/// <summary>
/// Attempt to load the session header from the specified entry, returning null if it can't be loaded
/// </summary>
/// <param name="zipEntry">The current entry</param>
/// <returns>The session header, or null if it can't be loaded</returns>
private static SessionHeader LoadSessionHeader(ZipArchiveEntry zipEntry)
{
if (!Log.SilentMode)
{
Log.Write(LogMessageSeverity.Verbose, LogCategory, "Opening session file from zip file to read header", "Opening zip entry '{0}'.", zipEntry.Name);
}
SessionHeader header = null;
try
{
using (var sourceFile = zipEntry.Open())
{
//we need a SEEKABLE stream, so we need to make a memory stream to be seek-able.
//read the file header first to find out how large the session header is (which can be any size)
var fileHeaderBuffer = new byte[FileHeader.HeaderSize];
sourceFile.Read(fileHeaderBuffer, 0, fileHeaderBuffer.Length);
FileHeader fileHeader = null;
using (var memoryStream = new MemoryStream(fileHeaderBuffer))
{
if (GLFReader.IsGLF(memoryStream, out fileHeader) == false)
{
if (!Log.SilentMode)
{
Log.Write(LogMessageSeverity.Verbose, LogCategory, "Session file does not check out as a GLF file, skipping", "Zip entry: '{0}'.", zipEntry.Name);
}
return(header);
}
}
var sessionHeaderBuffer = new byte[fileHeader.DataOffset];
//we have to copy the file header into it because we can't re-read those bytes (non-seek-able stream)
fileHeaderBuffer.CopyTo(sessionHeaderBuffer, 0);
sourceFile.Read(sessionHeaderBuffer, fileHeaderBuffer.Length, sessionHeaderBuffer.Length - fileHeaderBuffer.Length);
using (var memoryStream = new MemoryStream(sessionHeaderBuffer))
{
using (var sourceGlfFile = new GLFReader(memoryStream))
{
if (sourceGlfFile.IsSessionStream)
{
header = sourceGlfFile.SessionHeader;
}
}
}
}
}
catch (Exception ex)
{
if (!Log.SilentMode)
{
Log.Write(LogMessageSeverity.Warning, LogWriteMode.Queued, ex, LogCategory, "Unexpected exception while attempting to load a session header",
"While opening the zip file entry '{0}' an exception was thrown reading the session header. Since this routine is designed to not generate exceptions this may indicate a flaw in the logic of the routine.\r\nException: {1}\r\n",
zipEntry.Name, ex.Message);
}
}
return(header);
}
/// <summary>
/// Adds the provided session to the package
/// </summary>
/// <param name="sessionStream"></param>
public void AddSession(Stream sessionStream)
{
using (GLFReader glfReader = new GLFReader(sessionStream)) // This will dispose the stream when it is disposed.
{
if (!glfReader.IsSessionStream)
{
throw new GibraltarException("The data stream provided is not a valid session data stream.");
}
if (!Log.SilentMode)
{
Log.Write(LogMessageSeverity.Verbose, LogCategory, "Stream is session file, attempting to load", null);
}
lock (m_Lock)
{
//Add this stream to our zip archive
string fileName = glfReader.SessionHeader.HasFileInfo ? string.Format("{0}~{1}.{2}", glfReader.SessionHeader.Id, glfReader.SessionHeader.FileId, Log.LogExtension)
: string.Format("{0}.{1}", glfReader.SessionHeader.Id, Log.LogExtension);
string zipFilePath = GenerateFragmentPath(glfReader.SessionHeader.FileId);
ZipArchiveEntry fragmentEntry;
if (m_Archive.Mode == ZipArchiveMode.Update)
{
fragmentEntry = m_Archive.GetEntry(zipFilePath);
if (fragmentEntry != null)
{
fragmentEntry.Delete(); //wipe out any existing entry
}
}
fragmentEntry = m_Archive.CreateEntry(FragmentsFolder + "\\" + fileName, CompressionLevel.NoCompression); //session files are already highly compressed, no reason to waste effort.
using (var zipStream = fragmentEntry.Open())
{
FileSystemTools.StreamContentCopy(sessionStream, zipStream, false); // Copy the stream into our package's temp directory.
}
IsDirty = true;
}
}
}
/// <summary>
/// Load the specified session
/// </summary>
/// <returns>The loaded session. If no session can be found with the specified Id an ArgumentOutOfRangeException will be thrown.</returns>
public Session GetSession(Guid sessionId, Guid?fileId = null)
{
Session requestedSession = null;
lock (m_Lock)
{
SessionFileInfo <ZipArchiveEntry> sessionFileInfo;
if (m_Sessions.TryGetValue(sessionId, out sessionFileInfo) == false)
{
throw new ArgumentOutOfRangeException(nameof(sessionId), "There is no session in the package with the provided id");
}
//now load up all of the session fragments.
var loadingCollection = new SessionCollection();
foreach (var fragment in sessionFileInfo.Fragments)
{
//we need a seek-able stream - so we'll extract the fragment into a temp file and go with that.
if (fileId != null)
{
//we need to check the file Id to see if it's what they requested
using (var reader = new GLFReader(FileSystemTools.GetTempFileStreamCopy(fragment.Open())))
{
if (reader.SessionHeader.FileId != fileId.Value)
{
continue;
}
}
}
requestedSession = loadingCollection.Add(FileSystemTools.GetTempFileStreamCopy(fragment.Open()), true);
}
}
if (requestedSession == null)
{
throw new ArgumentOutOfRangeException(nameof(fileId), "There is no session file in the package with the provided file id");
}
return(requestedSession);
}
/// <summary>
/// Retrieve the ids of the sessions files known locally for the specified session
/// </summary>
/// <param name="sessionId"></param>
/// <returns></returns>
public IList <Guid> GetSessionFileIds(Guid sessionId)
{
lock (m_Lock)
{
SessionFileInfo <ZipArchiveEntry> sessionFileInfo;
if (m_Sessions.TryGetValue(sessionId, out sessionFileInfo) == false)
{
throw new ArgumentOutOfRangeException(nameof(sessionId), "There is no session in the package with the provided id");
}
var fileIds = new List <Guid>();
foreach (var fragment in sessionFileInfo.Fragments)
{
//this is kinda crappy - we have to make a copy of the whole fragment to get a seekable stream to read the id.
using (var reader = new GLFReader(FileSystemTools.GetTempFileStreamCopy(fragment.Open())))
{
fileIds.Add(reader.SessionHeader.FileId);
}
}
return(fileIds);
}
}
