mirror of
https://github.com/nspcc-dev/neo-go.git
synced 2024-10-16 23:46:26 +00:00
278 lines
8.2 KiB
Go
278 lines
8.2 KiB
Go
/*
|
|
Package unwrap provides a set of proxy methods to process invocation results.
|
|
|
|
Functions implemented there are intended to be used as wrappers for other
|
|
functions that return (*result.Invoke, error) pair (of which there are many).
|
|
These functions will check for error, check for VM state, check the number
|
|
of results, cast them to appropriate type (if everything is OK) and then
|
|
return a result or error. They're mostly useful for other higher-level
|
|
contract-specific packages.
|
|
*/
|
|
package unwrap
|
|
|
|
import (
|
|
"crypto/elliptic"
|
|
"errors"
|
|
"fmt"
|
|
"math/big"
|
|
"unicode/utf8"
|
|
|
|
"github.com/google/uuid"
|
|
"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
|
|
"github.com/nspcc-dev/neo-go/pkg/neorpc/result"
|
|
"github.com/nspcc-dev/neo-go/pkg/util"
|
|
"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
|
|
"github.com/nspcc-dev/neo-go/pkg/vm/vmstate"
|
|
)
|
|
|
|
// BigInt expects correct execution (HALT state) with a single stack item
|
|
// returned. A big.Int is extracted from this item and returned.
|
|
func BigInt(r *result.Invoke, err error) (*big.Int, error) {
|
|
itm, err := Item(r, err)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return itm.TryInteger()
|
|
}
|
|
|
|
// Bool expects correct execution (HALT state) with a single stack item
|
|
// returned. A bool is extracted from this item and returned.
|
|
func Bool(r *result.Invoke, err error) (bool, error) {
|
|
itm, err := Item(r, err)
|
|
if err != nil {
|
|
return false, err
|
|
}
|
|
return itm.TryBool()
|
|
}
|
|
|
|
// Int64 expects correct execution (HALT state) with a single stack item
|
|
// returned. An int64 is extracted from this item and returned.
|
|
func Int64(r *result.Invoke, err error) (int64, error) {
|
|
itm, err := Item(r, err)
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
i, err := itm.TryInteger()
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
if !i.IsInt64() {
|
|
return 0, errors.New("int64 overflow")
|
|
}
|
|
return i.Int64(), nil
|
|
}
|
|
|
|
// LimitedInt64 is similar to Int64 except it allows to set minimum and maximum
|
|
// limits to be checked, so if it doesn't return an error the value is more than
|
|
// min and less than max.
|
|
func LimitedInt64(r *result.Invoke, err error, min int64, max int64) (int64, error) {
|
|
i, err := Int64(r, err)
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
if i < min {
|
|
return 0, errors.New("too small value")
|
|
}
|
|
if i > max {
|
|
return 0, errors.New("too big value")
|
|
}
|
|
return i, nil
|
|
}
|
|
|
|
// Bytes expects correct execution (HALT state) with a single stack item
|
|
// returned. A slice of bytes is extracted from this item and returned.
|
|
func Bytes(r *result.Invoke, err error) ([]byte, error) {
|
|
itm, err := Item(r, err)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return itm.TryBytes()
|
|
}
|
|
|
|
// UTF8String expects correct execution (HALT state) with a single stack item
|
|
// returned. A string is extracted from this item and checked for UTF-8
|
|
// correctness, valid strings are then returned.
|
|
func UTF8String(r *result.Invoke, err error) (string, error) {
|
|
b, err := Bytes(r, err)
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
if !utf8.Valid(b) {
|
|
return "", errors.New("not a UTF-8 string")
|
|
}
|
|
return string(b), nil
|
|
}
|
|
|
|
// PrintableASCIIString expects correct execution (HALT state) with a single
|
|
// stack item returned. A string is extracted from this item and checked to
|
|
// only contain ASCII characters in printable range, valid strings are then
|
|
// returned.
|
|
func PrintableASCIIString(r *result.Invoke, err error) (string, error) {
|
|
s, err := UTF8String(r, err)
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
for _, c := range s {
|
|
if c < 32 || c >= 127 {
|
|
return "", errors.New("not a printable ASCII string")
|
|
}
|
|
}
|
|
return s, nil
|
|
}
|
|
|
|
// Uint160 expects correct execution (HALT state) with a single stack item
|
|
// returned. An util.Uint160 is extracted from this item and returned.
|
|
func Uint160(r *result.Invoke, err error) (util.Uint160, error) {
|
|
b, err := Bytes(r, err)
|
|
if err != nil {
|
|
return util.Uint160{}, err
|
|
}
|
|
return util.Uint160DecodeBytesBE(b)
|
|
}
|
|
|
|
// Uint256 expects correct execution (HALT state) with a single stack item
|
|
// returned. An util.Uint256 is extracted from this item and returned.
|
|
func Uint256(r *result.Invoke, err error) (util.Uint256, error) {
|
|
b, err := Bytes(r, err)
|
|
if err != nil {
|
|
return util.Uint256{}, err
|
|
}
|
|
return util.Uint256DecodeBytesBE(b)
|
|
}
|
|
|
|
// SessionIterator expects correct execution (HALT state) with a single stack
|
|
// item returned. If this item is an iterator it's returned to the caller along
|
|
// with the session ID.
|
|
func SessionIterator(r *result.Invoke, err error) (uuid.UUID, result.Iterator, error) {
|
|
itm, err := Item(r, err)
|
|
if err != nil {
|
|
return uuid.UUID{}, result.Iterator{}, err
|
|
}
|
|
if t := itm.Type(); t != stackitem.InteropT {
|
|
return uuid.UUID{}, result.Iterator{}, fmt.Errorf("expected InteropInterface, got %s", t)
|
|
}
|
|
iter, ok := itm.Value().(result.Iterator)
|
|
if !ok {
|
|
return uuid.UUID{}, result.Iterator{}, errors.New("the item is InteropInterface, but not an Iterator")
|
|
}
|
|
if (r.Session == uuid.UUID{}) && iter.ID != nil {
|
|
return uuid.UUID{}, result.Iterator{}, errors.New("server returned iterator ID, but no session ID")
|
|
}
|
|
return r.Session, iter, nil
|
|
}
|
|
|
|
// Array expects correct execution (HALT state) with a single array stack item
|
|
// returned. This item is returned to the caller. Notice that this function can
|
|
// be used for structures as well since they're also represented as slices of
|
|
// stack items (the number of them and their types are structure-specific).
|
|
func Array(r *result.Invoke, err error) ([]stackitem.Item, error) {
|
|
itm, err := Item(r, err)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
arr, ok := itm.Value().([]stackitem.Item)
|
|
if !ok {
|
|
return nil, errors.New("not an array")
|
|
}
|
|
return arr, nil
|
|
}
|
|
|
|
// ArrayOfBytes checks the result for correct state (HALT) and then extracts a
|
|
// slice of byte slices from the returned stack item.
|
|
func ArrayOfBytes(r *result.Invoke, err error) ([][]byte, error) {
|
|
a, err := Array(r, err)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
res := make([][]byte, len(a))
|
|
for i := range a {
|
|
b, err := a[i].TryBytes()
|
|
if err != nil {
|
|
return nil, fmt.Errorf("element %d is not a byte string: %w", i, err)
|
|
}
|
|
res[i] = b
|
|
}
|
|
return res, nil
|
|
}
|
|
|
|
// ArrayOfUint160 checks the result for correct state (HALT) and then extracts a
|
|
// slice of util.Uint160 from the returned stack item.
|
|
func ArrayOfUint160(r *result.Invoke, err error) ([]util.Uint160, error) {
|
|
a, err := Array(r, err)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
res := make([]util.Uint160, len(a))
|
|
for i := range a {
|
|
b, err := a[i].TryBytes()
|
|
if err != nil {
|
|
return nil, fmt.Errorf("element %d is not a byte string: %w", i, err)
|
|
}
|
|
u, err := util.Uint160DecodeBytesBE(b)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("element %d is not a uint160: %w", i, err)
|
|
}
|
|
res[i] = u
|
|
}
|
|
return res, nil
|
|
}
|
|
|
|
// ArrayOfPublicKeys checks the result for correct state (HALT) and then
|
|
// extracts a slice of public keys from the returned stack item.
|
|
func ArrayOfPublicKeys(r *result.Invoke, err error) (keys.PublicKeys, error) {
|
|
arr, err := Array(r, err)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
pks := make(keys.PublicKeys, len(arr))
|
|
for i, item := range arr {
|
|
val, err := item.TryBytes()
|
|
if err != nil {
|
|
return nil, fmt.Errorf("invalid array element #%d: %s", i, item.Type())
|
|
}
|
|
pks[i], err = keys.NewPublicKeyFromBytes(val, elliptic.P256())
|
|
if err != nil {
|
|
return nil, fmt.Errorf("array element #%d in not a key: %w", i, err)
|
|
}
|
|
}
|
|
return pks, nil
|
|
}
|
|
|
|
// Map expects correct execution (HALT state) with a single stack item
|
|
// returned. A stackitem.Map is extracted from this item and returned.
|
|
func Map(r *result.Invoke, err error) (*stackitem.Map, error) {
|
|
itm, err := Item(r, err)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if t := itm.Type(); t != stackitem.MapT {
|
|
return nil, fmt.Errorf("%s is not a map", t.String())
|
|
}
|
|
return itm.(*stackitem.Map), nil
|
|
}
|
|
|
|
func checkResOK(r *result.Invoke, err error) error {
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if r.State != vmstate.Halt.String() {
|
|
return fmt.Errorf("invocation failed: %s", r.FaultException)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Item returns a stack item from the result if execution was successful (HALT
|
|
// state) and if it's the only element on the result stack.
|
|
func Item(r *result.Invoke, err error) (stackitem.Item, error) {
|
|
err = checkResOK(r, err)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if len(r.Stack) == 0 {
|
|
return nil, errors.New("result stack is empty")
|
|
}
|
|
if len(r.Stack) > 1 {
|
|
return nil, fmt.Errorf("too many (%d) result items", len(r.Stack))
|
|
}
|
|
return r.Stack[0], nil
|
|
}
|