Add test for attributes

structure/attributes/README.md

@@ -0,0 +1,14 @@
+# Attributes
+
+## Fields
+
+ * `Int{32}`
+
+one regular and one attribute field.
+
+## Entries
+
+1. Simple values
+2. Zero / empty values
+
+The values can be found in the reference file `structure.attributes.json`.

structure/attributes/read.C

@@ -0,0 +1,127 @@
+#include <ROOT/RNTupleReader.hxx>
+#include <ROOT/RVersion.hxx>
+
+#include <iostream>
+
+void read(std::string_view input = "structure.attributes.root",
+          std::string_view output = "structure.attributes.json") {
+#if ROOT_VERSION_CODE < ROOT_VERSION(6, 40, 0)
+  std::cout << "Skipped structure/attributes/read.C - ROOT version too old."
+            << std::endl;
+#else
+  // same logic as is read_structure.hxx, with additional special part for
+  // attributes
+  std::unique_ptr<ROOT::RNTupleReader> reader;
+  try {
+    reader = ROOT::RNTupleReader::Open("ntpl", input);
+  } catch (const ROOT::RException &e) {
+    std::ofstream os(std::string{output});
+    std::string msgWithoutStacktrace;
+    std::getline(std::istringstream(e.what()), msgWithoutStacktrace);
+    os << "{\n";
+    os << "  \"error\": \"" << msgWithoutStacktrace << "\"\n";
+    os << "}\n";
+    return;
+  } catch (const runtime_error &e) {
+    cout << "Skipped structure/attributes/read.C - " << e.what() << endl;
+    return;
+  }
+
+  std::ofstream os(std::string{output});
+  os << "[\n";
+  auto Int32 =
+      reader->GetModel().GetDefaultEntry().GetPtr<std::int32_t>("Int32");
+  bool first = true;
+  // for (auto index : *reader) {
+  //   reader->LoadEntry(index);
+
+  //   if (first) {
+  //     first = false;
+  //   } else {
+  //     os << ",\n";
+  //   }
+  //   os << "  {\n";
+  //   os << "    \"Int32\": " << *Int32 << "\n";
+  //   os << "  }";
+  //   // Newline is intentionally missing, may need to print a comma before the
+  //   // next entry.
+  // }
+
+  // // read available attribute sets
+  // for (const auto &attrSetDesc : reader->GetDescriptor().GetAttrSetIterable()) {
+  //   os << ",\n";
+  //   os << "  {\n";
+  //   os << "    \"Attribute set\": \"" << attrSetDesc.GetName() << "\"\n";
+  //   os << "  }";
+  // }
+
+  // auto attrSet = reader->OpenAttributeSet("Attributes");
+  // os << ",\n";
+  // os << "  {\n";
+  // os << "    \"Description\": \"" << attrSet->GetDescriptor().GetDescription() << "\"\n";
+  // os << "  }";
+
+  // auto attr = attrSet->GetModel().GetDefaultEntry().GetPtr<std::int32_t>("attr");
+
+  // for (auto idx : reader->GetEntryRange()) {
+  //   std::cout << "Entry " << idx << " has the following attributes associated to it:\n";
+  //   for (auto attrIdx : attrSet->GetAttributes(idx)) {
+  //     auto range = attrSet->LoadEntry(attrIdx);
+  //     std::cout << "  runNumber = " << *attr << " (valid for range [" << *range.GetFirst() << ", "
+  //               << *range.GetLast() << "])\n";
+  //   }
+  // }
+
+  auto attrSet = reader->OpenAttributeSet("Attributes");
+  auto attr1 = attrSet->GetModel().GetDefaultEntry().GetPtr<std::int32_t>("attr1");
+  auto attr2 = attrSet->GetModel().GetDefaultEntry().GetPtr<std::int32_t>("attr2");
+
+  std::cout << "\nOpened attribute set '" << attrSet->GetDescriptor().GetName() << "' with description: \""
+            << attrSet->GetDescriptor().GetDescription() << "\"\n";
+
+  os << "  {\n";
+  os << "    \"Attribute set name\": \"" << attrSet->GetDescriptor().GetName() << "\"\n";
+  os << "  }, \n";
+  os << "  {\n";
+  os << "    \"Description\": \"" << attrSet->GetDescriptor().GetDescription() << "\"\n";
+  os << "  },\n";
+
+  first = true;
+  for (auto mainIdx : reader->GetEntryRange()) {
+    reader->LoadEntry(mainIdx);
+    std::cout << "Entry " << mainIdx << " with value " << *Int32 << " has the following attributes associated to it:\n";
+
+    if (first) {
+      first = false;
+    } else {
+      os << ",\n";
+    }
+    os << "  {\n";
+    os << "    \"Int32\": " << *Int32 << "\n";
+    os << "  }";
+    for (auto attrIdx : attrSet->GetAttributes(mainIdx)) {
+        auto range = attrSet->LoadEntry(attrIdx);
+        if (*attr1 > 0) {
+          os << ",\n  {\n";
+          os << "    \"Attr1\": " << *attr1 << "\n";
+          os << "  }";
+        }
+        if (*attr2 > 0) {
+          os << ",\n  {\n";
+          os << "    \"Attr2\": " << *attr2 << "\n";
+          os << "  }";
+        }
+        std::cout << "  attr1 = " << *attr1 << " (valid for range [" << *range.GetFirst() << ", "
+                  << *range.GetLast() << "])\n";
+        std::cout << "  attr2 = " << *attr2 << " (valid for range [" << *range.GetFirst() << ", "
+                  << *range.GetLast() << "])\n";
+    }
+   }
+
+  if (!first) {
+    os << "\n";
+  }
+
+  os << "]\n";
+#endif
+}

structure/attributes/write.C

@@ -0,0 +1,56 @@
+#include <ROOT/RNTupleModel.hxx>
+#include <ROOT/RNTupleWriteOptions.hxx>
+#include <ROOT/RNTupleWriter.hxx>
+#include <ROOT/RVersion.hxx>
+
+#include <TFile.h>
+#include <cstdint>
+#include <string_view>
+
+void write(std::string_view filename = "structure.attributes.root") {
+#if ROOT_VERSION_CODE < ROOT_VERSION(6, 40, 0)
+  std::cout << "Skipped structure/attributes/write.C - ROOT version too old."
+            << std::endl;
+#else
+  auto model = ROOT::RNTupleModel::Create();
+  auto Int32 = model->MakeField<std::int32_t>("Int32");
+
+  auto file = std::unique_ptr<TFile>(TFile::Open(std::string(filename).c_str(), "RECREATE"));
+  auto writer = ROOT::RNTupleWriter::Append(std::move(model), "ntpl", *file);
+
+  // definition of attribute set with attribute fields
+  auto attrModel = ROOT::RNTupleModel::Create();
+  attrModel->SetDescription("Informationless description for attribute set");
+  auto attr1 = attrModel->MakeField<std::int32_t>("attr1");
+  auto attr2 = attrModel->MakeField<std::int32_t>("attr2");
+
+  // creation of attribute set
+  auto attrSet = writer->CreateAttributeSet(std::move(attrModel), "Attributes");
+  auto attrRange = attrSet->BeginRange();
+  *attr1 = 0;
+  *attr2 = 0;
+
+  int num_entries = 3;
+  for (int i=0; i<num_entries; i++) {
+    *Int32 = (i+1) * 5;
+    writer->Fill();
+
+    // attr1 attached to first entry, attr2 attached to second and third entry
+    if (i == 0) {
+      *attr1 = i+1;
+      attrSet->CommitRange(std::move(attrRange));
+      attrRange = attrSet->BeginRange();
+      *attr1 = 0;
+    } else {
+      *attr2 = i+1;
+      attrSet->CommitRange(std::move(attrRange));
+      attrRange = attrSet->BeginRange();
+      *attr2 = 0;
+    }
+  }
+
+  if (attrRange) {
+    attrSet->CommitRange(std::move(attrRange));
+  }
+#endif
+}