evm/precompile/precompileconfig/config.go

// (c) 2023-2024, Lux Partners Limited. All rights reserved.
// See the file LICENSE for licensing terms.

// Defines the stateless interface for unmarshalling an arbitrary config of a precompile
package precompileconfig

import (
	"github.com/luxdefi/node/chains/atomic"
	"github.com/luxdefi/node/ids"
	"github.com/luxdefi/node/snow"
	"github.com/luxdefi/node/snow/engine/snowman/block"
	"github.com/luxdefi/node/vms/platformvm/warp"
	"github.com/luxdefi/evm/commontype"
	"github.com/ethereum/go-ethereum/common"
)

// StatefulPrecompileConfig defines the interface for a stateful precompile to
// be enabled via a network upgrade.
type Config interface {
	// Key returns the unique key for the stateful precompile.
	Key() string
	// Timestamp returns the timestamp at which this stateful precompile should be enabled.
	// 1) 0 indicates that the precompile should be enabled from genesis.
	// 2) n indicates that the precompile should be enabled in the first block with timestamp >= [n].
	// 3) nil indicates that the precompile is never enabled.
	Timestamp() *uint64
	// IsDisabled returns true if this network upgrade should disable the precompile.
	IsDisabled() bool
	// Equal returns true if the provided argument configures the same precompile with the same parameters.
	Equal(Config) bool
	// Verify is called on startup and an error is treated as fatal. Configure can assume the Config has passed verification.
	Verify(ChainConfig) error
}

// PredicateContext is the context passed in to the Predicater interface to verify
// a precompile predicate within a specific ProposerVM wrapper.
type PredicateContext struct {
	SnowCtx *snow.Context
	// ProposerVMBlockCtx defines the ProposerVM context the predicate is verified within
	ProposerVMBlockCtx *block.Context
}

// Predicater is an optional interface for StatefulPrecompileContracts to implement.
// If implemented, the predicate will be enforced on every transaction in a block, prior to
// the block's execution.
// If VerifyPredicate returns an error, the block will fail verification with no further processing.
// WARNING: If you are implementing a custom precompile, beware that subnet-evm
// will not maintain backwards compatibility of this interface and your code should not
// rely on this. Designed for use only by precompiles that ship with subnet-evm.
type Predicater interface {
	PredicateGas(predicateBytes []byte) (uint64, error)
	VerifyPredicate(predicateContext *PredicateContext, predicateBytes []byte) error
}

// SharedMemoryWriter defines an interface to allow a precompile's Accepter to write operations
// into shared memory to be committed atomically on block accept.
type SharedMemoryWriter interface {
	AddSharedMemoryRequests(chainID ids.ID, requests *atomic.Requests)
}

type WarpMessageWriter interface {
	AddMessage(unsignedMessage *warp.UnsignedMessage) error
}

// AcceptContext defines the context passed in to a precompileconfig's Accepter
type AcceptContext struct {
	SnowCtx      *snow.Context
	SharedMemory SharedMemoryWriter
	Warp         WarpMessageWriter
}

// Accepter is an optional interface for StatefulPrecompiledContracts to implement.
// If implemented, Accept will be called for every log with the address of the precompile when the block is accepted.
// WARNING: If you are implementing a custom precompile, beware that subnet-evm
// will not maintain backwards compatibility of this interface and your code should not
// rely on this. Designed for use only by precompiles that ship with subnet-evm.
type Accepter interface {
	Accept(acceptCtx *AcceptContext, blockHash common.Hash, blockNumber uint64, txHash common.Hash, logIndex int, topics []common.Hash, logData []byte) error
}

// ChainContext defines an interface that provides information to a stateful precompile
// about the chain configuration. The precompile can access this information to initialize
// its state.
type ChainConfig interface {
	// GetFeeConfig returns the original FeeConfig that was set in the genesis.
	GetFeeConfig() commontype.FeeConfig
	// AllowedFeeRecipients returns true if fee recipients are allowed in the genesis.
	AllowedFeeRecipients() bool
	// IsDUpgrade returns true if the time is after the DUpgrade.
	IsDUpgrade(time uint64) bool
}