public abstract void Write(BuilderContext context);
public IdTableWriter(BuilderContext context)
{
_context = context;
_ids = new List <int>();
}
private void WriteDirectory(BuilderContext context)
{
MetadataRef startPos = context.DirectoryWriter.Position;
int currentChild = 0;
int numDirs = 0;
while (currentChild < _children.Count)
{
long thisBlock = _children[currentChild].Node.InodeRef.Block;
int firstInode = _children[currentChild].Node.InodeNumber;
int count = 1;
while (currentChild + count < _children.Count &&
_children[currentChild + count].Node.InodeRef.Block == thisBlock &&
_children[currentChild + count].Node.InodeNumber - firstInode < 0x7FFF)
{
++count;
}
DirectoryHeader hdr = new DirectoryHeader()
{
Count = count - 1,
InodeNumber = firstInode,
StartBlock = (int)thisBlock
};
hdr.WriteTo(context.IoBuffer, 0);
context.DirectoryWriter.Write(context.IoBuffer, 0, hdr.Size);
for (int i = 0; i < count; ++i)
{
Entry child = _children[currentChild + i];
DirectoryRecord record = new DirectoryRecord()
{
Offset = (ushort)child.Node.InodeRef.Offset,
InodeNumber = (short)(child.Node.InodeNumber - firstInode),
Type = child.Node.Inode.Type,
Name = child.Name
};
record.WriteTo(context.IoBuffer, 0);
context.DirectoryWriter.Write(context.IoBuffer, 0, record.Size);
if (child.Node.Inode.Type == InodeType.Directory ||
child.Node.Inode.Type == InodeType.ExtendedDirectory)
{
++numDirs;
}
}
currentChild += count;
}
long size = context.DirectoryWriter.DistanceFrom(startPos);
if (size > uint.MaxValue)
{
throw new NotImplementedException("Writing large directories");
}
NumLinks = numDirs + 2; // +1 for self, +1 for parent
_inode.StartBlock = (uint)startPos.Block;
_inode.Offset = (ushort)startPos.Offset;
_inode.FileSize = (uint)size + 3; // For some reason, always +3
}
/// <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;
}
