public static AtomicHeader Deserialize(Stream stream)
{
AtomicHeader header = new AtomicHeader();
stream.Seek(0, SeekOrigin.Begin);
byte[] buffer = new byte[SIZE];
if (stream.Read(buffer, 0, SIZE) != SIZE)
{
throw new Exception(String.Format("Invalid {0} header.", TITLE));
}
using (MemoryStream ms = new MemoryStream(buffer))
{
BinaryReader reader = new BinaryReader(ms);
string title = reader.ReadString();
if (title != TITLE)
{
throw new Exception(String.Format("Invalid {0} header.", TITLE));
}
header.Version = reader.ReadInt32();
header.UseCompression = reader.ReadBoolean();
//last flush location
header.SystemData = Ptr.Deserialize(reader);
//tag
int tagLength = reader.ReadInt32();
header.Tag = tagLength >= 0 ? reader.ReadBytes(tagLength) : null;
}
return(header);
}
public Heap(Stream stream, bool useCompression = false, AllocationStrategy strategy = AllocationStrategy.FromTheCurrentBlock)
{
stream.Seek(0, SeekOrigin.Begin); //support Seek?
Stream = stream;
space = new Space();
used = new Dictionary <long, Pointer>();
reserved = new Dictionary <long, Pointer>();
if (stream.Length < AtomicHeader.SIZE) //create new
{
header = new AtomicHeader();
header.UseCompression = useCompression;
space.Add(new Ptr(AtomicHeader.SIZE, long.MaxValue - AtomicHeader.SIZE));
}
else //open exist (ignore the useCompression flag)
{
header = AtomicHeader.Deserialize(Stream);
stream.Seek(header.SystemData.Position, SeekOrigin.Begin);
Deserialize(new BinaryReader(stream));
//manual alloc header.SystemData
var ptr = space.Alloc(header.SystemData.Size);
if (ptr.Position != header.SystemData.Position)
{
throw new Exception("Logical error.");
}
}
Strategy = strategy;
currentVersion++;
}