This commit adds pluggable consensus engines to go-ethereum. In short, it
introduces a generic consensus interface, and refactors the entire codebase to
use this interface.
This commit solves several issues concerning the genesis block:
* Genesis/ChainConfig loading was handled by cmd/geth code. This left
library users in the cold. They could specify a JSON-encoded
string and overwrite the config, but didn't get any of the additional
checks performed by geth.
* Decoding and writing of genesis JSON was conflated in
WriteGenesisBlock. This made it a lot harder to embed the genesis
block into the forthcoming config file loader. This commit changes
things so there is a single Genesis type that represents genesis
blocks. All uses of Write*Genesis* are changed to use the new type
instead.
* If the chain config supplied by the user was incompatible with the
current chain (i.e. the chain had already advanced beyond a scheduled
fork), it got overwritten. This is not an issue in practice because
previous forks have always had the highest total difficulty. It might
matter in the future though. The new code reverts the local chain to
the point of the fork when upgrading configuration.
The change to genesis block data removes compression library
dependencies from package core.
* common/math: optimize PaddedBigBytes, use it more
name old time/op new time/op delta
PaddedBigBytes-8 71.1ns ± 5% 46.1ns ± 1% -35.15% (p=0.000 n=20+19)
name old alloc/op new alloc/op delta
PaddedBigBytes-8 48.0B ± 0% 32.0B ± 0% -33.33% (p=0.000 n=20+20)
* all: unify big.Int zero checks
Various checks were in use. This commit replaces them all with Int.Sign,
which is cheaper and less code.
eg templates:
func before(x *big.Int) bool { return x.BitLen() == 0 }
func after(x *big.Int) bool { return x.Sign() == 0 }
func before(x *big.Int) bool { return x.BitLen() > 0 }
func after(x *big.Int) bool { return x.Sign() != 0 }
func before(x *big.Int) int { return x.Cmp(common.Big0) }
func after(x *big.Int) int { return x.Sign() }
* common/math, crypto/secp256k1: make ReadBits public in package math
This commit implements EIP158 part 1, 2, 3 & 4
1. If an account is empty it's no longer written to the trie. An empty
account is defined as (balance=0, nonce=0, storage=0, code=0).
2. Delete an empty account if it's touched
3. An empty account is redefined as either non-existent or empty.
4. Zero value calls and zero value suicides no longer consume the 25k
reation costs.
params: moved core/config to params
Signed-off-by: Jeffrey Wilcke <jeffrey@ethereum.org>
Added chain configuration options and write out during genesis database
insertion. If no "config" was found, nothing is written to the database.
Configurations are written on a per genesis base. This means
that any chain (which is identified by it's genesis hash) can have their
own chain settings.
