public static Memo GetRevision(string title, int revision)
{
var memo = GetMemo(title);
string rawTitle = title;
title = ConvertTitle(title);
string revPath = Path.Combine(Root, $"{title}.{revision}.rev");
if (memo != null && memo.Title == rawTitle && memo.Revision == revision)
{
return(memo);
}
if (File.Exists(revPath))
{
var revMemo = new Memo();
lock (m_lockDic)
{
revMemo.Load(revPath);
}
if (revMemo.Title == rawTitle)
{
return(revMemo);
}
}
return(null);
}
public static Memo GetMemo(string title)
{
title = ConvertTitle(title);
lock (m_lockDic)
{
if (m_dic.ContainsKey(title))
{
return(m_dic[title].Clone());
}
}
string path = Path.Combine(Root, title + ".txt");
if (File.Exists(path))
{
var memo = new Memo();
lock (m_lockDic)
{
memo.Load(path);
m_dic.Add(title, memo);
}
return(memo.Clone());
}
return(null);
}
public static int UpdateMemo(string title, string content)
{
var oldMemo = GetMemo(title);
string rawTitle = title;
title = ConvertTitle(title);
string path = Path.Combine(Root, title + ".txt");
string backupPath = string.Empty;
if (oldMemo == null)
{
string lastBackupPath = Path.Combine(Root, $"{title}.bak");
if (File.Exists(lastBackupPath))
{
oldMemo = new Memo();
lock (m_lockDic)
{
oldMemo.Load(lastBackupPath);
}
if (oldMemo.Title != rawTitle)
{
oldMemo = null;
}
}
}
if (oldMemo != null)
{
backupPath = Path.Combine(Root, $"{title}.{oldMemo.Revision}.rev");
}
var memo = new Memo
{
Title = rawTitle,
Content = content,
Revision = (oldMemo?.Revision ?? -1) + 1,
};
lock (m_lockDic)
{
if (oldMemo != null)
{
oldMemo.Save(backupPath);
}
m_dic[title] = memo;
memo.Save(path);
memo.LastModifiedTime = File.GetLastWriteTimeUtc(path);
}
lock (m_lockRecentMemos)
{
m_recentMemos.Add(memo.Clone());
if (m_recentMemos.Count > 20)
{
m_recentMemos.RemoveAt(0);
}
}
return(memo.Revision);
}
public static bool RevertMemo(string title)
{
string rawTitle = title;
var memo = GetMemo(title);
title = ConvertTitle(title);
if (memo == null)
{
string lastBackupPath = Path.Combine(Root, $"{title}.bak");
if (File.Exists(lastBackupPath))
{
memo = new Memo();
lock (m_lockDic)
{
memo.Load(lastBackupPath);
if (memo.Title == rawTitle)
{
var tempMemo = memo.Clone();
tempMemo.Revision += 1;
tempMemo.Content = " ";
string path = Path.Combine(Root, $"{title}.txt");
tempMemo.Save(path);
}
}
if (memo.Title == rawTitle)
{
if (string.IsNullOrWhiteSpace(memo.Content))
{
DeleteMemo(rawTitle);
}
else
{
UpdateMemo(rawTitle, memo.Content);
}
return(true);
}
}
}
else if (memo.Revision > 0)
{
string revPath = Path.Combine(Root, $"{title}.{memo.Revision - 1}.rev");
if (File.Exists(revPath))
{
var revMemo = new Memo();
lock (m_lockDic)
{
revMemo.Load(revPath);
}
if (revMemo.Title == rawTitle)
{
if (string.IsNullOrWhiteSpace(revMemo.Content))
{
DeleteMemo(rawTitle);
}
else
{
UpdateMemo(rawTitle, revMemo.Content);
}
return(true);
}
}
}
return(false);
}