Properly order the metrics results

[mcserep]

C++ metrics results are not properly sorted, since currently the results are returned in a std::map, whose key is the ASTNode ID (or File ID), interpreted as strings. However, these IDs are stored as signed integers in the database, while in the CodeCompass codebase they are unsigned integers. Their comparison should therefore be performed as integers (because the database engine also does this for the ORDER BY clause), otherwise it is not certain that the last element will be the largest ID in the given result set. This is especially troubling for paginated results.

[Copilot]

Pull Request Overview

This PR changes the C++ metrics API from returning results in std::map containers (keyed by string representations of IDs) to returning results in ordered std::vector containers. This addresses a sorting issue where string-based comparison of IDs was inconsistent with integer-based database ordering, particularly problematic for paginated results.

• Replaced std::map return types with std::vector of structured entry types
• Added explicit ORDER BY clauses to database queries for consistent ordering
• Introduced new Thrift struct types to support the vector-based API

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 4 comments.

File	Description
cxxmetrics.thrift	Defines new entry struct types for vector-based API
cppmetricsservice.h	Updates method signatures to use vector return types
cppmetricsservice.cpp	Implements vector-based logic with proper ordering

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[Copilot]

Converting string to unsigned long long for every comparison creates a performance bottleneck. Consider storing the numeric ID alongside the string ID in the entry struct to avoid repeated conversions.

[Copilot]

Converting string to unsigned long long for every comparison creates a performance bottleneck. Consider storing the numeric ID alongside the string ID in the entry struct to avoid repeated conversions.

Suggested change

	return std::stoull(entry.astNodeId) == node.astNodeId;
	return entry.astNodeIdNum == node.astNodeId;

[Copilot]

Converting string to unsigned long long for every comparison creates a performance bottleneck. Consider storing the numeric ID alongside the string ID in the entry struct to avoid repeated conversions.

Suggested change

	return std::stoull(entry.fileId) == file.fileId;
	return entry.fileIdNumeric == file.fileId;