Handle errors returned from Wait() if context is cancelled/exceeded

ethereum/blockwatch/client.go

@@ -30,7 +30,7 @@ type RpcClient struct {
 	rpcClient      *rpc.Client
 	client         *ethclient.Client
 	requestTimeout time.Duration
-	rateLimiter *ratelimit.RateLimiter
+	rateLimiter    *ratelimit.RateLimiter
 }
 
 // NewRpcClient returns a new Client for fetching Ethereum blocks using the given
@@ -45,10 +45,10 @@ func NewRpcClient(rpcURL string, requestTimeout time.Duration, rateLimiter *rate
 		return nil, err
 	}
 	return &RpcClient{
-		rpcClient: rpcClient,
-		client: ethClient,
+		rpcClient:      rpcClient,
+		client:         ethClient,
 		requestTimeout: requestTimeout,
-		rateLimiter: rateLimiter,
+		rateLimiter:    rateLimiter,
 	}, nil
 }
 
@@ -61,7 +61,11 @@ type GetBlockByNumberResponse struct {
 // HeaderByNumber fetches a block header by its number. If no `number` is supplied, it will return the latest
 // block header. If no block exists with this number it will return a `ethereum.NotFound` error.
 func (rc *RpcClient) HeaderByNumber(number *big.Int) (*miniheader.MiniHeader, error) {
-	rc.rateLimiter.Wait(context.Background())
+	err := rc.rateLimiter.Wait(context.Background())
+	if err != nil {
+		// Context cancelled or deadline exceeded
+		return nil, err
+	}
 
 	ctx, cancel := context.WithTimeout(context.Background(), rc.requestTimeout)
 	defer cancel()
@@ -80,7 +84,7 @@ func (rc *RpcClient) HeaderByNumber(number *big.Int) (*miniheader.MiniHeader, er
 	// RPC response rather than re-compute it from the block header.
 	// Source: https://github.com/ethereum/go-ethereum/pull/18166
 	var header GetBlockByNumberResponse
-	err := rc.rpcClient.CallContext(ctx, &header, "eth_getBlockByNumber", blockParam, shouldIncludeTransactions)
+	err = rc.rpcClient.CallContext(ctx, &header, "eth_getBlockByNumber", blockParam, shouldIncludeTransactions)
 	if err != nil {
 		return nil, err
 	}
@@ -104,7 +108,11 @@ func (rc *RpcClient) HeaderByNumber(number *big.Int) (*miniheader.MiniHeader, er
 // HeaderByHash fetches a block header by its block hash. If no block exists with this number it will return
 // a `ethereum.NotFound` error.
 func (rc *RpcClient) HeaderByHash(hash common.Hash) (*miniheader.MiniHeader, error) {
-	rc.rateLimiter.Wait(context.Background())
+	err := rc.rateLimiter.Wait(context.Background())
+	if err != nil {
+		// Context cancelled or deadline exceeded
+		return nil, err
+	}
 
 	ctx, cancel := context.WithTimeout(context.Background(), rc.requestTimeout)
 	defer cancel()
@@ -122,7 +130,11 @@ func (rc *RpcClient) HeaderByHash(hash common.Hash) (*miniheader.MiniHeader, err
 
 // FilterLogs returns the logs that satisfy the supplied filter query.
 func (rc *RpcClient) FilterLogs(q ethereum.FilterQuery) ([]types.Log, error) {
-	rc.rateLimiter.Wait(context.Background())
+	err := rc.rateLimiter.Wait(context.Background())
+	if err != nil {
+		// Context cancelled or deadline exceeded
+		return nil, err
+	}
 
 	ctx, cancel := context.WithTimeout(context.Background(), rc.requestTimeout)
 	defer cancel()

ethereum/eth_watcher.go

@@ -190,7 +190,11 @@ func (e *ETHWatcher) getBalances(addresses []common.Address) (map[common.Address
 		go func(chunk []common.Address) {
 			defer wg.Done()
 
-			e.rateLimiter.Wait(context.Background())
+			err := e.rateLimiter.Wait(context.Background())
+			if err != nil {
+				// Context cancelled or deadline exceeded
+				return // Give up
+			}
 
 			// Pass a context with a 20 second timeout to `GetEthBalances` in order to avoid
 			// any one request from taking longer then 20 seconds and as a consequence, hold

zeroex/ordervalidator/order_validator.go

@@ -337,7 +337,11 @@ func (o *OrderValidator) BatchValidate(rawSignedOrders []*zeroex.SignedOrder, ar
 			}
 
 			for {
-				o.rateLimiter.Wait(context.Background())
+				err := o.rateLimiter.Wait(context.Background())
+				if err != nil {
+					// Context cancelled or deadline exceeded
+					return // Give up
+				}
 
 				// Pass a context with a 15 second timeout to `GetOrderRelevantStates` in order to avoid
 				// any one request from taking longer then 15 seconds
@@ -473,7 +477,11 @@ func (o *OrderValidator) batchValidateSoftCancelled(signedOrders []*zeroex.Signe
 		}
 		endpoint, ok := o.cachedFeeRecipientToEndpoint[signedOrder.FeeRecipientAddress]
 		if !ok {
-			o.rateLimiter.Wait(context.Background())
+			err = o.rateLimiter.Wait(context.Background())
+			if err != nil {
+				// Context cancelled or deadline exceeded
+				continue // Give up
+			}
 
 			ctx, cancel := context.WithTimeout(context.Background(), getCoordinatorEndpointTimeout)
 			defer cancel()