This modifies the blockNode and BestState structs in the blockchain
package to store hashes directly instead of pointers to them and updates
callers to deal with the API change in the exported BestState struct.
In general, the preferred approach for hashes moving forward is to store
hash values in complex data structures, particularly those that will be
used for cache entries, and accept pointers to hashes in arguments to
functions.
Some of the reasoning behind making this change is:
- It is generally preferred to avoid storing pointers to data in cache
objects since doing so can easily lead to storing interior pointers
into other structs that then can't be GC'd
- Keeping the hash values directly in the block node provides better
cache locality
This adds a full-blown testing infrastructure in order to test consensus
validation rules. It is built around the idea of dynamically generating
full blocks that target specific rules linked together to form a block
chain. In order to properly test the rules, each test instance starts
with a valid block that is then modified in the specific way needed to
test a specific rule.
Blocks which exercise following rules have been added for this initial
version. These tests were largely ported from the original Java-based
'official' block acceptance tests as well as some additional tests
available in the Core python port. It is expected that further tests
can be added over time as consensus rules change.
* Enough valid blocks to have a stable base of mature coinbases to spend
for futher tests
* Basic forking and chain reorganization
* Double spends on forks
* Too much proof-of-work coinbase (extending main chain, in block that
forces a reorg, and in a valid fork)
* Max and too many signature operations via various combinations of
OP_CHECKSIG, OP_MULTISIG, OP_CHECKSIGVERIFY, and OP_MULTISIGVERIFY
* Too many and max signature operations with offending sigop after
invalid data push
* Max and too many signature operations via pay-to-script-hash redeem
scripts
* Attempt to spend tx created on a different fork
* Attempt to spend immature coinbase (on main chain and fork)
* Max size block and block that exceeds the max size
* Children of rejected blocks are either orphans or rejected
* Coinbase script too small and too large
* Max length coinbase script
* Attempt to spend tx in blocks that failed to connect
* Valid non-coinbase tx in place of coinbase
* Block with no transactions
* Invalid proof-of-work
* Block with a timestamp too far in the future
* Invalid merkle root
* Invalid proof-of-work limit (bits header field)
* Negative proof-of-work limit (bits header field)
* Two coinbase transactions
* Duplicate transactions
* Spend from transaction that does not exist
* Timestamp exactly at and one second after the median time
* Blocks with same hash via merkle root tricks
* Spend from transaction index that is out of range
* Transaction that spends more that its inputs provide
* Transaction with same hash as an existing tx that has not been
fully spent (BIP0030)
* Non-final coinbase and non-coinbase txns
* Max size block with canonical encoding which exceeds max size with
non-canonical encoding
* Spend from transaction earlier in same block
* Spend from transaction later in same block
* Double spend transaction from earlier in same block
* Coinbase that pays more than subsidy + fees
* Coinbase that includes subsidy + fees
* Invalid opcode in dead execution path
* Reorganization of txns with OP_RETURN outputs
* Spend of an OP_RETURN output
* Transaction with multiple OP_RETURN outputs
* Large max-sized block reorganization test (disabled by default since
it takes a long time and a lot of memory to run)
Finally, the README.md files in the main and docs directories have been
updated to reflect the use of the new testing framework.
