/// <summary>
/// reads in all the indexes from the specified input stream.
/// </summary>
/// <param name="input"></param>
public void ReadIndexes(Stream input)
{
// reads all the index data from the filestream
while (input.Position < input.Length)
{
// get the starting position of the index block.
long indexStartPosition = input.Position;
int indexLength = 0;
// read in the raw index descriptor:
RawIndex raw = ReadNextIndexBlock(input, out indexLength);
// add a new index to the list:
_fileIndex.Add(new ArchiveFileIndex()
{
// keep the length, name, start index, and index block position/length
FileLength = raw.L,
FileName = raw.N,
FileStartIndex = input.Position,
IndexBlockPositionStart = indexStartPosition,
IndexBlockLength = indexLength
});
// skip the appropriate amount of the file:
input.Position += raw.L;
}
}
/// <summary>
/// writes the index data and the raw file blocks to the destination stream.
/// </summary>
/// <param name="destStream"></param>
/// <param name="idx"></param>
/// <param name="dataArray"></param>
/// <param name="updIndex"></param>
public static void AddRawData(Stream destStream, RawIndex idx, byte[] dataArray, IndexHandler updIndex)
{
// serialize and compress the index data:
byte[] indexData = RawIndex.ToByteArray(idx);
// generate the header bytes:
byte[] header = BitConverter.GetBytes((ushort)indexData.Length);
// move to the end of the stream:
destStream.Position = destStream.Length;
// write the header data:
destStream.Write(header, 0, header.Length);
// write the index data:
destStream.Write(indexData, 0, indexData.Length);
// add the index record to the handler:
updIndex.ArchiveIndex.Add(new ArchiveFileIndex()
{
FileLength = idx.L,
FileName = idx.N,
FileStartIndex = destStream.Position
});
// write the data to the stream
destStream.Write(dataArray, 0, dataArray.Length);
}
/// <summary>
/// adds a list of files to an archive.
/// </summary>
/// <param name="data"></param>
/// <param name="destStream"></param>
/// <param name="updIndex"></param>
public static void AddData(List <ArchiveFile> data, Stream destStream, IndexHandler updIndex)
{
if (!destStream.CanWrite)
{
throw new ArgumentException("Cannot Write to Stream");
}
if (!destStream.CanSeek)
{
throw new ArgumentException("Cannot Seek!");
}
// enumerate the archive files: generate the index and the data.
foreach (var file in data)
{
// serialize and compress the archive file
byte[] serialData = file.ToByteArray();
// generate a new index:
RawIndex idx = new RawIndex()
{
N = file.ToString(),
L = serialData.Length
};
AddRawData(destStream, idx, serialData, updIndex);
}
}
/// <summary>
/// read in the next index descriptor, and pass out the length.
/// this assumes that the position of the filestream is at the start of an index.
/// </summary>
/// <param name="fs"></param>
/// <returns></returns>
public static RawIndex ReadNextIndexBlock(Stream fs, out int length)
{
// read in the length of the index data
length = readNextIndexDataLength(fs);
// read in the block of index data:
byte[] idxBlock = ReadBuffer(fs, length);
// deserialize it:
return(RawIndex.FromByteArray(idxBlock));
}
/// <summary>
/// remove a list of files from the archive by the archive file index.
/// this works by duplicating the archive file into a temp location, skipping the files due to be deleted
/// and then copying the duplicate back over the original.
/// not the most inspired solution but better than nothing.
/// </summary>
/// <param name="filesToRemove"></param>
public void RemoveFiles(List <ArchiveFileIndex> filesToRemove)
{
// create a temporary file:
String tempFileName = Path.GetTempFileName();
// create a temporary archive:
StreamingArchiveFile tempArc = new StreamingArchiveFile(tempFileName);
// extract each file from this archive, add it to the other archive,
// except the files to be deleted.
using (Stream input = GetStream())
{
using (Stream output = tempArc.GetStream())
{
// enumerate the indexes:
foreach (ArchiveFileIndex idx in _index.ArchiveIndex)
{
if (!filesToRemove.Contains(idx))
{
// process this... read in the raw data block:
input.Seek(idx.FileStartIndex, SeekOrigin.Begin);
// read the compressed file data:
byte[] data = IndexHandler.ReadBuffer(input, idx.FileLength);
// now generate the raw index:
RawIndex rawIndex = new RawIndex()
{
N = idx.FileName,
L = idx.FileLength
};
// add to the destination:
AddRawData(output, rawIndex, data, tempArc._index);
}
}
}
}
// now copy the temp file back over the archive:
File.Delete(_fileName);
File.Move(tempFileName, _fileName);
// now re-read the indexes:
OpenArchive(_fileName);
}
/// <summary>
/// compresses an array of RawIndex objects to a byte-array.
/// </summary>
/// <param name="indexData"></param>
/// <returns></returns>
public static byte[] ToByteArray(RawIndex indexData)
{
return TinySerializer.Serialize(indexData, true);
}
/// <summary>
/// writes the index data and the raw file blocks to the destination stream.
/// </summary>
/// <param name="destStream"></param>
/// <param name="idx"></param>
/// <param name="dataArray"></param>
/// <param name="updIndex"></param>
public static void AddRawData(Stream destStream, RawIndex idx, byte[] dataArray, IndexHandler updIndex)
{
// serialize and compress the index data:
byte[] indexData = RawIndex.ToByteArray(idx);
// generate the header bytes:
byte[] header = BitConverter.GetBytes((ushort)indexData.Length);
// move to the end of the stream:
destStream.Position = destStream.Length;
// write the header data:
destStream.Write(header, 0, header.Length);
// write the index data:
destStream.Write(indexData, 0, indexData.Length);
// add the index record to the handler:
updIndex.ArchiveIndex.Add(new ArchiveFileIndex()
{
FileLength = idx.L,
FileName = idx.N,
FileStartIndex = destStream.Position
});
// write the data to the stream
destStream.Write(dataArray, 0, dataArray.Length);
}
/// <summary>
/// adds a list of files to an archive.
/// </summary>
/// <param name="data"></param>
/// <param name="destStream"></param>
/// <param name="updIndex"></param>
public static void AddData(List<ArchiveFile> data, Stream destStream, IndexHandler updIndex)
{
if (!destStream.CanWrite)
throw new ArgumentException("Cannot Write to Stream");
if (!destStream.CanSeek)
throw new ArgumentException("Cannot Seek!");
// enumerate the archive files: generate the index and the data.
foreach (var file in data)
{
// serialize and compress the archive file
byte[] serialData = file.ToByteArray();
// generate a new index:
RawIndex idx = new RawIndex()
{
N = file.ToString(),
L = serialData.Length
};
AddRawData(destStream, idx, serialData, updIndex);
}
}
/// <summary>
/// remove a list of files from the archive by the archive file index.
/// this works by duplicating the archive file into a temp location, skipping the files due to be deleted
/// and then copying the duplicate back over the original.
/// not the most inspired solution but better than nothing.
/// </summary>
/// <param name="filesToRemove"></param>
public void RemoveFiles(List<ArchiveFileIndex> filesToRemove)
{
// create a temporary file:
String tempFileName = Path.GetTempFileName();
// create a temporary archive:
StreamingArchiveFile tempArc = new StreamingArchiveFile(tempFileName);
// extract each file from this archive, add it to the other archive,
// except the files to be deleted.
using (Stream input = GetStream())
{
using (Stream output = tempArc.GetStream())
{
// enumerate the indexes:
foreach (ArchiveFileIndex idx in _index.ArchiveIndex)
{
if (!filesToRemove.Contains(idx))
{
// process this... read in the raw data block:
input.Seek(idx.FileStartIndex, SeekOrigin.Begin);
// read the compressed file data:
byte[] data = IndexHandler.ReadBuffer(input, idx.FileLength);
// now generate the raw index:
RawIndex rawIndex = new RawIndex()
{
N = idx.FileName,
L = idx.FileLength
};
// add to the destination:
AddRawData(output, rawIndex, data, tempArc._index);
}
}
}
}
// now copy the temp file back over the archive:
File.Delete(_fileName);
File.Move(tempFileName, _fileName);
// now re-read the indexes:
OpenArchive(_fileName);
}
/// <summary>
/// compresses an array of RawIndex objects to a byte-array.
/// </summary>
/// <param name="indexData"></param>
/// <returns></returns>
public static byte[] ToByteArray(RawIndex indexData)
{
return(TinySerializer.Serialize(indexData, true));
}
