Code cleanup and extended changelog for v0.12.4

Author: jmuehlig

CHANGELOG.md

@@ -3,7 +3,10 @@
 ## v0.12.4
 This update enables exporting sampled data to the standard perf format for analysis with existing tools.
 
-- **Perf Data Export**: Samples can now be written as *perf data files* using `Sampler::to_perf_file()`, enabling analysis with standard perf ecosystem tools like perf report (see the [documentation](docs/analyzing-samples-with-perf-report.md)).
+- **Bugfix**: The library crashed when events loaded from an external CSV file contained empty spaces (see [#8](https://github.com/jmuehlig/perf-cpp/issues/8)). Thanks to [@Liteom](https://github.com/Liteom).
+- **Bugfix**: The library could not compile for specific Linux kernels not providing `PERF_MEM_LVLNUM_UNC` and `PERF_MEM_SNOOPX_PEER` (see [#7](https://github.com/jmuehlig/perf-cpp/issues/7)). Thanks to [@Raphalex46](https://github.com/Raphalex46) for pointing out. 
+- **Perf Data Export**: Samples can now be written as *perf data files* using `Sampler::to_perf_file()`, enabling analysis with standard perf ecosystem tools like perf report (see the [documentation](docs/analyzing-samples-with-perf-report.md)). **Note that this feature is experimental.**
+
 
 ## v0.12.3
 This update simplifies the handling of counter definitions by introducing a default instance.

docs/analyzing-samples-with-perf-report.md

@@ -11,6 +11,10 @@ This gives you the best of both worlds:
 
 → [For a practical implementation, check out our perf data export example.](../examples/sampling/perf_record.cpp)
 
+> [!IMPORTANT]
+> This feature is considered as being **experimental**.
+
+
 ---
 ## Table of Contents
 - [Overview](#overview)

src/event_provider.cpp

@@ -332,21 +332,25 @@ perf::SystemSpecificEventProvider::parse_event_file_descriptor_format(std::files
 std::optional<std::uint64_t>
 perf::SystemSpecificEventProvider::parse_integer(const std::string& value)
 {
-  std::string copied_str = value;
-  copied_str.erase(std::remove_if(copied_str.begin(), copied_str.end(), [](unsigned char c){return std::isspace(c);}), copied_str.end());
-
-  if (copied_str.empty()) {
+  if (value.empty()) {
     return std::nullopt;
   }
 
+  /// Remove all whitespaces if the value has at least one.
+  if (value.find_first_of(' ') != std::string::npos) {
+    auto value_without_leading_whitespace = value;
+    value_without_leading_whitespace.erase(std::remove_if(value_without_leading_whitespace.begin(), value_without_leading_whitespace.end(), ::isspace), value_without_leading_whitespace.end());
+    return SystemSpecificEventProvider::parse_integer(value_without_leading_whitespace);
+  }
+
   /// Strings starting with '0x' are considered hex numbers.
-  if (copied_str.rfind("0x", 0ULL) == 0ULL) {
-    return std::stoull(copied_str.substr(2ULL), nullptr, 16);
+  if (value.rfind("0x", 0ULL) == 0ULL) {
+    return std::stoull(value.substr(2ULL), nullptr, 16);
   }
 
   /// Strings containing digits are considered dec numbers.
-  if (std::all_of(copied_str.begin(), copied_str.end(), [](const auto c) { return std::isdigit(c); })) {
-    return std::stoull(copied_str, nullptr, 0);
+  if (std::all_of(value.begin(), value.end(), [](const auto c) { return std::isdigit(c); })) {
+    return std::stoull(value, nullptr, 0);
   }
 
   return std::nullopt;

src/record_file_writer.cpp

@@ -75,7 +75,8 @@ perf::RecordFileWriter::write(const Sampler::Values& sampler_values,
 
   /// Write attributes with proper file structure.
   for (const auto& counter : sample_counters) {
-    const auto& perf_event_attribute = counter.group().member(0U).perf_event_attribute();
+    const auto event_index = 0U + static_cast<std::uint8_t>(counter.has_intel_auxiliary_event());
+    const auto& perf_event_attribute = counter.group().member(event_index).perf_event_attribute();
 
     /// Create attribute file section (offset and size are empty by default).
     auto attribute_section = AttributeFileSection{};