public BlockHeader GetHeader(ChainedHeader chainedHeader, uint256 hash)
{
if (this.nearTipHeaders.TryGetValue(hash, out BlockHeader blockHeader))
{
return(blockHeader);
}
if (this.recentHeaders.TryGetValue(hash, out blockHeader))
{
return(blockHeader);
}
ReadOnlySpan <byte> bytes = hash.ToReadOnlySpan();
lock (this.locker)
{
bytes = this.leveldb.Get(DBH.Key(HeaderTableName, bytes));
}
if (bytes == null)
{
throw new ApplicationException("Header must exist if requested");
}
blockHeader = this.network.Consensus.ConsensusFactory.CreateBlockHeader();
blockHeader.FromBytes(bytes.ToArray(), this.network.Consensus.ConsensusFactory);
// If the header is 500 blocks behind tip or 100 blocks ahead cache it.
if ((chainedHeader.Height > this.ChainIndexer.Height - 500) && (chainedHeader.Height <= this.ChainIndexer.Height + 100))
{
this.nearTipHeaders.AddOrUpdate(hash, blockHeader);
}
else
{
this.recentHeaders.AddOrUpdate(hash, blockHeader);
}
return(blockHeader);
}