Change error handling to not panic when querying block info from runtime

onflow · Jun 2, 2020 · a968f04 · a968f04
1 parent 9a527fb
commit a968f04
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Showing 3 changed files with 23 additions and 11 deletions.
diff --git a/runtime/interface.go b/runtime/interface.go
@@ -65,7 +65,7 @@ type Interface interface {
 	// GetCurrentBlockHeight returns the current block height.
 	GetCurrentBlockHeight() uint64
 	// GetBlockAtHeight returns the block at the given height.
-	GetBlockAtHeight(height uint64) (hash BlockHash, timestamp int64, exists bool)
+	GetBlockAtHeight(height uint64) (hash BlockHash, timestamp int64, exists bool, err error)
 }
 
 type Metrics interface {
@@ -142,6 +142,6 @@ func (i *EmptyRuntimeInterface) GetCurrentBlockHeight() uint64 {
 	return 0
 }
 
-func (i *EmptyRuntimeInterface) GetBlockAtHeight(_ uint64) (hash BlockHash, timestamp int64, exists bool) {
+func (i *EmptyRuntimeInterface) GetBlockAtHeight(_ uint64) (hash BlockHash, timestamp int64, exists bool, err error) {
 	return
 }
diff --git a/runtime/runtime.go b/runtime/runtime.go
@@ -1206,36 +1206,47 @@ func (r *interpreterRuntime) getCurrentBlockHeight(runtimeInterface Interface) (
 	return
 }
 
-func (r *interpreterRuntime) getBlockAtHeight(height uint64, runtimeInterface Interface) *BlockValue {
+func (r *interpreterRuntime) getBlockAtHeight(height uint64, runtimeInterface Interface) (*BlockValue, error) {
 
 	var hash BlockHash
 	var timestamp int64
 	var exists bool
+	var err error
 
 	wrapPanic(func() {
-		hash, timestamp, exists = runtimeInterface.GetBlockAtHeight(height)
+		hash, timestamp, exists, err = runtimeInterface.GetBlockAtHeight(height)
 	})
 
+	if err != nil {
+		return nil, err
+	}
+
 	if !exists {
-		return nil
+		return nil, nil
 	}
 
 	block := NewBlockValue(height, hash, time.Unix(0, timestamp))
-	return &block
+	return &block, nil
 }
 
 func (r *interpreterRuntime) newGetCurrentBlockFunction(runtimeInterface Interface) interpreter.HostFunction {
 	return func(invocation interpreter.Invocation) trampoline.Trampoline {
 		height := r.getCurrentBlockHeight(runtimeInterface)
-		block := r.getBlockAtHeight(height, runtimeInterface)
+		block, err := r.getBlockAtHeight(height, runtimeInterface)
+		if err != nil {
+			panic(err)
+		}
 		return trampoline.Done{Result: *block}
 	}
 }
 
 func (r *interpreterRuntime) newGetBlockFunction(runtimeInterface Interface) interpreter.HostFunction {
 	return func(invocation interpreter.Invocation) trampoline.Trampoline {
 		height := uint64(invocation.Arguments[0].(interpreter.UInt64Value))
-		block := r.getBlockAtHeight(height, runtimeInterface)
+		block, err := r.getBlockAtHeight(height, runtimeInterface)
+		if err != nil {
+			panic(err)
+		}
 		var result interpreter.Value
 		if block == nil {
 			result = interpreter.NilValue{}

diff --git a/runtime/runtime_test.go b/runtime/runtime_test.go
@@ -222,17 +222,18 @@ func (i *testRuntimeInterface) GetCurrentBlockHeight() uint64 {
 	return 1
 }
 
-func (i *testRuntimeInterface) GetBlockAtHeight(height uint64) (hash BlockHash, timestamp int64, exists bool) {
+func (i *testRuntimeInterface) GetBlockAtHeight(height uint64) (hash BlockHash, timestamp int64, exists bool,
+	err error) {
 	buf := new(bytes.Buffer)
-	err := binary.Write(buf, binary.BigEndian, height)
+	err = binary.Write(buf, binary.BigEndian, height)
 	if err != nil {
 		panic(err)
 	}
 
 	encoded := buf.Bytes()
 	copy(hash[stdlib.BlockIDSize-len(encoded):], encoded)
 
-	return hash, time.Unix(int64(height), 0).UnixNano(), true
+	return hash, time.Unix(int64(height), 0).UnixNano(), true, nil
 }
 
 func TestRuntimeImport(t *testing.T) {