internal void Persist()
{
if (_ids.Count * 4 > _context.DataBlockSize)
{
throw new NotImplementedException("Large numbers of user / group id's");
}
for (int i = 0; i < _ids.Count; ++i)
{
Utilities.WriteBytesLittleEndian(_ids[i], _context.IoBuffer, i * 4);
}
// Persist the table that references the block containing the id's
long blockPos = _context.RawStream.Position + 8;
byte[] tableBuffer = new byte[8];
Utilities.WriteBytesLittleEndian(blockPos, tableBuffer, 0);
_context.RawStream.Write(tableBuffer, 0, 8);
// Persist the actual Id's
MetablockWriter writer = new MetablockWriter();
writer.Write(_context.IoBuffer, 0, _ids.Count * 4);
writer.Persist(_context.RawStream);
}
internal void Persist()
{
if (_fragmentBlocks.Count > 0)
{
if (_fragmentBlocks.Count * FragmentRecord.RecordSize > _context.DataBlockSize)
{
throw new NotImplementedException("Large numbers of fragments");
}
// Persist the table that references the block containing the fragment records
long blockPos = _context.RawStream.Position + 8;
byte[] tableBuffer = new byte[8];
Utilities.WriteBytesLittleEndian(blockPos, tableBuffer, 0);
_context.RawStream.Write(tableBuffer, 0, 8);
int recordSize = FragmentRecord.RecordSize;
byte[] buffer = new byte[_fragmentBlocks.Count * recordSize];
for (int i = 0; i < _fragmentBlocks.Count; ++i)
{
_fragmentBlocks[i].WriteTo(buffer, i * recordSize);
}
MetablockWriter writer = new MetablockWriter();
writer.Write(buffer, 0, buffer.Length);
writer.Persist(_context.RawStream);
}
}
/// <summary>
/// Writes the file system to an existing stream.
/// </summary>
/// <param name="output">The stream to write to.</param>
/// <remarks>The <c>output</c> stream must support seeking and writing.</remarks>
public void Build(Stream output)
{
if (output == null)
{
throw new ArgumentNullException("output");
}
if (!output.CanWrite)
{
throw new ArgumentException("Output stream must be writable", "output");
}
if (!output.CanSeek)
{
throw new ArgumentException("Output stream must support seeking", "output");
}
_context = new BuilderContext()
{
RawStream = output,
DataBlockSize = DefaultBlockSize,
IoBuffer = new byte[DefaultBlockSize],
};
MetablockWriter inodeWriter = new MetablockWriter();
MetablockWriter dirWriter = new MetablockWriter();
FragmentWriter fragWriter = new FragmentWriter(_context);
IdTableWriter idWriter = new IdTableWriter(_context);
_context.AllocateInode = AllocateInode;
_context.AllocateId = idWriter.AllocateId;
_context.WriteDataBlock = WriteDataBlock;
_context.WriteFragment = fragWriter.WriteFragment;
_context.InodeWriter = inodeWriter;
_context.DirectoryWriter = dirWriter;
_nextInode = 1;
SuperBlock superBlock = new SuperBlock();
superBlock.Magic = SuperBlock.SquashFsMagic;
superBlock.CreationTime = DateTime.Now;
superBlock.BlockSize = (uint)_context.DataBlockSize;
superBlock.Compression = 1; // DEFLATE
superBlock.BlockSizeLog2 = (ushort)Utilities.Log2(superBlock.BlockSize);
superBlock.MajorVersion = 4;
superBlock.MinorVersion = 0;
output.Position = superBlock.Size;
GetRoot().Reset();
GetRoot().Write(_context);
fragWriter.Flush();
superBlock.RootInode = GetRoot().InodeRef;
superBlock.InodesCount = _nextInode - 1;
superBlock.FragmentsCount = (uint)fragWriter.FragmentCount;
superBlock.UidGidCount = (ushort)idWriter.IdCount;
superBlock.InodeTableStart = output.Position;
inodeWriter.Persist(output);
superBlock.DirectoryTableStart = output.Position;
dirWriter.Persist(output);
if (fragWriter.FragmentCount > 0)
{
superBlock.FragmentTableStart = output.Position;
fragWriter.Persist();
}
else
{
superBlock.FragmentTableStart = -1;
}
superBlock.LookupTableStart = -1;
if (idWriter.IdCount > 0)
{
superBlock.UidGidTableStart = output.Position;
idWriter.Persist();
}
else
{
superBlock.UidGidTableStart = -1;
}
superBlock.ExtendedAttrsTableStart = -1;
superBlock.BytesUsed = output.Position;
// Pad to 4KB
long end = Utilities.RoundUp(output.Position, 4 * Sizes.OneKiB);
if (end != output.Position)
{
byte[] padding = new byte[(int)(end - output.Position)];
output.Write(padding, 0, padding.Length);
}
// Go back and write the superblock
output.Position = 0;
byte[] buffer = new byte[superBlock.Size];
superBlock.WriteTo(buffer, 0);
output.Write(buffer, 0, buffer.Length);
output.Position = end;
}