1 files changed, 68 insertions, 21 deletions

diff --git a/core/vm/log.go b/core/vm/log.go
index e4cc6021b..b292f5f43 100644
--- a/core/vm/log.go
+++ b/core/vm/log.go
@@ -18,6 +18,7 @@ package vm
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 
@@ -25,18 +26,33 @@ import (
 	"github.com/ethereum/go-ethereum/rlp"
 )
 
+var errMissingLogFields = errors.New("missing required JSON log fields")
+
+// Log represents a contract log event. These events are generated by the LOG
+// opcode and stored/indexed by the node.
 type Log struct {
-	// Consensus fields
-	Address common.Address
-	Topics  []common.Hash
-	Data    []byte
+	// Consensus fields.
+	Address common.Address // address of the contract that generated the event
+	Topics  []common.Hash  // list of topics provided by the contract.
+	Data    []byte         // supplied by the contract, usually ABI-encoded
+
+	// Derived fields (don't reorder!).
+	BlockNumber uint64      // block in which the transaction was included
+	TxHash      common.Hash // hash of the transaction
+	TxIndex     uint        // index of the transaction in the block
+	BlockHash   common.Hash // hash of the block in which the transaction was included
+	Index       uint        // index of the log in the receipt
+}
 
-	// Derived fields (don't reorder!)
-	BlockNumber uint64
-	TxHash      common.Hash
-	TxIndex     uint
-	BlockHash   common.Hash
-	Index       uint
+type jsonLog struct {
+	Address     *common.Address `json:"address"`
+	Topics      *[]common.Hash  `json:"topics"`
+	Data        string          `json:"data"`
+	BlockNumber string          `json:"blockNumber"`
+	TxIndex     string          `json:"transactionIndex"`
+	TxHash      *common.Hash    `json:"transactionHash"`
+	BlockHash   *common.Hash    `json:"blockHash"`
+	Index       string          `json:"logIndex"`
 }
 
 func NewLog(address common.Address, topics []common.Hash, data []byte, number uint64) *Log {
@@ -64,19 +80,50 @@ func (l *Log) String() string {
 	return fmt.Sprintf(`log: %x %x %x %x %d %x %d`, l.Address, l.Topics, l.Data, l.TxHash, l.TxIndex, l.BlockHash, l.Index)
 }
 
+// MarshalJSON implements json.Marshaler.
 func (r *Log) MarshalJSON() ([]byte, error) {
-	fields := map[string]interface{}{
-		"address":          r.Address,
-		"data":             fmt.Sprintf("%#x", r.Data),
-		"blockNumber":      fmt.Sprintf("%#x", r.BlockNumber),
-		"logIndex":         fmt.Sprintf("%#x", r.Index),
-		"blockHash":        r.BlockHash,
-		"transactionHash":  r.TxHash,
-		"transactionIndex": fmt.Sprintf("%#x", r.TxIndex),
-		"topics":           r.Topics,
-	}
+	return json.Marshal(&jsonLog{
+		Address:     &r.Address,
+		Topics:      &r.Topics,
+		Data:        fmt.Sprintf("0x%x", r.Data),
+		BlockNumber: fmt.Sprintf("0x%x", r.BlockNumber),
+		TxIndex:     fmt.Sprintf("0x%x", r.TxIndex),
+		TxHash:      &r.TxHash,
+		BlockHash:   &r.BlockHash,
+		Index:       fmt.Sprintf("0x%x", r.Index),
+	})
+}
 
-	return json.Marshal(fields)
+// UnmarshalJSON implements json.Umarshaler.
+func (r *Log) UnmarshalJSON(input []byte) error {
+	var dec jsonLog
+	if err := json.Unmarshal(input, &dec); err != nil {
+		return err
+	}
+	if dec.Address == nil || dec.Topics == nil || dec.Data == "" || dec.BlockNumber == "" ||
+		dec.TxIndex == "" || dec.TxHash == nil || dec.BlockHash == nil || dec.Index == "" {
+		return errMissingLogFields
+	}
+	declog := Log{
+		Address:   *dec.Address,
+		Topics:    *dec.Topics,
+		TxHash:    *dec.TxHash,
+		BlockHash: *dec.BlockHash,
+	}
+	if _, err := fmt.Sscanf(dec.Data, "0x%x", &declog.Data); err != nil {
+		return fmt.Errorf("invalid hex log data")
+	}
+	if _, err := fmt.Sscanf(dec.BlockNumber, "0x%x", &declog.BlockNumber); err != nil {
+		return fmt.Errorf("invalid hex log block number")
+	}
+	if _, err := fmt.Sscanf(dec.TxIndex, "0x%x", &declog.TxIndex); err != nil {
+		return fmt.Errorf("invalid hex log tx index")
+	}
+	if _, err := fmt.Sscanf(dec.Index, "0x%x", &declog.Index); err != nil {
+		return fmt.Errorf("invalid hex log index")
+	}
+	*r = declog
+	return nil
 }
 
 type Logs []*Log