Split database into separate file

TimberWinR/Inputs/LogsFileDatabase.cs

@@ -0,0 +1,174 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using Newtonsoft.Json;
+using NLog;
+
+using LogQuery = Interop.MSUtil.LogQueryClassClass;
+using TextLineInputFormat = Interop.MSUtil.COMTextLineInputContextClass;
+using LogRecordSet = Interop.MSUtil.ILogRecordset;
+
+namespace TimberWinR.Inputs
+{
+    //
+    // Maintain persistent state for Log files (to be used across restarts)
+    //
+    public class LogsFileDatabase
+    {
+        private static readonly object _locker = new object();
+        private List<LogsFileDatabaseEntry> Entries { get; set; }
+        private string DatabaseDirectory { get; set; }      
+        public string DatabaseFileName
+        {
+            get { return Path.Combine(DatabaseDirectory, ".timberwinrdb"); }
+        }
+
+        public static Manager Manager { get; set; }
+
+        private static LogsFileDatabase instance;
+
+        private bool ExistingFile(string logName)
+        {
+            lock (_locker)
+            {
+                return ExistingFileTest(logName);
+            }
+        }
+
+        private bool ExistingFileTest(string logName)
+        {
+            var existingEntry = (from e in Entries where e.FileName == logName select e).FirstOrDefault();
+            return existingEntry != null;
+        }
+
+        private void RemoveFileEntry(string logName)
+        {
+            lock (_locker)
+            {
+                var existingEntry = (from e in Entries where e.FileName == logName select e).FirstOrDefault();
+                if (existingEntry != null)
+                {
+                    Entries.Remove(existingEntry);
+                    WriteDatabaseFileNoLock();
+                }
+            }
+        }
+
+        private LogsFileDatabaseEntry AddFileEntry(string logName, TextLineInputFormat fmt)
+        {
+            var de = new LogsFileDatabaseEntry();
+            lock (_locker)
+            {
+                var lq = new LogQuery();
+                var fi = new FileInfo(logName);
+                de.FileName = logName;
+                de.Size = fi.Length;
+                de.SampleTime = DateTime.UtcNow;
+                de.CreationTime = fi.CreationTimeUtc;
+                if (fi.Exists)
+                {
+                    var qcount = string.Format("SELECT max(Index) as MaxRecordNumber FROM {0}", logName);
+                    var rcount = lq.Execute(qcount, fmt);
+                    var qr = rcount.getRecord();
+                    var lrn = (Int64)qr.getValueEx("MaxRecordNumber");
+                    de.MaxRecords = lrn;
+                }
+                Entries.Add(de);
+                WriteDatabaseFileNoLock();
+            }
+            return de;
+        }
+
+        public static LogsFileDatabaseEntry AddLogFile(string logName, TextLineInputFormat fmt)
+        {
+            Instance.RemoveFileEntry(logName); // Remove if already exists, otherwise ignores.
+            return Instance.AddFileEntry(logName, fmt);
+        }
+
+        public static LogsFileDatabase Instance
+        {
+            get
+            {
+                if (instance == null)
+                {
+                    instance = new LogsFileDatabase(Manager.LogfileDir);
+                    lock (_locker)
+                    {
+                        if (!Directory.Exists(instance.DatabaseDirectory))
+                            Directory.CreateDirectory(instance.DatabaseDirectory);
+                        // If it exists, read the current state, otherwise create an empty database.
+                        if (File.Exists(instance.DatabaseFileName))
+                            instance.ReadDatabaseNoLock();
+                        else
+                            instance.WriteDatabaseFileNoLock();
+                    }
+                }
+                return instance;
+            }
+        }
+
+        private void ReadDatabaseNoLock()
+        {
+            try
+            {
+                var serializer = new JsonSerializer();
+                if (File.Exists(DatabaseFileName))
+                    Entries =
+                        JsonConvert.DeserializeObject<List<LogsFileDatabaseEntry>>(File.ReadAllText(DatabaseFileName));
+            }
+            catch (Exception ex)
+            {
+                LogManager.GetCurrentClassLogger()
+                    .Error("Error reading database '{0}': {1}", DatabaseFileName, ex.ToString());
+            }
+        }
+        private void WriteDatabaseFileNoLock()
+        {
+            try
+            {
+                File.WriteAllText(DatabaseFileName, JsonConvert.SerializeObject(instance.Entries), Encoding.UTF8);
+            }
+            catch (Exception ex)
+            {
+                LogManager.GetCurrentClassLogger()
+                    .Error("Error saving database '{0}': {1}", DatabaseFileName, ex.ToString());
+            }
+        }
+
+
+        private void ReadDatabaseLock()
+        {
+            lock (_locker)
+            {
+                ReadDatabaseNoLock();
+            }
+
+        }
+        private void WriteDatabaseLock()
+        {
+            lock (_locker)
+            {
+                WriteDatabaseFileNoLock();
+            }
+        }
+
+        private LogsFileDatabase(string databaseDirectory)
+        {         
+            DatabaseDirectory = databaseDirectory;
+            Entries = new List<LogsFileDatabaseEntry>();
+        }
+
+    }
+
+    public class LogsFileDatabaseEntry
+    {
+        public string FileName { get; set; }
+        public Int64 MaxRecords { get; set; }
+        public DateTime CreationTime { get; set; }
+        public DateTime SampleTime { get; set; }
+        public long Size { get; set; }
+    }
+
+}

TimberWinR/ReleaseNotes.md

@@ -6,7 +6,7 @@ Version History
 
 ### 1.3.19.0 - 01/12/2015
 
-1. Added support for Multiline codecs for Stdin and Logs listeners, addresses issue #23
+1. Added support for Multiline codecs for Stdin and Logs listeners, closes issue [#23](https://github.com/Cimpress-MCP/TimberWinR/issues/23)
 
 ### 1.3.18.0 - 12/22/2014