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-rw-r--r--src/math/big/intmarsh.go83
1 files changed, 83 insertions, 0 deletions
diff --git a/src/math/big/intmarsh.go b/src/math/big/intmarsh.go
new file mode 100644
index 0000000..ce429ff
--- /dev/null
+++ b/src/math/big/intmarsh.go
@@ -0,0 +1,83 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements encoding/decoding of Ints.
+
+package big
+
+import (
+ "bytes"
+ "fmt"
+)
+
+// Gob codec version. Permits backward-compatible changes to the encoding.
+const intGobVersion byte = 1
+
+// GobEncode implements the gob.GobEncoder interface.
+func (x *Int) GobEncode() ([]byte, error) {
+ if x == nil {
+ return nil, nil
+ }
+ buf := make([]byte, 1+len(x.abs)*_S) // extra byte for version and sign bit
+ i := x.abs.bytes(buf) - 1 // i >= 0
+ b := intGobVersion << 1 // make space for sign bit
+ if x.neg {
+ b |= 1
+ }
+ buf[i] = b
+ return buf[i:], nil
+}
+
+// GobDecode implements the gob.GobDecoder interface.
+func (z *Int) GobDecode(buf []byte) error {
+ if len(buf) == 0 {
+ // Other side sent a nil or default value.
+ *z = Int{}
+ return nil
+ }
+ b := buf[0]
+ if b>>1 != intGobVersion {
+ return fmt.Errorf("Int.GobDecode: encoding version %d not supported", b>>1)
+ }
+ z.neg = b&1 != 0
+ z.abs = z.abs.setBytes(buf[1:])
+ return nil
+}
+
+// MarshalText implements the encoding.TextMarshaler interface.
+func (x *Int) MarshalText() (text []byte, err error) {
+ if x == nil {
+ return []byte("<nil>"), nil
+ }
+ return x.abs.itoa(x.neg, 10), nil
+}
+
+// UnmarshalText implements the encoding.TextUnmarshaler interface.
+func (z *Int) UnmarshalText(text []byte) error {
+ if _, ok := z.setFromScanner(bytes.NewReader(text), 0); !ok {
+ return fmt.Errorf("math/big: cannot unmarshal %q into a *big.Int", text)
+ }
+ return nil
+}
+
+// The JSON marshalers are only here for API backward compatibility
+// (programs that explicitly look for these two methods). JSON works
+// fine with the TextMarshaler only.
+
+// MarshalJSON implements the json.Marshaler interface.
+func (x *Int) MarshalJSON() ([]byte, error) {
+ if x == nil {
+ return []byte("null"), nil
+ }
+ return x.abs.itoa(x.neg, 10), nil
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface.
+func (z *Int) UnmarshalJSON(text []byte) error {
+ // Ignore null, like in the main JSON package.
+ if string(text) == "null" {
+ return nil
+ }
+ return z.UnmarshalText(text)
+}