Subscription service to detect address accesses

0xjagadbumi · Sep 16, 2024 · af9fe8f · af9fe8f
1 parent 1a3bd86
commit af9fe8f
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Showing 3 changed files with 63 additions and 0 deletions.
diff --git a/quai/api_backend.go b/quai/api_backend.go
@@ -240,6 +240,11 @@ func (b *QuaiAPIBackend) GetBloom(hash common.Hash) (*types.Bloom, error) {
 	return b.quai.core.Slice().HeaderChain().GetBloom(hash)
 }
 
+// GetBlock returns the Block for the given block hash
+func (b *QuaiAPIBackend) GetBlock(hash common.Hash, number uint64) (*types.WorkObject, error) {
+	return b.quai.core.Slice().HeaderChain().GetBlock(hash, number), nil
+}
+
 func (b *QuaiAPIBackend) GetLogs(ctx context.Context, hash common.Hash) ([][]*types.Log, error) {
 	nodeCtx := b.quai.core.NodeCtx()
 	if nodeCtx != common.ZONE_CTX {

diff --git a/quai/filters/api.go b/quai/filters/api.go
@@ -289,6 +289,63 @@ func (api *PublicFilterAPI) NewHeads(ctx context.Context) (*rpc.Subscription, er
 	return rpcSub, nil
 }
 
+// Accesses send a notification each time the specified address is accessed
+func (api *PublicFilterAPI) Accesses(ctx context.Context, addr common.Address) (*rpc.Subscription, error) {
+	notifier, supported := rpc.NotifierFromContext(ctx)
+	if !supported {
+		return &rpc.Subscription{}, rpc.ErrNotificationsUnsupported
+	}
+
+	rpcSub := notifier.CreateSubscription()
+
+	go func() {
+		defer func() {
+			if r := recover(); r != nil {
+				api.backend.Logger().WithFields(log.Fields{
+					"error":      r,
+					"stacktrace": string(debug.Stack()),
+				}).Fatal("Go-Quai Panicked")
+			}
+		}()
+		headers := make(chan *types.WorkObject)
+		headersSub := api.events.SubscribeNewHeads(headers)
+
+		for {
+			select {
+			case h := <-headers:
+				// Marshal the header data
+				hash := h.Hash()
+				nodeLocation := api.backend.NodeLocation()
+				nodeCtx := nodeLocation.Context()
+				if block, err := api.backend.GetBlock(h.Hash(), h.NumberU64(nodeCtx)); err != nil {
+					for _, tx := range block.Transactions() {
+						// Check for external accesses
+						if tx.To() == &addr || tx.From(nodeLocation) == &addr {
+							notifier.Notify(rpcSub.ID, hash)
+							break
+						}
+						// Check for EVM accesses
+						for _, access := range tx.AccessList() {
+							if access.Address == addr {
+								notifier.Notify(rpcSub.ID, hash)
+								break
+							}
+						}
+					}
+				}
+			case <-rpcSub.Err():
+				headersSub.Unsubscribe()
+				return
+			case <-notifier.Closed():
+				headersSub.Unsubscribe()
+				return
+			}
+		}
+	}()
+
+	return rpcSub, nil
+}
+
 // Logs creates a subscription that fires for all new log that match the given filter criteria.
 func (api *PublicFilterAPI) Logs(ctx context.Context, crit FilterCriteria) (*rpc.Subscription, error) {
 	notifier, supported := rpc.NotifierFromContext(ctx)

diff --git a/quai/filters/filter.go b/quai/filters/filter.go
@@ -38,6 +38,7 @@ type Backend interface {
 	GetReceipts(ctx context.Context, blockHash common.Hash) (types.Receipts, error)
 	GetLogs(ctx context.Context, blockHash common.Hash) ([][]*types.Log, error)
 	GetBloom(blockHash common.Hash) (*types.Bloom, error)
+	GetBlock(hash common.Hash, number uint64) (*types.WorkObject, error)
 	SubscribeChainEvent(ch chan<- core.ChainEvent) event.Subscription
 	SubscribeRemovedLogsEvent(ch chan<- core.RemovedLogsEvent) event.Subscription
 	SubscribeLogsEvent(ch chan<- []*types.Log) event.Subscription