accounts/abi: add event binding for go language

accounts/abi/bind/backend.go

@@ -50,6 +50,10 @@ type ContractCaller interface {
 	// ContractCall executes an Ethereum contract call with the specified data as the
 	// input.
 	CallContract(ctx context.Context, call ethereum.CallMsg, blockNumber *big.Int) ([]byte, error)
+	// SubscribeFilterLogs subscribes to the results of a streaming filter query.
+	SubscribeFilterLogs(ctx context.Context, q ethereum.FilterQuery, ch chan<- types.Log) (ethereum.Subscription, error)
+	// FilterLogs executes a filter query.
+	FilterLogs(ctx context.Context, q ethereum.FilterQuery) ([]*types.Log, error)
 }
 
 // DeployBackend wraps the operations needed by WaitMined and WaitDeployed.

accounts/abi/bind/backends/simulated.go

@@ -40,6 +40,7 @@ import (
 var _ bind.ContractBackend = (*SimulatedBackend)(nil)
 
 var errBlockNumberUnsupported = errors.New("SimulatedBackend cannot access blocks other than the latest block")
+var errLogsUnsupported = errors.New("SimulatedBackend cannot query logs")
 
 // SimulatedBackend implements bind.ContractBackend, simulating a blockchain in
 // the background. Its main purpose is to allow easily testing contract bindings.
@@ -284,6 +285,16 @@ func (b *SimulatedBackend) SendTransaction(ctx context.Context, tx *types.Transa
 	return nil
 }
 
+//cannot query logs on simulated blockchain
+func (b *SimulatedBackend) SubscribeFilterLogs(ctx context.Context, q ethereum.FilterQuery, ch chan<- types.Log) (ethereum.Subscription, error) {
+	return nil, errLogsUnsupported
+}
+
+//cannot query logs on simulated blockchain
+func (b *SimulatedBackend) FilterLogs(ctx context.Context, q ethereum.FilterQuery) ([]*types.Log, error) {
+	return nil, errLogsUnsupported
+}
+
 // callmsg implements core.Message to allow passing it as a transaction simulator.
 type callmsg struct {
 	ethereum.CallMsg

accounts/abi/bind/base.go

@@ -145,6 +145,33 @@ func (c *BoundContract) Call(opts *CallOpts, result interface{}, method string,
 	return c.abi.Unpack(result, method, output)
 }
 
+// SubscribeFilterLogs  query logs on blockchain with q.
+// it returns a channel which tell all the already happed logs and the logs that will happen.
+// you can cancel listen logs by Subscription's Unsubscribe
+func (c *BoundContract) SubscribeFilterLogs(opts *CallOpts, q ethereum.FilterQuery) (<-chan types.Log, ethereum.Subscription, error) {
+	if opts == nil {
+		opts = new(CallOpts)
+	}
+	var ctx = ensureContext(opts.Context)
+	q.Addresses = []common.Address{c.address}
+	//first get all happened logs on the blockchain.
+	logs, err := c.caller.FilterLogs(ctx, q)
+	if err != nil {
+		return nil, nil, err
+	}
+	var ch = make(chan types.Log, len(logs))
+	//subcribe logs that will happen.
+	sub, err := c.caller.SubscribeFilterLogs(ctx, q, ch)
+	if err != nil {
+		close(ch)
+		return nil, nil, err
+	}
+	for _, log := range logs {
+		ch <- *log
+	}
+	return ch, sub, err
+}
+
 // Transact invokes the (paid) contract method with params as input values.
 func (c *BoundContract) Transact(opts *TransactOpts, method string, params ...interface{}) (*types.Transaction, error) {
 	// Otherwise pack up the parameters and invoke the contract

accounts/abi/bind/bind.go

@@ -67,6 +67,7 @@ func Bind(types []string, abis []string, bytecodes []string, pkg string, lang La
 		var (
 			calls     = make(map[string]*tmplMethod)
 			transacts = make(map[string]*tmplMethod)
+			events    = make(map[string]string)
 		)
 		for _, original := range evmABI.Methods {
 			// Normalize the method for capital cases and non-anonymous inputs/outputs
@@ -94,6 +95,9 @@ func Bind(types []string, abis []string, bytecodes []string, pkg string, lang La
 				transacts[original.Name] = &tmplMethod{Original: original, Normalized: normalized, Structured: structured(original)}
 			}
 		}
+		for _, ev := range evmABI.Events {
+			events[ev.Name] = ev.Name
+		}
 		contracts[types[i]] = &tmplContract{
 			Type:        capitalise(types[i]),
 			InputABI:    strings.Replace(strippedABI, "\"", "\\\"", -1),
@@ -101,6 +105,7 @@ func Bind(types []string, abis []string, bytecodes []string, pkg string, lang La
 			Constructor: evmABI.Constructor,
 			Calls:       calls,
 			Transacts:   transacts,
+			Events:      events,
 		}
 	}
 	// Generate the contract template data content and render it

accounts/abi/bind/template.go

@@ -32,6 +32,7 @@ type tmplContract struct {
 	Constructor abi.Method             // Contract constructor for deploy parametrization
 	Calls       map[string]*tmplMethod // Contract calls that only read state data
 	Transacts   map[string]*tmplMethod // Contract calls that write state data
+	Events      map[string]string      //all contract events except the anonymous events todo events's indexed argument information should be used to generate code.
 }
 
 // tmplMethod is a wrapper around an abi.Method that contains a few preprocessed
@@ -263,6 +264,56 @@ package {{.Package}}
 		  return _{{$contract.Type}}.Contract.{{.Normalized.Name}}(&_{{$contract.Type}}.TransactOpts {{range $i, $_ := .Normalized.Inputs}}, {{.Name}}{{end}})
 		}
 	{{end}}
+        func (_{{$contract.Type}} *{{$contract.Type}}Caller) EventSubscribe(opts *bind.CallOpts, fromBlock rpc.BlockNumber,
+            toBlock rpc.BlockNumber, eventName string) (<-chan types.Log, ethereum.Subscription, error) {
+            parsed, err := abi.JSON(strings.NewReader(MyTokenABI))
+            if err != nil {
+                return nil, nil, err
+            }
+            var q ethereum.FilterQuery
+            q.FromBlock = big.NewInt(int64(fromBlock))
+            if toBlock == rpc.LatestBlockNumber {
+                q.ToBlock = nil
+            } else {
+                q.ToBlock = big.NewInt(int64(toBlock))
+            }
+            q.Topics = [][]common.Hash{
+                {parsed.Events[eventName].Id()}, //event signature
+            }
+            return _{{$contract.Type}}.contract.SubscribeFilterLogs(opts, q)
+        }
+
+    {{range $name,$value := .Events}}
+    /*
+    get all event {{$name}} happened from [fromBlock] to [toBlock]
+    if [toBlock] is -1, you can get all the events that will happen later.
+    you can cancel event listenging through Subscription's Unsubscribe
+    */
+    func (t *{{$contract.Type}}Caller) Event{{$name}}Subscribe(opts *bind.CallOpts, fromBlock rpc.BlockNumber,
+    	toBlock rpc.BlockNumber) (<-chan types.Log, ethereum.Subscription, error) {
+    	return t.EventSubscribe(opts, fromBlock, toBlock, "{{$name}}")
+    }
+
+	/*
+   get all event {{$name}} happened from [fromBlock] to [toBlock]
+   if [toBlock] is -1, you can get all the events that will happen later.
+   you can cancel event listenging through Subscription's Unsubscribe
+	*/
+	func (t *{{$contract.Type}}Session) Event{{$name}}Subscribe(fromBlock rpc.BlockNumber,
+		toBlock rpc.BlockNumber) (<-chan types.Log, ethereum.Subscription, error) {
+		return t.Contract.Event{{$name}}Subscribe(&t.CallOpts, fromBlock, toBlock)
+	}
+
+	/*
+	   get all event {{$name}} happened from [fromBlock] to [toBlock]
+	   if [toBlock] is -1, you can get all the events that will happen later.
+	   you can cancel event listenging through Subscription's Unsubscribe
+	*/
+	func (t *{{$contract.Type}}CallerSession) Event{{$name}}Subscribe(opts *bind.CallOpts, fromBlock rpc.BlockNumber,
+		toBlock rpc.BlockNumber) (<-chan types.Log, ethereum.Subscription, error) {
+		return t.Contract.Event{{$name}}Subscribe(&t.CallOpts, fromBlock, toBlock)
+	}
+    {{end}}
 {{end}}
 `
 

eth/bind.go

@@ -20,10 +20,12 @@ import (
 	"context"
 	"math/big"
 
+	"errors"
 	"github.com/ethereum/go-ethereum"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/eth/filters"
 	"github.com/ethereum/go-ethereum/internal/ethapi"
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/ethereum/go-ethereum/rpc"
@@ -40,6 +42,7 @@ type ContractBackend struct {
 	eapi  *ethapi.PublicEthereumAPI        // Wrapper around the Ethereum object to access metadata
 	bcapi *ethapi.PublicBlockChainAPI      // Wrapper around the blockchain to access chain data
 	txapi *ethapi.PublicTransactionPoolAPI // Wrapper around the transaction pool to access transaction data
+	fapi  *filters.PublicFilterAPI         //wrapper around the filter to filter logs
 }
 
 // NewContractBackend creates a new native contract backend using an existing
@@ -49,6 +52,7 @@ func NewContractBackend(apiBackend ethapi.Backend) *ContractBackend {
 		eapi:  ethapi.NewPublicEthereumAPI(apiBackend),
 		bcapi: ethapi.NewPublicBlockChainAPI(apiBackend),
 		txapi: ethapi.NewPublicTransactionPoolAPI(apiBackend, new(ethapi.AddrLocker)),
+		fapi:  filters.NewPublicFilterAPI(apiBackend, false),
 	}
 }
 
@@ -136,3 +140,17 @@ func (b *ContractBackend) SendTransaction(ctx context.Context, tx *types.Transac
 	_, err := b.txapi.SendRawTransaction(ctx, raw)
 	return err
 }
+
+func (b *ContractBackend) SubscribeFilterLogs(ctx context.Context, q ethereum.FilterQuery, ch chan<- types.Log) (ethereum.Subscription, error) {
+	return nil, errors.New("not support right now")
+}
+
+func (b *ContractBackend) FilterLogs(ctx context.Context, q ethereum.FilterQuery) ([]*types.Log, error) {
+	crit := filters.FilterCriteria{
+		FromBlock: q.FromBlock,
+		ToBlock:   q.ToBlock,
+		Addresses: q.Addresses,
+		Topics:    q.Topics,
+	}
+	return b.fapi.GetLogs(ctx, crit)
+}

ethclient/ethclient.go

@@ -304,8 +304,8 @@ func (ec *Client) NonceAt(ctx context.Context, account common.Address, blockNumb
 // Filters
 
 // FilterLogs executes a filter query.
-func (ec *Client) FilterLogs(ctx context.Context, q ethereum.FilterQuery) ([]types.Log, error) {
-	var result []types.Log
+func (ec *Client) FilterLogs(ctx context.Context, q ethereum.FilterQuery) ([]*types.Log, error) {
+	var result []*types.Log
 	err := ec.c.CallContext(ctx, &result, "eth_getLogs", toFilterArg(q))
 	return result, err
 }

internal/ethapi/backend.go

@@ -67,6 +67,9 @@ type Backend interface {
 	TxPoolContent() (map[common.Address]types.Transactions, map[common.Address]types.Transactions)
 	SubscribeTxPreEvent(chan<- core.TxPreEvent) event.Subscription
 
+	SubscribeRemovedLogsEvent(ch chan<- core.RemovedLogsEvent) event.Subscription
+	SubscribeLogsEvent(ch chan<- []*types.Log) event.Subscription
+
 	ChainConfig() *params.ChainConfig
 	CurrentBlock() *types.Block
 }