runtime

Documentation

Overview

Package runtime provides various service functions related to execution environment. It has similar function to Runtime class in .net framwork for Neo.

Index

• Constants
• func BurnGas(gas int)
• func CheckWitness(hashOrKey []byte) bool
• func GasLeft() int
• func GetCallingScriptHash() interop.Hash160
• func GetEntryScriptHash() interop.Hash160
• func GetExecutingScriptHash() interop.Hash160
• func GetInvocationCounter() int
• func GetNetwork() int
• func GetNotifications(h interop.Hash160) [][]interface{}
• func GetRandom() int
• func GetScriptContainer() *ledger.Transaction
• func GetTime() int
• func GetTrigger() byte
• func Log(message string)
• func Notify(name string, args ...interface{})
• func Platform() []byte

Constants

const (
	OnPersist    byte = 0x01
	PostPersist  byte = 0x02
	Application  byte = 0x40
	Verification byte = 0x20
)

Trigger values to compare with GetTrigger result.

Functions

func BurnGas

func BurnGas(gas int)

BurnGas burns provided amount of GAS. It uses `System.Runtime.BurnGas` syscall.

func CheckWitness

func CheckWitness(hashOrKey []byte) bool

CheckWitness verifies if the given script hash (160-bit BE value in a 20 byte slice) or key (compressed serialized 33-byte form) is one of the signers of this invocation. It uses `System.Runtime.CheckWitness` syscall.

func GasLeft

func GasLeft() int

GasLeft returns the amount of gas available for the current execution. This function uses `System.Runtime.GasLeft` syscall.

func GetCallingScriptHash

func GetCallingScriptHash() interop.Hash160

GetCallingScriptHash returns script hash (160 bit in BE form represented as 20-byte slice) of the contract that started the execution of the currently running context (caller of current contract or function), so it's one level above the GetExecutingScriptHash in the call stack. It uses `System.Runtime.GetCallingScriptHash` syscall.

func GetEntryScriptHash

func GetEntryScriptHash() interop.Hash160

GetEntryScriptHash returns script hash (160 bit in BE form represented as 20-byte slice) of the contract that initially started current execution (this is a script that is contained in a transaction returned by GetScriptContainer) execution from the start. This function uses `System.Runtime.GetEntryScriptHash` syscall.

func GetExecutingScriptHash

func GetExecutingScriptHash() interop.Hash160

GetExecutingScriptHash returns script hash (160 bit in BE form represented as 20-byte slice) of the contract that is currently being executed. Any AppCall can change the value returned by this function if it calls a different contract. This function uses `System.Runtime.GetExecutingScriptHash` syscall.

func GetInvocationCounter

func GetInvocationCounter() int

GetInvocationCounter returns how many times current contract was invoked during current tx execution. This function uses `System.Runtime.GetInvocationCounter` syscall.

func GetNetwork

func GetNetwork() int

GetNetwork returns network magic number. This function uses `System.Runtime.GetNetwork` syscall.

func GetNotifications

func GetNotifications(h interop.Hash160) [][]interface{}

GetNotifications returns notifications emitted by contract h. 'nil' literal means no filtering. It returns slice consisting of following elements: [ scripthash of notification's contract , emitted item ]. This function uses `System.Runtime.GetNotifications` syscall.

func GetRandom

func GetRandom() int

GetRandom returns pseudo-random number which depends on block nonce and tx hash. Each invocation will return a different number. This function uses `System.Runtime.GetRandom` syscall.

func GetScriptContainer

func GetScriptContainer() *ledger.Transaction

GetScriptContainer returns the transaction that initially triggered current execution context. It never changes in a single execution, no matter how deep this execution goes. This function uses `System.Runtime.GetScriptContainer` syscall.

func GetTime

func GetTime() int

GetTime returns the timestamp of the most recent block. Note that when running script in test mode this would be the last accepted (persisted) block in the chain, but when running as a part of the new block the time returned is the time of this (currently being processed) block. This function uses `System.Runtime.GetTime` syscall.

func GetTrigger

func GetTrigger() byte

GetTrigger returns the smart contract invocation trigger which can be either verification or application. It can be used to differentiate running contract as a part of verification process from running it as a regular application. Some interop functions (especially ones that change the state in any way) are not available when running with verification trigger. This function uses `System.Runtime.GetTrigger` syscall.

func Log

func Log(message string)

Log instructs VM to log the given message. It's mostly used for debugging purposes as these messages are not saved anywhere normally and usually are only visible in the VM logs. This function uses `System.Runtime.Log` syscall.

func Notify

func Notify(name string, args ...interface{})

Notify sends a notification (collecting all arguments in an array) to the executing environment. Unlike Log it can accept any data along with the event name and resulting notification is saved in application log. It's intended to be used as a part of contract's API to external systems, these events can be monitored from outside and act upon accordingly. This function uses `System.Runtime.Notify` syscall.

func Platform

func Platform() []byte

Platform returns the platform name, which is set to be `NEO`. This function uses `System.Runtime.Platform` syscall.