(), static_cast<std::string_view::size_type>(size)}, std::nullopt);
+  static constexpr std::string_view backtrace_key = "trace";
+  static constexpr size_t BACKTRACE_BUFFER_SIZE = 1024UZ * 4UZ;
+  std::array<char, BACKTRACE_BUFFER_SIZE> backtrace_buffer;
+  std::string_view backtrace;
+  if (auto backtrace_symbols{kphp::diagnostic::backtrace_symbols(*trace)}; !backtrace_symbols.empty()) {
+    const auto [trace_out, trace_size]{std::format_to_n(backtrace_buffer.data(), backtrace_buffer.size() - 1, "\n{}", backtrace_symbols)};
+    *trace_out = '\0';
+    backtrace = std::string_view{backtrace_buffer.data(), static_cast<std::string_view::size_type>(trace_size + 1)};
+  } else if (auto backtrace_addresses{kphp::diagnostic::backtrace_addresses(*trace)}; !backtrace_addresses.empty()) {
+    const auto [trace_out, trace_size]{std::format_to_n(backtrace_buffer.data(), backtrace_buffer.size() - 1, "{}", backtrace_addresses)};
+    *trace_out = '\0';
+    backtrace = std::string_view{backtrace_buffer.data(), static_cast<std::string_view::size_type>(trace_size + 1)};
+  }
+  std::array<k2::LogKeyValuePair, 1> kv_pairs = {{
+      k2::LogKeyValuePair{.key = backtrace_key.data(), .value = backtrace.data(), .key_len = backtrace_key.size(), .value_len = backtrace.size()}}};
+  k2::log(std::to_underlying(level), message, std::span(kv_pairs.data(), kv_pairs.size()));
 }
 
 template<typename... Args>
diff --git a/tests/python/lib/web_server.py b/tests/python/lib/web_server.py
index 4db9ad1718..5c5cf318ad 100644
--- a/tests/python/lib/web_server.py
+++ b/tests/python/lib/web_server.py
@@ -28,6 +28,7 @@ def start(self, start_msgs=None):
         super(WebServer, self).start(start_msgs)
         self._json_logs = []
         if (self._json_log_file is not None):
+            time.sleep(1.0 / 1e1)
             self._json_log_file_read_fd = open(self._json_log_file, 'r')
 
     def stop(self):
@@ -91,6 +92,42 @@ def _read_new_json_logs(self):
     def _process_json_log(self, log_record):
         return log_record
 
+    def assert_json_log_tags(self, expect, message="Can't wait expected json log", timeout=60):
+        """
+        Check web server json log contains tags
+        :param expect: Expected json record
+        :param message: Error message in case of failure
+        :param timeout: Json records waiting time
+        """
+        start = time.time()
+        expected_records = expect[:]
+        print(expected_records)
+
+        while expected_records:
+            self._assert_availability()
+            self._read_new_json_logs()
+            self._json_logs = list(filter(None, self._json_logs))
+            for index, json_log_record in enumerate(self._json_logs):
+                if not expected_records:
+                    return
+                expected_record = expected_records[0]
+                expected_msg = expected_record["msg"]
+                got_msg = json_log_record["msg"]
+                if re.search(expected_msg, got_msg):
+                    expected_record_copy = expected_record.copy()
+                    expected_record_copy["msg"] = ""
+                    json_log_record_copy = json_log_record.copy()
+                    json_log_record_copy["msg"] = ""
+                    print("match")
+                    if set(expected_record_copy.keys()).issubset(json_log_record_copy.keys()):
+                        expected_records.pop(0)
+                        self._json_logs[index] = None
+
+            time.sleep(0.05)
+            if time.time() - start > timeout:
+                expected_str = json.dumps(obj=expected_records, indent=2)
+                raise RuntimeError("{}; Missed messages: {}".format(message, expected_str))
+
     def assert_json_log(self, expect, message="Can't wait expected json log", timeout=60):
         """
         Check kphp server json log
@@ -100,6 +137,7 @@ def assert_json_log(self, expect, message="Can't wait expected json log", timeou
         """
         start = time.time()
         expected_records = expect[:]
+        print(expected_records)
 
         while expected_records:
             self._assert_availability()
@@ -116,6 +154,7 @@ def assert_json_log(self, expect, message="Can't wait expected json log", timeou
                     expected_record_copy["msg"] = ""
                     json_log_record_copy = json_log_record.copy()
                     json_log_record_copy["msg"] = ""
+                    print("match")
                     if expected_record_copy == json_log_record_copy:
                         expected_records.pop(0)
                         self._json_logs[index] = None
diff --git a/tests/python/tests/json_logs/test_warnings.py b/tests/python/tests/json_logs/test_warnings.py
index c331069010..a37df1ab72 100644
--- a/tests/python/tests/json_logs/test_warnings.py
+++ b/tests/python/tests/json_logs/test_warnings.py
@@ -5,12 +5,25 @@
 from python.lib.kphp_server import KphpServer
 
 
-@pytest.mark.k2_skip_suite
 class TestJsonLogsWarnings(WebServerAutoTestCase):
     @classmethod
     def extra_class_setup(cls):
         cls.web_server.ignore_log_errors()
+        if cls.should_use_k2():
+            cls.web_server.update_options({"--log-file": "log-file"})
 
+    def test_warning_backtrace(self):
+        resp = self.web_server.http_post(
+            json=[
+                {"op": "warning", "msg": "hello"},
+            ])
+        self.assertEqual(resp.text, "ok")
+        self.web_server.assert_json_log_tags(
+            expect=[
+                {"msg": "hello", "trace": ""}
+            ])
+
+    @pytest.mark.k2_skip
     def test_warning_no_context(self):
         resp = self.web_server.http_post(
             json=[
@@ -24,6 +37,7 @@ def test_warning_no_context(self):
                 {"version": 0, "hostname": socket.gethostname(), "type": 2, "env": "", "msg": "world", "tags": {"uncaught": False}}
             ])
 
+    @pytest.mark.k2_skip
     def test_warning_with_special_chars(self):
         resp = self.web_server.http_post(json=[{"op": "warning", "msg": 'aaa"bbb"\nccc'}])
         self.assertEqual(resp.text, "ok")
@@ -33,6 +47,7 @@ def test_warning_with_special_chars(self):
                 "tags": {"uncaught": False}
             }])
 
+    @pytest.mark.k2_skip
     def test_warning_with_tags(self):
         resp = self.web_server.http_post(
             json=[
@@ -46,6 +61,7 @@ def test_warning_with_tags(self):
                 "tags": {"uncaught": False, "a": "b"}
             }])
 
+    @pytest.mark.k2_skip
     def test_warning_with_extra_info(self):
         resp = self.web_server.http_post(
             json=[
@@ -59,6 +75,7 @@ def test_warning_with_extra_info(self):
                 "tags": {"uncaught": False}, "extra_info": {"a": "b"}
             }])
 
+    @pytest.mark.k2_skip
     def test_warning_with_env(self):
         resp = self.web_server.http_post(
             json=[
@@ -69,6 +86,7 @@ def test_warning_with_env(self):
         self.web_server.assert_json_log(
             expect=[{"version": 0, "hostname": socket.gethostname(), "type": 2, "msg": "aaa", "env": "abc", "tags": {"uncaught": False}}])
 
+    @pytest.mark.k2_skip
     def test_warning_with_env_special_chars(self):
         resp = self.web_server.http_post(
             json=[
@@ -79,6 +97,7 @@ def test_warning_with_env_special_chars(self):
         self.web_server.assert_json_log(
             expect=[{"version": 0, "hostname": socket.gethostname(), "type": 2, "msg": "aaa", "env": "a b c/d\\e?f", "tags": {"uncaught": False}}])
 
+    @pytest.mark.k2_skip
     def test_warning_with_long_env(self):
         resp = self.web_server.http_post(
             json=[
@@ -89,6 +108,7 @@ def test_warning_with_long_env(self):
         self.web_server.assert_json_log(
             expect=[{"version": 0, "hostname": socket.gethostname(), "type": 2, "msg": "aaa", "env": "", "tags": {"uncaught": False}}])
 
+    @pytest.mark.k2_skip
     def test_warning_with_full_context(self):
         resp = self.web_server.http_post(
             json=[
@@ -102,6 +122,7 @@ def test_warning_with_full_context(self):
                 "tags": {"uncaught": False, "a": "b"}, "extra_info": {"c": "d"}
             }])
 
+    @pytest.mark.k2_skip
     def test_warning_override_context(self):
         resp = self.web_server.http_post(
             json=[
@@ -132,6 +153,7 @@ def test_warning_override_context(self):
                 }
             ])
 
+    @pytest.mark.k2_skip
     def test_warning_vector_context(self):
         resp = self.web_server.http_post(
             json=[
@@ -145,6 +167,7 @@ def test_warning_vector_context(self):
                 "tags": {"uncaught": False, "0": "a", "1": "b"}, "extra_info": {"0": "c", "1": "d"}
             }], timeout=1)
 
+    @pytest.mark.k2_skip
     def test_error_tag_context(self):
         if isinstance(self.web_server, KphpServer):
             self.web_server.set_error_tag(100500)

From 105e92efd89139c22c2d35318020dd1cf713259c Mon Sep 17 00:00:00 2001
From: Vadim Sadokhov <v.sadokhov@vk.team>
Date: Mon, 7 Jul 2025 14:17:37 +0300
Subject: [PATCH 02/22] remove misc

---
 .idea/misc.xml | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/.idea/misc.xml b/.idea/misc.xml
index 307dd609cd..9f883b3c5b 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,8 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
-  <component name="Black">
-    <option name="sdkName" value="Python 3.10" />
-  </component>
   <component name="CMakePythonSetting">
     <option name="pythonIntegrationState" value="YES" />
   </component>

From 9b8094cb3b058f986eade5984f58abbd42e95080 Mon Sep 17 00:00:00 2001
From: Vadim Sadokhov <v.sadokhov@vk.team>
Date: Mon, 7 Jul 2025 14:19:00 +0300
Subject: [PATCH 03/22] format file

---
 runtime-light/k2-platform/k2-header.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/runtime-light/k2-platform/k2-header.h b/runtime-light/k2-platform/k2-header.h
index c9beb0c8dc..d9e01248fa 100644
--- a/runtime-light/k2-platform/k2-header.h
+++ b/runtime-light/k2-platform/k2-header.h
@@ -314,8 +314,8 @@ void k2_free_descriptor(uint64_t descriptor);
 uint8_t k2_take_update(uint64_t* update_d);
 
 struct LogKeyValuePair {
-  const char * key;
-  const char * value;
+  const char* key;
+  const char* value;
   size_t key_len;
   size_t value_len;
 };

From fb39ae1896c390a76df39730ad01a16448ee1fd8 Mon Sep 17 00:00:00 2001
From: Vadim Sadokhov <v.sadokhov@vk.team>
Date: Mon, 7 Jul 2025 14:27:24 +0300
Subject: [PATCH 04/22] rewrite api

---
 runtime-light/utils/logs.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/runtime-light/utils/logs.h b/runtime-light/utils/logs.h
index b8983c37af..d7fc4b812b 100644
--- a/runtime-light/utils/logs.h
+++ b/runtime-light/utils/logs.h
@@ -52,7 +52,7 @@ void log(level level, std::optional<std::span<void* const>> trace, std::format_s
   auto [out, size]{std::format_to_n<decltype(log_buffer.data()), impl::wrapped_arg_t<Args>...>(log_buffer.data(), log_buffer.size() - 1, fmt,
                                                                                                impl::wrap_log_argument(std::forward<Args>(args))...)};
   *out = '\0';
-  auto message{std::span(log_buffer.data(), size + 1)};
+  auto message{std::string_view{log_buffer.data(), static_cast<std::string_view::size_type>(size + 1)}};
   if (!trace.has_value()) {
     k2::log(std::to_underlying(level), message, std::nullopt);
     return;

From 4de63b3ff30697a2b0a6c0a2c9c866b21a936ab3 Mon Sep 17 00:00:00 2001
From: Vadim Sadokhov <v.sadokhov@vk.team>
Date: Mon, 7 Jul 2025 14:30:48 +0300
Subject: [PATCH 05/22] small fix

---
 tests/python/lib/web_server.py | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/tests/python/lib/web_server.py b/tests/python/lib/web_server.py
index 5c5cf318ad..3f9ec0b6c3 100644
--- a/tests/python/lib/web_server.py
+++ b/tests/python/lib/web_server.py
@@ -28,7 +28,7 @@ def start(self, start_msgs=None):
         super(WebServer, self).start(start_msgs)
         self._json_logs = []
         if (self._json_log_file is not None):
-            time.sleep(1.0 / 1e1)
+            time.sleep(0.1)
             self._json_log_file_read_fd = open(self._json_log_file, 'r')
 
     def stop(self):
@@ -137,7 +137,6 @@ def assert_json_log(self, expect, message="Can't wait expected json log", timeou
         """
         start = time.time()
         expected_records = expect[:]
-        print(expected_records)
 
         while expected_records:
             self._assert_availability()
@@ -154,7 +153,6 @@ def assert_json_log(self, expect, message="Can't wait expected json log", timeou
                     expected_record_copy["msg"] = ""
                     json_log_record_copy = json_log_record.copy()
                     json_log_record_copy["msg"] = ""
-                    print("match")
                     if expected_record_copy == json_log_record_copy:
                         expected_records.pop(0)
                         self._json_logs[index] = None

From fa5c8353095f80b692480d5adc6e69831656b74c Mon Sep 17 00:00:00 2001
From: Vadim Sadokhov <v.sadokhov@vk.team>
Date: Mon, 7 Jul 2025 15:02:55 +0300
Subject: [PATCH 06/22] small fix

---
 runtime-light/utils/logs.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/runtime-light/utils/logs.h b/runtime-light/utils/logs.h
index d7fc4b812b..936b87f785 100644
--- a/runtime-light/utils/logs.h
+++ b/runtime-light/utils/logs.h
@@ -70,6 +70,8 @@ void log(level level, std::optional<std::span<void* const>> trace, std::format_s
     const auto [trace_out, trace_size]{std::format_to_n(backtrace_buffer.data(), backtrace_buffer.size() - 1, "{}", backtrace_addresses)};
     *trace_out = '\0';
     backtrace = std::string_view{backtrace_buffer.data(), static_cast<std::string_view::size_type>(trace_size + 1)};
+  } else {
+    backtrace = "can't resolve trace";
   }
   std::array<k2::LogKeyValuePair, 1> kv_pairs = {{
       k2::LogKeyValuePair{.key = backtrace_key.data(), .value = backtrace.data(), .key_len = backtrace_key.size(), .value_len = backtrace.size()}}};

From 9195775d6383d3b9cd739936c2e45f903f442036 Mon Sep 17 00:00:00 2001
From: Vadim Sadokhov <v.sadokhov@vk.team>
Date: Mon, 7 Jul 2025 17:45:25 +0300
Subject: [PATCH 07/22] format file

---
 runtime-light/utils/logs.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/runtime-light/utils/logs.h b/runtime-light/utils/logs.h
index 936b87f785..27abc16f1b 100644
--- a/runtime-light/utils/logs.h
+++ b/runtime-light/utils/logs.h
@@ -73,8 +73,8 @@ void log(level level, std::optional<std::span<void* const>> trace, std::format_s
   } else {
     backtrace = "can't resolve trace";
   }
-  std::array<k2::LogKeyValuePair, 1> kv_pairs = {{
-      k2::LogKeyValuePair{.key = backtrace_key.data(), .value = backtrace.data(), .key_len = backtrace_key.size(), .value_len = backtrace.size()}}};
+  std::array<k2::LogKeyValuePair, 1> kv_pairs = {
+      {k2::LogKeyValuePair{.key = backtrace_key.data(), .value = backtrace.data(), .key_len = backtrace_key.size(), .value_len = backtrace.size()}}};
   k2::log(std::to_underlying(level), message, std::span(kv_pairs.data(), kv_pairs.size()));
 }
 

From aa5c1b53a92a6837fe9898c6cf2dcc5716638f4e Mon Sep 17 00:00:00 2001
From: Vadim Sadokhov <v.sadokhov@vk.team>
Date: Tue, 8 Jul 2025 15:22:59 +0300
Subject: [PATCH 08/22] fix tests

---
 tests/python/lib/web_server.py                | 7 +------
 tests/python/tests/json_logs/test_warnings.py | 3 ++-
 2 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/tests/python/lib/web_server.py b/tests/python/lib/web_server.py
index 3f9ec0b6c3..58d41c1d88 100644
--- a/tests/python/lib/web_server.py
+++ b/tests/python/lib/web_server.py
@@ -114,12 +114,7 @@ def assert_json_log_tags(self, expect, message="Can't wait expected json log", t
                 expected_msg = expected_record["msg"]
                 got_msg = json_log_record["msg"]
                 if re.search(expected_msg, got_msg):
-                    expected_record_copy = expected_record.copy()
-                    expected_record_copy["msg"] = ""
-                    json_log_record_copy = json_log_record.copy()
-                    json_log_record_copy["msg"] = ""
-                    print("match")
-                    if set(expected_record_copy.keys()).issubset(json_log_record_copy.keys()):
+                    if expected_record["tags"].issubset(json_log_record.keys()):
                         expected_records.pop(0)
                         self._json_logs[index] = None
 
diff --git a/tests/python/tests/json_logs/test_warnings.py b/tests/python/tests/json_logs/test_warnings.py
index a37df1ab72..a28b5ea741 100644
--- a/tests/python/tests/json_logs/test_warnings.py
+++ b/tests/python/tests/json_logs/test_warnings.py
@@ -12,6 +12,7 @@ def extra_class_setup(cls):
         if cls.should_use_k2():
             cls.web_server.update_options({"--log-file": "log-file"})
 
+    @pytest.mark.kphp_skip
     def test_warning_backtrace(self):
         resp = self.web_server.http_post(
             json=[
@@ -20,7 +21,7 @@ def test_warning_backtrace(self):
         self.assertEqual(resp.text, "ok")
         self.web_server.assert_json_log_tags(
             expect=[
-                {"msg": "hello", "trace": ""}
+                {"msg": "hello", "tags": {"trace"}}
             ])
 
     @pytest.mark.k2_skip

From 5bbd8c71c396859a99c8c53043b6a43d3f4c331a Mon Sep 17 00:00:00 2001
From: Vadim Sadokhov <v.sadokhov@vk.team>
Date: Tue, 8 Jul 2025 15:25:30 +0300
Subject: [PATCH 09/22] fix doc message

---
 runtime-light/k2-platform/k2-header.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/runtime-light/k2-platform/k2-header.h b/runtime-light/k2-platform/k2-header.h
index d9e01248fa..a935a33ded 100644
--- a/runtime-light/k2-platform/k2-header.h
+++ b/runtime-light/k2-platform/k2-header.h
@@ -313,6 +313,14 @@ void k2_free_descriptor(uint64_t descriptor);
  */
 uint8_t k2_take_update(uint64_t* update_d);
 
+/**
+ * Represents a key-value pair that can be added to a log.
+ * Each instance of this struct must contain valid, non-null pointers for both the key and the value.
+ * The lengths of the key and value are specified by `key_len` and `value_len`, respectively.
+ *
+ * If an instance is intended to represent only a key without an associated value,
+ * the `value` pointer should point to an empty string (""), and `value_len` should be set to zero.
+ */
 struct LogKeyValuePair {
   const char* key;
   const char* value;

From fc69d4e3ed63c3a5125936c80caadf9bf722a679 Mon Sep 17 00:00:00 2001
From: Vadim Sadokhov <v.sadokhov@vk.team>
Date: Tue, 8 Jul 2025 16:09:58 +0300
Subject: [PATCH 10/22] fix conftest.py

---
 tests/python/tests/conftest.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/python/tests/conftest.py b/tests/python/tests/conftest.py
index 3184e57a6a..4af7ee6c4a 100644
--- a/tests/python/tests/conftest.py
+++ b/tests/python/tests/conftest.py
@@ -1,4 +1,4 @@
 import os
 import pytest
 
-from python.lib.conftest_impl import skip_k2_unsupported_test, skip_k2_unsupported_test_suite
+from python.lib.conftest_impl import skip_k2_unsupported_test, skip_k2_unsupported_test_suite, skip_kphp_unsupported_test, skip_kphp_unsupported_test_suite

From b3ef3e8c8679ee979b1218cdb28b1a344b2de3a0 Mon Sep 17 00:00:00 2001
From: Vadim Sadokhov <v.sadokhov@vk.team>
Date: Tue, 8 Jul 2025 17:54:27 +0300
Subject: [PATCH 11/22] fix file creation wait

---
 tests/python/lib/file_utils.py | 5 +++++
 tests/python/lib/web_server.py | 4 ++--
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/tests/python/lib/file_utils.py b/tests/python/lib/file_utils.py
index 967a5478a7..73dd068616 100644
--- a/tests/python/lib/file_utils.py
+++ b/tests/python/lib/file_utils.py
@@ -3,6 +3,7 @@
 import re
 import sys
 import shutil
+import time
 
 _SUPPORTED_PHP_VERSIONS = ["php7.4", "php8", "php8.1", "php8.2", "php8.3"]
 
@@ -122,3 +123,7 @@ def search_php_bin(php_version: str):
 
 def search_k2_bin():
     return os.getenv("K2_BIN")
+
+def wait_for_file_creation(file_path, check_interval=0.1):
+    while not os.path.exists(file_path):
+        time.sleep(check_interval)
\ No newline at end of file
diff --git a/tests/python/lib/web_server.py b/tests/python/lib/web_server.py
index 58d41c1d88..aa9003d8b6 100644
--- a/tests/python/lib/web_server.py
+++ b/tests/python/lib/web_server.py
@@ -5,6 +5,7 @@
 from .engine import Engine
 from .http_client import send_http_request, send_http_request_raw
 from .port_generator import get_port
+from .file_utils import wait_for_file_creation
 
 
 class WebServer(Engine):
@@ -23,12 +24,11 @@ def __init__(self, web_server_bin, working_dir, options=None):
         self._json_log_file = None
         self._json_logs = []
 
-
     def start(self, start_msgs=None):
         super(WebServer, self).start(start_msgs)
         self._json_logs = []
         if (self._json_log_file is not None):
-            time.sleep(0.1)
+            wait_for_file_creation(self._json_log_file)
             self._json_log_file_read_fd = open(self._json_log_file, 'r')
 
     def stop(self):

From bd3fb86a01c6fb14a6cf93c5cf45dcc9bae52a7a Mon Sep 17 00:00:00 2001
From: Vadim Sadokhov <v.sadokhov@vk.team>
Date: Wed, 9 Jul 2025 12:17:32 +0300
Subject: [PATCH 12/22] change log file path

---
 tests/python/tests/json_logs/test_warnings.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tests/python/tests/json_logs/test_warnings.py b/tests/python/tests/json_logs/test_warnings.py
index a28b5ea741..3dfdd9a00c 100644
--- a/tests/python/tests/json_logs/test_warnings.py
+++ b/tests/python/tests/json_logs/test_warnings.py
@@ -1,3 +1,4 @@
+import os
 import socket
 import pytest
 
@@ -10,7 +11,7 @@ class TestJsonLogsWarnings(WebServerAutoTestCase):
     def extra_class_setup(cls):
         cls.web_server.ignore_log_errors()
         if cls.should_use_k2():
-            cls.web_server.update_options({"--log-file": "log-file"})
+            cls.web_server.update_options({"--log-file": os.path.join(cls.web_server._working_dir, "data/log-file")})
 
     @pytest.mark.kphp_skip
     def test_warning_backtrace(self):

From 188488e794c9eb7d7f21edeb2ccb4149aabdb08b Mon Sep 17 00:00:00 2001
From: Vadim Sadokhov <v.sadokhov@vk.team>
Date: Wed, 9 Jul 2025 13:31:22 +0300
Subject: [PATCH 13/22] fix tests

---
 tests/python/lib/k2_server.py | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/tests/python/lib/k2_server.py b/tests/python/lib/k2_server.py
index 4bb0a70d79..07a6592c91 100644
--- a/tests/python/lib/k2_server.py
+++ b/tests/python/lib/k2_server.py
@@ -39,8 +39,15 @@ def start(self, start_msgs=None):
         else:
             start_msgs = start_msgs or []
             start_msgs.append("Starting to accept clients.")
+
         super(K2Server, self).start(start_msgs)
 
+        if self._is_json_log_enabled():
+            self.assert_json_log_tags(expect=[
+                {"msg": "Starting to accept clients.", "tags": set()}
+            ])
+
+
     def stop(self):
         super(K2Server, self).stop()
 

From d72079003030a325d7a1959c47095619cee5c976 Mon Sep 17 00:00:00 2001
From: Vadim Sadokhov <v.sadokhov@vk.team>
Date: Fri, 11 Jul 2025 16:53:35 +0300
Subject: [PATCH 14/22] small fix

---
 runtime-light/k2-platform/k2-header.h | 15 ---------------
 tests/python/lib/file_utils.py        | 10 +++++++---
 2 files changed, 7 insertions(+), 18 deletions(-)

diff --git a/runtime-light/k2-platform/k2-header.h b/runtime-light/k2-platform/k2-header.h
index a935a33ded..6b32163045 100644
--- a/runtime-light/k2-platform/k2-header.h
+++ b/runtime-light/k2-platform/k2-header.h
@@ -328,21 +328,6 @@ struct LogKeyValuePair {
   size_t value_len;
 };
 
-/**
- * Represents a key-value pair that can be added to a log.
- * Each instance of this struct must contain valid, non-null pointers for both the key and the value.
- * The lengths of the key and value are specified by `key_len` and `value_len`, respectively.
- *
- * If an instance is intended to represent only a key without an associated value,
- * the `value` pointer should point to an empty string (""), and `value_len` should be set to zero.
- */
-struct LogKeyValuePair {
-  const char* key;
-  const char* value;
-  size_t key_len;
-  size_t value_len;
-};
-
 /**
  * Writes a structured log message. Only UTF-8 encoded strings are supported.
  *
diff --git a/tests/python/lib/file_utils.py b/tests/python/lib/file_utils.py
index 73dd068616..8088df2216 100644
--- a/tests/python/lib/file_utils.py
+++ b/tests/python/lib/file_utils.py
@@ -121,9 +121,13 @@ def search_php_bin(php_version: str):
 
     return None
 
+
 def search_k2_bin():
     return os.getenv("K2_BIN")
 
-def wait_for_file_creation(file_path, check_interval=0.1):
-    while not os.path.exists(file_path):
-        time.sleep(check_interval)
\ No newline at end of file
+
+def wait_for_file_creation(file_path, check_interval=0.1, attempts=20):
+    for i in range(attempts):
+        if os.path.exists(file_path):
+            break
+        time.sleep(check_interval)

From 1eb056e04cbfc8d14bf786631d6a92c7d354ca34 Mon Sep 17 00:00:00 2001
From: Vadim Sadokhov <v.sadokhov@vk.team>
Date: Mon, 14 Jul 2025 16:43:23 +0300
Subject: [PATCH 15/22] save addresses as strings

---
 runtime-light/stdlib/diagnostics/backtrace.h | 22 ++++++++++++++++++++
 runtime-light/utils/logs.h                   |  4 ++--
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/runtime-light/stdlib/diagnostics/backtrace.h b/runtime-light/stdlib/diagnostics/backtrace.h
index 4ab690f72c..fe15426202 100644
--- a/runtime-light/stdlib/diagnostics/backtrace.h
+++ b/runtime-light/stdlib/diagnostics/backtrace.h
@@ -4,10 +4,12 @@
 
 #pragma once
 
+#include <algorithm>
 #include <cstddef>
 #include <cstdint>
 #include <expected>
 #include <format>
+#include <iterator>
 #include <ranges>
 #include <span>
 #include <type_traits>
@@ -57,6 +59,26 @@ inline auto backtrace_symbols(std::span<void* const> addresses) noexcept {
 
 } // namespace kphp::diagnostic
 
+template<>
+struct std::formatter<std::invoke_result_t<decltype(kphp::diagnostic::backtrace_addresses), std::span<void* const>>> {
+  using addresses_t = std::invoke_result_t<decltype(kphp::diagnostic::backtrace_addresses), std::span<void* const>>;
+  template<typename ParseContext>
+  constexpr auto parse(ParseContext& ctx) const noexcept {
+    return ctx.begin();
+  }
+
+  template<typename FmtContext>
+  auto format(const addresses_t& addresses, FmtContext& ctx) const noexcept {
+    format_to(ctx.out(), "[");
+    if (!addresses.empty()) {
+      std::for_each(addresses.begin(), std::prev(addresses.end()), [&](void* addr) { format_to(ctx.out(), "\"{:p}\", ", addr); });
+      format_to(ctx.out(), "\"{:p}\"", *std::prev(addresses.end()));
+    }
+    format_to(ctx.out(), "]");
+    return ctx.out();
+  }
+};
+
 template<>
 struct std::formatter<std::invoke_result_t<decltype(kphp::diagnostic::backtrace_symbols), std::span<void* const>>> {
   using symbols_info_t = std::invoke_result_t<decltype(kphp::diagnostic::backtrace_symbols), std::span<void* const>>;
diff --git a/runtime-light/utils/logs.h b/runtime-light/utils/logs.h
index 27abc16f1b..22503f9f1a 100644
--- a/runtime-light/utils/logs.h
+++ b/runtime-light/utils/logs.h
@@ -73,8 +73,8 @@ void log(level level, std::optional<std::span<void* const>> trace, std::format_s
   } else {
     backtrace = "can't resolve trace";
   }
-  std::array<k2::LogKeyValuePair, 1> kv_pairs = {
-      {k2::LogKeyValuePair{.key = backtrace_key.data(), .value = backtrace.data(), .key_len = backtrace_key.size(), .value_len = backtrace.size()}}};
+  std::array<k2::LogTaggedEntry , 1> kv_pairs = {
+      {k2::LogTaggedEntry{.key = backtrace_key.data(), .value = backtrace.data(), .key_len = backtrace_key.size(), .value_len = backtrace.size()}}};
   k2::log(std::to_underlying(level), message, std::span(kv_pairs.data(), kv_pairs.size()));
 }
 

From 7785d5e068e42a50f3bddce22a9291afd3dcfaef Mon Sep 17 00:00:00 2001
From: Vadim Sadokhov <v.sadokhov@vk.team>
Date: Mon, 14 Jul 2025 16:48:17 +0300
Subject: [PATCH 16/22] small fixes

---
 runtime-light/utils/logs.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/runtime-light/utils/logs.h b/runtime-light/utils/logs.h
index 22503f9f1a..4863a78e71 100644
--- a/runtime-light/utils/logs.h
+++ b/runtime-light/utils/logs.h
@@ -52,7 +52,7 @@ void log(level level, std::optional<std::span<void* const>> trace, std::format_s
   auto [out, size]{std::format_to_n<decltype(log_buffer.data()), impl::wrapped_arg_t<Args>...>(log_buffer.data(), log_buffer.size() - 1, fmt,
                                                                                                impl::wrap_log_argument(std::forward<Args>(args))...)};
   *out = '\0';
-  auto message{std::string_view{log_buffer.data(), static_cast<std::string_view::size_type>(size + 1)}};
+  auto message{std::string_view{log_buffer.data(), static_cast<std::string_view::size_type>(size)}};
   if (!trace.has_value()) {
     k2::log(std::to_underlying(level), message, std::nullopt);
     return;
@@ -65,11 +65,11 @@ void log(level level, std::optional<std::span<void* const>> trace, std::format_s
   if (auto backtrace_symbols{kphp::diagnostic::backtrace_symbols(*trace)}; !backtrace_symbols.empty()) {
     const auto [trace_out, trace_size]{std::format_to_n(backtrace_buffer.data(), backtrace_buffer.size() - 1, "\n{}", backtrace_symbols)};
     *trace_out = '\0';
-    backtrace = std::string_view{backtrace_buffer.data(), static_cast<std::string_view::size_type>(trace_size + 1)};
+    backtrace = std::string_view{backtrace_buffer.data(), static_cast<std::string_view::size_type>(trace_size)};
   } else if (auto backtrace_addresses{kphp::diagnostic::backtrace_addresses(*trace)}; !backtrace_addresses.empty()) {
     const auto [trace_out, trace_size]{std::format_to_n(backtrace_buffer.data(), backtrace_buffer.size() - 1, "{}", backtrace_addresses)};
     *trace_out = '\0';
-    backtrace = std::string_view{backtrace_buffer.data(), static_cast<std::string_view::size_type>(trace_size + 1)};
+    backtrace = std::string_view{backtrace_buffer.data(), static_cast<std::string_view::size_type>(trace_size)};
   } else {
     backtrace = "can't resolve trace";
   }

From ee45515627b18aca2cd6f94a7d1390b90bcfb834 Mon Sep 17 00:00:00 2001
From: Vadim Sadokhov <v.sadokhov@vk.team>
Date: Mon, 14 Jul 2025 16:49:31 +0300
Subject: [PATCH 17/22] format file

---
 runtime-light/utils/logs.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/runtime-light/utils/logs.h b/runtime-light/utils/logs.h
index 4863a78e71..05251d8593 100644
--- a/runtime-light/utils/logs.h
+++ b/runtime-light/utils/logs.h
@@ -73,7 +73,7 @@ void log(level level, std::optional<std::span<void* const>> trace, std::format_s
   } else {
     backtrace = "can't resolve trace";
   }
-  std::array<k2::LogTaggedEntry , 1> kv_pairs = {
+  std::array<k2::LogTaggedEntry, 1> kv_pairs = {
       {k2::LogTaggedEntry{.key = backtrace_key.data(), .value = backtrace.data(), .key_len = backtrace_key.size(), .value_len = backtrace.size()}}};
   k2::log(std::to_underlying(level), message, std::span(kv_pairs.data(), kv_pairs.size()));
 }

From 7ea658bb129e32c888451152d377ec16d7374c37 Mon Sep 17 00:00:00 2001
From: Vadim Sadokhov <v.sadokhov@vk.team>
Date: Mon, 14 Jul 2025 19:09:47 +0300
Subject: [PATCH 18/22] apply review

---
 runtime-light/stdlib/diagnostics/backtrace.h | 2 +-
 runtime-light/utils/logs.h                   | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/runtime-light/stdlib/diagnostics/backtrace.h b/runtime-light/stdlib/diagnostics/backtrace.h
index fe15426202..d90f1f5893 100644
--- a/runtime-light/stdlib/diagnostics/backtrace.h
+++ b/runtime-light/stdlib/diagnostics/backtrace.h
@@ -71,7 +71,7 @@ struct std::formatter<std::invoke_result_t<decltype(kphp::diagnostic::backtrace_
   auto format(const addresses_t& addresses, FmtContext& ctx) const noexcept {
     format_to(ctx.out(), "[");
     if (!addresses.empty()) {
-      std::for_each(addresses.begin(), std::prev(addresses.end()), [&](void* addr) { format_to(ctx.out(), "\"{:p}\", ", addr); });
+      std::ranges::for_each(addresses | std::views::take(addresses.size() - 1), [&ctx](void* addr) noexcept { format_to(ctx.out(), "\"{:p}\", ", addr); });
       format_to(ctx.out(), "\"{:p}\"", *std::prev(addresses.end()));
     }
     format_to(ctx.out(), "]");
diff --git a/runtime-light/utils/logs.h b/runtime-light/utils/logs.h
index 05251d8593..c2408a995a 100644
--- a/runtime-light/utils/logs.h
+++ b/runtime-light/utils/logs.h
@@ -47,7 +47,7 @@ void log(level level, std::optional<std::span<void* const>> trace, std::format_s
     return;
   }
 
-  static constexpr size_t LOG_BUFFER_SIZE = 512;
+  static constexpr size_t LOG_BUFFER_SIZE = 512UZ;
   std::array<char, LOG_BUFFER_SIZE> log_buffer;
   auto [out, size]{std::format_to_n<decltype(log_buffer.data()), impl::wrapped_arg_t<Args>...>(log_buffer.data(), log_buffer.size() - 1, fmt,
                                                                                                impl::wrap_log_argument(std::forward<Args>(args))...)};
@@ -73,9 +73,9 @@ void log(level level, std::optional<std::span<void* const>> trace, std::format_s
   } else {
     backtrace = "can't resolve trace";
   }
-  std::array<k2::LogTaggedEntry, 1> kv_pairs = {
+  std::array<k2::LogTaggedEntry, 1> tagged_entries{
       {k2::LogTaggedEntry{.key = backtrace_key.data(), .value = backtrace.data(), .key_len = backtrace_key.size(), .value_len = backtrace.size()}}};
-  k2::log(std::to_underlying(level), message, std::span(kv_pairs.data(), kv_pairs.size()));
+  k2::log(std::to_underlying(level), message, std::span(tagged_entries.data(), tagged_entries.size()));
 }
 
 template<typename... Args>

From dbf816cc1d6d44917c7cec9edfc29396e1a97cc0 Mon Sep 17 00:00:00 2001
From: Vadim Sadokhov <v.sadokhov@vk.team>
Date: Mon, 14 Jul 2025 19:14:50 +0300
Subject: [PATCH 19/22] remove less include

---
 runtime-light/stdlib/diagnostics/backtrace.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/runtime-light/stdlib/diagnostics/backtrace.h b/runtime-light/stdlib/diagnostics/backtrace.h
index d90f1f5893..815adaa770 100644
--- a/runtime-light/stdlib/diagnostics/backtrace.h
+++ b/runtime-light/stdlib/diagnostics/backtrace.h
@@ -4,7 +4,6 @@
 
 #pragma once
 
-#include <algorithm>
 #include <cstddef>
 #include <cstdint>
 #include <expected>

From 1bb14da6b114063e4f21862fdce6f27fe30d3e4e Mon Sep 17 00:00:00 2001
From: Vadim Sadokhov <v.sadokhov@vk.team>
Date: Tue, 15 Jul 2025 12:30:08 +0300
Subject: [PATCH 20/22] remove less print

---
 tests/python/lib/web_server.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/tests/python/lib/web_server.py b/tests/python/lib/web_server.py
index aa9003d8b6..4986c2ed83 100644
--- a/tests/python/lib/web_server.py
+++ b/tests/python/lib/web_server.py
@@ -101,7 +101,6 @@ def assert_json_log_tags(self, expect, message="Can't wait expected json log", t
         """
         start = time.time()
         expected_records = expect[:]
-        print(expected_records)
 
         while expected_records:
             self._assert_availability()

From 14279b2141b9835c8d956c3a0c7da11d9f877879 Mon Sep 17 00:00:00 2001
From: Vadim Sadokhov <v.sadokhov@vk.team>
Date: Tue, 15 Jul 2025 12:34:38 +0300
Subject: [PATCH 21/22] small fix

---
 runtime-light/utils/logs.h | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/runtime-light/utils/logs.h b/runtime-light/utils/logs.h
index c2408a995a..bbb867d155 100644
--- a/runtime-light/utils/logs.h
+++ b/runtime-light/utils/logs.h
@@ -61,7 +61,7 @@ void log(level level, std::optional<std::span<void* const>> trace, std::format_s
   static constexpr std::string_view backtrace_key = "trace";
   static constexpr size_t BACKTRACE_BUFFER_SIZE = 1024UZ * 4UZ;
   std::array<char, BACKTRACE_BUFFER_SIZE> backtrace_buffer;
-  std::string_view backtrace;
+  std::string_view backtrace = "[]";
   if (auto backtrace_symbols{kphp::diagnostic::backtrace_symbols(*trace)}; !backtrace_symbols.empty()) {
     const auto [trace_out, trace_size]{std::format_to_n(backtrace_buffer.data(), backtrace_buffer.size() - 1, "\n{}", backtrace_symbols)};
     *trace_out = '\0';
@@ -70,8 +70,6 @@ void log(level level, std::optional<std::span<void* const>> trace, std::format_s
     const auto [trace_out, trace_size]{std::format_to_n(backtrace_buffer.data(), backtrace_buffer.size() - 1, "{}", backtrace_addresses)};
     *trace_out = '\0';
     backtrace = std::string_view{backtrace_buffer.data(), static_cast<std::string_view::size_type>(trace_size)};
-  } else {
-    backtrace = "can't resolve trace";
   }
   std::array<k2::LogTaggedEntry, 1> tagged_entries{
       {k2::LogTaggedEntry{.key = backtrace_key.data(), .value = backtrace.data(), .key_len = backtrace_key.size(), .value_len = backtrace.size()}}};

From 2f675c4ce4f5b3d0da4c2359c45a1310b7001525 Mon Sep 17 00:00:00 2001
From: Vadim Sadokhov <v.sadokhov@vk.team>
Date: Tue, 15 Jul 2025 12:56:31 +0300
Subject: [PATCH 22/22] small fix

---
 runtime-light/utils/logs.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/runtime-light/utils/logs.h b/runtime-light/utils/logs.h
index bbb867d155..d294ea1069 100644
--- a/runtime-light/utils/logs.h
+++ b/runtime-light/utils/logs.h
@@ -61,7 +61,7 @@ void log(level level, std::optional<std::span<void* const>> trace, std::format_s
   static constexpr std::string_view backtrace_key = "trace";
   static constexpr size_t BACKTRACE_BUFFER_SIZE = 1024UZ * 4UZ;
   std::array<char, BACKTRACE_BUFFER_SIZE> backtrace_buffer;
-  std::string_view backtrace = "[]";
+  std::string_view backtrace{"[]"};
   if (auto backtrace_symbols{kphp::diagnostic::backtrace_symbols(*trace)}; !backtrace_symbols.empty()) {
     const auto [trace_out, trace_size]{std::format_to_n(backtrace_buffer.data(), backtrace_buffer.size() - 1, "\n{}", backtrace_symbols)};
     *trace_out = '\0';