[projmgr] Improve performance of yml file content comparison

Author: grasci-arm

tools/projmgr/include/ProjMgrUtils.h

@@ -295,6 +295,13 @@ class ProjMgrUtils {
   */
   static const std::string FileTypeFromExtension(const std::string& file);
 
+  /**
+   * @brief normalize line endings for consistent string comparison
+   * @param input string
+   * @return output normalized string
+  */
+  static const std::string NormalizeLineEndings(const std::string& in);
+
 protected:
   /**
    * @brief get filtered list of contexts

tools/projmgr/include/ProjMgrYamlEmitter.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020-2024 Arm Limited. All rights reserved.
+ * Copyright (c) 2020-2025 Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -114,6 +114,7 @@ class ProjMgrYamlEmitter {
   bool CompareFile(const std::string& filename, const YAML::Node& rootNode);
   bool CompareNodes(const YAML::Node& lhs, const YAML::Node& rhs);
   bool NeedRebuild(const std::string& filename, const YAML::Node& rootNode);
+  std::string EraseGeneratedByNode(const std::string& inStr);
 };
 
 #endif  // PROJMGRYAMLEMITTER_H

tools/projmgr/src/ProjMgrUtils.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020-2021 Arm Limited. All rights reserved.
+ * Copyright (c) 2020-2025 Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -464,3 +464,16 @@ const string ProjMgrUtils::FileTypeFromExtension(const string& file) {
   }
   return RteUtils::EMPTY_STRING;
 }
+
+const std::string ProjMgrUtils::NormalizeLineEndings(const std::string& in) {
+  string out = in;
+  size_t pos = 0;
+  while ((pos = out.find("\r\n", pos)) != std::string::npos) {
+    out.replace(pos++, 2, "\n");
+  }
+  pos = 0;
+  while ((pos = out.find("\r", pos)) != std::string::npos) {
+    out.replace(pos, 1, "\n");
+  }
+  return out;
+}

tools/projmgr/src/ProjMgrYamlEmitter.cpp

@@ -87,29 +87,29 @@ bool ProjMgrYamlEmitter::WriteFile(YAML::Node& rootNode, const std::string& file
   return true;
 }
 
+string ProjMgrYamlEmitter::EraseGeneratedByNode(const string& inStr) {
+  size_t startIndex, endIndex;
+  string outStr = inStr;
+  startIndex = outStr.find(YAML_GENERATED_BY, 0);
+  endIndex = outStr.find('\n', startIndex);
+  if (startIndex != std::string::npos && endIndex != std::string::npos) {
+    outStr = outStr.erase(startIndex, endIndex - startIndex);
+  }
+  return outStr;
+};
+
 bool ProjMgrYamlEmitter::CompareFile(const string& filename, const YAML::Node& rootNode) {
-  if (!RteFsUtils::Exists(filename)) {
+  string inBuffer;
+  if (!RteFsUtils::Exists(filename) || !RteFsUtils::ReadFile(filename, inBuffer)) {
     return false;
   }
-  const YAML::Node& yamlRoot = YAML::LoadFile(filename);
-
-  // emit and load rootNode to ensure both comparison sides have the same formatting
   YAML::Emitter emitter;
-  return CompareNodes(yamlRoot, YAML::Load((emitter << rootNode).c_str()));
+  const auto& outBuffer = string((emitter << rootNode).c_str()) + '\n';
+  return ProjMgrUtils::NormalizeLineEndings(EraseGeneratedByNode(inBuffer)) ==
+    ProjMgrUtils::NormalizeLineEndings(EraseGeneratedByNode(outBuffer));
 }
 
 bool ProjMgrYamlEmitter::CompareNodes(const YAML::Node& lhs, const YAML::Node& rhs) {
-  auto eraseGenNode = [](const string& inStr) {
-    size_t startIndex, endIndex;
-    string outStr = inStr;
-    startIndex = outStr.find(YAML_GENERATED_BY, 0);
-    endIndex = outStr.find('\n', startIndex);
-    if (startIndex != std::string::npos && endIndex != std::string::npos) {
-      outStr = outStr.erase(startIndex, endIndex - startIndex);
-    }
-    return outStr;
-  };
-
   YAML::Emitter lhsEmitter, rhsEmitter;
   string lhsData, rhsData;
 
@@ -118,8 +118,8 @@ bool ProjMgrYamlEmitter::CompareNodes(const YAML::Node& lhs, const YAML::Node& r
   rhsEmitter << rhs;
 
   // remove generated-by node from the string
-  lhsData = eraseGenNode(lhsEmitter.c_str());
-  rhsData = eraseGenNode(rhsEmitter.c_str());
+  lhsData = EraseGeneratedByNode(lhsEmitter.c_str());
+  rhsData = EraseGeneratedByNode(rhsEmitter.c_str());
 
   return (lhsData == rhsData) ? true : false;
 }

tools/projmgr/test/src/ProjMgrUtilsUnitTests.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020-2024 Arm Limited. All rights reserved.
+ * Copyright (c) 2020-2025 Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -531,3 +531,11 @@ TEST_F(ProjMgrUtilsUnitTests, ULLToHex) {
   EXPECT_EQ("0xDEADBEEF", ProjMgrUtils::ULLToHex(3735928559));
   EXPECT_EQ("0xFFFFFFFF", ProjMgrUtils::ULLToHex(4294967295));
 }
+
+TEST_F(ProjMgrUtilsUnitTests, NormalizeLineEndings) {
+  EXPECT_EQ("abc\ndef\n", ProjMgrUtils::NormalizeLineEndings("abc\r\ndef\r\n"));
+  EXPECT_EQ("abc\ndef\n", ProjMgrUtils::NormalizeLineEndings("abc\rdef\r"));
+  EXPECT_EQ("abc\ndef\n", ProjMgrUtils::NormalizeLineEndings("abc\rdef\n"));
+  EXPECT_EQ("abc\ndef\n", ProjMgrUtils::NormalizeLineEndings("abc\ndef\r"));
+  EXPECT_EQ("abc\ndef\n", ProjMgrUtils::NormalizeLineEndings("abc\ndef\n"));
+}