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 does the minimum work necessary to refactor the CPU miner code into
its own package. The idea is that separating this code into its own
package will improve its testability and ultimately be useful to other
parts of the codebase such as the various tests which currently
effectively have their own stripped-down versions of this code.
The API will certainly need some additional cleanup and changes to make
it more usable outside of the specific circumstances it was originally
designed to support (namely the generate RPC), however it is better to
do that in future commits in order to keep the changeset as small as
possible during this refactor.
Overview of the major changes:
- Create the new package
- Move cpuminer.go -> cpuminer/cpuminer.go
- Update mining logging to use the new cpuminer package logger
- Rename cpuminerConfig to Config (so it's now cpuminer.Config)
- Rename newCPUMiner to New (so it's now cpuminer.New)
- Update all references to the cpuminer to use the package
- Add a skeleton README.md
