/// <summary>
/// Retrieves information about a file in the archive.
/// </summary>
/// <param name="filePath">The virual path to the file.</param>
/// <returns>The <see cref="AegisFileInfo"/> about the file, or null if it isn't found.</returns>
public AegisFileInfo GetFileInfo(AegisVirtualFilePath filePath)
{
ArgCheck.NotNull(filePath, nameof(filePath));
this.ThrowIfLocked();
return(this.FileIndex.GetFileInfo(filePath));
}
/// <summary>
/// Removes a file from the archive.
/// </summary>
/// <param name="filePath">The virtual path to the file.</param>
/// <remarks>If no file exists at that path, this operation is a silent no-op.</remarks>
public void RemoveFile(AegisVirtualFilePath filePath)
{
ArgCheck.NotNull(filePath, nameof(filePath));
this.ThrowIfLocked();
var fileInfo = this.GetFileInfo(filePath);
if (fileInfo != null)
{
this.RemoveFile(fileInfo.FileId);
}
}
/// <summary>
/// Adds a file to the archive.
/// </summary>
/// <param name="virtualPath">The virtual path to add the file at.</param>
/// <param name="fileStream">The file data stream.</param>
/// <param name="overwriteIfExists">
/// Whether or not to overwrite existing files at that path.
/// If false, an <see cref="InvalidOperationException"/> is thrown if a file already exists at the path.
/// </param>
/// <returns>Metadata about the file added to the archive.</returns>
public AegisFileInfo PutFile(AegisVirtualFilePath virtualPath, Stream fileStream, bool overwriteIfExists = false)
{
ArgCheck.NotNull(virtualPath, nameof(virtualPath));
ArgCheck.NotNull(fileStream, nameof(fileStream));
this.ThrowIfLocked();
// Remove any existing files stored at the path, if we're allowed to.
var existingFileInfo = this.FileIndex.GetFileInfo(virtualPath);
if (existingFileInfo != null)
{
if (!overwriteIfExists)
{
throw new InvalidOperationException(
$"A file with ID '{existingFileInfo.FileId}' already exists at virtual path '{virtualPath}'!");
}
this.RemoveFile(existingFileInfo.FileId);
}
var currentTime = DateTimeOffset.UtcNow;
var fileInfo = existingFileInfo ?? new AegisFileInfo(
virtualPath,
new FileIndexEntry
{
FileId = Guid.NewGuid(),
FilePath = virtualPath.ToString(),
AddedTime = currentTime,
LastModifiedTime = currentTime,
});
fileInfo.IndexEntry.LastModifiedTime = currentTime;
// Encrypt the file.
// This mechanism won't work for very large files since it loads the whole thing into memory.
// For now, this is an acceptable limit for Aegis file archiving.
using var memoryStream = new MemoryStream();
fileStream.CopyTo(memoryStream);
var encryptedFile = this.ArchiveKey.Encrypt(
this.CryptoStrategy,
memoryStream.ToArray());
encryptedFile.WriteToBinaryStream(this.SecureArchive.GetEntryWriteStream(fileInfo.ArchiveEntryName));
try
{
this.FileIndex.Add(fileInfo);
this.PersistMetadata();
}
catch
{
// Creating file metadata failed.
// Revert adding file to keep the archive to keep it consistent.
this.SecureArchive.DeleteEntryIfExists(fileInfo.ArchiveEntryName);
throw;
}
this.FlushArchive();
return(fileInfo);
}
