switch to go vendoring

vendor/github.com/shamaton/msgpack/v2/internal/encoding/int.go

@@ -0,0 +1,48 @@
+package encoding
+
+import (
+	"math"
+
+	"github.com/shamaton/msgpack/v2/def"
+)
+
+func (e *encoder) isNegativeFixInt64(v int64) bool {
+	return def.NegativeFixintMin <= v && v <= def.NegativeFixintMax
+}
+
+func (e *encoder) calcInt(v int64) int {
+	if v >= 0 {
+		return e.calcUint(uint64(v))
+	} else if e.isNegativeFixInt64(v) {
+		// format code only
+		return 0
+	} else if v >= math.MinInt8 {
+		return def.Byte1
+	} else if v >= math.MinInt16 {
+		return def.Byte2
+	} else if v >= math.MinInt32 {
+		return def.Byte4
+	}
+	return def.Byte8
+}
+
+func (e *encoder) writeInt(v int64, offset int) int {
+	if v >= 0 {
+		offset = e.writeUint(uint64(v), offset)
+	} else if e.isNegativeFixInt64(v) {
+		offset = e.setByte1Int64(v, offset)
+	} else if v >= math.MinInt8 {
+		offset = e.setByte1Int(def.Int8, offset)
+		offset = e.setByte1Int64(v, offset)
+	} else if v >= math.MinInt16 {
+		offset = e.setByte1Int(def.Int16, offset)
+		offset = e.setByte2Int64(v, offset)
+	} else if v >= math.MinInt32 {
+		offset = e.setByte1Int(def.Int32, offset)
+		offset = e.setByte4Int64(v, offset)
+	} else {
+		offset = e.setByte1Int(def.Int64, offset)
+		offset = e.setByte8Int64(v, offset)
+	}
+	return offset
+}