package interop import ( "github.com/nspcc-dev/neo-go/pkg/core/block" "github.com/nspcc-dev/neo-go/pkg/core/blockchainer" "github.com/nspcc-dev/neo-go/pkg/core/dao" "github.com/nspcc-dev/neo-go/pkg/core/state" "github.com/nspcc-dev/neo-go/pkg/core/transaction" "github.com/nspcc-dev/neo-go/pkg/crypto" "github.com/nspcc-dev/neo-go/pkg/crypto/hash" "github.com/nspcc-dev/neo-go/pkg/io" "github.com/nspcc-dev/neo-go/pkg/smartcontract" "github.com/nspcc-dev/neo-go/pkg/smartcontract/manifest" "github.com/nspcc-dev/neo-go/pkg/smartcontract/trigger" "github.com/nspcc-dev/neo-go/pkg/util" "github.com/nspcc-dev/neo-go/pkg/vm" "github.com/nspcc-dev/neo-go/pkg/vm/emit" "github.com/nspcc-dev/neo-go/pkg/vm/stackitem" "go.uber.org/zap" ) // Context represents context in which interops are executed. type Context struct { Chain blockchainer.Blockchainer Container crypto.Verifiable Natives []Contract Trigger trigger.Type Block *block.Block Tx *transaction.Transaction DAO *dao.Cached Notifications []state.NotificationEvent Log *zap.Logger Invocations map[util.Uint160]int ScriptGetter vm.ScriptHashGetter } // NewContext returns new interop context. func NewContext(trigger trigger.Type, bc blockchainer.Blockchainer, d dao.DAO, natives []Contract, block *block.Block, tx *transaction.Transaction, log *zap.Logger) *Context { dao := dao.NewCached(d) nes := make([]state.NotificationEvent, 0) return &Context{ Chain: bc, Natives: natives, Trigger: trigger, Block: block, Tx: tx, DAO: dao, Notifications: nes, Log: log, Invocations: make(map[util.Uint160]int), } } // Function binds function name, id with the function itself and price, // it's supposed to be inited once for all interopContexts, so it doesn't use // vm.InteropFuncPrice directly. type Function struct { ID uint32 Name string Func func(*Context, *vm.VM) error Price int64 // AllowedTriggers is a set of triggers which are allowed to initiate invocation. AllowedTriggers trigger.Type // RequiredFlags is a set of flags which must be set during script invocations. // Default value is NoneFlag i.e. no flags are required. RequiredFlags smartcontract.CallFlag } // Method is a signature for a native method. type Method = func(ic *Context, args []stackitem.Item) stackitem.Item // MethodAndPrice is a native-contract method descriptor. type MethodAndPrice struct { Func Method Price int64 RequiredFlags smartcontract.CallFlag } // Contract is an interface for all native contracts. type Contract interface { Initialize(*Context) error Metadata() *ContractMD } // ContractMD represents native contract instance. type ContractMD struct { Manifest manifest.Manifest ServiceName string ServiceID uint32 ContractID int32 Script []byte Hash util.Uint160 Methods map[string]MethodAndPrice } // NewContractMD returns Contract with the specified list of methods. func NewContractMD(name string) *ContractMD { c := &ContractMD{ ServiceName: name, ServiceID: emit.InteropNameToID([]byte(name)), Methods: make(map[string]MethodAndPrice), } w := io.NewBufBinWriter() emit.Syscall(w.BinWriter, c.ServiceName) c.Script = w.Bytes() c.Hash = hash.Hash160(c.Script) c.Manifest = *manifest.DefaultManifest(c.Hash) return c } // AddMethod adds new method to a native contract. func (c *ContractMD) AddMethod(md *MethodAndPrice, desc *manifest.Method, safe bool) { c.Manifest.ABI.Methods = append(c.Manifest.ABI.Methods, *desc) c.Methods[desc.Name] = *md if safe { c.Manifest.SafeMethods.Add(desc.Name) } } // AddEvent adds new event to a native contract. func (c *ContractMD) AddEvent(name string, ps ...manifest.Parameter) { c.Manifest.ABI.Events = append(c.Manifest.ABI.Events, manifest.Event{ Name: name, Parameters: ps, }) }