/// <summary>
/// Appends a new metadata section to the end of the file.
/// </summary>
public Task WriteMetadata(ArchiveMetadataProvider metadata)
{
if (metadata == null)
throw new ArgumentNullException(nameof(metadata));
int metadataCount = metadata.GetCount();
if (metadataCount < 0)
throw new InvalidOperationException(nameof(ArchiveMetadataProvider) + " returned negative count.");
// TODO: wait for completion of pending writes
mMetadataPosition = mAppendPosition;
mArchiveStream.Position = mAppendPosition;
// TODO: we'll want to write the metadata into a stream, compress it, calculate the checksum on the fly
// TODO: we'll probably also want to have a scratch buffer to assembly vectors with no allocation overhead and in a single iteration
// (a scratch buffer allows to record the vector in a single iteration and if it was unnecessary it doesn't need to be forwarded to the actual stream)
var subStreamCount = mDecoderSections.Sum(x => x != null ? x.Streams.Length : 0);
WriteToken(ArchiveMetadataToken.Header);
if (mDecoderSections.Count > 0)
{
WriteToken(ArchiveMetadataToken.MainStreams);
WritePackInfo();
WriteUnpackInfo();
WriteSubStreamsInfo();
WriteToken(ArchiveMetadataToken.End);
}
if (subStreamCount > 0)
{
WriteToken(ArchiveMetadataToken.Files);
WriteNumber(metadataCount);
#region Types
{
int emptyStreamCount = 0;
for (int i = 0; i < metadataCount; i++)
if (!metadata.HasStream(i))
emptyStreamCount++;
if (emptyStreamCount > 0)
{
WriteBitVectorWithHeader(ArchiveMetadataToken.EmptyStream,
Enumerable.Range(0, metadataCount)
.Select(x => !metadata.HasStream(x)),
metadataCount);
if (Enumerable.Range(0, metadataCount).Where(x => !metadata.HasStream(x)).Any(x => !metadata.IsDirectory(x)))
WriteBitVectorWithHeader(ArchiveMetadataToken.EmptyFile,
Enumerable.Range(0, metadataCount)
.Where(x => !metadata.HasStream(x))
.Select(x => !metadata.IsDirectory(x)),
emptyStreamCount);
if (Enumerable.Range(0, metadataCount).Where(x => !metadata.HasStream(x)).Any(x => metadata.IsDeleted(x)))
WriteBitVectorWithHeader(ArchiveMetadataToken.Anti,
Enumerable.Range(0, metadataCount)
.Where(x => !metadata.HasStream(x))
.Select(x => metadata.IsDeleted(x)),
emptyStreamCount);
}
}
#endregion
#region Names
{
bool hasNames = false;
int nameSize = 1;
for (int i = 0; i < subStreamCount; i++)
{
var name = metadata.GetName(i);
if (!string.IsNullOrEmpty(name))
{
hasNames = true;
nameSize += (name.Length + 1) * 2;
}
else
{
nameSize += 2;
}
}
if (hasNames)
{
WritePadding(2 + GetNumberSize(nameSize), 16);
WriteToken(ArchiveMetadataToken.Name);
WriteNumber(nameSize);
WriteByte(0);
System.Diagnostics.Debug.Assert((mArchiveStream.Position & 15) == 0);
for (int i = 0; i < subStreamCount; i++)
{
var name = metadata.GetName(i);
foreach (char ch in name)
{
WriteByte((byte)ch);
WriteByte((byte)(ch >> 8));
}
WriteByte(0);
WriteByte(0);
}
}
}
#endregion
WriteDateVector(Enumerable.Range(0, metadataCount).Select(x => metadata.GetCreationDate(x)), ArchiveMetadataToken.CTime);
WriteDateVector(Enumerable.Range(0, metadataCount).Select(x => metadata.GetLastAccessDate(x)), ArchiveMetadataToken.ATime);
WriteDateVector(Enumerable.Range(0, metadataCount).Select(x => metadata.GetLastWriteDate(x)), ArchiveMetadataToken.MTime);
// TODO: what does the start position mean? it doesn't seem to be what I thought it was.
WriteUInt64Vector(Enumerable.Range(0, metadataCount).Select(x => default(ulong?)), ArchiveMetadataToken.StartPos);
WriteUInt32Vector(Enumerable.Range(0, metadataCount).Select(x => {
var attr = metadata.GetAttributes(x);
return attr.HasValue ? (uint)attr.Value : default(uint?);
}), ArchiveMetadataToken.WinAttributes);
WriteToken(ArchiveMetadataToken.End);
}
WriteToken(ArchiveMetadataToken.End);
mMetadataLength = mArchiveStream.Position - mMetadataPosition;
// TODO: this is only a temporary implementation; the checksum can be calculated on the fly in the final implementation
{
var buffer = new byte[0x1000];
mArchiveStream.Position = mMetadataPosition;
var checksum = CRC.kInitCRC;
int offset = 0;
while (offset < mMetadataLength)
{
var fetched = mArchiveStream.Read(buffer, 0, (int)Math.Min(mMetadataLength - offset, buffer.Length));
if (fetched <= 0 || fetched > mMetadataLength - offset)
throw new InternalFailureException();
offset += fetched;
checksum = CRC.Update(checksum, buffer, 0, fetched);
}
mMetadataChecksum = new Checksum((int)CRC.Finish(checksum));
}
return Utilities.CompletedTask;
}
/// <summary>
/// Appends a new metadata section to the end of the file.
/// </summary>
public Task WriteMetadata(ArchiveMetadataProvider metadata)
{
if (metadata == null)
{
throw new ArgumentNullException(nameof(metadata));
}
int metadataCount = metadata.GetCount();
if (metadataCount < 0)
{
throw new InvalidOperationException(nameof(ArchiveMetadataProvider) + " returned negative count.");
}
// TODO: wait for completion of pending writes
mMetadataPosition = mAppendPosition;
mArchiveStream.Position = mAppendPosition;
// TODO: we'll want to write the metadata into a stream, compress it, calculate the checksum on the fly
// TODO: we'll probably also want to have a scratch buffer to assembly vectors with no allocation overhead and in a single iteration
// (a scratch buffer allows to record the vector in a single iteration and if it was unnecessary it doesn't need to be forwarded to the actual stream)
var subStreamCount = mDecoderSections.Sum(x => x != null ? x.Streams.Length : 0);
WriteToken(ArchiveMetadataToken.Header);
if (mDecoderSections.Count > 0)
{
WriteToken(ArchiveMetadataToken.MainStreams);
WritePackInfo();
WriteUnpackInfo();
WriteSubStreamsInfo();
WriteToken(ArchiveMetadataToken.End);
}
if (subStreamCount > 0)
{
WriteToken(ArchiveMetadataToken.Files);
WriteNumber(metadataCount);
#region Types
{
int emptyStreamCount = 0;
for (int i = 0; i < metadataCount; i++)
{
if (!metadata.HasStream(i))
{
emptyStreamCount++;
}
}
if (emptyStreamCount > 0)
{
WriteBitVectorWithHeader(ArchiveMetadataToken.EmptyStream,
Enumerable.Range(0, metadataCount)
.Select(x => !metadata.HasStream(x)),
metadataCount);
if (Enumerable.Range(0, metadataCount).Where(x => !metadata.HasStream(x)).Any(x => !metadata.IsDirectory(x)))
{
WriteBitVectorWithHeader(ArchiveMetadataToken.EmptyFile,
Enumerable.Range(0, metadataCount)
.Where(x => !metadata.HasStream(x))
.Select(x => !metadata.IsDirectory(x)),
emptyStreamCount);
}
if (Enumerable.Range(0, metadataCount).Where(x => !metadata.HasStream(x)).Any(x => metadata.IsDeleted(x)))
{
WriteBitVectorWithHeader(ArchiveMetadataToken.Anti,
Enumerable.Range(0, metadataCount)
.Where(x => !metadata.HasStream(x))
.Select(x => metadata.IsDeleted(x)),
emptyStreamCount);
}
}
}
#endregion
#region Names
{
bool hasNames = false;
int nameSize = 1;
for (int i = 0; i < subStreamCount; i++)
{
var name = metadata.GetName(i);
if (!string.IsNullOrEmpty(name))
{
hasNames = true;
nameSize += (name.Length + 1) * 2;
}
else
{
nameSize += 2;
}
}
if (hasNames)
{
WritePadding(2 + GetNumberSize(nameSize), 16);
WriteToken(ArchiveMetadataToken.Name);
WriteNumber(nameSize);
WriteByte(0);
System.Diagnostics.Debug.Assert((mArchiveStream.Position & 15) == 0);
for (int i = 0; i < subStreamCount; i++)
{
var name = metadata.GetName(i);
foreach (char ch in name)
{
WriteByte((byte)ch);
WriteByte((byte)(ch >> 8));
}
WriteByte(0);
WriteByte(0);
}
}
}
#endregion
WriteDateVector(Enumerable.Range(0, metadataCount).Select(x => metadata.GetCreationDate(x)), ArchiveMetadataToken.CTime);
WriteDateVector(Enumerable.Range(0, metadataCount).Select(x => metadata.GetLastAccessDate(x)), ArchiveMetadataToken.ATime);
WriteDateVector(Enumerable.Range(0, metadataCount).Select(x => metadata.GetLastWriteDate(x)), ArchiveMetadataToken.MTime);
// TODO: what does the start position mean? it doesn't seem to be what I thought it was.
WriteUInt64Vector(Enumerable.Range(0, metadataCount).Select(x => default(ulong?)), ArchiveMetadataToken.StartPos);
WriteUInt32Vector(Enumerable.Range(0, metadataCount).Select(x => {
var attr = metadata.GetAttributes(x);
return(attr.HasValue ? (uint)attr.Value : default(uint?));
}), ArchiveMetadataToken.WinAttributes);
WriteToken(ArchiveMetadataToken.End);
}
WriteToken(ArchiveMetadataToken.End);
mMetadataLength = mArchiveStream.Position - mMetadataPosition;
// TODO: this is only a temporary implementation; the checksum can be calculated on the fly in the final implementation
{
var buffer = new byte[0x1000];
mArchiveStream.Position = mMetadataPosition;
var checksum = CRC.kInitCRC;
int offset = 0;
while (offset < mMetadataLength)
{
var fetched = mArchiveStream.Read(buffer, 0, (int)Math.Min(mMetadataLength - offset, buffer.Length));
if (fetched <= 0 || fetched > mMetadataLength - offset)
{
throw new InternalFailureException();
}
offset += fetched;
checksum = CRC.Update(checksum, buffer, 0, fetched);
}
mMetadataChecksum = new Checksum((int)CRC.Finish(checksum));
}
return(Utilities.CompletedTask);
}
