Scaidome.Logging 1.2.2

Scaidome.Logging

A logging provider for Microsoft.Extensions.Logging that writes to a rolling file. Depends on Microsoft.Extensions.Logging.Abstractions. Namespace: Scaidome.Logging.File.

Usage

The host binds the options from configuration and constructs the provider itself:

var fileLogging = new FileLoggerProvider(options);
builder.Logging.AddProvider(fileLogging);

// The file keeps its own levels, so the framework passes everything through and the file's loggers decide.
builder.Logging.AddFilter<FileLoggerProvider>(null, LogLevel.Trace);

// ... run the host ...

fileLogging.Dispose(); // last, after the host has stopped

Construct the provider before the host is built and dispose it after the host has stopped. The last lines before a shutdown often explain it, and a provider disposed by the container could be gone before those lines are written.

Options

FileLoggerOptions is usually bound from a File section under Logging. The provider's alias is File.

A logger's level is decided once, when the logger is created. The longest configured category that the logger's category starts with decides the level; otherwise Default does, and it is Information if not given.

Behaviour

• Callers never wait on the file. Every logger queues its entries, and one background thread writes them to the file in order.

• Nothing holds the file between entries. It is opened for each entry and closed again, and it is shared for reading and deleting.

• Rolling happens before a write. When the live file has reached the size limit, the oldest numbered file is deleted, the other numbered files move up one (app.log.1 becomes app.log.2), and the live file becomes app.log.1. With MaxRollingFiles at 1, the live file is simply deleted.

• Logging never fails its caller. A failed write is dropped, because there is nowhere else to report it. An entry logged after disposal is dropped too.

• Disposal waits, but not forever. It waits up to two seconds for queued entries to be written, then cancels. Any entries not written by then are dropped.

• Entry format. Local time with its offset, the level in brackets, the category (with a non-zero event id in brackets), then a colon and the message. The exception's full text follows on the next lines.

  2026-09-26 11:08:36.123+02:00 [Warning] Scai.Core.Auth[12]: Message text
  

Known defect

Scopes aren't supported: BeginScope returns null, so a caller that disposes the result must allow for null. The fix is to return a scope object that does nothing. A test pins the current behaviour.