1 files changed, 22 insertions, 2 deletions
diff --git a/core/types/bloom9.go b/core/types/bloom9.go
index ecf2bffc2..d3945a734 100644
--- a/core/types/bloom9.go
+++ b/core/types/bloom9.go
@@ -31,28 +31,34 @@ type bytesBacked interface {
 
 const bloomLength = 256
 
+// Bloom represents a 256 bit bloom filter.
 type Bloom [bloomLength]byte
 
+// BytesToBloom converts a byte slice to a bloom filter.
+// It panics if b is not of suitable size.
 func BytesToBloom(b []byte) Bloom {
 	var bloom Bloom
 	bloom.SetBytes(b)
 	return bloom
 }
 
+// SetBytes sets the content of b to the given bytes.
+// It panics if d is not of suitable size.
 func (b *Bloom) SetBytes(d []byte) {
 	if len(b) < len(d) {
 		panic(fmt.Sprintf("bloom bytes too big %d %d", len(b), len(d)))
 	}
-
 	copy(b[bloomLength-len(d):], d)
 }
 
+// Add adds d to the filter. Future calls of Test(d) will return true.
 func (b *Bloom) Add(d *big.Int) {
 	bin := new(big.Int).SetBytes(b[:])
 	bin.Or(bin, bloom9(d.Bytes()))
 	b.SetBytes(bin.Bytes())
 }
 
+// Big converts b to a big integer.
 func (b Bloom) Big() *big.Int {
 	return common.Bytes2Big(b[:])
 }
@@ -69,8 +75,22 @@ func (b Bloom) TestBytes(test []byte) bool {
 	return b.Test(common.BytesToBig(test))
 }
 
+// MarshalJSON encodes b as a hex string with 0x prefix.
 func (b Bloom) MarshalJSON() ([]byte, error) {
-	return []byte(fmt.Sprintf(`"%#x"`, b.Bytes())), nil
+	return []byte(fmt.Sprintf(`"%#x"`, b[:])), nil
+}
+
+// UnmarshalJSON b as a hex string with 0x prefix.
+func (b *Bloom) UnmarshalJSON(input []byte) error {
+	var dec hexBytes
+	if err := dec.UnmarshalJSON(input); err != nil {
+		return err
+	}
+	if len(dec) != bloomLength {
+		return fmt.Errorf("invalid bloom size, want %d bytes", bloomLength)
+	}
+	copy((*b)[:], dec)
+	return nil
 }
 
 func CreateBloom(receipts Receipts) Bloom {