This commit optimizes InsertBlock slightly by using the cached transaction
hashes instead of recomputing them. Also, while here, use the
ShaHash.IsEqual function to do comparisons for consistency.
This is ongoing work towards conformal/btcd#25.
ok @drahn.
FetchTxBySha changes what it returns, it can now return a TxListReply and
and error if none are found.
FetchTxByShaList is renamed to FetchUnSpentTxByShaList to indicate that
it will (likey/eventually) only return Tx that have some unspent TxOuts.
Tx which are fully spent may not be (reliably) looked up using this API.
improved error handling
Fix testing, no point in running tests multiple times
Fix error when no blocks in database, reopen would misreport NewstSha() return
This code is still prototype at this time.
It appears to function correctly but something
consumes more memory than is considered reasonable
for the dataset comprised of the full bitcoind chain.
Not recommened for use at this time.
