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duplicati/Duplicati/Library/Main/Operation/Backup/StreamBlockSplitter.cs
T

190 lines
10 KiB
C#

// Copyright (C) 2016, The Duplicati Team
// http://www.duplicati.com, info@duplicati.com
//
// This library is free software; you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation; either version 2.1 of the
// License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
using System;
using CoCoL;
using Duplicati.Library.Main.Operation.Common;
using System.Threading.Tasks;
using System.Collections.Generic;
using Duplicati.Library.Utility;
using System.Linq;
using Duplicati.Library.Interface;
using System.IO;
namespace Duplicati.Library.Main.Operation.Backup
{
internal static class StreamBlockSplitter
{
public static Task Run(Options options, BackupDatabase database, ITaskReader taskreader)
{
return AutomationExtensions.RunTask(
new
{
Input = Channels.StreamBlock.ForRead,
LogChannel = Common.Channels.LogChannel.ForWrite,
ProgressChannel = Channels.ProgressEvents.ForWrite,
BlockOutput = Channels.OutputBlocks.ForWrite
},
async self =>
{
var log = new LogWrapper(self.LogChannel);
var blocksize = options.Blocksize;
var filehasher = Duplicati.Library.Utility.HashAlgorithmHelper.Create(options.FileHashAlgorithm);
var blockhasher = Duplicati.Library.Utility.HashAlgorithmHelper.Create(options.BlockHashAlgorithm);
var emptymetadata = Utility.WrapMetadata(new Dictionary<string, string>(), options);
var maxmetadatasize = (options.Blocksize / (long)options.BlockhashSize) * options.Blocksize;
if (blockhasher == null)
throw new UserInformationException(Strings.Common.InvalidHashAlgorithm(options.BlockHashAlgorithm));
if (filehasher == null)
throw new UserInformationException(Strings.Common.InvalidHashAlgorithm(options.FileHashAlgorithm));
if (!blockhasher.CanReuseTransform)
throw new UserInformationException(Strings.Common.InvalidCryptoSystem(options.BlockHashAlgorithm));
if (!filehasher.CanReuseTransform)
throw new UserInformationException(Strings.Common.InvalidCryptoSystem(options.FileHashAlgorithm));
using (var empty_metadata_stream = new MemoryStream(emptymetadata.Blob))
while (await taskreader.ProgressAsync)
{
var send_close = false;
var filesize = 0L;
var e = await self.Input.ReadAsync();
var cur = e.Result;
try
{
var stream = e.Stream;
using (var blocklisthashes = new Library.Utility.FileBackedStringList())
using (var hashcollector = new Library.Utility.FileBackedStringList())
{
var blocklistbuffer = new byte[blocksize];
var blocklistoffset = 0L;
long fslen = -1;
try { fslen = stream.Length; }
catch (Exception ex) { await log.WriteWarningAsync(string.Format("Failed to read file length for file {0}", e.Path), ex); }
if (e.IsMetadata && fslen > maxmetadatasize)
{
//TODO: To fix this, the "WriteFileset" method in BackupHandler needs to
// be updated such that it can select sets even when there are multiple
// blocklist hashes for the metadata.
// This could be done such that an extra query is made if the metadata
// spans multiple blocklist hashes, as it is not expected to be common
await log.WriteWarningAsync(string.Format("Metadata size is {0}, but the largest accepted size is {1}, recording empty metadata for {2}", fslen, maxmetadatasize, e.Path), null);
empty_metadata_stream.Position = 0;
stream = empty_metadata_stream;
fslen = stream.Length;
}
await self.ProgressChannel.WriteAsync(new ProgressEvent() { Filepath = e.Path, Length = fslen, Type = EventType.FileStarted });
send_close = true;
filehasher.Initialize();
var lastread = 0;
var buf = new byte[blocksize];
var lastupdate = DateTime.Now;
// Core processing loop, read blocks of data and hash individually
while (((lastread = await stream.ForceStreamReadAsync(buf, blocksize)) != 0))
{
// Run file hashing concurrently to squeeze a little extra concurrency out of it
var pftask = Task.Run(() => filehasher.TransformBlock(buf, 0, lastread, buf, 0));
var hashdata = blockhasher.ComputeHash(buf, 0, lastread);
var hashkey = Convert.ToBase64String(hashdata);
// If we have too many hashes, flush the blocklist
if (blocklistbuffer.Length - blocklistoffset < hashdata.Length)
{
var blkey = Convert.ToBase64String(blockhasher.ComputeHash(blocklistbuffer, 0, (int)blocklistoffset));
blocklisthashes.Add(blkey);
await DataBlock.AddBlockToOutputAsync(self.BlockOutput, blkey, blocklistbuffer, 0, blocklistoffset, CompressionHint.Noncompressible, true);
blocklistoffset = 0;
blocklistbuffer = new byte[blocksize];
}
// Store the current hash in the blocklist
Array.Copy(hashdata, 0, blocklistbuffer, blocklistoffset, hashdata.Length);
blocklistoffset += hashdata.Length;
hashcollector.Add(hashkey);
filesize += lastread;
// Don't spam updates
if ((DateTime.Now - lastupdate).TotalSeconds > 10)
{
await self.ProgressChannel.WriteAsync(new ProgressEvent() { Filepath = e.Path, Length = filesize, Type = EventType.FileProgressUpdate });
lastupdate = DateTime.Now;
}
// Make sure the filehasher is done with the buf instance before we pass it on
await pftask;
await DataBlock.AddBlockToOutputAsync(self.BlockOutput, hashkey, buf, 0, lastread, e.Hint, false);
buf = new byte[blocksize];
}
// If we have more than a single block of data, output the (trailing) blocklist
if (hashcollector.Count > 1)
{
var blkey = Convert.ToBase64String(blockhasher.ComputeHash(blocklistbuffer, 0, (int)blocklistoffset));
blocklisthashes.Add(blkey);
await DataBlock.AddBlockToOutputAsync(self.BlockOutput, blkey, blocklistbuffer, 0, blocklistoffset, CompressionHint.Noncompressible, true);
}
filehasher.TransformFinalBlock(new byte[0], 0, 0);
var filehash = Convert.ToBase64String(filehasher.Hash);
var blocksetid = await database.AddBlocksetAsync(filehash, filesize, blocksize, hashcollector, blocklisthashes);
cur.SetResult(new StreamProcessResult() { Streamlength = filesize, Streamhash = filehash, Blocksetid = blocksetid });
cur = null;
}
}
catch (Exception ex)
{
try
{
if (cur != null)
cur.TrySetException(ex);
}
catch { }
// Rethrow
if (ex.IsRetiredException())
throw;
}
finally
{
if (cur != null)
{
try { cur.TrySetCanceled(); }
catch { }
cur = null;
}
if (send_close)
await self.ProgressChannel.WriteAsync(new ProgressEvent() { Filepath = e.Path, Length = filesize, Type = EventType.FileClosed });
send_close = false;
}
}
});
}
}
}