This avoids having to rely on implicit casts when passing them to the
various functions allocating the caches.
This also ensures that if the requested amount of db_cache does not fit
in a size_t, it is clamped to the maximum value of a size_t.
Also take this opportunity to make the total amounts of cache in the
chainstate manager a size_t too.
They are not related to the txdb, so a better place for them is the
new kernel and node cache file. Re-use the default amount of kernel
cache for the default node cache.
Carrying non-kernel related fields in the cache sizes for the indexes is
confusing for kernel library users. The cache sizes also are set
currently with magic numbers in bitcoin-chainstate. The comments for the
cache size calculations are also not completely clear.
Solve these things by moving the kernel-specific cache size fields to
their own struct.
This slightly changes the way the cache is allocated if the txindex
and/or blockfilterindex is used. Since they are now given precedence
over the block tree db cache, this results in a bit less cache being
allocated to the block tree db, coinsdb and coins caches. The effect is
negligible though, i.e. cache sizes with default dbcache reported
through the logs are:
master:
Cache configuration:
* Using 2.0 MiB for block index database
* Using 56.0 MiB for transaction index database
* Using 49.0 MiB for basic block filter index database
* Using 8.0 MiB for chain state database
* Using 335.0 MiB for in-memory UTXO set (plus up to 286.1 MiB of unused mempool space)
this branch:
Cache configuration:
* Using 2.0 MiB for block index database
* Using 56.2 MiB for transaction index database
* Using 49.2 MiB for basic block filter index database
* Using 8.0 MiB for chain state database
* Using 334.5 MiB for in-memory UTXO set (plus up to 286.1 MiB of unused mempool space)
I strongly recommend reviewing with the following git-diff flags:
--color-moved=dimmed_zebra --color-moved-ws=allow-indentation-change
[META] In a future commit, this function will be re-used in TestingSetup
so that the behaviour matches across test and non-test init
codepaths.
