roll-by-time now supports keepFiles argument

src/WinSW.Core/Configuration/Log.cs

@@ -52,7 +52,16 @@ namespace WinSW.Configuration
                     return new RollingLogAppender(this.Directory, this.Name, this.OutFileDisabled, this.ErrFileDisabled, this.OutFilePattern, this.ErrFilePattern);
 
                 case "roll-by-time":
-                    return new TimeBasedRollingLogAppender(this.Directory, this.Name, this.OutFileDisabled, this.ErrFileDisabled, this.OutFilePattern, this.ErrFilePattern, this.Pattern, this.Period.GetValueOrDefault(1));
+                    return new TimeBasedRollingLogAppender(
+                        this.Directory,
+                        this.Name,
+                        this.OutFileDisabled,
+                        this.ErrFileDisabled,
+                        this.OutFilePattern,
+                        this.ErrFilePattern,
+                        this.Pattern,
+                        this.Period.GetValueOrDefault(1),
+                        this.KeepFiles);
 
                 case "roll-by-size":
                     return new SizeBasedRollingLogAppender(
@@ -104,4 +113,4 @@ namespace WinSW.Configuration
             }
         }
     }
-}
+}

src/WinSW.Core/Configuration/XmlServiceConfig.cs

@@ -351,7 +351,14 @@ namespace WinSW
 
             public override int? SizeThreshold => this.config.SingleIntElement(this.Element, "sizeThreshold", 10 * 1024);
 
-            public override int? KeepFiles => this.config.SingleIntElement(this.Element, "keepFiles", SizeBasedRollingLogAppender.DefaultFilesToKeep);
+            public override int? KeepFiles
+            {
+                get
+                {
+                    var keepFiles = this.Element.SelectSingleNode("keepFiles");
+                    return keepFiles is null ? null : int.Parse(keepFiles.InnerText);
+                }
+            }
 
             public override int? Period => this.config.SingleIntElement(this.Element, "period", 1);
 

src/WinSW.Core/LogAppenders.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.Diagnostics;
 #if VNEXT
 using System.IO.Compression;
@@ -85,10 +86,13 @@ namespace WinSW
 
         protected string ErrFilePattern { get; private set; }
 
+        protected string LogDirectory { get; private set; }
+
         protected AbstractFileLogAppender(string logDirectory, string baseName, bool outFileDisabled, bool errFileDisabled, string outFilePattern, string errFilePattern)
             : base(outFileDisabled, errFileDisabled)
         {
             this.BaseLogFileName = Path.Combine(logDirectory, baseName);
+            this.LogDirectory = logDirectory;
             this.OutFilePattern = outFilePattern;
             this.ErrFilePattern = errFilePattern;
         }
@@ -171,15 +175,20 @@ namespace WinSW
 
     public class TimeBasedRollingLogAppender : AbstractFileLogAppender
     {
+        public static int? DefaultFilesToKeep = null;
+
         public string Pattern { get; private set; }
 
         public int Period { get; private set; }
 
-        public TimeBasedRollingLogAppender(string logDirectory, string baseName, bool outFileDisabled, bool errFileDisabled, string outFilePattern, string errFilePattern, string pattern, int period)
+        public int? FilesToKeep { get; private set; }
+
+        public TimeBasedRollingLogAppender(string logDirectory, string baseName, bool outFileDisabled, bool errFileDisabled, string outFilePattern, string errFilePattern, string pattern, int period, int? filesToKeep)
             : base(logDirectory, baseName, outFileDisabled, errFileDisabled, outFilePattern, errFilePattern)
         {
             this.Pattern = pattern;
             this.Period = period;
+            this.FilesToKeep = filesToKeep;
         }
 
         protected override void LogOutput(StreamReader outputReader)
@@ -208,6 +217,40 @@ namespace WinSW
                 {
                     writer.Dispose();
                     copy.Writer = writer = new FileStream(this.BaseLogFileName + "_" + periodicRollingCalendar.Format + ext, FileMode.Create);
+
+                    if (this.FilesToKeep != null)
+                    {
+                        var logFiles = new List<string>();
+
+                        foreach (string file in Directory.GetFiles(this.LogDirectory, "*" + ext))
+                        {
+                            DateTime createdAt = File.GetCreationTime(file);
+
+                            if (this.BaseLogFileName + "_" + periodicRollingCalendar.GetFormatForDateTime(createdAt) + ext == file)
+                            {
+                                logFiles.Add(file);
+                            }
+                        }
+
+                        logFiles.Sort((x, y) => File.GetCreationTime(x).CompareTo(File.GetCreationTime(y)));
+                        try
+                        {
+                            while (this.FilesToKeep < logFiles.Count)
+                            {
+                                var filename = logFiles[0];
+                                if (File.Exists(filename))
+                                {
+                                    File.Delete(filename);
+                                }
+
+                                logFiles.RemoveAt(0);
+                            }
+                        }
+                        catch (IOException e)
+                        {
+                            this.EventLogger.LogEvent("Failed to roll log: " + e.Message);
+                        }
+                    }
                 }
             }
 

src/WinSW.Core/PeriodicRollingCalendar.cs

@@ -113,6 +113,8 @@ namespace WinSW
             }
         }
 
-        public string Format => this.currentRoll.ToString(this.format);
+        public string GetFormatForDateTime(DateTime datetime) => datetime.ToString(this.format);
+
+        public string Format => this.GetFormatForDateTime(this.currentRoll);
     }
 }