diff options
author | Péter Szilágyi <peterke@gmail.com> | 2018-01-05 18:39:24 +0800 |
---|---|---|
committer | Péter Szilágyi <peterke@gmail.com> | 2018-01-24 16:54:13 +0800 |
commit | 1bf508b449ebd42653f521ada92c782e8cb664d2 (patch) | |
tree | 1895aeb44d68b189a40a4023ca4869b1f3d1b955 /accounts/abi/bind/base.go | |
parent | 02aeb3d76652a4c0451e5c3734e6881aefe46249 (diff) | |
download | dexon-1bf508b449ebd42653f521ada92c782e8cb664d2.tar dexon-1bf508b449ebd42653f521ada92c782e8cb664d2.tar.gz dexon-1bf508b449ebd42653f521ada92c782e8cb664d2.tar.bz2 dexon-1bf508b449ebd42653f521ada92c782e8cb664d2.tar.lz dexon-1bf508b449ebd42653f521ada92c782e8cb664d2.tar.xz dexon-1bf508b449ebd42653f521ada92c782e8cb664d2.tar.zst dexon-1bf508b449ebd42653f521ada92c782e8cb664d2.zip |
accounts/abi/bind: support event filtering in abigen
Diffstat (limited to 'accounts/abi/bind/base.go')
-rw-r--r-- | accounts/abi/bind/base.go | 121 |
1 files changed, 119 insertions, 2 deletions
diff --git a/accounts/abi/bind/base.go b/accounts/abi/bind/base.go index 2bd683f22..83ad1c8ae 100644 --- a/accounts/abi/bind/base.go +++ b/accounts/abi/bind/base.go @@ -27,6 +27,7 @@ import ( "github.com/ethereum/go-ethereum/common" "github.com/ethereum/go-ethereum/core/types" "github.com/ethereum/go-ethereum/crypto" + "github.com/ethereum/go-ethereum/event" ) // SignerFn is a signer function callback when a contract requires a method to @@ -55,6 +56,22 @@ type TransactOpts struct { Context context.Context // Network context to support cancellation and timeouts (nil = no timeout) } +// FilterOpts is the collection of options to fine tune filtering for events +// within a bound contract. +type FilterOpts struct { + Start uint64 // Start of the queried range + End *uint64 // End of the range (nil = latest) + + Context context.Context // Network context to support cancellation and timeouts (nil = no timeout) +} + +// WatchOpts is the collection of options to fine tune subscribing for events +// within a bound contract. +type WatchOpts struct { + Start *uint64 // Start of the queried range (nil = latest) + Context context.Context // Network context to support cancellation and timeouts (nil = no timeout) +} + // BoundContract is the base wrapper object that reflects a contract on the // Ethereum network. It contains a collection of methods that are used by the // higher level contract bindings to operate. @@ -63,16 +80,18 @@ type BoundContract struct { abi abi.ABI // Reflect based ABI to access the correct Ethereum methods caller ContractCaller // Read interface to interact with the blockchain transactor ContractTransactor // Write interface to interact with the blockchain + filterer ContractFilterer // Event filtering to interact with the blockchain } // NewBoundContract creates a low level contract interface through which calls // and transactions may be made through. -func NewBoundContract(address common.Address, abi abi.ABI, caller ContractCaller, transactor ContractTransactor) *BoundContract { +func NewBoundContract(address common.Address, abi abi.ABI, caller ContractCaller, transactor ContractTransactor, filterer ContractFilterer) *BoundContract { return &BoundContract{ address: address, abi: abi, caller: caller, transactor: transactor, + filterer: filterer, } } @@ -80,7 +99,7 @@ func NewBoundContract(address common.Address, abi abi.ABI, caller ContractCaller // deployment address with a Go wrapper. func DeployContract(opts *TransactOpts, abi abi.ABI, bytecode []byte, backend ContractBackend, params ...interface{}) (common.Address, *types.Transaction, *BoundContract, error) { // Otherwise try to deploy the contract - c := NewBoundContract(common.Address{}, abi, backend, backend) + c := NewBoundContract(common.Address{}, abi, backend, backend, backend) input, err := c.abi.Pack("", params...) if err != nil { @@ -225,6 +244,104 @@ func (c *BoundContract) transact(opts *TransactOpts, contract *common.Address, i return signedTx, nil } +// FilterLogs filters contract logs for past blocks, returning the necessary +// channels to construct a strongly typed bound iterator on top of them. +func (c *BoundContract) FilterLogs(opts *FilterOpts, name string, query ...[]interface{}) (chan types.Log, event.Subscription, error) { + // Don't crash on a lazy user + if opts == nil { + opts = new(FilterOpts) + } + // Append the event selector to the query parameters and construct the topic set + query = append([][]interface{}{{c.abi.Events[name].Id()}}, query...) + + topics, err := makeTopics(query...) + if err != nil { + return nil, nil, err + } + // Start the background filtering + logs := make(chan types.Log, 128) + + config := ethereum.FilterQuery{ + Addresses: []common.Address{c.address}, + Topics: topics, + FromBlock: new(big.Int).SetUint64(opts.Start), + } + if opts.End != nil { + config.ToBlock = new(big.Int).SetUint64(*opts.End) + } + /* TODO(karalabe): Replace the rest of the method below with this when supported + sub, err := c.filterer.SubscribeFilterLogs(ensureContext(opts.Context), config, logs) + */ + buff, err := c.filterer.FilterLogs(ensureContext(opts.Context), config) + if err != nil { + return nil, nil, err + } + sub, err := event.NewSubscription(func(quit <-chan struct{}) error { + for _, log := range buff { + select { + case logs <- log: + case <-quit: + return nil + } + } + return nil + }), nil + + if err != nil { + return nil, nil, err + } + return logs, sub, nil +} + +// WatchLogs filters subscribes to contract logs for future blocks, returning a +// subscription object that can be used to tear down the watcher. +func (c *BoundContract) WatchLogs(opts *WatchOpts, name string, query ...[]interface{}) (chan types.Log, event.Subscription, error) { + // Don't crash on a lazy user + if opts == nil { + opts = new(WatchOpts) + } + // Append the event selector to the query parameters and construct the topic set + query = append([][]interface{}{{c.abi.Events[name].Id()}}, query...) + + topics, err := makeTopics(query...) + if err != nil { + return nil, nil, err + } + // Start the background filtering + logs := make(chan types.Log, 128) + + config := ethereum.FilterQuery{ + Addresses: []common.Address{c.address}, + Topics: topics, + } + if opts.Start != nil { + config.FromBlock = new(big.Int).SetUint64(*opts.Start) + } + sub, err := c.filterer.SubscribeFilterLogs(ensureContext(opts.Context), config, logs) + if err != nil { + return nil, nil, err + } + return logs, sub, nil +} + +// UnpackLog unpacks a retrieved log into the provided output structure. +func (c *BoundContract) UnpackLog(out interface{}, event string, log types.Log) error { + if len(log.Data) > 0 { + if err := c.abi.Unpack(out, event, log.Data); err != nil { + return err + } + } + var indexed abi.Arguments + for _, arg := range c.abi.Events[event].Inputs { + if arg.Indexed { + indexed = append(indexed, arg) + } + } + return parseTopics(out, indexed, log.Topics[1:]) +} + +// ensureContext is a helper method to ensure a context is not nil, even if the +// user specified it as such. func ensureContext(ctx context.Context) context.Context { if ctx == nil { return context.TODO() |