contracts/release,eth,accounts/abi/bind/backends updated contract code + support subscribe logs

- update release contract code for solidity 0.4
- add support for subscribing to filter events in simulated backend and contract backend

accounts/abi/bind/backends/simulated.go

@@ -303,6 +303,13 @@ func (b *SimulatedBackend) AdjustTime(adjustment time.Duration) error {
 	return nil
 }
 
+// SubscribeFilterLogs emits logs that match the given criteria over the given channel.
+//
+// Note: it is currently not implemented.
+func (b *SimulatedBackend) SubscribeFilterLogs(ctx context.Context, q ethereum.FilterQuery, ch chan<- types.Log) (ethereum.Subscription, error) {
+	return nil, fmt.Errorf("not implemented")
+}
+
 // callmsg implements core.Message to allow passing it as a transaction simulator.
 type callmsg struct {
 	ethereum.CallMsg

contracts/release/contract.sol

@@ -58,7 +58,7 @@ contract ReleaseOracle {
   // isSigner is a modifier to authorize contract transactions.
   modifier isSigner() {
     if (authorised[msg.sender]) {
-      _
+      _;
     }
   }
 

contracts/release/release.go

@@ -28,6 +28,7 @@ import (
 	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/eth"
+	"github.com/ethereum/go-ethereum/eth/filters"
 	"github.com/ethereum/go-ethereum/internal/ethapi"
 	"github.com/ethereum/go-ethereum/les"
 	"github.com/ethereum/go-ethereum/log"
@@ -62,19 +63,26 @@ type ReleaseService struct {
 func NewReleaseService(ctx *node.ServiceContext, config Config) (node.Service, error) {
 	// Retrieve the Ethereum service dependency to access the blockchain
 	var apiBackend ethapi.Backend
+	var filterBackend filters.Backend
 	var ethereum *eth.Ethereum
+	lightMode := false
+
 	if err := ctx.Service(&ethereum); err == nil {
 		apiBackend = ethereum.ApiBackend
+		filterBackend = ethereum.ApiBackend
 	} else {
 		var ethereum *les.LightEthereum
 		if err := ctx.Service(&ethereum); err == nil {
 			apiBackend = ethereum.ApiBackend
+			filterBackend = ethereum.ApiBackend
+			lightMode = true
 		} else {
 			return nil, err
 		}
 	}
+
 	// Construct the release service
-	contract, err := NewReleaseOracle(config.Oracle, eth.NewContractBackend(apiBackend))
+	contract, err := NewReleaseOracle(config.Oracle, eth.NewContractBackend(apiBackend, filterBackend, lightMode))
 	if err != nil {
 		return nil, err
 	}

eth/bind.go

@@ -24,6 +24,7 @@ import (
 	"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"
@@ -40,15 +41,17 @@ 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
+	es    *filters.EventSystem             // Enable log subscriptions
 }
 
 // NewContractBackend creates a new native contract backend using an existing
 // Ethereum object.
-func NewContractBackend(apiBackend ethapi.Backend) *ContractBackend {
+func NewContractBackend(apiBackend ethapi.Backend, filterBackend filters.Backend, lightMode bool) *ContractBackend {
 	return &ContractBackend{
 		eapi:  ethapi.NewPublicEthereumAPI(apiBackend),
 		bcapi: ethapi.NewPublicBlockChainAPI(apiBackend),
 		txapi: ethapi.NewPublicTransactionPoolAPI(apiBackend, new(ethapi.AddrLocker)),
+		es:    filters.NewEventSystem(apiBackend.EventMux(), filterBackend, lightMode),
 	}
 }
 
@@ -136,3 +139,32 @@ func (b *ContractBackend) SendTransaction(ctx context.Context, tx *types.Transac
 	_, err := b.txapi.SendRawTransaction(ctx, raw)
 	return err
 }
+
+// SubscribeFilterLogs emits logs that match the given criteria over the given channel.
+func (b *ContractBackend) SubscribeFilterLogs(ctx context.Context, q ethereum.FilterQuery, logs chan<- types.Log) (ethereum.Subscription, error) {
+	f := filters.FilterCriteria{q.FromBlock, q.ToBlock, q.Addresses, q.Topics}
+	l := make(chan []*types.Log)
+
+	sub, err := b.es.SubscribeLogs(f, l)
+	if err != nil {
+		return nil, err
+	}
+
+	// TODO: rewrite filters.EventSystem so SubscribeLogs
+	// accepts chan types.Log instead of chan []*type.Log
+	go func() {
+		for {
+			select {
+			case <-sub.Err():
+				close(l)
+				return
+			case ls := <-l:
+				for _, l := range ls {
+					logs <- *l
+				}
+			}
+		}
+	}()
+
+	return sub, nil
+}