b5fea8d0cc
This adds a new CuckooCache in validation, caching whether all of a transaction's scripts were valid with a given set of script flags. Unlike previous attempts at caching an entire transaction's validity, which have nearly universally introduced consensus failures, this only caches the validity of a transaction's scriptSigs. As these are pure functions of the transaction and data it commits to, this should be much safer. This is somewhat duplicative with the sigcache, as entries in the new cache will also have several entries in the sigcache. However, the sigcache is kept both as ATMP relies on it and because it prevents malleability-based DoS attacks on the new higher-level cache. Instead, the -sigcachesize option is re-used - cutting the sigcache size in half and using the newly freed memory for the script execution cache. Transactions which match the script execution cache never even have entries in the script check thread's workqueue created. Note that the cache is indexed only on the script execution flags and the transaction's witness hash. While this is sufficient to make the CScriptCheck() calls pure functions, this introduces dependancies on the mempool calculating things such as the PrecomputedTransactionData object, filling the CCoinsViewCache, etc in the exact same way as ConnectBlock. I belive this is a reasonable assumption, but should be noted carefully. In a rather naive benchmark (reindex-chainstate up to block 284k with cuckoocache always returning true for contains(), -assumevalid=0 and a very large dbcache), this connected blocks ~1.7x faster.
Compiling/running unit tests
Unit tests will be automatically compiled if dependencies were met in ./configure
and tests weren't explicitly disabled.
After configuring, they can be run with make check.
To run the bitcoind tests manually, launch src/test/test_bitcoin.
To add more bitcoind tests, add BOOST_AUTO_TEST_CASE functions to the existing
.cpp files in the test/ directory or add new .cpp files that
implement new BOOST_AUTO_TEST_SUITE sections.
To run the bitcoin-qt tests manually, launch src/qt/test/test_bitcoin-qt
To add more bitcoin-qt tests, add them to the src/qt/test/ directory and
the src/qt/test/test_main.cpp file.
Running individual tests
test_bitcoin has some built-in command-line arguments; for example, to run just the getarg_tests verbosely:
test_bitcoin --log_level=all --run_test=getarg_tests
... or to run just the doubledash test:
test_bitcoin --run_test=getarg_tests/doubledash
Run test_bitcoin --help for the full list.
Note on adding test cases
The sources in this directory are unit test cases. Boost includes a unit testing framework, and since bitcoin already uses boost, it makes sense to simply use this framework rather than require developers to configure some other framework (we want as few impediments to creating unit tests as possible).
The build system is setup to compile an executable called test_bitcoin
that runs all of the unit tests. The main source file is called
test_bitcoin.cpp. To add a new unit test file to our test suite you need
to add the file to src/Makefile.test.include. The pattern is to create
one test file for each class or source file for which you want to create
unit tests. The file naming convention is <source_filename>_tests.cpp
and such files should wrap their tests in a test suite
called <source_filename>_tests. For an example of this pattern,
examine uint256_tests.cpp.
For further reading, I found the following website to be helpful in explaining how the boost unit test framework works: http://www.alittlemadness.com/2009/03/31/c-unit-testing-with-boosttest/.