Implement faucet funds reallocation logic

chain/stmgr/forks.go

@@ -3,11 +3,23 @@ package stmgr
 import (
 	"context"
 
+	"github.com/filecoin-project/go-address"
 	"github.com/filecoin-project/go-state-types/abi"
+	"github.com/filecoin-project/go-state-types/big"
+	"github.com/filecoin-project/lotus/build"
+	"github.com/filecoin-project/lotus/chain/state"
 	"github.com/filecoin-project/lotus/chain/types"
+	"github.com/filecoin-project/specs-actors/actors/builtin"
+	"github.com/filecoin-project/specs-actors/actors/builtin/miner"
+	"github.com/filecoin-project/specs-actors/actors/builtin/power"
+	"github.com/filecoin-project/specs-actors/actors/util/adt"
+	cbor "github.com/ipfs/go-ipld-cbor"
+	"golang.org/x/xerrors"
 )
 
-var ForksAtHeight = map[abi.ChainEpoch]func(context.Context, *StateManager, types.StateTree) error{}
+var ForksAtHeight = map[abi.ChainEpoch]func(context.Context, *StateManager, types.StateTree) error{
+	42000: UpgradeFaucetBurnRecovery,
+}
 
 func (sm *StateManager) handleStateForks(ctx context.Context, st types.StateTree, height abi.ChainEpoch) (err error) {
 	f, ok := ForksAtHeight[height]
@@ -20,3 +32,291 @@ func (sm *StateManager) handleStateForks(ctx context.Context, st types.StateTree
 
 	return nil
 }
+
+type forEachTree interface {
+	ForEach(func(address.Address, *types.Actor) error) error
+}
+
+func doTransfer(tree types.StateTree, from, to address.Address, amt abi.TokenAmount) error {
+	fromAct, err := tree.GetActor(from)
+	if err != nil {
+		return xerrors.Errorf("failed to get 'from' actor for transfer: %w", err)
+	}
+
+	fromAct.Balance = types.BigSub(fromAct.Balance, amt)
+	if fromAct.Balance.Sign() < 0 {
+		return xerrors.Errorf("(sanity) deducted more funds from target account than it had (%s, %s)", from, types.FIL(amt))
+	}
+
+	if err := tree.SetActor(from, fromAct); err != nil {
+		return xerrors.Errorf("failed to persist from actor: %w", err)
+	}
+
+	toAct, err := tree.GetActor(to)
+	if err != nil {
+		return xerrors.Errorf("failed to get 'to' actor for transfer: %w", err)
+	}
+
+	toAct.Balance = types.BigAdd(toAct.Balance, amt)
+
+	if err := tree.SetActor(to, toAct); err != nil {
+		return xerrors.Errorf("failed to persist to actor: %w", err)
+	}
+
+	return nil
+}
+
+func UpgradeFaucetBurnRecovery(ctx context.Context, sm *StateManager, tree types.StateTree) error {
+	// Some initial parameters
+	FundsForMiners := types.FromFil(1_000_000)
+	LookbackEpoch := abi.ChainEpoch(32000)
+	AccountCap := types.FromFil(0)
+	BaseMinerBalance := types.FromFil(20)
+	DesiredReimbursementBalance := types.FromFil(5_000_000)
+
+	isSystemAccount := func(addr address.Address) (bool, error) {
+		id, err := address.IDFromAddress(addr)
+		if err != nil {
+			return false, xerrors.Errorf("id address: %w", err)
+		}
+
+		if id < 1000 {
+			return true, nil
+		}
+		return false, nil
+	}
+
+	minerFundsAlloc := func(pow, tpow abi.StoragePower) abi.TokenAmount {
+		return types.BigDiv(types.BigMul(pow, FundsForMiners), tpow)
+	}
+
+	// Grab lookback state for account checks
+	lbts, err := sm.ChainStore().GetTipsetByHeight(ctx, LookbackEpoch, nil, false)
+	if err != nil {
+		return xerrors.Errorf("failed to get tipset at lookback height: %w", err)
+	}
+
+	var lbtree *state.StateTree
+	if err = sm.WithStateTree(lbts.ParentState(), func(state *state.StateTree) error {
+		lbtree = state
+		return nil
+	}); err != nil {
+		return xerrors.Errorf("loading state tree failed: %w", err)
+	}
+
+	ReserveAddress, err := address.NewFromString("t090")
+	if err != nil {
+		return xerrors.Errorf("failed to parse reserve address: %w", err)
+	}
+
+	fetree, ok := tree.(forEachTree)
+	if !ok {
+		return xerrors.Errorf("fork transition state tree doesnt support ForEach (%T)", tree)
+	}
+
+	type transfer struct {
+		From address.Address
+		To   address.Address
+		Amt  abi.TokenAmount
+	}
+
+	var transfers []transfer
+
+	// Take all excess funds away, put them into the reserve account
+	err = fetree.ForEach(func(addr address.Address, act *types.Actor) error {
+		switch act.Code {
+		case builtin.AccountActorCodeID, builtin.MultisigActorCodeID, builtin.PaymentChannelActorCodeID:
+			sysAcc, err := isSystemAccount(addr)
+			if err != nil {
+				return xerrors.Errorf("checking system account: %w", err)
+			}
+
+			if !sysAcc {
+				transfers = append(transfers, transfer{
+					From: addr,
+					To:   ReserveAddress,
+					Amt:  act.Balance,
+				})
+			}
+		case builtin.StorageMinerActorCodeID:
+			var st miner.State
+			if err := sm.WithActorState(ctx, &st)(act); err != nil {
+				return xerrors.Errorf("failed to load miner state: %w", err)
+			}
+
+			var available abi.TokenAmount
+			{
+				defer func() {
+					if err := recover(); err != nil {
+						log.Warnf("Get available balance failed (%s, %s, %s): %s", addr, act.Head, act.Balance, err)
+					}
+					available = abi.NewTokenAmount(0)
+				}()
+				// this panics if the miner doesnt have enough funds to cover their locked pledge
+				available = st.GetAvailableBalance(act.Balance)
+			}
+
+			transfers = append(transfers, transfer{
+				From: addr,
+				To:   ReserveAddress,
+				Amt:  available,
+			})
+		}
+		return nil
+	})
+	if err != nil {
+		return xerrors.Errorf("foreach over state tree failed: %w", err)
+	}
+
+	// Execute transfers from previous step
+	for _, t := range transfers {
+		if err := doTransfer(tree, t.From, t.To, t.Amt); err != nil {
+			return xerrors.Errorf("transfer %s %s->%s failed: %w", t.Amt, t.From, t.To, err)
+		}
+	}
+
+	// pull up power table to give miners back some funds proportional to their power
+	var ps power.State
+	powAct, err := tree.GetActor(builtin.StoragePowerActorAddr)
+	if err != nil {
+		return xerrors.Errorf("failed to load power actor: %w", err)
+	}
+
+	cst := cbor.NewCborStore(sm.ChainStore().Blockstore())
+	if err := cst.Get(ctx, powAct.Head, &ps); err != nil {
+		return xerrors.Errorf("failed to get power actor state: %w", err)
+	}
+
+	totalPower := ps.TotalBytesCommitted
+
+	var transfersBack []transfer
+	// Now, we return some funds to places where they are needed
+	err = fetree.ForEach(func(addr address.Address, act *types.Actor) error {
+		lbact, err := lbtree.GetActor(addr)
+		if err != nil {
+			if !xerrors.Is(err, types.ErrActorNotFound) {
+				return xerrors.Errorf("failed to get actor in lookback state")
+			}
+		}
+
+		prevBalance := abi.NewTokenAmount(0)
+		if lbact != nil {
+			prevBalance = lbact.Balance
+		}
+
+		switch act.Code {
+		case builtin.AccountActorCodeID, builtin.MultisigActorCodeID, builtin.PaymentChannelActorCodeID:
+			nbalance := big.Min(prevBalance, AccountCap)
+			if nbalance.Sign() != 0 {
+				transfersBack = append(transfersBack, transfer{
+					From: ReserveAddress,
+					To:   addr,
+					Amt:  nbalance,
+				})
+			}
+		case builtin.StorageMinerActorCodeID:
+			var st miner.State
+			if err := sm.WithActorState(ctx, &st)(act); err != nil {
+				return xerrors.Errorf("failed to load miner state: %w", err)
+			}
+
+			var minfo miner.MinerInfo
+			if err := cst.Get(ctx, st.Info, &minfo); err != nil {
+				return xerrors.Errorf("failed to get miner info: %w", err)
+			}
+
+			sectorsArr, err := adt.AsArray(sm.ChainStore().Store(ctx), st.Sectors)
+			if err != nil {
+				return xerrors.Errorf("failed to load sectors array: %w", err)
+			}
+
+			slen := sectorsArr.Length()
+
+			power := types.BigMul(types.NewInt(slen), types.NewInt(uint64(minfo.SectorSize)))
+
+			mfunds := minerFundsAlloc(power, totalPower)
+			transfersBack = append(transfersBack, transfer{
+				From: ReserveAddress,
+				To:   minfo.Worker,
+				Amt:  mfunds,
+			})
+
+			// Now make sure to give each miner who had power at the lookback some FIL
+			lbact, err := lbtree.GetActor(addr)
+			if err == nil {
+				var lbst miner.State
+				if err := sm.WithActorState(ctx, &lbst)(lbact); err != nil {
+					return xerrors.Errorf("failed to load miner state: %w", err)
+				}
+
+				lbsectors, err := adt.AsArray(sm.ChainStore().Store(ctx), lbst.Sectors)
+				if err != nil {
+					return xerrors.Errorf("failed to load lb sectors array: %w", err)
+				}
+
+				if lbsectors.Length() > 0 {
+					transfersBack = append(transfersBack, transfer{
+						From: ReserveAddress,
+						To:   minfo.Worker,
+						Amt:  BaseMinerBalance,
+					})
+				}
+
+			} else {
+				log.Warnf("failed to get miner in lookback state: %s", err)
+			}
+		}
+		return nil
+	})
+	if err != nil {
+		return xerrors.Errorf("foreach over state tree failed: %w", err)
+	}
+
+	for _, t := range transfersBack {
+		if err := doTransfer(tree, t.From, t.To, t.Amt); err != nil {
+			return xerrors.Errorf("transfer %s %s->%s failed: %w", t.Amt, t.From, t.To, err)
+		}
+	}
+
+	// transfer all burnt funds back to the reserve account
+	burntAct, err := tree.GetActor(builtin.BurntFundsActorAddr)
+	if err != nil {
+		return xerrors.Errorf("failed to load burnt funds actor: %w", err)
+	}
+	if err := doTransfer(tree, builtin.BurntFundsActorAddr, ReserveAddress, burntAct.Balance); err != nil {
+		return xerrors.Errorf("failed to unburn funds: %w", err)
+	}
+
+	// Top up the reimbursement service
+	reimbAddr, err := address.NewFromString("t0111")
+	if err != nil {
+		return xerrors.Errorf("failed to parse reimbursement service address")
+	}
+
+	reimb, err := tree.GetActor(reimbAddr)
+	if err != nil {
+		return xerrors.Errorf("failed to load reimbursement account actor: %w", err)
+	}
+
+	difference := types.BigSub(DesiredReimbursementBalance, reimb.Balance)
+	if err := doTransfer(tree, ReserveAddress, reimbAddr, difference); err != nil {
+		return xerrors.Errorf("failed to top up reimbursement account: %w", err)
+	}
+
+	// Now, a final sanity check to make sure the balances all check out
+	total := abi.NewTokenAmount(0)
+	err = fetree.ForEach(func(addr address.Address, act *types.Actor) error {
+		total = types.BigAdd(total, act.Balance)
+		return nil
+	})
+	if err != nil {
+		return xerrors.Errorf("checking final state balance failed: %w", err)
+	}
+
+	exp := types.FromFil(build.FilBase)
+	if !exp.Equals(total) {
+		return xerrors.Errorf("resultant state tree account balance was not correct: %s", total)
+	}
+
+	return nil
+}