interop

Documentation

Overview

Package interop contains implementations of Neo interop functions.

This is not the package you use from smart contracts, refer to pkg/interop for that.

Index

• Constants
• func Sort(fs []Function)
• type Context
  • func NewContext(trigger trigger.Type, bc Ledger, d *dao.Simple, ...) *Context
  • func (ic *Context) AddNotification(hash util.Uint160, name string, item *stackitem.Array)
  • func (ic *Context) BaseExecFee() int64
  • func (ic *Context) BaseStorageFee() int64
  • func (ic *Context) BlockHeight() uint32
  • func (ic *Context) CurrentBlockHash() util.Uint256
  • func (ic *Context) Exec() error
  • func (ic *Context) Finalize()
  • func (ic *Context) GetBlock(hash util.Uint256) (*block.Block, error)
  • func (ic *Context) GetContract(hash util.Uint160) (*state.Contract, error)
  • func (ic *Context) GetFunction(id uint32) *Function
  • func (ic *Context) GetPrice(op opcode.Opcode, parameter []byte) int64
  • func (ic *Context) InitNonceData()
  • func (ic *Context) IsHardforkEnabled(hf config.Hardfork) bool
  • func (ic *Context) LoadToken(id int32) error
  • func (ic *Context) RegisterCancelFunc(f context.CancelFunc)
  • func (ic *Context) ReuseVM(v *vm.VM)
  • func (ic *Context) Signers() []transaction.Signer
  • func (ic *Context) SpawnVM() *vm.VM
  • func (ic *Context) SyscallHandler(_ *vm.VM, id uint32) error
  • func (ic *Context) UseSigners(s []transaction.Signer)
• type Contract
• type ContractMD
  • func NewContractMD(name string, id int32) *ContractMD
  • func (c *ContractMD) AddEvent(name string, ps ...manifest.Parameter)
  • func (c *ContractMD) AddMethod(md *MethodAndPrice, desc *manifest.Method)
  • func (c *ContractMD) GetMethod(name string, paramCount int) (MethodAndPrice, bool)
  • func (c *ContractMD) GetMethodByOffset(offset int) (MethodAndPrice, bool)
  • func (c *ContractMD) IsActive(height uint32) bool
  • func (c *ContractMD) UpdateHash()
• type Function
• type Ledger
• type Method
• type MethodAndPrice

Constants

const (
	// DefaultBaseExecFee specifies the default multiplier for opcode and syscall prices.
	DefaultBaseExecFee = 30
)

Functions

func Sort

func Sort(fs []Function)

Sort sorts interop functions by id.

Types

type Context

type Context struct {
	Chain         Ledger
	Container     hash.Hashable
	Network       uint32
	Hardforks     map[string]uint32
	Natives       []Contract
	Trigger       trigger.Type
	Block         *block.Block
	NonceData     [16]byte
	Tx            *transaction.Transaction
	DAO           *dao.Simple
	Notifications []state.NotificationEvent
	Log           *zap.Logger
	VM            *vm.VM
	Functions     []Function
	Invocations   map[util.Uint160]int

	GetRandomCounter uint32
	// contains filtered or unexported fields
}

Context represents context in which interops are executed.

func NewContext

func NewContext(trigger trigger.Type, bc Ledger, d *dao.Simple, baseExecFee, baseStorageFee int64,
	getContract func(*dao.Simple, util.Uint160) (*state.Contract, error), natives []Contract,
	loadTokenFunc func(ic *Context, id int32) error,
	block *block.Block, tx *transaction.Transaction, log *zap.Logger) *Context

NewContext returns new interop context.

func (*Context) AddNotification

func (ic *Context) AddNotification(hash util.Uint160, name string, item *stackitem.Array)

AddNotification creates notification event and appends it to the notification list.

func (*Context) BaseExecFee

func (ic *Context) BaseExecFee() int64

BaseExecFee represents factor to multiply syscall prices with.

func (*Context) BaseStorageFee

func (ic *Context) BaseStorageFee() int64

BaseStorageFee represents price for storing one byte of data in the contract storage.

func (*Context) BlockHeight

func (ic *Context) BlockHeight() uint32

BlockHeight returns current block height got from Context's block if it's set.

func (*Context) CurrentBlockHash

func (ic *Context) CurrentBlockHash() util.Uint256

CurrentBlockHash returns current block hash got from Context's block if it's set.

func (*Context) Exec

func (ic *Context) Exec() error

Exec executes loaded VM script and calls registered finalizers to release the occupied resources.

func (*Context) Finalize

func (ic *Context) Finalize()

Finalize calls all registered cancel functions to release the occupied resources.

func (*Context) GetBlock

func (ic *Context) GetBlock(hash util.Uint256) (*block.Block, error)

GetBlock returns block if it exists and available at the current Context's height.

func (*Context) GetContract

func (ic *Context) GetContract(hash util.Uint160) (*state.Contract, error)

GetContract returns a contract by its hash in the current interop context.

func (*Context) GetFunction

func (ic *Context) GetFunction(id uint32) *Function

GetFunction returns metadata for interop with the specified id.

func (*Context) GetPrice

func (ic *Context) GetPrice(op opcode.Opcode, parameter []byte) int64

GetPrice returns a price for executing op with the provided parameter.

func (*Context) InitNonceData

func (ic *Context) InitNonceData()

InitNonceData initializes nonce to be used in `GetRandom` calculations.

func (*Context) IsHardforkEnabled

func (ic *Context) IsHardforkEnabled(hf config.Hardfork) bool

IsHardforkEnabled tells whether specified hard-fork enabled at the current context height.

func (*Context) LoadToken

func (ic *Context) LoadToken(id int32) error

LoadToken wraps externally provided load-token loading function providing it with context, this function can then be easily used by VM.

func (*Context) RegisterCancelFunc

func (ic *Context) RegisterCancelFunc(f context.CancelFunc)

RegisterCancelFunc adds the given function to the list of functions to be called after the VM finishes script execution.

func (*Context) ReuseVM

func (ic *Context) ReuseVM(v *vm.VM)

ReuseVM resets given VM and allows to reuse it in the current context.

func (*Context) Signers

func (ic *Context) Signers() []transaction.Signer

Signers returns signers witnessing the current execution context.

func (*Context) SpawnVM

func (ic *Context) SpawnVM() *vm.VM

SpawnVM spawns a new VM with the specified gas limit and set context.VM field.

func (*Context) SyscallHandler

func (ic *Context) SyscallHandler(_ *vm.VM, id uint32) error

SyscallHandler handles syscall with id.

func (*Context) UseSigners

func (ic *Context) UseSigners(s []transaction.Signer)

UseSigners allows overriding signers used in this context.

type Contract

type Contract interface {
	Initialize(*Context) error
	Metadata() *ContractMD
	OnPersist(*Context) error
	PostPersist(*Context) error
}

Contract is an interface for all native contracts.

type ContractMD

type ContractMD struct {
	state.NativeContract
	Name    string
	Methods []MethodAndPrice
}

ContractMD represents a native contract instance.

func NewContractMD

func NewContractMD(name string, id int32) *ContractMD

NewContractMD returns Contract with the specified list of methods.

func (*ContractMD) AddEvent

func (c *ContractMD) AddEvent(name string, ps ...manifest.Parameter)

AddEvent adds a new event to the native contract.

func (*ContractMD) AddMethod

func (c *ContractMD) AddMethod(md *MethodAndPrice, desc *manifest.Method)

AddMethod adds a new method to a native contract.

func (*ContractMD) GetMethod

func (c *ContractMD) GetMethod(name string, paramCount int) (MethodAndPrice, bool)

GetMethod returns method `name` with the specified number of parameters.

func (*ContractMD) GetMethodByOffset

func (c *ContractMD) GetMethodByOffset(offset int) (MethodAndPrice, bool)

GetMethodByOffset returns method with the provided offset. Offset is offset of `System.Contract.CallNative` syscall.

func (*ContractMD) IsActive

func (c *ContractMD) IsActive(height uint32) bool

IsActive returns true if the contract was deployed by the specified height.

func (*ContractMD) UpdateHash

func (c *ContractMD) UpdateHash()

UpdateHash creates a native contract script and updates hash.

type Function

type Function struct {
	ID   uint32
	Name string
	Func func(*Context) error
	// ParamCount is a number of function parameters.
	ParamCount int
	Price      int64
	// RequiredFlags is a set of flags which must be set during script invocations.
	// Default value is NoneFlag i.e. no flags are required.
	RequiredFlags callflag.CallFlag
}

Function binds function name, id with the function itself and the price, it's supposed to be inited once for all interopContexts, so it doesn't use vm.InteropFuncPrice directly.

type Ledger

type Ledger interface {
	BlockHeight() uint32
	CurrentBlockHash() util.Uint256
	GetBlock(hash util.Uint256) (*block.Block, error)
	GetConfig() config.ProtocolConfiguration
	GetHeaderHash(int) util.Uint256
}

Ledger is the interface to Blockchain required for Context functionality.

type Method

type Method = func(ic *Context, args []stackitem.Item) stackitem.Item

Method is a signature for a native method.

type MethodAndPrice

type MethodAndPrice struct {
	Func          Method
	MD            *manifest.Method
	CPUFee        int64
	StorageFee    int64
	SyscallOffset int
	RequiredFlags callflag.CallFlag
}

MethodAndPrice is a native-contract method descriptor.