GenericChannelDiagnosticFormatterFactory.cs

Go to the documentation of this file.

using System;
using System.Linq;
 
namespace IKVM.Tools.Core.Diagnostics
{
 
    abstract class GenericChannelDiagnosticFormatterFactory<TFormatter, TOptions> : IDiagnosticFormatterFactory
        where TFormatter : IDiagnosticFormatter
        where TOptions : DiagnosticChannelFormatterOptions, new()
    {
 
        static readonly char[] SEPARATOR = ['='];
 
        readonly DiagnosticChannelProvider _channels;
        readonly string _format;
        readonly string _formatPrefix;
 
        public GenericChannelDiagnosticFormatterFactory(DiagnosticChannelProvider channels, string format)
        {
            _channels = channels ?? throw new ArgumentNullException(nameof(channels));
            _format = format ?? throw new ArgumentNullException(nameof(format));
            _formatPrefix = $"{_format},";
        }
 
        public IDiagnosticFormatter? GetFormatter(string spec)
        {
            if (spec != _format && spec.StartsWith(_formatPrefix) == false)
                return null;
 
            // strip format
            var specArray = spec.Split(',');
            if (specArray.Length == 0 || specArray[0] != _format)
                return null;
 
            // split and parse option information
            var opts = new TOptions();
            foreach (var optionSpec in specArray.Skip(1))
                ParseOption(opts, optionSpec);
 
            // set default channel if missing
            opts.TraceChannel ??= GetOrCreateChannel(FileDiagnosticChannelFactory.STDOUT);
            opts.InfoChannel ??= GetOrCreateChannel(FileDiagnosticChannelFactory.STDOUT);
            opts.WarningChannel ??= GetOrCreateChannel(FileDiagnosticChannelFactory.STDERR);
            opts.ErrorChannel ??= GetOrCreateChannel(FileDiagnosticChannelFactory.STDERR);
            opts.FatalChannel ??= GetOrCreateChannel(FileDiagnosticChannelFactory.STDERR);
 
            // process options and create formatter
            return CreateFormatter(opts);
        }
 
        protected abstract TFormatter CreateFormatter(TOptions options);
 
        void ParseOption(TOptions options, string spec)
        {
            var a = spec.Split(SEPARATOR, 2, StringSplitOptions.None);
            var key = a.Length >= 1 ? a[0] : "";
            var val = a.Length >= 2 ? a[1] : "";
 
            if (string.IsNullOrWhiteSpace(key))
                return;
 
            if (key is "file" or "trace:file")
                options.TraceChannel = GetOrCreateChannel(val);
            if (key is "file" or "info:file")
                options.InfoChannel = GetOrCreateChannel(val);
            if (key is "file" or "warning:file")
                options.WarningChannel = GetOrCreateChannel(val);
            if (key is "file" or "error:file")
                options.ErrorChannel = GetOrCreateChannel(val);
            if (key is "file" or "fatal:file")
                options.FatalChannel = GetOrCreateChannel(val);
        }
 
        IDiagnosticChannel GetOrCreateChannel(string spec)
        {
            return _channels.GetOrCreateChannel(spec) ?? throw new InvalidOperationException($"Cannot find channel for specification '{spec}'.");
        }
 
    }
 
}