| | | 1 | | using System; |
| | | 2 | | |
| | | 3 | | using Microsoft.Extensions.Logging; |
| | | 4 | | |
| | | 5 | | namespace NexusLabs.Needlr.Logging; |
| | | 6 | | |
| | | 7 | | /// <summary> |
| | | 8 | | /// Marks a <c>partial</c> method whose body Needlr will source-generate into a |
| | | 9 | | /// high-performance, cancellation-aware logging method. |
| | | 10 | | /// </summary> |
| | | 11 | | /// <remarks> |
| | | 12 | | /// <para> |
| | | 13 | | /// This attribute mirrors the surface of <c>Microsoft.Extensions.Logging.LoggerMessageAttribute</c> |
| | | 14 | | /// (<see cref="EventId"/>, <see cref="EventName"/>, <see cref="Level"/>, <see cref="Message"/>, |
| | | 15 | | /// <see cref="SkipEnabledCheck"/>) so migrating an existing <c>[LoggerMessage]</c> method is a |
| | | 16 | | /// near drop-in swap. The generated body reuses the public |
| | | 17 | | /// <see cref="LoggerMessage.Define(LogLevel, EventId, string)"/> primitive — the same fast path the |
| | | 18 | | /// built-in generator targets — so there is no performance penalty for the common case. |
| | | 19 | | /// </para> |
| | | 20 | | /// <para> |
| | | 21 | | /// The difference from the built-in attribute is the <em>cancellation guard</em>: when the method |
| | | 22 | | /// has a parameter assignable to <see cref="System.Exception"/> and that argument is a cancellation |
| | | 23 | | /// (an <see cref="OperationCanceledException"/> by default), the generated body consults |
| | | 24 | | /// <see cref="NeedlrCancellationLogging"/> and, by default, <strong>skips the log entirely</strong>. |
| | | 25 | | /// Cancellation is normal control flow in production code, so logging it as a warning or error is |
| | | 26 | | /// usually noise. The behavior can be globally overridden at startup (force-log or demote to a lower |
| | | 27 | | /// level) via <see cref="NeedlrCancellationLogging"/>. |
| | | 28 | | /// </para> |
| | | 29 | | /// <para> |
| | | 30 | | /// The decorated method must be <c>partial</c>, return <c>void</c>, be non-generic, and live in a |
| | | 31 | | /// <c>partial</c> type. For an <c>instance</c> method, the containing type must expose an |
| | | 32 | | /// <see cref="ILogger"/> field or property; for a <c>static</c> method, an <see cref="ILogger"/> |
| | | 33 | | /// parameter supplies the logger. |
| | | 34 | | /// </para> |
| | | 35 | | /// <para> |
| | | 36 | | /// This is a source-generation only feature. It requires the |
| | | 37 | | /// <c>NexusLabs.Needlr.Logging</c> package and the generator that ships with it. |
| | | 38 | | /// </para> |
| | | 39 | | /// </remarks> |
| | | 40 | | /// <example> |
| | | 41 | | /// <code> |
| | | 42 | | /// using Microsoft.Extensions.Logging; |
| | | 43 | | /// using NexusLabs.Needlr.Logging; |
| | | 44 | | /// |
| | | 45 | | /// public partial class OrderService |
| | | 46 | | /// { |
| | | 47 | | /// private readonly ILogger<OrderService> _logger; |
| | | 48 | | /// |
| | | 49 | | /// public OrderService(ILogger<OrderService> logger) => _logger = logger; |
| | | 50 | | /// |
| | | 51 | | /// // When 'error' is an OperationCanceledException, this logs nothing by default. |
| | | 52 | | /// [NeedlrLoggerMessage(EventId = 42, Level = LogLevel.Warning, Message = "Order {OrderId} failed")] |
| | | 53 | | /// public partial void LogOrderFailed(int orderId, Exception error); |
| | | 54 | | /// } |
| | | 55 | | /// </code> |
| | | 56 | | /// </example> |
| | | 57 | | [AttributeUsage(AttributeTargets.Method, Inherited = false, AllowMultiple = false)] |
| | | 58 | | public sealed class NeedlrLoggerMessageAttribute : Attribute |
| | | 59 | | { |
| | | 60 | | /// <summary> |
| | | 61 | | /// Initializes a new instance of the <see cref="NeedlrLoggerMessageAttribute"/> class. |
| | | 62 | | /// All values are supplied via the named properties. |
| | | 63 | | /// </summary> |
| | 0 | 64 | | public NeedlrLoggerMessageAttribute() |
| | | 65 | | { |
| | 0 | 66 | | } |
| | | 67 | | |
| | | 68 | | /// <summary> |
| | | 69 | | /// Initializes a new instance of the <see cref="NeedlrLoggerMessageAttribute"/> class with a |
| | | 70 | | /// message template. The <see cref="Level"/> defaults to <see cref="LogLevel.Information"/>. |
| | | 71 | | /// </summary> |
| | | 72 | | /// <param name="message">The structured message template (e.g. <c>"Order {OrderId} failed"</c>).</param> |
| | 0 | 73 | | public NeedlrLoggerMessageAttribute(string message) |
| | | 74 | | { |
| | 0 | 75 | | Message = message; |
| | 0 | 76 | | } |
| | | 77 | | |
| | | 78 | | /// <summary> |
| | | 79 | | /// Initializes a new instance of the <see cref="NeedlrLoggerMessageAttribute"/> class with a |
| | | 80 | | /// log level and message template. |
| | | 81 | | /// </summary> |
| | | 82 | | /// <param name="level">The level at which the message is logged.</param> |
| | | 83 | | /// <param name="message">The structured message template (e.g. <c>"Order {OrderId} failed"</c>).</param> |
| | 0 | 84 | | public NeedlrLoggerMessageAttribute(LogLevel level, string message) |
| | | 85 | | { |
| | 0 | 86 | | Level = level; |
| | 0 | 87 | | Message = message; |
| | 0 | 88 | | } |
| | | 89 | | |
| | | 90 | | /// <summary> |
| | | 91 | | /// Initializes a new instance of the <see cref="NeedlrLoggerMessageAttribute"/> class with an |
| | | 92 | | /// event id, log level, and message template. |
| | | 93 | | /// </summary> |
| | | 94 | | /// <param name="eventId">The numeric event id assigned to the log entry.</param> |
| | | 95 | | /// <param name="level">The level at which the message is logged.</param> |
| | | 96 | | /// <param name="message">The structured message template (e.g. <c>"Order {OrderId} failed"</c>).</param> |
| | 0 | 97 | | public NeedlrLoggerMessageAttribute(int eventId, LogLevel level, string message) |
| | | 98 | | { |
| | 0 | 99 | | EventId = eventId; |
| | 0 | 100 | | Level = level; |
| | 0 | 101 | | Message = message; |
| | 0 | 102 | | } |
| | | 103 | | |
| | | 104 | | /// <summary> |
| | | 105 | | /// Gets or sets the numeric event id assigned to the generated log entry. Defaults to <c>0</c>. |
| | | 106 | | /// </summary> |
| | 0 | 107 | | public int EventId { get; set; } |
| | | 108 | | |
| | | 109 | | /// <summary> |
| | | 110 | | /// Gets or sets the event name assigned to the generated log entry. When <see langword="null"/>, |
| | | 111 | | /// the decorated method's name is used. |
| | | 112 | | /// </summary> |
| | 0 | 113 | | public string? EventName { get; set; } |
| | | 114 | | |
| | | 115 | | /// <summary> |
| | | 116 | | /// Gets or sets the level at which the message is logged. Defaults to |
| | | 117 | | /// <see cref="LogLevel.Information"/> when not supplied via a constructor. |
| | | 118 | | /// </summary> |
| | 0 | 119 | | public LogLevel Level { get; set; } = LogLevel.Information; |
| | | 120 | | |
| | | 121 | | /// <summary> |
| | | 122 | | /// Gets or sets the structured message template. Placeholders (e.g. <c>{OrderId}</c>) bind to the |
| | | 123 | | /// method's non-exception parameters in declaration order, exactly as with the built-in attribute. |
| | | 124 | | /// </summary> |
| | 0 | 125 | | public string Message { get; set; } = string.Empty; |
| | | 126 | | |
| | | 127 | | /// <summary> |
| | | 128 | | /// Gets or sets a value indicating whether the generated body omits the |
| | | 129 | | /// <see cref="ILogger.IsEnabled(LogLevel)"/> guard. Set to <see langword="true"/> only when the |
| | | 130 | | /// caller has already checked that the level is enabled. Defaults to <see langword="false"/>. |
| | | 131 | | /// </summary> |
| | 0 | 132 | | public bool SkipEnabledCheck { get; set; } |
| | | 133 | | } |