/// <summary>
/// Checks a single file and handles changes if
/// any occured (modification, creation).
/// </summary>
/// <param name="file">Path to the file.</param>
private void HandleFile(string file)
{
// Without this, used files would be treated as deleted.
if (FileHelper.FileInUse(file))
{
filesChecked.Add(file);
return;
}
if (!System.IO.File.Exists(file) || FileHelper.FileInUse(file) ||
file.EndsWith(".tmp") || filesChecked.Contains(file) || Ignored(file))
{
return;
}
filesChecked.Add(file);
DB.File tmp = null;
var files = db.GetFiles();
var date = System.IO.File.GetLastWriteTime(file);
if (!files.TryGet(file, out tmp) && canCreateFiles)
{
var f = new DB.File();
f.Name = file;
f.DateModified = date;
f.Access = null;
files.Add(f);
filesCreated.Add(file);
}
else if (tmp != null && tmp.OlderThan(date))
{
tmp.Update(date);
filesChanged.Add(file);
}
}
/// <summary>
/// Updates a file based on data sent by a client.
/// </summary>
/// <param name="file">Path to the file.</param>
/// <param name="operation">Type of operation to be done with the file.</param>
/// <param name="reader">StreamReader used as a source for the new file data.</param>
/// <returns>True if the file was successfully updated, false otherwise.</returns>
private bool WriteContentsToFile(DB.File file, Protocol operation, StreamReader reader)
{
lock (file)
{
if (operation == Protocol.FILE_CHANGED)
{
BackupFile(file.Name);
}
string tmpFile = file.Name + ".tmp";
try
{
string line;
using (var stream = System.IO.File.OpenWrite(tmpFile))
using (var fileWriter = new StreamWriter(stream, encoding))
{
while ((line = reader.ReadLine()) != null && line != "TRANSMISSION_END")
{
fileWriter.WriteLine(line);
}
fileWriter.BaseStream.SetLength(fileWriter.BaseStream.Position);
}
if (line != "TRANSMISSION_END")
{
FileHelper.Delete(tmpFile);
Console.WriteLine("[ERROR] Wrong file transmission end token.");
return(false);
}
else
{
FileHelper.Move(tmpFile, file.Name);
}
}
catch (IOException e)
{ // Most probably time out.
try
{
Console.WriteLine("[ERROR] Cannot write to file: {0}", e.Message);
FileHelper.Delete(tmpFile);
}
catch (IOException)
{ /* Just in case Delete throws, which should not propagate. */ }
return(false);
}
}
return(true);
}
/// <summary>
/// Requests (and reads if authorized) contents of a given file from
/// the server.
/// </summary>
/// <param name="reader">StreamReader used to read authorization result and the contents of the file.</param>
/// <param name="writer">StreamWriter used to send the request.</param>
/// <param name="file">Path to the file.</param>
private void RequestFileContents(StreamReader reader, StreamWriter writer, string file)
{
writer.WriteLine(Protocol.REQUEST_FILE_CONTENTS);
writer.WriteLine(subTreePrefix + file);
string line = reader.ReadLine();
string tmpFile = file + ".tmp";
if (ProtocolHelper.ExtractProtocol(line) == Protocol.SUCCESS)
{
DB.File tmp = null;
if (!db.GetFiles().TryGet(file, out tmp))
{
tmp = new DB.File(file);
db.GetFiles().Add(tmp);
}
try
{
reader.ReadLine(); // File name resent, here we can discard it.
writer.WriteLine(Protocol.SUCCESS);
Directory.CreateDirectory(Path.GetDirectoryName(file));
using (var stream = System.IO.File.OpenWrite(tmpFile))
using (var fileWriter = new StreamWriter(stream, encoding))
{
while ((line = reader.ReadLine()) != null && line != "TRANSMISSION_END" && line != "FAIL")
{
fileWriter.WriteLine(line);
}
}
FileHelper.Move(tmpFile, file);
tmp.DateModified = System.IO.File.GetLastWriteTime(file);
}
catch (SocketException)
{ // This should be connection interruption or time out.
FileHelper.Delete(tmpFile);
}
catch (IOException)
{ // Target file in use or nonexistent.
FileHelper.Delete(tmpFile);
}
}
}
/// <summary>
/// Updates a file based on the information sent by the user, this includes
/// changing contents, creating new files and deleting existing files.
/// </summary>
/// <param name="socket">Socket used for the communication.</param>
/// <param name="reader">StreamReader used to read data from the client.</param>
/// <param name="writer">StreamWriter used to write data to the client.</param>
/// <param name="operation">Type of operation to be done with the file.</param>
/// <param name="user">Database entry of the user (used for authorization).</param>
private void HandleFileUpdate(Socket socket, StreamReader reader, StreamWriter writer, Protocol operation, User user)
{
Group group;
var groups = db.GetGroups();
if (user == null || !groups.TryGet(user.Group, out group))
{
return;
}
string fileName = reader.ReadLine();
if (fileName == null)
{
return;
}
var files = db.GetFiles();
DB.File file = null;
if (!AuthorizeFileAccess(fileName, out file, operation, group))
{
writer.WriteLine(Protocol.FAIL);
return;
}
else
{
writer.WriteLine(Protocol.SUCCESS);
}
fileName = null;
if (operation == Protocol.FILE_DELETED)
{
DeleteFile(file);
}
else if (!WriteContentsToFile(file, operation, reader))
{
return;
}
InformAll(user, operation, file.Name);
file.DateModified = DateTime.Now; // So the clients don't all refresh the file contents.
return;
}
/// <summary>
/// Backs up and deletes a file (both from the database
/// and the directory tree).
/// </summary>
/// <param name="file">Path to the file.</param>
/// <returns>True if the file was deleted, false otherwise.</returns>
private bool DeleteFile(DB.File file)
{
lock (file)
{
try
{
BackupFile(file.Name);
System.IO.File.Delete(file.Name);
if (db.GetFiles().Contains(file.Name))
{
db.GetFiles().Remove(file);
}
return(true);
}
catch (IOException)
{
return(false);
}
}
}
/// <summary>
/// Checks if the user is allowed to perform a given operation on a given file.
/// </summary>
/// <param name="name">Path to the file.</param>
/// <param name="file">Database entry of the file which will be assigned to.</param>
/// <param name="type">Type of operation to be done with the file.</param>
/// <param name="group">Group the user belongs to.</param>
/// <returns></returns>
private bool AuthorizeFileAccess(string name, out DB.File file, Protocol type, Group group)
{
switch (type)
{
case Protocol.FILE_CHANGED:
case Protocol.FILE_DELETED:
return(db.GetFiles().TryGet(name, out file) && file.Test(group, AccessRight.WRITE));
case Protocol.FILE_CREATED:
if (group.CanCreateFiles && !db.GetFiles().Contains(name))
{
Directory.CreateDirectory(Path.GetDirectoryName(name));
file = db.CreateNewFile(name, group);
return(true);
}
else
{
file = null;
return(false);
}
case Protocol.REQUEST_FILE_CONTENTS:
if (!db.GetFiles().TryGet(name, out file))
{
return(false);
}
else
{
return(file.Test(group, AccessRight.READ));
}
default:
file = null;
return(false);
}
}
/// <summary>
/// Handles a notification from the server (mostly
/// regardin file changes).
/// </summary>
/// <param name="s">Socket used for the communication.</param>
private void HandleServerNotice(Socket s)
{
try
{
using (var stream = new NetworkStream(s))
using (var reader = new StreamReader(stream, encoding))
using (var writer = new StreamWriter(stream, encoding))
{
writer.AutoFlush = true;
//reader.BaseStream.ReadTimeout = 10000;
var message = ProtocolHelper.ExtractProtocol(reader.ReadLine());
string name = reader.ReadLine();
if (name.StartsWith(subTreePrefix + TrackedDirectory + @"\"))
{
name = name.Substring(subTreePrefix.Length);
if (message != Protocol.FILE_DELETED)
{
writer.WriteLine(Protocol.SUCCESS);
}
else
{
reader.ReadLine(); // T_E token, can be ignored here.
}
}
else
{
if (message != Protocol.FILE_DELETED)
{
writer.WriteLine(Protocol.FAIL);
}
else
{
reader.ReadLine(); // T_E token, can be ignored here.
}
writer.WriteLine(Protocol.TRANSMISSION_END);
return;
}
if (message == Protocol.NONE || name == null)
{
return;
}
DB.File file = null;
if (message == Protocol.FILE_CREATED ||
(name != null && !db.GetFiles().TryGet(name, out file) && message != Protocol.FILE_DELETED))
{
file = new DB.File(name);
file.DateModified = FileHelper.Create(file.Name);
if (file.DateModified != DateTime.MaxValue)
{
db.GetFiles().Add(file);
}
}
if (message == Protocol.FILE_DELETED)
{
FileHelper.Delete(name);
if (file != null)
{
db.GetFiles().Remove(file);
}
reader.ReadLine(); // T_E token, can be ignored here.
}
else
{
lock (file)
{
string tmpName = name + ".tmp";
try
{
string line;
using (var fstream = System.IO.File.OpenWrite(tmpName))
using (var fileWriter = new StreamWriter(fstream, encoding))
{
while ((line = reader.ReadLine()) != null && line != "TRANSMISSION_END")
{
fileWriter.WriteLine(line);
}
fileWriter.BaseStream.SetLength(fileWriter.BaseStream.Position);
}
FileHelper.Move(tmpName, file.Name);
file.DateModified = System.IO.File.GetLastWriteTime(file.Name);
}
catch (IOException e)
{
Console.WriteLine(e);
// TODO:
FileHelper.Delete(tmpName);
}
}
}
}
}
catch (IOException e)
{
// TODO:
Console.WriteLine("HUH? {0}", e.Message);
}
finally
{
db.Save();
}
}
