fix gas station (#268)

rpc/handler/cfx_gasstation.go

@@ -111,7 +111,7 @@ func (h *CfxGasStationHandler) trySync(cfx sdk.ClientOperator) (bool, error) {
 		return false, err
 	}
 
-	if latestEpoch == nil { // This shouldn't happen, but just in case...
+	if latestEpoch == nil {
 		return false, errors.New("latest epoch is nil")
 	}
 
@@ -127,7 +127,7 @@ func (h *CfxGasStationHandler) trySync(cfx sdk.ClientOperator) (bool, error) {
 		return false, err
 	}
 
-	if pivotBlock == nil { // This shouldn't happen, but just in case...
+	if pivotBlock == nil {
 		return false, errors.New("pivot block is nil")
 	}
 
@@ -172,6 +172,10 @@ func (h *CfxGasStationHandler) fetchBlocks(
 		return nil, nil, err
 	}
 
+	if len(blockHashes) == 0 {
+		return nil, nil, errors.New("empty block hashes")
+	}
+
 	pivotHash := blockHashes[len(blockHashes)-1]
 	if pivotBlock.Hash != pivotHash { // abandon this epoch due to pivot switched
 		return nil, nil, errors.New("pivot switched")
@@ -183,6 +187,9 @@ func (h *CfxGasStationHandler) fetchBlocks(
 		if err != nil {
 			return nil, nil, err
 		}
+		if block.GasUsed == nil {
+			return nil, nil, errors.New("unexecuted block")
+		}
 		blocks = append(blocks, &block)
 	}
 
@@ -204,6 +211,10 @@ func (h *CfxGasStationHandler) handleReorg() {
 }
 
 func (h *CfxGasStationHandler) handleBlock(block *cfxtypes.Block) {
+	if block.GasLimit == nil || block.GasLimit.ToInt().Int64() == 0 {
+		return
+	}
+
 	ratio, _ := new(big.Rat).SetFrac(block.GasUsed.ToInt(), block.GasLimit.ToInt()).Float64()
 	blockFee := &BlockPriorityFee{
 		number:       block.BlockNumber.ToInt().Uint64(),

rpc/handler/eth_gasstation.go

@@ -117,7 +117,7 @@ func (h *EthGasStationHandler) trySync(eth *node.Web3goClient) (bool, error) {
 		return false, err
 	}
 
-	if block == nil { // this shouldn't happen, but just in case...
+	if block == nil {
 		return false, errors.New("invalid nil block")
 	}
 
@@ -150,6 +150,10 @@ func (h *EthGasStationHandler) handleReorg() {
 }
 
 func (h *EthGasStationHandler) handleBlock(block *ethtypes.Block) {
+	if block.GasLimit == 0 {
+		return
+	}
+
 	ratio := float64(block.GasUsed) / float64(block.GasLimit)
 	blockFee := &BlockPriorityFee{
 		number:       block.Number.Uint64(),

rpc/handler/gasstation.go

@@ -213,7 +213,7 @@ func (w *PriorityFeeWindow) Push(blockFee *BlockPriorityFee) {
 	w.mu.Lock()
 	defer w.mu.Unlock()
 
-	if _, ok := w.hashToFee[blockFee.hash]; ok { // Block already exists
+	if _, ok := w.hashToFee[blockFee.hash]; ok { // Block already exists?
 		return
 	}
 
@@ -223,7 +223,11 @@ func (w *PriorityFeeWindow) Push(blockFee *BlockPriorityFee) {
 
 	// If the window is full, prune the oldest block.
 	for w.feeChain.Len() > w.capacity {
-		w.feeChain.Remove(w.feeChain.Front())
+		e := w.feeChain.Front()
+		blockFee := e.Value.(*BlockPriorityFee)
+
+		delete(w.hashToFee, blockFee.hash)
+		w.feeChain.Remove(e)
 	}
 }
 
@@ -245,6 +249,10 @@ func (w *PriorityFeeWindow) insertBlock(blockFee *BlockPriorityFee) {
 }
 
 func (w *PriorityFeeWindow) updateHistoricalBaseFeeRange(blockFee *BlockPriorityFee) {
+	if blockFee.baseFee == nil {
+		return
+	}
+
 	// Update the historical base fee range
 	if w.historicalBaseFeeRanges == nil { // initial setup
 		w.historicalBaseFeeRanges = []*big.Int{