public static void EntryCheck(this LogEntry entry, LogEntry previous, ILogEntryHashProvider hashProvider)
{
if (previous.Index + 1 != entry.Index)
{
var message = $"Invalid index: expected '{previous.Index + 1}' but was '{entry.Index}'";
throw new LogException(message);
}
if (!previous.Hash.SequenceEqual(entry.PreviousHash))
{
var message =
$"Invalid previous hash: expected '{Crypto.ToHexString(previous.Hash)}' but was '{Crypto.ToHexString(entry.PreviousHash)}'";
throw new LogException(message);
}
var hashRoot = hashProvider.ComputeHashRootBytes(entry);
if (!hashRoot.SequenceEqual(entry.HashRoot))
{
var message =
$"Invalid hash root: expected '{Crypto.ToHexString(hashRoot)}' but was '{Crypto.ToHexString(entry.HashRoot)}'";
throw new LogException(message);
}
for (var i = 0; i < entry.Objects.Count; i++)
{
if (entry.Objects[i].Index == i)
{
continue;
}
var message = $"Invalid object index: expected '{i}' but was '{entry.Objects[i].Index}'";
throw new LogException(message);
}
var hash = hashProvider.ComputeHashBytes(entry);
if (!hash.SequenceEqual(entry.Hash))
{
var message =
$"Invalid hash: expected '{Crypto.ToHexString(hash)}' but was '{Crypto.ToHexString(entry.Hash)}'";
throw new LogException(message);
}
}
internal LogEntry Wrap <T>(T model) where T : ILogSerialized
{
var type = _typeProvider.Get(typeof(Page)).GetValueOrDefault();
var version = LogSerializeContext.FormatVersion;
var @object = new LogObject
{
Timestamp = TimestampFactory.Now,
Type = type,
Version = version,
Data = model
};
@object.Hash = _hashProvider.ComputeHashBytes(@object);
// FIXME: inefficient, cache the last value somewhere?
var previousHash = new byte[0];
foreach (var item in _store.StreamEntries())
{
previousHash = item.Hash;
}
var entry = new LogEntry
{
PreviousHash = previousHash,
Timestamp = @object.Timestamp,
Nonce = Crypto.Nonce(64U),
Objects = new[] { @object }
};
entry.HashRoot = _hashProvider.ComputeHashRootBytes(entry);
entry.Hash = _hashProvider.ComputeHashBytes(entry);
return(entry);
}