[EXPORTER] ostream log exporter, fix memory ownership issues (#3417)

Author: marcalff

CHANGELOG.md

@@ -61,6 +61,28 @@ Increment the:
 * [SEMANTIC CONVENTIONS] Upgrade to semantic conventions 1.34.0
   [#3428](https://github.com/open-telemetry/opentelemetry-cpp/pull/3428)
 
+* [EXPORTER] ostream log exporter, fixed memory ownership issues
+  [#3417](https://github.com/open-telemetry/opentelemetry-cpp/pull/3417)
+
+Important changes:
+
+* [EXPORTER] ostream log exporter, fixed memory ownership issues
+  [#3417](https://github.com/open-telemetry/opentelemetry-cpp/pull/3417)
+
+  * In the SDK, the following classes implementation has changed:
+
+    * opentelemetry::sdk::logs::ReadableLogRecord
+    * opentelemetry::sdk::logs::ReadWriteLogRecord
+
+  * An application implementing a custom log record exporter,
+    that reuses these classes from the opentelemetry-cpp SDK,
+    will need code adjustments, in particular for methods:
+
+    * GetBody()
+    * GetAttributes()
+
+  * Applications not using these SDK classes directly are not affected.
+
 ## [1.20 2025-04-01]
 
 * [BUILD] Update opentelemetry-proto version

sdk/include/opentelemetry/sdk/logs/read_write_log_record.h

@@ -82,7 +82,7 @@ class ReadWriteLogRecord final : public ReadableLogRecord
    * Get body field of this log.
    * @return the body field for this log.
    */
-  const opentelemetry::common::AttributeValue &GetBody() const noexcept override;
+  const opentelemetry::sdk::common::OwnedAttributeValue &GetBody() const noexcept override;
 
   /**
    * Set the Event Id object
@@ -151,8 +151,8 @@ class ReadWriteLogRecord final : public ReadableLogRecord
    * Get attributes of this log.
    * @return the body field of this log
    */
-  const std::unordered_map<std::string, opentelemetry::common::AttributeValue> &GetAttributes()
-      const noexcept override;
+  const std::unordered_map<std::string, opentelemetry::sdk::common::OwnedAttributeValue> &
+  GetAttributes() const noexcept override;
 
   /**
    * Get resource of this log
@@ -187,8 +187,8 @@ class ReadWriteLogRecord final : public ReadableLogRecord
   const opentelemetry::sdk::resource::Resource *resource_;
   const opentelemetry::sdk::instrumentationscope::InstrumentationScope *instrumentation_scope_;
 
-  std::unordered_map<std::string, opentelemetry::common::AttributeValue> attributes_map_;
-  opentelemetry::common::AttributeValue body_;
+  std::unordered_map<std::string, opentelemetry::sdk::common::OwnedAttributeValue> attributes_map_;
+  opentelemetry::sdk::common::OwnedAttributeValue body_;
   opentelemetry::common::SystemTimestamp timestamp_;
   opentelemetry::common::SystemTimestamp observed_timestamp_;
 

sdk/include/opentelemetry/sdk/logs/readable_log_record.h

@@ -75,7 +75,7 @@ class ReadableLogRecord : public Recordable
    * Get body field of this log.
    * @return the body field for this log.
    */
-  virtual const opentelemetry::common::AttributeValue &GetBody() const noexcept = 0;
+  virtual const opentelemetry::sdk::common::OwnedAttributeValue &GetBody() const noexcept = 0;
 
   /**
    * Get the Event id.
@@ -111,7 +111,7 @@ class ReadableLogRecord : public Recordable
    * Get attributes of this log.
    * @return the body field of this log
    */
-  virtual const std::unordered_map<std::string, opentelemetry::common::AttributeValue> &
+  virtual const std::unordered_map<std::string, opentelemetry::sdk::common::OwnedAttributeValue> &
   GetAttributes() const noexcept = 0;
 
   /**

sdk/src/logs/read_write_log_record.cc

@@ -12,6 +12,7 @@
 #include "opentelemetry/logs/severity.h"
 #include "opentelemetry/nostd/string_view.h"
 #include "opentelemetry/nostd/variant.h"
+#include "opentelemetry/sdk/common/attribute_utils.h"
 #include "opentelemetry/sdk/instrumentationscope/instrumentation_scope.h"
 #include "opentelemetry/sdk/logs/read_write_log_record.h"
 #include "opentelemetry/sdk/resource/resource.h"
@@ -30,7 +31,7 @@ ReadWriteLogRecord::ReadWriteLogRecord()
     : severity_(opentelemetry::logs::Severity::kInvalid),
       resource_(nullptr),
       instrumentation_scope_(nullptr),
-      body_(nostd::string_view()),
+      body_(std::string()),
       observed_timestamp_(std::chrono::system_clock::now()),
       event_id_(0),
       event_name_("")
@@ -71,10 +72,11 @@ opentelemetry::logs::Severity ReadWriteLogRecord::GetSeverity() const noexcept
 
 void ReadWriteLogRecord::SetBody(const opentelemetry::common::AttributeValue &message) noexcept
 {
-  body_ = message;
+  opentelemetry::sdk::common::AttributeConverter converter;
+  body_ = nostd::visit(converter, message);
 }
 
-const opentelemetry::common::AttributeValue &ReadWriteLogRecord::GetBody() const noexcept
+const opentelemetry::sdk::common::OwnedAttributeValue &ReadWriteLogRecord::GetBody() const noexcept
 {
   return body_;
 }
@@ -161,10 +163,12 @@ const opentelemetry::trace::TraceFlags &ReadWriteLogRecord::GetTraceFlags() cons
 void ReadWriteLogRecord::SetAttribute(nostd::string_view key,
                                       const opentelemetry::common::AttributeValue &value) noexcept
 {
-  attributes_map_[static_cast<std::string>(key)] = value;
+  std::string safe_key(key);
+  opentelemetry::sdk::common::AttributeConverter converter;
+  attributes_map_[safe_key] = nostd::visit(converter, value);
 }
 
-const std::unordered_map<std::string, opentelemetry::common::AttributeValue> &
+const std::unordered_map<std::string, opentelemetry::sdk::common::OwnedAttributeValue> &
 ReadWriteLogRecord::GetAttributes() const noexcept
 {
   return attributes_map_;

sdk/test/logs/log_record_test.cc

@@ -9,8 +9,8 @@
 #include <string>
 #include <unordered_map>
 #include <utility>
+#include <vector>
 
-#include "opentelemetry/common/attribute_value.h"
 #include "opentelemetry/common/key_value_iterable.h"
 #include "opentelemetry/common/timestamp.h"
 #include "opentelemetry/logs/log_record.h"
@@ -22,6 +22,7 @@
 #include "opentelemetry/nostd/string_view.h"
 #include "opentelemetry/nostd/unique_ptr.h"
 #include "opentelemetry/nostd/variant.h"
+#include "opentelemetry/sdk/common/attribute_utils.h"
 #include "opentelemetry/sdk/logs/read_write_log_record.h"
 #include "opentelemetry/sdk/resource/resource.h"
 #include "opentelemetry/trace/span_id.h"
@@ -72,13 +73,9 @@ TEST(ReadWriteLogRecord, SetAndGet)
 
   // Test that all fields match what was set
   ASSERT_EQ(record.GetSeverity(), logs_api::Severity::kInvalid);
-  if (nostd::holds_alternative<const char *>(record.GetBody()))
+  if (nostd::holds_alternative<std::string>(record.GetBody()))
   {
-    ASSERT_EQ(std::string(nostd::get<const char *>(record.GetBody())), "Message");
-  }
-  else if (nostd::holds_alternative<nostd::string_view>(record.GetBody()))
-  {
-    ASSERT_TRUE(nostd::get<nostd::string_view>(record.GetBody()) == "Message");
+    ASSERT_EQ(std::string(nostd::get<std::string>(record.GetBody())), "Message");
   }
   ASSERT_TRUE(nostd::get<bool>(record.GetResource().GetAttributes().at("res1")));
   ASSERT_EQ(nostd::get<int64_t>(record.GetAttributes().at("attr1")), 314159);
@@ -109,13 +106,13 @@ class TestBodyLogger : public opentelemetry::logs::Logger
     }
   }
 
-  const opentelemetry::common::AttributeValue &GetLastLogRecord() const noexcept
+  const opentelemetry::sdk::common::OwnedAttributeValue &GetLastLogRecord() const noexcept
   {
     return last_body_;
   }
 
 private:
-  opentelemetry::common::AttributeValue last_body_;
+  opentelemetry::sdk::common::OwnedAttributeValue last_body_;
 };
 
 // Define a basic LoggerProvider class that returns an instance of the logger class defined above
@@ -173,28 +170,19 @@ TEST(LogBody, BodyConversation)
 
   real_logger->EmitLogRecord(opentelemetry::logs::Severity::kInfo, "128");
   ASSERT_TRUE(
-      opentelemetry::nostd::holds_alternative<const char *>(real_logger->GetLastLogRecord()) ||
-      opentelemetry::nostd::holds_alternative<nostd::string_view>(real_logger->GetLastLogRecord()));
-  if (opentelemetry::nostd::holds_alternative<const char *>(real_logger->GetLastLogRecord()))
-  {
-    ASSERT_EQ(nostd::string_view{"128"},
-              opentelemetry::nostd::get<const char *>(real_logger->GetLastLogRecord()));
-  }
-  else
-  {
-    ASSERT_EQ(nostd::string_view{"128"},
-              opentelemetry::nostd::get<nostd::string_view>(real_logger->GetLastLogRecord()));
-  }
+      opentelemetry::nostd::holds_alternative<std::string>(real_logger->GetLastLogRecord()));
+  ASSERT_EQ(nostd::string_view{"128"},
+            opentelemetry::nostd::get<std::string>(real_logger->GetLastLogRecord()));
 
   {
     bool data[]                       = {true, false, true};
     nostd::span<const bool> data_span = data;
     real_logger->EmitLogRecord(opentelemetry::logs::Severity::kInfo, data_span);
-    ASSERT_TRUE(opentelemetry::nostd::holds_alternative<nostd::span<const bool>>(
+    ASSERT_TRUE(opentelemetry::nostd::holds_alternative<std::vector<bool>>(
         real_logger->GetLastLogRecord()));
 
-    nostd::span<const bool> output =
-        opentelemetry::nostd::get<nostd::span<const bool>>(real_logger->GetLastLogRecord());
+    std::vector<bool> output =
+        opentelemetry::nostd::get<std::vector<bool>>(real_logger->GetLastLogRecord());
 
     ASSERT_EQ(data_span.size(), output.size());
 
@@ -208,11 +196,11 @@ TEST(LogBody, BodyConversation)
     int32_t data[]                       = {221, 222, 223};
     nostd::span<const int32_t> data_span = data;
     real_logger->EmitLogRecord(opentelemetry::logs::Severity::kInfo, data_span);
-    ASSERT_TRUE(opentelemetry::nostd::holds_alternative<nostd::span<const int32_t>>(
+    ASSERT_TRUE(opentelemetry::nostd::holds_alternative<std::vector<int32_t>>(
         real_logger->GetLastLogRecord()));
 
     nostd::span<const int32_t> output =
-        opentelemetry::nostd::get<nostd::span<const int32_t>>(real_logger->GetLastLogRecord());
+        opentelemetry::nostd::get<std::vector<int32_t>>(real_logger->GetLastLogRecord());
 
     ASSERT_EQ(data_span.size(), output.size());
 
@@ -226,11 +214,11 @@ TEST(LogBody, BodyConversation)
     uint32_t data[]                       = {231, 232, 233};
     nostd::span<const uint32_t> data_span = data;
     real_logger->EmitLogRecord(opentelemetry::logs::Severity::kInfo, data_span);
-    ASSERT_TRUE(opentelemetry::nostd::holds_alternative<nostd::span<const uint32_t>>(
+    ASSERT_TRUE(opentelemetry::nostd::holds_alternative<std::vector<uint32_t>>(
         real_logger->GetLastLogRecord()));
 
-    nostd::span<const uint32_t> output =
-        opentelemetry::nostd::get<nostd::span<const uint32_t>>(real_logger->GetLastLogRecord());
+    std::vector<uint32_t> output =
+        opentelemetry::nostd::get<std::vector<uint32_t>>(real_logger->GetLastLogRecord());
 
     ASSERT_EQ(data_span.size(), output.size());
 
@@ -244,11 +232,11 @@ TEST(LogBody, BodyConversation)
     int64_t data[]                       = {241, 242, 243};
     nostd::span<const int64_t> data_span = data;
     real_logger->EmitLogRecord(opentelemetry::logs::Severity::kInfo, data_span);
-    ASSERT_TRUE(opentelemetry::nostd::holds_alternative<nostd::span<const int64_t>>(
+    ASSERT_TRUE(opentelemetry::nostd::holds_alternative<std::vector<int64_t>>(
         real_logger->GetLastLogRecord()));
 
-    nostd::span<const int64_t> output =
-        opentelemetry::nostd::get<nostd::span<const int64_t>>(real_logger->GetLastLogRecord());
+    std::vector<int64_t> output =
+        opentelemetry::nostd::get<std::vector<int64_t>>(real_logger->GetLastLogRecord());
 
     ASSERT_EQ(data_span.size(), output.size());
 
@@ -262,11 +250,11 @@ TEST(LogBody, BodyConversation)
     uint64_t data[]                       = {251, 252, 253};
     nostd::span<const uint64_t> data_span = data;
     real_logger->EmitLogRecord(opentelemetry::logs::Severity::kInfo, data_span);
-    ASSERT_TRUE(opentelemetry::nostd::holds_alternative<nostd::span<const uint64_t>>(
+    ASSERT_TRUE(opentelemetry::nostd::holds_alternative<std::vector<uint64_t>>(
         real_logger->GetLastLogRecord()));
 
-    nostd::span<const uint64_t> output =
-        opentelemetry::nostd::get<nostd::span<const uint64_t>>(real_logger->GetLastLogRecord());
+    std::vector<uint64_t> output =
+        opentelemetry::nostd::get<std::vector<uint64_t>>(real_logger->GetLastLogRecord());
 
     ASSERT_EQ(data_span.size(), output.size());
 
@@ -280,11 +268,11 @@ TEST(LogBody, BodyConversation)
     uint8_t data[]                       = {161, 162, 163};
     nostd::span<const uint8_t> data_span = data;
     real_logger->EmitLogRecord(opentelemetry::logs::Severity::kInfo, data_span);
-    ASSERT_TRUE(opentelemetry::nostd::holds_alternative<nostd::span<const uint8_t>>(
+    ASSERT_TRUE(opentelemetry::nostd::holds_alternative<std::vector<uint8_t>>(
         real_logger->GetLastLogRecord()));
 
-    nostd::span<const uint8_t> output =
-        opentelemetry::nostd::get<nostd::span<const uint8_t>>(real_logger->GetLastLogRecord());
+    std::vector<uint8_t> output =
+        opentelemetry::nostd::get<std::vector<uint8_t>>(real_logger->GetLastLogRecord());
 
     ASSERT_EQ(data_span.size(), output.size());
 
@@ -298,11 +286,11 @@ TEST(LogBody, BodyConversation)
     double data[]                       = {271.0, 272.0, 273.0};
     nostd::span<const double> data_span = data;
     real_logger->EmitLogRecord(opentelemetry::logs::Severity::kInfo, data_span);
-    ASSERT_TRUE(opentelemetry::nostd::holds_alternative<nostd::span<const double>>(
+    ASSERT_TRUE(opentelemetry::nostd::holds_alternative<std::vector<double>>(
         real_logger->GetLastLogRecord()));
 
-    nostd::span<const double> output =
-        opentelemetry::nostd::get<nostd::span<const double>>(real_logger->GetLastLogRecord());
+    std::vector<double> output =
+        opentelemetry::nostd::get<std::vector<double>>(real_logger->GetLastLogRecord());
 
     ASSERT_EQ(data_span.size(), output.size());
 
@@ -317,12 +305,11 @@ TEST(LogBody, BodyConversation)
     nostd::string_view data[] = {data_origin[0], data_origin[1], data_origin[2]};
     nostd::span<const nostd::string_view> data_span = data;
     real_logger->EmitLogRecord(opentelemetry::logs::Severity::kInfo, data_span);
-    ASSERT_TRUE(opentelemetry::nostd::holds_alternative<nostd::span<const nostd::string_view>>(
+    ASSERT_TRUE(opentelemetry::nostd::holds_alternative<std::vector<std::string>>(
         real_logger->GetLastLogRecord()));
 
-    nostd::span<const nostd::string_view> output =
-        opentelemetry::nostd::get<nostd::span<const nostd::string_view>>(
-            real_logger->GetLastLogRecord());
+    std::vector<std::string> output =
+        opentelemetry::nostd::get<std::vector<std::string>>(real_logger->GetLastLogRecord());
 
     ASSERT_EQ(data_span.size(), output.size());