private ImmutableObject ReadObject(long beginning, long end)
{
ImmutableObject obj = null;
lock (_chainStreamLock)
{
_chainStream.Position = beginning;
byte[] data = new byte[end - beginning];
_chainStream.Read(data, 0, data.Length);
obj = ZeroFormatterSerializer.Deserialize <ImmutableObject>(data);
}
return(obj);
}
public int Insert(ImmutableObject obj)
{
ImmutableObject previousObject = LastObject();
// If the object is new then we need to set the id to the next unique id available
if (obj.Version == -1)
{
obj.Id = _latestVersionIndex.Last() + 1;
}
obj.InsertOp(previousObject.Index + 1, previousObject.Hash);
WriteObject(obj);
return(obj.Id);
}
private void WriteObject(ImmutableObject obj)
{
byte[] data = ZeroFormatterSerializer.Serialize(obj);
lock (_chainStreamLock)
{
long pos = _chainStream.Length;
_chainStream.Position = pos;
_index.SetAtIndex(obj.Index, pos);
_latestVersionIndex.Add(obj.Id, obj.Index);
_chainStream.Write(data, 0, data.Length);
_chainStream.Flush();
}
}
public Chain(string dbName)
{
_index = new Index <long>(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments), $"{dbName}.index"));
_latestVersionIndex = new LinkedIndex <int>(Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments), $"{dbName}.latestVersion");
_chainStream = new FileStream(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments), $"{dbName}.data"), FileMode.OpenOrCreate, FileAccess.ReadWrite);
if (!Any)
{
var genesis = new ImmutableObject()
{
Json = string.Empty
};
genesis.InsertOp(0, string.Empty);
WriteObject(genesis);
}
}
public bool Validate()
{
bool valid = true;
string previousHash = null;
int count = _index.Count();
for (int i = 0; i < count; i++)
{
ImmutableObject obj = ReadObject(i);
if (previousHash != null && obj.PreviousHash != previousHash)
{
valid = false;
break;
}
previousHash = obj.CalculateHash();
}
return(valid);
}