Implemented contract ABI

1 files changed, 106 insertions, 0 deletions

diff --git a/accounts/abi/numbers.go b/accounts/abi/numbers.go
new file mode 100644
index 000000000..378f6541e
--- /dev/null
+++ b/accounts/abi/numbers.go
@@ -0,0 +1,106 @@
+package abi
+
+import (
+	"math/big"
+	"reflect"
+
+	"github.com/ethereum/go-ethereum/ethutil"
+)
+
+var big_t = reflect.TypeOf(&big.Int{})
+var ubig_t = reflect.TypeOf(&big.Int{})
+var byte_t = reflect.TypeOf(byte(0))
+var byte_ts = reflect.TypeOf([]byte(nil))
+var uint_t = reflect.TypeOf(uint(0))
+var uint8_t = reflect.TypeOf(uint8(0))
+var uint16_t = reflect.TypeOf(uint16(0))
+var uint32_t = reflect.TypeOf(uint32(0))
+var uint64_t = reflect.TypeOf(uint64(0))
+var int_t = reflect.TypeOf(int(0))
+var int8_t = reflect.TypeOf(int8(0))
+var int16_t = reflect.TypeOf(int16(0))
+var int32_t = reflect.TypeOf(int32(0))
+var int64_t = reflect.TypeOf(int64(0))
+
+var uint_ts = reflect.TypeOf([]uint(nil))
+var uint8_ts = reflect.TypeOf([]uint8(nil))
+var uint16_ts = reflect.TypeOf([]uint16(nil))
+var uint32_ts = reflect.TypeOf([]uint32(nil))
+var uint64_ts = reflect.TypeOf([]uint64(nil))
+var ubig_ts = reflect.TypeOf([]*big.Int(nil))
+
+var int_ts = reflect.TypeOf([]int(nil))
+var int8_ts = reflect.TypeOf([]int8(nil))
+var int16_ts = reflect.TypeOf([]int16(nil))
+var int32_ts = reflect.TypeOf([]int32(nil))
+var int64_ts = reflect.TypeOf([]int64(nil))
+var big_ts = reflect.TypeOf([]*big.Int(nil))
+
+// U256 will ensure unsigned 256bit on big nums
+func U256(n *big.Int) []byte {
+	return ethutil.LeftPadBytes(ethutil.U256(n).Bytes(), 32)
+}
+
+func S256(n *big.Int) []byte {
+	sint := ethutil.S256(n)
+	ret := ethutil.LeftPadBytes(sint.Bytes(), 32)
+	if sint.Cmp(ethutil.Big0) < 0 {
+		for i, b := range ret {
+			if b == 0 {
+				ret[i] = 1
+				continue
+			}
+			break
+		}
+	}
+
+	return ret
+}
+
+// S256 will ensure signed 256bit on big nums
+func U2U256(n uint64) []byte {
+	return U256(big.NewInt(int64(n)))
+}
+
+func S2S256(n int64) []byte {
+	return S256(big.NewInt(n))
+}
+
+// packNum packs the given number (using the reflect value) and will cast it to appropriate number representation
+func packNum(value reflect.Value, to byte) []byte {
+	switch kind := value.Kind(); kind {
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		if to == UintTy {
+			return U2U256(value.Uint())
+		} else {
+			return S2S256(int64(value.Uint()))
+		}
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		if to == UintTy {
+			return U2U256(uint64(value.Int()))
+		} else {
+			return S2S256(value.Int())
+		}
+	case reflect.Ptr:
+		// This only takes care of packing and casting. No type checking is done here. It should be done prior to using this function.
+		if to == UintTy {
+			return U256(value.Interface().(*big.Int))
+		} else {
+			return S256(value.Interface().(*big.Int))
+		}
+
+	}
+
+	return nil
+}
+
+// checks whether the given reflect value is signed. This also works for slices with a number type
+func isSigned(v reflect.Value) bool {
+	switch v.Type() {
+	case ubig_ts, big_ts, big_t, ubig_t:
+		return true
+	case int_ts, int8_ts, int16_ts, int32_ts, int64_ts, int_t, int8_t, int16_t, int32_t, int64_t:
+		return true
+	}
+	return false
+}