DP44/enriched-qwen3-coder-next/Common/DTS.Common.Storage/Classes/Static.md

source_files, generated_at, model, schema_version, sha256

source_files	generated_at	model	schema_version	sha256
Common/DTS.Common.Storage/Classes/Static/CustomChannelFieldSizeAttribute.cs	2026-04-16T02:11:01.276588+00:00	Qwen/Qwen3-Coder-Next-FP8	1	96c94c51da2a1b2d

Static

1. Purpose

This module provides a mechanism to associate custom, non-default field sizes with enum values representing channel fields in the MMETables.MMEPossibleChannelsFields enumeration. It enables runtime retrieval of field-specific size metadata via a custom attribute (CustomChannelFieldSizeAttribute) and extension methods, supporting scenarios where the default size inference (e.g., based on underlying type or convention) is insufficient or incorrect.

2. Public Interface

• CustomChannelFieldSizeAttribute(int size)
  Constructor. Creates an attribute instance with the specified field size. size must be non-negative (enforced by caller; no validation in constructor).
• int Size { get; }
  Property. Returns the field size stored in the attribute. Read-only after construction.
• int GetFieldSize(MMETables.MMEPossibleChannelsFields field)
  Extension method. Retrieves the field size for a given MMEPossibleChannelsFields enum value by inspecting its CustomChannelFieldSizeAttribute. Throws NullReferenceException if the attribute is not applied to the enum value (since .Size is accessed on a null reference returned by GetAttribute<>()).
• TAttribute GetAttribute<TAttribute>(this Enum value)
  Extension method. Returns the first (and expected only) custom attribute of type TAttribute applied to the enum value, or null if none exists. Uses reflection to inspect the enum field’s attributes.

3. Invariants

• CustomChannelFieldSizeAttribute is only intended for use on MMETables.MMEPossibleChannelsFields enum members.
• The Size property must be set at construction and remains immutable thereafter.
• GetFieldSize assumes exactly one CustomChannelFieldSizeAttribute per enum member; behavior is undefined if multiple attributes are applied (though SingleOrDefault() would return the first if duplicates exist, which is invalid per attribute semantics).
• GetAttribute<TAttribute> returns null if no attribute of type TAttribute is present on the enum value.

4. Dependencies

• Internal dependencies:
  • MMETables.MMEPossibleChannelsFields enum (from MMETables namespace—external to this file but referenced in GetFieldSize).
  • Standard .NET reflection APIs (System.Type, System.Reflection.FieldInfo, System.Linq.Enumerable).
• No external NuGet or third-party dependencies beyond the base class library.
• Dependent modules: Any code that needs to retrieve field sizes for MMEPossibleChannelsFields values—likely storage or serialization components dealing with channel data.

5. Gotchas

• Null reference risk: GetFieldSize will throw NullReferenceException if CustomChannelFieldSizeAttribute is not applied to the queried enum member (since GetAttribute<>() returns null, and .Size is dereferenced unconditionally). Callers must ensure the attribute is present or guard against null.
• No validation on size: The constructor accepts any int, including negative values. No runtime checks enforce valid size constraints (e.g., size ≥ 0).
• Reflection overhead: GetAttribute<TAttribute> uses reflection on every call; not suitable for hot paths without caching.
• Ambiguity in MMETables namespace: The MMETables.MMEPossibleChannelsFields type is referenced but not defined here; its actual definition and available members are unknown from this file alone.
• No XML documentation: The source contains no comments; behavior is inferred solely from code structure.