Exemplo n.º 1
0
        /// <summary>
        /// Generates a signature stream for the given file and compares it with an existing signature stream, if one exists.
        /// </summary>
        /// <param name="fs">The file to examine, the filestream should be at position 0</param>
        /// <param name="s">The full name of the file</param>
        /// <param name="signaturefile">The signature archive file</param>
        /// <returns>The signature stream if the file is new or modified, null if the file has not been modified</returns>
        private System.IO.Stream ProccessDiff(System.IO.Stream fs, string s, Library.Interface.ICompression signaturefile)
        {
            string relpath = GetRelativeName(s);

            m_examinedfilesize += fs.Length;
            m_examinedfiles++;

            System.IO.MemoryStream ms = new MemoryStream();
            SharpRSync.ChecksumFileWriter ws = new Duplicati.Library.SharpRSync.ChecksumFileWriter(ms);

            //Expand the memorystream to contain all bytes, which avoids re-allocation
            ms.Capacity = Math.Max(ws.BytesGeneratedForSignature((long)(fs.Length * FILESIZE_GROW_MARGIN_MULTIPLIER)), ms.Capacity);
            ws.AddStream(fs);
            ms.Position = 0;

            if (!m_oldSignatures.ContainsKey(relpath))
            {
                m_newfiles.Add(s, null);
                return ms;
            }
            else
            {
                bool equals;
                //File exists in archive, check if signature has changed
                using (System.IO.Stream s2 = m_oldSignatures[relpath].OpenRead(relpath))
                    equals = Utility.Utility.CompareStreams(s2, ms, false);

                ms.Position = 0;

                if (!equals)
                {
                    //Yes, changed, return the signature stream
                    m_modifiedFiles.Add(s, null);
                    return ms;
                }
                else
                {
                    //No changes, discard the signature stream
                    ms.Close();
                    ms.Dispose();
                    m_oldSignatures.Remove(relpath);
                    return null;
                }
            }
        }
Exemplo n.º 2
0
 /// <summary>
 /// Generates a signature, and writes it to the stream
 /// </summary>
 /// <param name="input">The stream to create the signature for</param>
 /// <param name="output">The stream to write the signature into</param>
 public static void GenerateSignature(Stream input, Stream output)
 {
     SharpRSync.ChecksumFileWriter cs = new Duplicati.Library.SharpRSync.ChecksumFileWriter(output);
     cs.AddStream(input);
 }