This commit prunes several unused functions from the Db interface and the
underlying implementations. For the most part these are holdovers from
the original sqlite implementation. It also removes the types associated
with those functions since they are no longer needed. The following
functions and types have been removed:
- InvalidateCache
- InvalidateBlockCache
- InvalidateTxCache
- SetDBInsertMode
- InsertMode type and associated constants
- NewIterateBlocks
- BlockIterator interface
The reasons for removing these are broken out below.
- Neither of two current implementations implement these functions nor
does any of the fully functional code using the interface invoke them.
- After contemplating and testing caching of blocks and transactions at
this layer, it doesn't seem to provide any real benefit unless very
specific assumptions about the use case are made. Making those
assumptions can make other use cases worse. For example, assuming a
large cache is harmful to memory-constrained use cases. Leaving it up
to the caller to choose when to cache block and transactions allows much
greater flexibility.
- The DB insert mode was an artifact of the original sqlite implementation
and probably should have only been exposed specifically on the
implementation as opposed through generic interface. If a specific
implementation wishes to provide functionality such as special modes,
that should be done through type assertions.
The btcutil code was recently changed to provide a new Tx type which
provides hash caching (among other things). As a result, the notion of
obtaining a transaction hashes via TxShas was deprecated as well. This
commit updates the tests and backend implementation code accordingly.
This commit adds the infrastructure needed to re-run the integrity tests
after calling the InvalidBlockCache, InvalidateTxCache, and
InvalidateCache functions. The tests intentially randomize the order the
invalidate functions are called in to increase the likelyhood of finding
in issues realted to ordering of the calls.
This commit changes the interface test errors to all report the block
height and hash prior to the failure. Test failures that transactions
also now report the transaction number and hash. The makes it much
easier to track down where a test failure occurs.
The idea here is that interface_test.go will be directly usable in each
implementation to increase test coverage there as well, but also works at
the top-most level to test arbitrary backends.
This is simply at start at providing generic interface tests. The only
thing is tests so far is the empty database conditions on NewestSha, but
it adds infrastructure for creating and opening databases with special
type handling based on the database and necessary logic to teardown so
multiple backends can be tested simultaneously.
This and the next series of commits all discussed with drahn@.
