neo-go/pkg/interop/native/oracle/oracle.go
Anna Shaleva 6b21ad9922 *: replace interface{} with any keyword
Everywhere including examples, external interop APIs, bindings generators
code and in other valuable places. A couple of `interface{}` usages are
intentionally left in the CHANGELOG.md, documentation and tests.
2023-04-04 13:22:42 +03:00

82 lines
3.1 KiB
Go

/*
Package oracle provides an interface to OracleContract native contract.
Oracles allow you to get external (non-blockchain) data using HTTPS or NeoFS
protocols.
*/
package oracle
import (
"github.com/nspcc-dev/neo-go/pkg/interop/contract"
"github.com/nspcc-dev/neo-go/pkg/interop/neogointernal"
)
// These are potential response codes you get in your callback completing
// oracle request. Resulting data is only passed with Success code, it's
// nil otherwise.
const (
Success = 0x00
ProtocolNotSupported = 0x10
ConsensusUnreachable = 0x12
NotFound = 0x14
Timeout = 0x16
Forbidden = 0x18
ResponseTooLarge = 0x1a
InsufficientFunds = 0x1c
Error = 0xff
)
// Hash represents Oracle contract hash.
const Hash = "\x58\x87\x17\x11\x7e\x0a\xa8\x10\x72\xaf\xab\x71\xd2\xdd\x89\xfe\x7c\x4b\x92\xfe"
// MinimumResponseGas is the minimum response fee permitted for a request (that is
// you can't attach less than that to your request). It's 0.1 GAS at the moment.
const MinimumResponseGas = 10_000_000
// Request makes an oracle request. It can only be successfully invoked by
// a deployed contract and it takes the following parameters:
//
// - url
// URL to fetch, only https and neofs URLs are supported like
// https://example.com/some.json or
// neofs:6pJtLUnGqDxE2EitZYLsDzsfTDVegD6BrRUn8QAFZWyt/5Cyxb3wrHDw5pqY63hb5otCSsJ24ZfYmsA8NAjtho2gr
//
// - filter
// JSONPath filter to process the result; if specified, it will be
// applied to the data returned from HTTP/NeoFS and you'll only get
// filtered data in your callback method.
//
// - cb
// name of the method that will process oracle data, it must be a method
// of the same contract that invokes Request and it must have the following
// signature for correct invocation:
//
// - Method(url string, userData any, code int, result []byte)
// where url is the same url specified for Request, userData is anything
// passed in the next parameter, code is the status of the reply and
// result is the data returned from the request if any.
//
// - userData
// data to pass to the callback function.
//
// - gasForResponse
// GAS attached to this request for reply callback processing,
// note that it's different from the oracle request price, this
// GAS is used for oracle transaction's network and system fees,
// so it should be enough to pay for reply data as well as
// its processing.
func Request(url string, filter []byte, cb string, userData any, gasForResponse int) {
neogointernal.CallWithTokenNoRet(Hash, "request",
int(contract.States|contract.AllowNotify),
url, filter, cb, userData, gasForResponse)
}
// GetPrice returns the current oracle request price.
func GetPrice() int {
return neogointernal.CallWithToken(Hash, "getPrice", int(contract.ReadStates)).(int)
}
// SetPrice allows to set the oracle request price. This method can only be
// successfully invoked by the committee.
func SetPrice(amount int) {
neogointernal.CallWithTokenNoRet(Hash, "setPrice", int(contract.States), amount)
}