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-rw-r--r--accounts/abi/bind/backend.go247
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diff --git a/accounts/abi/bind/backend.go b/accounts/abi/bind/backend.go
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+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package bind
+
+import (
+ "encoding/json"
+ "fmt"
+ "math/big"
+ "sync"
+ "sync/atomic"
+
+ "github.com/ethereum/go-ethereum/common"
+ "github.com/ethereum/go-ethereum/core/types"
+ "github.com/ethereum/go-ethereum/rlp"
+ "github.com/ethereum/go-ethereum/rpc"
+)
+
+// ContractCaller defines the methods needed to allow operating with contract on a read
+// only basis.
+type ContractCaller interface {
+ // ContractCall executes an Ethereum contract call with the specified data as
+ // the input.
+ ContractCall(contract common.Address, data []byte) ([]byte, error)
+}
+
+// ContractTransactor defines the methods needed to allow operating with contract
+// on a write only basis. Beside the transacting method, the remainder are helpers
+// used when the user does not provide some needed values, but rather leaves it up
+// to the transactor to decide.
+type ContractTransactor interface {
+ // Nonce retrieves the current pending nonce associated with an account.
+ AccountNonce(account common.Address) (uint64, error)
+
+ // GasPrice retrieves the currently suggested gas price to allow a timely execution
+ // of a transaction.
+ GasPrice() (*big.Int, error)
+
+ // GasLimit tries to estimate the gas needed to execute a specific transaction.
+ GasLimit(sender, contract common.Address, value *big.Int, data []byte) (*big.Int, error)
+
+ // SendTransaction injects the transaction into the pending pool for execution.
+ SendTransaction(*types.Transaction) error
+}
+
+// ContractBackend defines the methods needed to allow operating with contract
+// on a read-write basis.
+type ContractBackend interface {
+ ContractCaller
+ ContractTransactor
+}
+
+// nilBackend implements bind.ContractBackend, but panics on any method call.
+// Its sole purpose is to support the binding tests to construct the generated
+// wrappers without calling any methods on them.
+type nilBackend struct{}
+
+func (*nilBackend) ContractCall(common.Address, []byte) ([]byte, error) { panic("not implemented") }
+func (*nilBackend) SendTransaction(*types.Transaction) error { panic("not implemented") }
+func (*nilBackend) AccountNonce(common.Address) (uint64, error) { panic("not implemented") }
+func (*nilBackend) GasPrice() (*big.Int, error) { panic("not implemented") }
+func (*nilBackend) GasLimit(common.Address, common.Address, *big.Int, []byte) (*big.Int, error) {
+ panic("not implemented")
+}
+
+// Helper backend for internal tests. Will panic on any invocation!
+var NilBackend = new(nilBackend)
+
+// rpcBackend implements bind.ContractBackend, and acts as the data provider to
+// Ethereum contracts bound to Go structs. It uses an RPC connection to delegate
+// all its functionality.
+//
+// Note: The current implementation is a blocking one. This should be replaced
+// by a proper async version when a real RPC client is created.
+type rpcBackend struct {
+ client rpc.Client // RPC client connection to interact with an API server
+ autoid uint32 // ID number to use for the next API request
+ lock sync.Mutex // Singleton access until we get to request multiplexing
+}
+
+// NewRPCBackend creates a new binding backend to an RPC provider that can be
+// used to interact with remote contracts.
+func NewRPCBackend(client rpc.Client) ContractBackend {
+ return &rpcBackend{
+ client: client,
+ }
+}
+
+// request is a JSON RPC request package assembled internally from the client
+// method calls.
+type request struct {
+ JsonRpc string `json:"jsonrpc"` // Version of the JSON RPC protocol, always set to 2.0
+ Id int `json:"id"` // Auto incrementing ID number for this request
+ Method string `json:"method"` // Remote procedure name to invoke on the server
+ Params []interface{} `json:"params"` // List of parameters to pass through (keep types simple)
+}
+
+// response is a JSON RPC response package sent back from the API server.
+type response struct {
+ JsonRpc string `json:"jsonrpc"` // Version of the JSON RPC protocol, always set to 2.0
+ Id int `json:"id"` // Auto incrementing ID number for this request
+ Error json.RawMessage `json:"error"` // Any error returned by the remote side
+ Result json.RawMessage `json:"result"` // Whatever the remote side sends us in reply
+}
+
+// request forwards an API request to the RPC server, and parses the response.
+//
+// This is currently painfully non-concurrent, but it will have to do until we
+// find the time for niceties like this :P
+func (backend *rpcBackend) request(method string, params []interface{}) (json.RawMessage, error) {
+ backend.lock.Lock()
+ defer backend.lock.Unlock()
+
+ // Ugly hack to serialize an empty list properly
+ if params == nil {
+ params = []interface{}{}
+ }
+ // Assemble the request object
+ req := &request{
+ JsonRpc: "2.0",
+ Id: int(atomic.AddUint32(&backend.autoid, 1)),
+ Method: method,
+ Params: params,
+ }
+ if err := backend.client.Send(req); err != nil {
+ return nil, err
+ }
+ res := new(response)
+ if err := backend.client.Recv(res); err != nil {
+ return nil, err
+ }
+ if len(res.Error) > 0 {
+ return nil, fmt.Errorf("remote error: %s", string(res.Error))
+ }
+ return res.Result, nil
+}
+
+// ContractCall implements ContractCaller.ContractCall, delegating the execution of
+// a contract call to the remote node, returning the reply to for local processing.
+func (b *rpcBackend) ContractCall(contract common.Address, data []byte) ([]byte, error) {
+ // Pack up the request into an RPC argument
+ args := struct {
+ To common.Address `json:"to"`
+ Data string `json:"data"`
+ }{
+ To: contract,
+ Data: common.ToHex(data),
+ }
+ // Execute the RPC call and retrieve the response
+ res, err := b.request("eth_call", []interface{}{args, "pending"})
+ if err != nil {
+ return nil, err
+ }
+ var hex string
+ if err := json.Unmarshal(res, &hex); err != nil {
+ return nil, err
+ }
+ // Convert the response back to a Go byte slice and return
+ return common.FromHex(hex), nil
+}
+
+// AccountNonce implements ContractTransactor.AccountNonce, delegating the
+// current account nonce retrieval to the remote node.
+func (b *rpcBackend) AccountNonce(account common.Address) (uint64, error) {
+ res, err := b.request("eth_getTransactionCount", []interface{}{account.Hex(), "pending"})
+ if err != nil {
+ return 0, err
+ }
+ var hex string
+ if err := json.Unmarshal(res, &hex); err != nil {
+ return 0, err
+ }
+ return new(big.Int).SetBytes(common.FromHex(hex)).Uint64(), nil
+}
+
+// GasPrice implements ContractTransactor.GasPrice, delegating the gas price
+// oracle request to the remote node.
+func (b *rpcBackend) GasPrice() (*big.Int, error) {
+ res, err := b.request("eth_gasPrice", nil)
+ if err != nil {
+ return nil, err
+ }
+ var hex string
+ if err := json.Unmarshal(res, &hex); err != nil {
+ return nil, err
+ }
+ return new(big.Int).SetBytes(common.FromHex(hex)), nil
+}
+
+// GasLimit implements ContractTransactor.GasLimit, delegating the gas estimation
+// to the remote node.
+func (b *rpcBackend) GasLimit(sender, contract common.Address, value *big.Int, data []byte) (*big.Int, error) {
+ // Pack up the request into an RPC argument
+ args := struct {
+ From common.Address `json:"from"`
+ To common.Address `json:"to"`
+ Value *rpc.HexNumber `json:"value"`
+ Data string `json:"data"`
+ }{
+ From: sender,
+ To: contract,
+ Data: common.ToHex(data),
+ Value: rpc.NewHexNumber(value),
+ }
+ // Execute the RPC call and retrieve the response
+ res, err := b.request("eth_estimateGas", []interface{}{args})
+ if err != nil {
+ return nil, err
+ }
+ var hex string
+ if err := json.Unmarshal(res, &hex); err != nil {
+ return nil, err
+ }
+ // Convert the response back to a Go byte slice and return
+ return new(big.Int).SetBytes(common.FromHex(hex)), nil
+}
+
+// Transact implements ContractTransactor.SendTransaction, delegating the raw
+// transaction injection to the remote node.
+func (b *rpcBackend) SendTransaction(tx *types.Transaction) error {
+ data, err := rlp.EncodeToBytes(tx)
+ if err != nil {
+ return err
+ }
+ res, err := b.request("eth_sendRawTransaction", []interface{}{common.ToHex(data)})
+ if err != nil {
+ return err
+ }
+ var hex string
+ if err := json.Unmarshal(res, &hex); err != nil {
+ return err
+ }
+ return nil
+}