lotus/chain/vm/vm.go
2020-08-27 17:34:45 -04:00

823 lines
22 KiB
Go

package vm
import (
"bytes"
"context"
"fmt"
"reflect"
"time"
bstore "github.com/filecoin-project/lotus/lib/blockstore"
"github.com/filecoin-project/specs-actors/actors/abi/big"
"github.com/filecoin-project/specs-actors/actors/builtin"
block "github.com/ipfs/go-block-format"
cid "github.com/ipfs/go-cid"
cbor "github.com/ipfs/go-ipld-cbor"
logging "github.com/ipfs/go-log/v2"
mh "github.com/multiformats/go-multihash"
cbg "github.com/whyrusleeping/cbor-gen"
"go.opencensus.io/trace"
"golang.org/x/xerrors"
"github.com/filecoin-project/go-address"
"github.com/filecoin-project/specs-actors/actors/abi"
"github.com/filecoin-project/specs-actors/actors/builtin/account"
"github.com/filecoin-project/specs-actors/actors/crypto"
"github.com/filecoin-project/specs-actors/actors/runtime/exitcode"
"github.com/filecoin-project/lotus/build"
"github.com/filecoin-project/lotus/chain/actors/aerrors"
"github.com/filecoin-project/lotus/chain/state"
"github.com/filecoin-project/lotus/chain/types"
"github.com/filecoin-project/lotus/lib/blockstore"
"github.com/filecoin-project/lotus/lib/bufbstore"
)
var log = logging.Logger("vm")
var actorLog = logging.Logger("actors")
var gasOnActorExec = newGasCharge("OnActorExec", 0, 0)
// ResolveToKeyAddr returns the public key type of address (`BLS`/`SECP256K1`) of an account actor identified by `addr`.
func ResolveToKeyAddr(state types.StateTree, cst cbor.IpldStore, addr address.Address) (address.Address, aerrors.ActorError) {
if addr.Protocol() == address.BLS || addr.Protocol() == address.SECP256K1 {
return addr, nil
}
act, err := state.GetActor(addr)
if err != nil {
return address.Undef, aerrors.Newf(exitcode.SysErrInvalidParameters, "failed to find actor: %s", addr)
}
if act.Code != builtin.AccountActorCodeID {
return address.Undef, aerrors.Newf(exitcode.SysErrInvalidParameters, "address %s was not for an account actor", addr)
}
var aast account.State
if err := cst.Get(context.TODO(), act.Head, &aast); err != nil {
return address.Undef, aerrors.Absorb(err, exitcode.SysErrInvalidParameters, fmt.Sprintf("failed to get account actor state for %s", addr))
}
return aast.Address, nil
}
var _ cbor.IpldBlockstore = (*gasChargingBlocks)(nil)
type gasChargingBlocks struct {
chargeGas func(GasCharge)
pricelist Pricelist
under cbor.IpldBlockstore
}
func (bs *gasChargingBlocks) Get(c cid.Cid) (block.Block, error) {
bs.chargeGas(bs.pricelist.OnIpldGet())
blk, err := bs.under.Get(c)
if err != nil {
return nil, aerrors.Escalate(err, "failed to get block from blockstore")
}
bs.chargeGas(newGasCharge("OnIpldGetEnd", 0, 0).WithExtra(len(blk.RawData())))
bs.chargeGas(gasOnActorExec)
return blk, nil
}
func (bs *gasChargingBlocks) Put(blk block.Block) error {
bs.chargeGas(bs.pricelist.OnIpldPut(len(blk.RawData())))
if err := bs.under.Put(blk); err != nil {
return aerrors.Escalate(err, "failed to write data to disk")
}
bs.chargeGas(gasOnActorExec)
return nil
}
func (vm *VM) makeRuntime(ctx context.Context, msg *types.Message, origin address.Address, originNonce uint64, usedGas int64, nac uint64) *Runtime {
rt := &Runtime{
ctx: ctx,
vm: vm,
state: vm.cstate,
origin: origin,
originNonce: originNonce,
height: vm.blockHeight,
gasUsed: usedGas,
gasAvailable: msg.GasLimit,
numActorsCreated: nac,
pricelist: PricelistByEpoch(vm.blockHeight),
allowInternal: true,
callerValidated: false,
executionTrace: types.ExecutionTrace{Msg: msg},
}
rt.cst = &cbor.BasicIpldStore{
Blocks: &gasChargingBlocks{rt.chargeGasFunc(2), rt.pricelist, vm.cst.Blocks},
Atlas: vm.cst.Atlas,
}
rt.sys = pricedSyscalls{
under: vm.Syscalls(ctx, vm.cstate, rt.cst),
chargeGas: rt.chargeGasFunc(1),
pl: rt.pricelist,
}
vmm := *msg
resF, ok := rt.ResolveAddress(msg.From)
if !ok {
rt.Abortf(exitcode.SysErrInvalidReceiver, "resolve msg.From address failed")
}
vmm.From = resF
rt.vmsg = &vmm
return rt
}
type UnsafeVM struct {
VM *VM
}
func (vm *UnsafeVM) MakeRuntime(ctx context.Context, msg *types.Message, origin address.Address, originNonce uint64, usedGas int64, nac uint64) *Runtime {
return vm.VM.makeRuntime(ctx, msg, origin, originNonce, usedGas, nac)
}
type CircSupplyCalculator func(context.Context, abi.ChainEpoch, *state.StateTree) (abi.TokenAmount, error)
type VM struct {
cstate *state.StateTree
base cid.Cid
cst *cbor.BasicIpldStore
buf *bufbstore.BufferedBS
blockHeight abi.ChainEpoch
inv *Invoker
rand Rand
circSupplyCalc CircSupplyCalculator
baseFee abi.TokenAmount
Syscalls SyscallBuilder
}
type VMOpts struct {
StateBase cid.Cid
Epoch abi.ChainEpoch
Rand Rand
Bstore bstore.Blockstore
Syscalls SyscallBuilder
CircSupplyCalc CircSupplyCalculator
BaseFee abi.TokenAmount
}
func NewVM(opts *VMOpts) (*VM, error) {
buf := bufbstore.NewBufferedBstore(opts.Bstore)
cst := cbor.NewCborStore(buf)
state, err := state.LoadStateTree(cst, opts.StateBase)
if err != nil {
return nil, err
}
return &VM{
cstate: state,
base: opts.StateBase,
cst: cst,
buf: buf,
blockHeight: opts.Epoch,
inv: NewInvoker(),
rand: opts.Rand, // TODO: Probably should be a syscall
circSupplyCalc: opts.CircSupplyCalc,
Syscalls: opts.Syscalls,
baseFee: opts.BaseFee,
}, nil
}
type Rand interface {
GetChainRandomness(ctx context.Context, pers crypto.DomainSeparationTag, round abi.ChainEpoch, entropy []byte) ([]byte, error)
GetBeaconRandomness(ctx context.Context, pers crypto.DomainSeparationTag, round abi.ChainEpoch, entropy []byte) ([]byte, error)
}
type ApplyRet struct {
types.MessageReceipt
ActorErr aerrors.ActorError
Penalty types.BigInt
MinerTip types.BigInt
ExecutionTrace types.ExecutionTrace
Duration time.Duration
}
func (vm *VM) send(ctx context.Context, msg *types.Message, parent *Runtime,
gasCharge *GasCharge, start time.Time) ([]byte, aerrors.ActorError, *Runtime) {
st := vm.cstate
origin := msg.From
on := msg.Nonce
var nac uint64 = 0
var gasUsed int64
if parent != nil {
gasUsed = parent.gasUsed
origin = parent.origin
on = parent.originNonce
nac = parent.numActorsCreated
}
rt := vm.makeRuntime(ctx, msg, origin, on, gasUsed, nac)
rt.lastGasChargeTime = start
if parent != nil {
rt.lastGasChargeTime = parent.lastGasChargeTime
rt.lastGasCharge = parent.lastGasCharge
defer func() {
parent.gasUsed = rt.gasUsed
parent.lastGasChargeTime = rt.lastGasChargeTime
parent.lastGasCharge = rt.lastGasCharge
}()
}
if gasCharge != nil {
if err := rt.chargeGasSafe(*gasCharge); err != nil {
// this should never happen
return nil, aerrors.Wrap(err, "not enough gas for initial message charge, this should not happen"), rt
}
}
ret, err := func() ([]byte, aerrors.ActorError) {
_ = rt.chargeGasSafe(newGasCharge("OnGetActor", 0, 0))
toActor, err := st.GetActor(msg.To)
if err != nil {
if xerrors.Is(err, types.ErrActorNotFound) {
a, err := TryCreateAccountActor(rt, msg.To)
if err != nil {
return nil, aerrors.Wrapf(err, "could not create account")
}
toActor = a
} else {
return nil, aerrors.Escalate(err, "getting actor")
}
}
if aerr := rt.chargeGasSafe(rt.Pricelist().OnMethodInvocation(msg.Value, msg.Method)); aerr != nil {
return nil, aerrors.Wrap(aerr, "not enough gas for method invocation")
}
// not charging any gas, just logging
//nolint:errcheck
defer rt.chargeGasSafe(newGasCharge("OnMethodInvocationDone", 0, 0))
if types.BigCmp(msg.Value, types.NewInt(0)) != 0 {
if err := vm.transfer(msg.From, msg.To, msg.Value); err != nil {
return nil, aerrors.Wrap(err, "failed to transfer funds")
}
}
if msg.Method != 0 {
var ret []byte
_ = rt.chargeGasSafe(gasOnActorExec)
ret, err := vm.Invoke(toActor, rt, msg.Method, msg.Params)
return ret, err
}
return nil, nil
}()
mr := types.MessageReceipt{
ExitCode: aerrors.RetCode(err),
Return: ret,
GasUsed: rt.gasUsed,
}
rt.executionTrace.MsgRct = &mr
rt.executionTrace.Duration = time.Since(start)
if err != nil {
rt.executionTrace.Error = err.Error()
}
return ret, err, rt
}
func checkMessage(msg *types.Message) error {
if msg.GasLimit == 0 {
return xerrors.Errorf("message has no gas limit set")
}
if msg.GasLimit < 0 {
return xerrors.Errorf("message has negative gas limit")
}
if msg.GasFeeCap == types.EmptyInt {
return xerrors.Errorf("message fee cap not set")
}
if msg.GasPremium == types.EmptyInt {
return xerrors.Errorf("message gas premium not set")
}
if msg.Value == types.EmptyInt {
return xerrors.Errorf("message no value set")
}
return nil
}
func (vm *VM) ApplyImplicitMessage(ctx context.Context, msg *types.Message) (*ApplyRet, error) {
start := build.Clock.Now()
ret, actorErr, rt := vm.send(ctx, msg, nil, nil, start)
rt.finilizeGasTracing()
return &ApplyRet{
MessageReceipt: types.MessageReceipt{
ExitCode: aerrors.RetCode(actorErr),
Return: ret,
GasUsed: 0,
},
ActorErr: actorErr,
ExecutionTrace: rt.executionTrace,
Penalty: types.NewInt(0),
MinerTip: types.NewInt(0),
Duration: time.Since(start),
}, actorErr
}
func (vm *VM) ApplyMessage(ctx context.Context, cmsg types.ChainMsg) (*ApplyRet, error) {
start := build.Clock.Now()
ctx, span := trace.StartSpan(ctx, "vm.ApplyMessage")
defer span.End()
msg := cmsg.VMMessage()
if span.IsRecordingEvents() {
span.AddAttributes(
trace.StringAttribute("to", msg.To.String()),
trace.Int64Attribute("method", int64(msg.Method)),
trace.StringAttribute("value", msg.Value.String()),
)
}
if err := checkMessage(msg); err != nil {
return nil, err
}
pl := PricelistByEpoch(vm.blockHeight)
msgGas := pl.OnChainMessage(cmsg.ChainLength())
msgGasCost := msgGas.Total()
// this should never happen, but is currently still exercised by some tests
if msgGasCost > msg.GasLimit {
return &ApplyRet{
MessageReceipt: types.MessageReceipt{
ExitCode: exitcode.SysErrOutOfGas,
GasUsed: 0,
},
Penalty: types.BigMul(vm.baseFee, abi.NewTokenAmount(msgGasCost)),
Duration: time.Since(start),
MinerTip: big.Zero(),
}, nil
}
st := vm.cstate
minerPenaltyAmount := types.BigMul(vm.baseFee, abi.NewTokenAmount(msg.GasLimit))
fromActor, err := st.GetActor(msg.From)
// this should never happen, but is currently still exercised by some tests
if err != nil {
if xerrors.Is(err, types.ErrActorNotFound) {
return &ApplyRet{
MessageReceipt: types.MessageReceipt{
ExitCode: exitcode.SysErrSenderInvalid,
GasUsed: 0,
},
ActorErr: aerrors.Newf(exitcode.SysErrSenderInvalid, "actor not found: %s", msg.From),
Penalty: minerPenaltyAmount,
Duration: time.Since(start),
MinerTip: big.Zero(),
}, nil
}
return nil, xerrors.Errorf("failed to look up from actor: %w", err)
}
// this should never happen, but is currently still exercised by some tests
if !fromActor.Code.Equals(builtin.AccountActorCodeID) {
return &ApplyRet{
MessageReceipt: types.MessageReceipt{
ExitCode: exitcode.SysErrSenderInvalid,
GasUsed: 0,
},
ActorErr: aerrors.Newf(exitcode.SysErrSenderInvalid, "send from not account actor: %s", fromActor.Code),
Penalty: minerPenaltyAmount,
Duration: time.Since(start),
MinerTip: big.Zero(),
}, nil
}
if msg.Nonce != fromActor.Nonce {
return &ApplyRet{
MessageReceipt: types.MessageReceipt{
ExitCode: exitcode.SysErrSenderStateInvalid,
GasUsed: 0,
},
ActorErr: aerrors.Newf(exitcode.SysErrSenderStateInvalid,
"actor nonce invalid: msg:%d != state:%d", msg.Nonce, fromActor.Nonce),
Penalty: minerPenaltyAmount,
Duration: time.Since(start),
MinerTip: big.Zero(),
}, nil
}
gascost := types.BigMul(types.NewInt(uint64(msg.GasLimit)), msg.GasFeeCap)
if fromActor.Balance.LessThan(gascost) {
return &ApplyRet{
MessageReceipt: types.MessageReceipt{
ExitCode: exitcode.SysErrSenderStateInvalid,
GasUsed: 0,
},
ActorErr: aerrors.Newf(exitcode.SysErrSenderStateInvalid,
"actor balance less than needed: %s < %s", types.FIL(fromActor.Balance), types.FIL(gascost)),
Penalty: minerPenaltyAmount,
Duration: time.Since(start),
MinerTip: big.Zero(),
}, nil
}
gasHolder := &types.Actor{Balance: types.NewInt(0)}
if err := vm.transferToGasHolder(msg.From, gasHolder, gascost); err != nil {
return nil, xerrors.Errorf("failed to withdraw gas funds: %w", err)
}
if err := vm.incrementNonce(msg.From); err != nil {
return nil, err
}
if err := st.Snapshot(ctx); err != nil {
return nil, xerrors.Errorf("snapshot failed: %w", err)
}
defer st.ClearSnapshot()
ret, actorErr, rt := vm.send(ctx, msg, nil, &msgGas, start)
if aerrors.IsFatal(actorErr) {
return nil, xerrors.Errorf("[from=%s,to=%s,n=%d,m=%d,h=%d] fatal error: %w", msg.From, msg.To, msg.Nonce, msg.Method, vm.blockHeight, actorErr)
}
if actorErr != nil {
log.Warnw("Send actor error", "from", msg.From, "to", msg.To, "nonce", msg.Nonce, "method", msg.Method, "height", vm.blockHeight, "error", fmt.Sprintf("%+v", actorErr))
}
if actorErr != nil && len(ret) != 0 {
// This should not happen, something is wonky
return nil, xerrors.Errorf("message invocation errored, but had a return value anyway: %w", actorErr)
}
if rt == nil {
return nil, xerrors.Errorf("send returned nil runtime, send error was: %s", actorErr)
}
if len(ret) != 0 {
// safely override actorErr since it must be nil
actorErr = rt.chargeGasSafe(rt.Pricelist().OnChainReturnValue(len(ret)))
if actorErr != nil {
ret = nil
}
}
var errcode exitcode.ExitCode
var gasUsed int64
if errcode = aerrors.RetCode(actorErr); errcode != 0 {
// revert all state changes since snapshot
if err := st.Revert(); err != nil {
return nil, xerrors.Errorf("revert state failed: %w", err)
}
}
rt.finilizeGasTracing()
gasUsed = rt.gasUsed
if gasUsed < 0 {
gasUsed = 0
}
gasOutputs := ComputeGasOutputs(gasUsed, msg.GasLimit, vm.baseFee, msg.GasFeeCap, msg.GasPremium)
if err := vm.transferFromGasHolder(builtin.BurntFundsActorAddr, gasHolder,
gasOutputs.BaseFeeBurn); err != nil {
return nil, xerrors.Errorf("failed to burn base fee: %w", err)
}
if err := vm.transferFromGasHolder(builtin.RewardActorAddr, gasHolder, gasOutputs.MinerTip); err != nil {
return nil, xerrors.Errorf("failed to give miner gas reward: %w", err)
}
if err := vm.transferFromGasHolder(builtin.BurntFundsActorAddr, gasHolder,
gasOutputs.OverEstimationBurn); err != nil {
return nil, xerrors.Errorf("failed to burn overestimation fee: %w", err)
}
// refund unused gas
if err := vm.transferFromGasHolder(msg.From, gasHolder, gasOutputs.Refund); err != nil {
return nil, xerrors.Errorf("failed to refund gas: %w", err)
}
if types.BigCmp(types.NewInt(0), gasHolder.Balance) != 0 {
return nil, xerrors.Errorf("gas handling math is wrong")
}
return &ApplyRet{
MessageReceipt: types.MessageReceipt{
ExitCode: errcode,
Return: ret,
GasUsed: gasUsed,
},
ActorErr: actorErr,
ExecutionTrace: rt.executionTrace,
Penalty: gasOutputs.MinerPenalty,
MinerTip: gasOutputs.MinerTip,
Duration: time.Since(start),
}, nil
}
func (vm *VM) ActorBalance(addr address.Address) (types.BigInt, aerrors.ActorError) {
act, err := vm.cstate.GetActor(addr)
if err != nil {
return types.EmptyInt, aerrors.Absorb(err, 1, "failed to find actor")
}
return act.Balance, nil
}
func (vm *VM) Flush(ctx context.Context) (cid.Cid, error) {
_, span := trace.StartSpan(ctx, "vm.Flush")
defer span.End()
from := vm.buf
to := vm.buf.Read()
root, err := vm.cstate.Flush(ctx)
if err != nil {
return cid.Undef, xerrors.Errorf("flushing vm: %w", err)
}
if err := Copy(from, to, root); err != nil {
return cid.Undef, xerrors.Errorf("copying tree: %w", err)
}
return root, nil
}
// MutateState usage: MutateState(ctx, idAddr, func(cst cbor.IpldStore, st *ActorStateType) error {...})
func (vm *VM) MutateState(ctx context.Context, addr address.Address, fn interface{}) error {
act, err := vm.cstate.GetActor(addr)
if err != nil {
return xerrors.Errorf("actor not found: %w", err)
}
st := reflect.New(reflect.TypeOf(fn).In(1).Elem())
if err := vm.cst.Get(ctx, act.Head, st.Interface()); err != nil {
return xerrors.Errorf("read actor head: %w", err)
}
out := reflect.ValueOf(fn).Call([]reflect.Value{reflect.ValueOf(vm.cst), st})
if !out[0].IsNil() && out[0].Interface().(error) != nil {
return out[0].Interface().(error)
}
head, err := vm.cst.Put(ctx, st.Interface())
if err != nil {
return xerrors.Errorf("put new actor head: %w", err)
}
act.Head = head
if err := vm.cstate.SetActor(addr, act); err != nil {
return xerrors.Errorf("set actor: %w", err)
}
return nil
}
func linksForObj(blk block.Block, cb func(cid.Cid)) error {
switch blk.Cid().Prefix().Codec {
case cid.DagCBOR:
err := cbg.ScanForLinks(bytes.NewReader(blk.RawData()), cb)
if err != nil {
return xerrors.Errorf("cbg.ScanForLinks: %w", err)
}
return nil
case cid.Raw:
// We implicitly have all children of raw blocks.
return nil
default:
return xerrors.Errorf("vm flush copy method only supports dag cbor")
}
}
func Copy(from, to blockstore.Blockstore, root cid.Cid) error {
var batch []block.Block
batchCp := func(blk block.Block) error {
batch = append(batch, blk)
if len(batch) > 100 {
if err := to.PutMany(batch); err != nil {
return xerrors.Errorf("batch put in copy: %w", err)
}
batch = batch[:0]
}
return nil
}
if err := copyRec(from, to, root, batchCp); err != nil {
return xerrors.Errorf("copyRec: %w", err)
}
if len(batch) > 0 {
if err := to.PutMany(batch); err != nil {
return xerrors.Errorf("batch put in copy: %w", err)
}
}
return nil
}
func copyRec(from, to blockstore.Blockstore, root cid.Cid, cp func(block.Block) error) error {
if root.Prefix().MhType == 0 {
// identity cid, skip
return nil
}
blk, err := from.Get(root)
if err != nil {
return xerrors.Errorf("get %s failed: %w", root, err)
}
var lerr error
err = linksForObj(blk, func(link cid.Cid) {
if lerr != nil {
// Theres no erorr return on linksForObj callback :(
return
}
prefix := link.Prefix()
if prefix.Codec == cid.FilCommitmentSealed || prefix.Codec == cid.FilCommitmentUnsealed {
return
}
// We always have blocks inlined into CIDs, but we may not have their children.
if prefix.MhType == mh.IDENTITY {
// Unless the inlined block has no children.
if prefix.Codec == cid.Raw {
return
}
} else {
// If we have an object, we already have its children, skip the object.
has, err := to.Has(link)
if err != nil {
lerr = xerrors.Errorf("has: %w", err)
return
}
if has {
return
}
}
if err := copyRec(from, to, link, cp); err != nil {
lerr = err
return
}
})
if err != nil {
return xerrors.Errorf("linksForObj (%x): %w", blk.RawData(), err)
}
if lerr != nil {
return lerr
}
if err := cp(blk); err != nil {
return xerrors.Errorf("copy: %w", err)
}
return nil
}
func (vm *VM) StateTree() types.StateTree {
return vm.cstate
}
func (vm *VM) SetBlockHeight(h abi.ChainEpoch) {
vm.blockHeight = h
}
func (vm *VM) Invoke(act *types.Actor, rt *Runtime, method abi.MethodNum, params []byte) ([]byte, aerrors.ActorError) {
ctx, span := trace.StartSpan(rt.ctx, "vm.Invoke")
defer span.End()
if span.IsRecordingEvents() {
span.AddAttributes(
trace.StringAttribute("to", rt.Message().Receiver().String()),
trace.Int64Attribute("method", int64(method)),
trace.StringAttribute("value", rt.Message().ValueReceived().String()),
)
}
var oldCtx context.Context
oldCtx, rt.ctx = rt.ctx, ctx
defer func() {
rt.ctx = oldCtx
}()
ret, err := vm.inv.Invoke(act.Code, rt, method, params)
if err != nil {
return nil, err
}
return ret, nil
}
func (vm *VM) SetInvoker(i *Invoker) {
vm.inv = i
}
func (vm *VM) GetCircSupply(ctx context.Context) (abi.TokenAmount, error) {
return vm.circSupplyCalc(ctx, vm.blockHeight, vm.cstate)
}
func (vm *VM) incrementNonce(addr address.Address) error {
return vm.cstate.MutateActor(addr, func(a *types.Actor) error {
a.Nonce++
return nil
})
}
func (vm *VM) transfer(from, to address.Address, amt types.BigInt) aerrors.ActorError {
if from == to {
return nil
}
fromID, err := vm.cstate.LookupID(from)
if err != nil {
return aerrors.Fatalf("transfer failed when resolving sender address: %s", err)
}
toID, err := vm.cstate.LookupID(to)
if err != nil {
return aerrors.Fatalf("transfer failed when resolving receiver address: %s", err)
}
if fromID == toID {
return nil
}
if amt.LessThan(types.NewInt(0)) {
return aerrors.Newf(exitcode.SysErrForbidden, "attempted to transfer negative value: %s", amt)
}
f, err := vm.cstate.GetActor(fromID)
if err != nil {
return aerrors.Fatalf("transfer failed when retrieving sender actor: %s", err)
}
t, err := vm.cstate.GetActor(toID)
if err != nil {
return aerrors.Fatalf("transfer failed when retrieving receiver actor: %s", err)
}
if err := deductFunds(f, amt); err != nil {
return aerrors.Newf(exitcode.SysErrInsufficientFunds, "transfer failed when deducting funds (%s): %s", types.FIL(amt), err)
}
depositFunds(t, amt)
if err := vm.cstate.SetActor(fromID, f); err != nil {
return aerrors.Fatalf("transfer failed when setting receiver actor: %s", err)
}
if err := vm.cstate.SetActor(toID, t); err != nil {
return aerrors.Fatalf("transfer failed when setting sender actor: %s", err)
}
return nil
}
func (vm *VM) transferToGasHolder(addr address.Address, gasHolder *types.Actor, amt types.BigInt) error {
if amt.LessThan(types.NewInt(0)) {
return xerrors.Errorf("attempted to transfer negative value to gas holder")
}
return vm.cstate.MutateActor(addr, func(a *types.Actor) error {
if err := deductFunds(a, amt); err != nil {
return err
}
depositFunds(gasHolder, amt)
return nil
})
}
func (vm *VM) transferFromGasHolder(addr address.Address, gasHolder *types.Actor, amt types.BigInt) error {
if amt.LessThan(types.NewInt(0)) {
return xerrors.Errorf("attempted to transfer negative value from gas holder")
}
if amt.Equals(big.NewInt(0)) {
return nil
}
return vm.cstate.MutateActor(addr, func(a *types.Actor) error {
if err := deductFunds(gasHolder, amt); err != nil {
return err
}
depositFunds(a, amt)
return nil
})
}
func deductFunds(act *types.Actor, amt types.BigInt) error {
if act.Balance.LessThan(amt) {
return fmt.Errorf("not enough funds")
}
act.Balance = types.BigSub(act.Balance, amt)
return nil
}
func depositFunds(act *types.Actor, amt types.BigInt) {
act.Balance = types.BigAdd(act.Balance, amt)
}