Switch from Blake3 to ProgPoW

[wizeguyy]

@dominant-strategies/core-dev

[Djadih]

Still some more files to review, but left a couple minor (get it?) comments.

[gameofpointers]

I have a general question. Why do we still have ethash in the code base and have made changes to it if we are not going to use it now

[wizeguyy]

Why do we still have ethash in the code base and have made changes to it if we are not going to use it now

Progpow is Ethash. You can think of it as Ethash V2.

Why does the file reference ethash? Because the ethereum devs wrote progpow as an extension of ethash and they documented it accordingly. Not sure what the hangup is here.

[gameofpointers]

@wizeguyy I meant blake3, didnt mean Ethash here I have a general question. Why do we still have ethash in the code base and have made changes to it if we are not going to use it now

[wizeguyy]

@wizeguyy I meant blake3, didnt mean Ethash here

• changes were made to blake3, because the consensus interface had to change
• The consensus interface had to change, because POEM needed to be moved into the consensus engine, and the interface needs to accommodate POEM now.
• POEM had to move into the consensus engine, because Ethash/Progpow do not use block hash for PoW, so POEM could no longer operate on block hashes to calc intrinsic entropy. With POEM in block.go, all it had access to was the block hash.
• Blake3pow was not removed from the codebase, because there has been discussion of scheduling a transition back to blake3. If we decide not to do any such transition, then it will be trivial to remove Blake3pow when the time comes.

Hope that answers your question.