DocSpace-buildtools/common/ASC.Data.Storage/ZipOperators/ChunkZipWriteOperator.cs

// (c) Copyright Ascensio System SIA 2010-2022
//
// This program is a free software product.
// You can redistribute it and/or modify it under the terms
// of the GNU Affero General Public License (AGPL) version 3 as published by the Free Software
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// to the effect that Ascensio System SIA expressly excludes the warranty of non-infringement of
// any third-party rights.
//
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// of MERCHANTABILITY or FITNESS FOR A PARTICULAR  PURPOSE. For details, see
// the GNU AGPL at: http://www.gnu.org/licenses/agpl-3.0.html
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namespace ASC.Data.Storage.ZipOperators;

public class ChunkZipWriteOperator : IDataWriteOperator
{
    private readonly TarOutputStream _tarOutputStream;
    private readonly GZipOutputStream _gZipOutputStream;
    private readonly CommonChunkedUploadSession _chunkedUploadSession;
    private readonly CommonChunkedUploadSessionHolder _sessionHolder;
    private readonly SHA256 _sha;
    private Stream _fileStream;
    private readonly TempStream _tempStream;

    public string Hash { get; private set; }
    public string StoragePath { get; private set; }
    public bool NeedUpload
    {
        get
        {
            return false;
        }
    }

    public ChunkZipWriteOperator(TempStream tempStream,
        CommonChunkedUploadSession chunkedUploadSession,
        CommonChunkedUploadSessionHolder sessionHolder)
    {
        _tempStream = tempStream; 
        _chunkedUploadSession = chunkedUploadSession;
        _sessionHolder = sessionHolder;

        _fileStream = _tempStream.Create();
        _gZipOutputStream = new GZipOutputStream(_fileStream)
        {
            IsStreamOwner = false
        };
        _tarOutputStream = new TarOutputStream(_gZipOutputStream, Encoding.UTF8);
        _sha = SHA256.Create();
    }

    public async Task WriteEntryAsync(string key, Stream stream)
    {
        if (_fileStream == null)
        {
            _fileStream = _tempStream.Create();
            _gZipOutputStream.baseOutputStream_ = _fileStream;
        }
        using (var buffered = _tempStream.GetBuffered(stream))
        {
            var entry = TarEntry.CreateTarEntry(key);
            entry.Size = buffered.Length;
            await _tarOutputStream.PutNextEntryAsync(entry, default);
            buffered.Position = 0;
            await buffered.CopyToAsync(_tarOutputStream);
            await _tarOutputStream.FlushAsync();
            await _tarOutputStream.CloseEntryAsync(default);
        }

        if (_fileStream.Length > _sessionHolder.MaxChunkUploadSize)
        {
            await UploadAsync(false);
        }
    }

    private async Task UploadAsync(bool last)
    {
        var chunkUploadSize = _sessionHolder.MaxChunkUploadSize;

        var buffer = new byte[chunkUploadSize];
        int bytesRead;
        _fileStream.Position = 0;
        while ((bytesRead = _fileStream.Read(buffer, 0, (int)chunkUploadSize)) > 0)
        {
            using (var theMemStream = new MemoryStream())
            {
                await theMemStream.WriteAsync(buffer, 0, bytesRead);
                theMemStream.Position = 0;
                if (bytesRead == chunkUploadSize || last)
                {
                    if (_fileStream.Position == _fileStream.Length && last)
                    {
                        _chunkedUploadSession.LastChunk = true;
                    }
                    
                    theMemStream.Position = 0;
                    StoragePath = await _sessionHolder.UploadChunkAsync(_chunkedUploadSession, theMemStream, theMemStream.Length);
                }
                else
                {
                    await _fileStream.DisposeAsync();
                    _fileStream = _tempStream.Create();
                    _gZipOutputStream.baseOutputStream_ = _fileStream;

                    await theMemStream.CopyToAsync(_fileStream);
                    _fileStream.Flush();
                }
                _sha.TransformBlock(buffer, 0, bytesRead, buffer, 0);
            }
        }
        if (last)
        {
            _sha.TransformFinalBlock(buffer, 0, 0);
        }
    }

    public async ValueTask DisposeAsync()
    {
        _tarOutputStream.Close();
        _tarOutputStream.Dispose();

        await UploadAsync(true);
        _fileStream.Dispose();

        Hash = BitConverter.ToString(_sha.Hash).Replace("-", string.Empty);
        _sha.Dispose();
    }
}