neoneo-go/pkg/rpc/client/helper.go

272 lines
12 KiB
Go

package client
import (
"crypto/elliptic"
"errors"
"fmt"
"github.com/nspcc-dev/neo-go/pkg/config"
"github.com/nspcc-dev/neo-go/pkg/core/interop/interopnames"
"github.com/nspcc-dev/neo-go/pkg/core/transaction"
"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
"github.com/nspcc-dev/neo-go/pkg/io"
"github.com/nspcc-dev/neo-go/pkg/rpc/client/nns"
"github.com/nspcc-dev/neo-go/pkg/rpc/response/result"
"github.com/nspcc-dev/neo-go/pkg/smartcontract"
"github.com/nspcc-dev/neo-go/pkg/smartcontract/callflag"
"github.com/nspcc-dev/neo-go/pkg/util"
"github.com/nspcc-dev/neo-go/pkg/vm/emit"
"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
)
// getInvocationError returns an error in case of bad VM state or an empty stack.
func getInvocationError(result *result.Invoke) error {
if result.State != "HALT" {
return fmt.Errorf("invocation failed: %s", result.FaultException)
}
if len(result.Stack) == 0 {
return errors.New("result stack is empty")
}
return nil
}
// topBoolFromStack returns the top boolean value from the stack.
func topBoolFromStack(st []stackitem.Item) (bool, error) {
index := len(st) - 1 // top stack element is last in the array
result, ok := st[index].Value().(bool)
if !ok {
return false, fmt.Errorf("invalid stack item type: %s", st[index].Type())
}
return result, nil
}
// topIntFromStack returns the top integer value from the stack.
func topIntFromStack(st []stackitem.Item) (int64, error) {
index := len(st) - 1 // top stack element is last in the array
bi, err := st[index].TryInteger()
if err != nil {
return 0, err
}
return bi.Int64(), nil
}
// topPublicKeysFromStack returns the top array of public keys from the stack.
func topPublicKeysFromStack(st []stackitem.Item) (keys.PublicKeys, error) {
index := len(st) - 1 // top stack element is last in the array
var (
pks keys.PublicKeys
err error
)
items, ok := st[index].Value().([]stackitem.Item)
if !ok {
return nil, fmt.Errorf("invalid stack item type: %s", st[index].Type())
}
pks = make(keys.PublicKeys, len(items))
for i, item := range items {
val, ok := item.Value().([]byte)
if !ok {
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, err
}
}
return pks, nil
}
// top string from stack returns the top string from the stack.
func topStringFromStack(st []stackitem.Item) (string, error) {
index := len(st) - 1 // top stack element is last in the array
bs, err := st[index].TryBytes()
if err != nil {
return "", err
}
return string(bs), nil
}
// topUint160FromStack returns the top util.Uint160 from the stack.
func topUint160FromStack(st []stackitem.Item) (util.Uint160, error) {
index := len(st) - 1 // top stack element is last in the array
bs, err := st[index].TryBytes()
if err != nil {
return util.Uint160{}, err
}
return util.Uint160DecodeBytesBE(bs)
}
// topMapFromStack returns the top stackitem.Map from the stack.
func topMapFromStack(st []stackitem.Item) (*stackitem.Map, error) {
index := len(st) - 1 // top stack element is last in the array
if t := st[index].Type(); t != stackitem.MapT {
return nil, fmt.Errorf("invalid return stackitem type: %s", t.String())
}
return st[index].(*stackitem.Map), nil
}
// InvokeAndPackIteratorResults creates a script containing System.Contract.Call
// of the specified contract with the specified arguments. It assumes that the
// specified operation will return iterator. The script traverses the resulting
// iterator, packs all its values into array and pushes the resulting array on
// stack. Constructed script is invoked via `invokescript` JSON-RPC API using
// the provided signers. The result of the script invocation contains single array
// stackitem on stack if invocation HALTed. InvokeAndPackIteratorResults can be
// used to interact with JSON-RPC server where iterator sessions are disabled to
// retrieve iterator values via single `invokescript` JSON-RPC call. It returns
// maxIteratorResultItems items at max which is set to
// config.DefaultMaxIteratorResultItems by default.
func (c *Client) InvokeAndPackIteratorResults(contract util.Uint160, operation string, params []smartcontract.Parameter, signers []transaction.Signer, maxIteratorResultItems ...int) (*result.Invoke, error) {
max := config.DefaultMaxIteratorResultItems
if len(maxIteratorResultItems) != 0 {
max = maxIteratorResultItems[0]
}
bytes, err := createIteratorUnwrapperScript(contract, operation, params, max)
if err != nil {
return nil, fmt.Errorf("failed to create iterator unwrapper script: %w", err)
}
return c.InvokeScript(bytes, signers)
}
func createIteratorUnwrapperScript(contract util.Uint160, operation string, params []smartcontract.Parameter, maxIteratorResultItems int) ([]byte, error) {
script := io.NewBufBinWriter()
emit.Int(script.BinWriter, int64(maxIteratorResultItems))
// Pack arguments for System.Contract.Call.
arr, err := smartcontract.ExpandParameterToEmitable(smartcontract.Parameter{
Type: smartcontract.ArrayType,
Value: params,
})
if err != nil {
return nil, fmt.Errorf("failed to expand parameters array to emitable: %w", err)
}
emit.Array(script.BinWriter, arr.([]interface{})...)
emit.AppCallNoArgs(script.BinWriter, contract, operation, callflag.All) // The System.Contract.Call itself, it will push Iterator on estack.
emit.Opcodes(script.BinWriter, opcode.NEWARRAY0) // Push new empty array to estack. This array will store iterator's elements.
// Start the iterator traversal cycle.
iteratorTraverseCycleStartOffset := script.Len()
emit.Opcodes(script.BinWriter, opcode.OVER) // Load iterator from 1-st cell of estack.
emit.Syscall(script.BinWriter, interopnames.SystemIteratorNext) // Call System.Iterator.Next, it will pop the iterator from estack and push `true` or `false` to estack.
jmpIfNotOffset := script.Len()
emit.Instruction(script.BinWriter, opcode.JMPIFNOT, // Pop boolean value (from the previous step) from estack, if `false`, then iterator has no more items => jump to the end of program.
[]byte{
0x00, // jump to loadResultOffset, but we'll fill this byte after script creation.
})
emit.Opcodes(script.BinWriter, opcode.DUP, // Duplicate the resulting array from 0-th cell of estack and push it to estack.
opcode.PUSH2, opcode.PICK) // Pick iterator from the 2-nd cell of estack.
emit.Syscall(script.BinWriter, interopnames.SystemIteratorValue) // Call System.Iterator.Value, it will pop the iterator from estack and push its current value to estack.
emit.Opcodes(script.BinWriter, opcode.APPEND) // Pop iterator value and the resulting array from estack. Append value to the resulting array. Array is a reference type, thus, value stored at the 1-th cell of local slot will also be updated.
emit.Opcodes(script.BinWriter, opcode.DUP, // Duplicate the resulting array from 0-th cell of estack and push it to estack.
opcode.SIZE, // Pop array from estack and push its size to estack.
opcode.PUSH3, opcode.PICK, // Pick maxIteratorResultItems from the 3-d cell of estack.
opcode.GE) // Compare len(arr) and maxIteratorResultItems
jmpIfMaxReachedOffset := script.Len()
emit.Instruction(script.BinWriter, opcode.JMPIF, // Pop boolean value (from the previous step) from estack, if `false`, then max array elements is reached => jump to the end of program.
[]byte{
0x00, // jump to loadResultOffset, but we'll fill this byte after script creation.
})
jmpOffset := script.Len()
emit.Instruction(script.BinWriter, opcode.JMP, // Jump to the start of iterator traverse cycle.
[]byte{
uint8(iteratorTraverseCycleStartOffset - jmpOffset), // jump to iteratorTraverseCycleStartOffset; offset is relative to JMP position.
})
// End of the program: push the result on stack and return.
loadResultOffset := script.Len()
emit.Opcodes(script.BinWriter, opcode.NIP, // Remove iterator from the 1-st cell of estack
opcode.NIP) // Remove maxIteratorResultItems from the 1-st cell of estack, so that only resulting array is left on estack.
if err := script.Err; err != nil {
return nil, fmt.Errorf("failed to build iterator unwrapper script: %w", err)
}
// Fill in JMPIFNOT instruction parameter.
bytes := script.Bytes()
bytes[jmpIfNotOffset+1] = uint8(loadResultOffset - jmpIfNotOffset) // +1 is for JMPIFNOT itself; offset is relative to JMPIFNOT position.
// Fill in jmpIfMaxReachedOffset instruction parameter.
bytes[jmpIfMaxReachedOffset+1] = uint8(loadResultOffset - jmpIfMaxReachedOffset) // +1 is for JMPIF itself; offset is relative to JMPIF position.
return bytes, nil
}
// topIterableFromStack returns the list of elements of `resultItemType` type from the top element
// of the provided stack. The top element is expected to be an Array, otherwise an error is returned.
func topIterableFromStack(st []stackitem.Item, resultItemType interface{}) ([]interface{}, error) {
index := len(st) - 1 // top stack element is the last in the array
if t := st[index].Type(); t != stackitem.ArrayT {
return nil, fmt.Errorf("invalid return stackitem type: %s (Array expected)", t.String())
}
items, ok := st[index].Value().([]stackitem.Item)
if !ok {
return nil, fmt.Errorf("failed to deserialize iterable from Array stackitem: invalid value type (Array expected)")
}
result := make([]interface{}, len(items))
for i := range items {
switch resultItemType.(type) {
case []byte:
bytes, err := items[i].TryBytes()
if err != nil {
return nil, fmt.Errorf("failed to deserialize []byte from stackitem #%d: %w", i, err)
}
result[i] = bytes
case string:
bytes, err := items[i].TryBytes()
if err != nil {
return nil, fmt.Errorf("failed to deserialize string from stackitem #%d: %w", i, err)
}
result[i] = string(bytes)
case util.Uint160:
bytes, err := items[i].TryBytes()
if err != nil {
return nil, fmt.Errorf("failed to deserialize uint160 from stackitem #%d: %w", i, err)
}
result[i], err = util.Uint160DecodeBytesBE(bytes)
if err != nil {
return nil, fmt.Errorf("failed to decode uint160 from stackitem #%d: %w", i, err)
}
case nns.RecordState:
rs, ok := items[i].Value().([]stackitem.Item)
if !ok {
return nil, fmt.Errorf("failed to decode RecordState from stackitem #%d: not a struct", i)
}
if len(rs) != 3 {
return nil, fmt.Errorf("failed to decode RecordState from stackitem #%d: wrong number of elements", i)
}
name, err := rs[0].TryBytes()
if err != nil {
return nil, fmt.Errorf("failed to decode RecordState from stackitem #%d: %w", i, err)
}
typ, err := rs[1].TryInteger()
if err != nil {
return nil, fmt.Errorf("failed to decode RecordState from stackitem #%d: %w", i, err)
}
data, err := rs[2].TryBytes()
if err != nil {
return nil, fmt.Errorf("failed to decode RecordState from stackitem #%d: %w", i, err)
}
u64Typ := typ.Uint64()
if !typ.IsUint64() || u64Typ > 255 {
return nil, fmt.Errorf("failed to decode RecordState from stackitem #%d: bad type", i)
}
result[i] = nns.RecordState{
Name: string(name),
Type: nns.RecordType(u64Typ),
Data: string(data),
}
default:
return nil, errors.New("unsupported iterable type")
}
}
return result, nil
}
// topIteratorFromStack returns the top Iterator from the stack.
func topIteratorFromStack(st []stackitem.Item) (result.Iterator, error) {
index := len(st) - 1 // top stack element is the last in the array
if t := st[index].Type(); t != stackitem.InteropT {
return result.Iterator{}, fmt.Errorf("expected InteropInterface on stack, got %s", t)
}
iter, ok := st[index].Value().(result.Iterator)
if !ok {
return result.Iterator{}, fmt.Errorf("failed to deserialize iterable from interop stackitem: invalid value type (Iterator expected)")
}
return iter, nil
}