internal ByteArrayBuffer PrepareRead(Transaction trans)
{
BTreeNodeCacheEntry cacheEntry = Btree().CacheEntry(this);
if (CanWrite())
{
return(null);
}
if (IsNew())
{
return(null);
}
Transaction systemTransaction = trans.SystemTransaction();
ByteArrayBuffer buffer = cacheEntry.Buffer();
if (buffer != null)
{
// Cache hit, still unread
buffer.Seek(0);
Read(systemTransaction, buffer);
cacheEntry.Buffer(null);
_btree.AddToProcessing(this);
return(null);
}
buffer = ProduceReadBuffer(systemTransaction);
ReadNodeHeader(buffer);
cacheEntry.Buffer(buffer);
return(buffer);
}