Ask a question about the code in func SetHead #20224
Description
func (bc *BlockChain) SetHead(head uint64) error {
log.Warn("Rewinding blockchain", "target", head)
bc.chainmu.Lock()
defer bc.chainmu.Unlock()
updateFn := func(db ethdb.KeyValueWriter, header *types.Header) {
// Rewind the block chain, ensuring we don't end up with a stateless head block
if currentBlock := bc.CurrentBlock(); currentBlock != nil && header.Number.Uint64() < currentBlock.NumberU64() {
newHeadBlock := bc.GetBlock(header.Hash(), header.Number.Uint64())
if newHeadBlock == nil {
newHeadBlock = bc.genesisBlock
} else {
if _, err := state.New(newHeadBlock.Root(), bc.stateCache); err != nil {
// Rewound state missing, rolled back to before pivot, reset to genesis
newHeadBlock = bc.genesisBlock
}
}
rawdb.WriteHeadBlockHash(db, newHeadBlock.Hash())
bc.currentBlock.Store(newHeadBlock)
headBlockGauge.Update(int64(newHeadBlock.NumberU64()))
}
...
I want to ask, why here not try to repair the chain (call the func repair)?. Just reset to genesisBlock?