Change legacy rando geth fork choice to be deterministic (#871)

* Change legacy rando geth fork choice to be deterministic, based on block hash.

* core: add forkchoice tests

* fix

---------

Co-authored-by: Manav Darji <manavdarji.india@gmail.com>
This commit is contained in:
Paul O'Leary 2023-10-19 00:26:30 -07:00 committed by GitHub
parent d1149daa0f
commit a9c57370cd
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2 changed files with 59 additions and 1 deletions

View file

@ -17,6 +17,7 @@
package core
import (
"bytes"
"errors"
"math/big"
@ -114,7 +115,8 @@ func (f *ForkChoice) ReorgNeeded(current *types.Header, extern *types.Header) (b
currentPreserve, externPreserve = f.preserve(current), f.preserve(extern)
}
reorg = !currentPreserve && (externPreserve || f.rand.Float64() < 0.5)
// Compare hashes of block in case of tie breaker. Lexicographically larger hash wins.
reorg = !currentPreserve && (externPreserve || bytes.Compare(current.Hash().Bytes(), extern.Hash().Bytes()) < 0)
}
return reorg, nil

View file

@ -10,6 +10,8 @@ import (
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/params"
"github.com/ethereum/go-ethereum/trie"
"github.com/stretchr/testify/require"
)
// chainValidatorFake is a mock for the chain validator service
@ -30,6 +32,60 @@ func newChainReaderFake(getTd func(hash common.Hash, number uint64) *big.Int) *c
return &chainReaderFake{getTd: getTd}
}
// nolint: tparallel
func TestForkChoice(t *testing.T) {
t.Parallel()
// Create mocks for forker
getTd := func(hash common.Hash, number uint64) *big.Int {
if number <= 2 {
return big.NewInt(int64(number))
}
return big.NewInt(0)
}
mockChainReader := newChainReaderFake(getTd)
mockForker := NewForkChoice(mockChainReader, nil, nil)
createHeader := func(number int64, extra []byte) *types.Header {
return &types.Header{
Number: big.NewInt(number),
Extra: extra,
}
}
// Create headers for different cases
headerA := createHeader(1, []byte("A"))
headerB := createHeader(2, []byte("B"))
headerC := createHeader(3, []byte("C"))
headerD := createHeader(4, []byte("D")) // 0x96b0f70c01f4d2b1ee2df5b0202c099776f24c9375ffc89d94b880007633961b (hash)
headerE := createHeader(4, []byte("E")) // 0xdc0acf54354ff86194baeaab983098a49a40218cffcc77a583726fc06c429685 (hash)
testCases := []struct {
name string
current *types.Header
incoming *types.Header
want bool
}{
{"tdd(incoming) > tdd(current)", headerA, headerB, true},
{"tdd(current) > tdd(incoming)", headerB, headerA, false},
{"tdd(current) = tdd(incoming), number(incoming) > number(current)", headerC, headerD, false},
{"tdd(current) = tdd(incoming), number(current) > number(incoming)", headerD, headerC, true},
{"tdd(current) = tdd(incoming), number(current) = number(incoming), hash(current) > hash(incoming)", headerE, headerD, false},
{"tdd(current) = tdd(incoming), number(current) = number(incoming), hash(incoming) > hash(current)", headerD, headerE, true},
}
// nolint: paralleltest
for _, tc := range testCases {
tc := tc
t.Run(tc.name, func(t *testing.T) {
res, err := mockForker.ReorgNeeded(tc.current, tc.incoming)
require.Equal(t, tc.want, res, tc.name)
require.NoError(t, err, tc.name)
})
}
}
func TestPastChainInsert(t *testing.T) {
t.Parallel()