frostfs-node/pkg/morph/client/nns.go
Pavel Karpy b492201a84 [] morph/nns: Add record existence check
Also, add ErrNNSRecordNotFound error that
indicates that required hash is not presented
in `NNS` contract.

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
2021-11-10 16:11:57 +03:00

143 lines
4.1 KiB
Go

package client
import (
"errors"
"fmt"
"strconv"
nns "github.com/nspcc-dev/neo-go/examples/nft-nd-nns"
"github.com/nspcc-dev/neo-go/pkg/rpc/client"
"github.com/nspcc-dev/neo-go/pkg/smartcontract"
"github.com/nspcc-dev/neo-go/pkg/util"
"github.com/nspcc-dev/neo-go/pkg/vm"
"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
)
const (
nnsContractID = 1 // NNS contract must be deployed first in side chain
// NNSAuditContractName is a name of the audit contract in NNS.
NNSAuditContractName = "audit.neofs"
// NNSBalanceContractName is a name of the balance contract in NNS.
NNSBalanceContractName = "balance.neofs"
// NNSContainerContractName is a name of the container contract in NNS.
NNSContainerContractName = "container.neofs"
// NNSNeoFSIDContractName is a name of the neofsid contract in NNS.
NNSNeoFSIDContractName = "neofsid.neofs"
// NNSNetmapContractName is a name of the netmap contract in NNS.
NNSNetmapContractName = "netmap.neofs"
// NNSProxyContractName is a name of the proxy contract in NNS.
NNSProxyContractName = "proxy.neofs"
// NNSReputationContractName is a name of the reputation contract in NNS.
NNSReputationContractName = "reputation.neofs"
)
var (
// ErrNNSRecordNotFound means that there is no such record in NNS contract.
ErrNNSRecordNotFound = errors.New("record has not been found in NNS contract")
errEmptyResultStack = errors.New("returned result stack is empty")
)
// NNSAlphabetContractName returns contract name of the alphabet contract in NNS
// based on alphabet index.
func NNSAlphabetContractName(index int) string {
return "alphabet" + strconv.Itoa(index) + ".neofs"
}
// NNSContractAddress returns contract address script hash based on its name
// in NNS contract.
// If script hash has not been found, returns ErrNNSRecordNotFound.
func (c *Client) NNSContractAddress(name string) (sh util.Uint160, err error) {
if c.multiClient != nil {
return sh, c.multiClient.iterateClients(func(c *Client) error {
sh, err = c.NNSContractAddress(name)
return err
})
}
cs, err := c.client.GetContractStateByID(nnsContractID) // cache it?
if err != nil {
return sh, fmt.Errorf("NNS contract state: %w", err)
}
sh, err = nnsResolve(c.client, cs.Hash, name)
if err != nil {
return sh, fmt.Errorf("NNS.resolve: %w", err)
}
return sh, nil
}
func nnsResolve(c *client.Client, nnsHash util.Uint160, domain string) (util.Uint160, error) {
found, err := exists(c, nnsHash, domain)
if err != nil {
return util.Uint160{}, fmt.Errorf("could not check presence in NNS contract for %s: %w", domain, err)
}
if !found {
return util.Uint160{}, ErrNNSRecordNotFound
}
result, err := c.InvokeFunction(nnsHash, "resolve", []smartcontract.Parameter{
{
Type: smartcontract.StringType,
Value: domain,
},
{
Type: smartcontract.IntegerType,
Value: int64(nns.TXT),
},
}, nil)
if err != nil {
return util.Uint160{}, err
}
if result.State != vm.HaltState.String() {
return util.Uint160{}, fmt.Errorf("invocation failed: %s", result.FaultException)
}
if len(result.Stack) == 0 {
return util.Uint160{}, errEmptyResultStack
}
// Parse the result of resolving NNS record.
// It works with multiple formats (corresponding to multiple NNS versions).
// If array of hashes is provided, it returns only the first one.
res := result.Stack[0]
if arr, ok := res.Value().([]stackitem.Item); ok {
if len(arr) == 0 {
return util.Uint160{}, errors.New("NNS record is missing")
}
res = arr[0]
}
bs, err := res.TryBytes()
if err != nil {
return util.Uint160{}, fmt.Errorf("malformed response: %w", err)
}
return util.Uint160DecodeStringLE(string(bs))
}
func exists(c *client.Client, nnsHash util.Uint160, domain string) (bool, error) {
result, err := c.InvokeFunction(nnsHash, "isAvailable", []smartcontract.Parameter{
{
Type: smartcontract.StringType,
Value: domain,
},
}, nil)
if err != nil {
return false, err
}
if len(result.Stack) == 0 {
return false, errEmptyResultStack
}
res := result.Stack[0]
available, err := res.TryBool()
if err != nil {
return false, fmt.Errorf("malformed response: %w", err)
}
// not available means that it is taken
// and, therefore, exists
return !available, nil
}