In this commit, we update all the indexers to use the stxo set for a
particular block rather than the utxo view for the block. We do this as
we can eliminate a large number of random reads for each block, and can
instead deserialize a single instance of all the outputs spent in that
block and feed in the prev input scripts to each indexer.
The index will hold three types of entries for each filter type, block
pair: filter, header, and hash. Since they all have similar methods
and implementations, refactor to reduce duplication.
Since the tx hash has moved to the basic filter, generating an extended filter
can result in `ErrNoData`. This is handled by writing a nil filter and giving
it a zero hash.
The cfilter BIP specifies that the filter type is a uint8. The
current code encodes it correctly on the wire, but everywhere else,
it's treated as a boolean (false for basic filter, true for
extended). This commit corrects that to account for possible
additional filter types in the future. All package changes are
done in one commit as they're all interdependent. The following
packages are updated:
* blockchain/indexers
* btcjson
* peer
* wire
* main (server.go and rpcserver.go)
