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-rw-r--r--accounts/abi/abi.go146
1 files changed, 69 insertions, 77 deletions
diff --git a/accounts/abi/abi.go b/accounts/abi/abi.go
index 3f05bfe2d..635dc43fe 100644
--- a/accounts/abi/abi.go
+++ b/accounts/abi/abi.go
@@ -20,75 +20,17 @@ import (
"encoding/json"
"fmt"
"io"
- "strings"
+ "math"
- "github.com/ethereum/go-ethereum/crypto"
+ "github.com/ethereum/go-ethereum/common"
+ "github.com/ethereum/go-ethereum/logger"
+ "github.com/ethereum/go-ethereum/logger/glog"
)
-// Callable method given a `Name` and whether the method is a constant.
-// If the method is `Const` no transaction needs to be created for this
-// particular Method call. It can easily be simulated using a local VM.
-// For example a `Balance()` method only needs to retrieve something
-// from the storage and therefor requires no Tx to be send to the
-// network. A method such as `Transact` does require a Tx and thus will
-// be flagged `true`.
-// Input specifies the required input parameters for this gives method.
-type Method struct {
- Name string
- Const bool
- Inputs []Argument
- Return Type // not yet implemented
-}
-
-// Returns the methods string signature according to the ABI spec.
-//
-// Example
-//
-// function foo(uint32 a, int b) = "foo(uint32,int256)"
-//
-// Please note that "int" is substitute for its canonical representation "int256"
-func (m Method) String() (out string) {
- out += m.Name
- types := make([]string, len(m.Inputs))
- i := 0
- for _, input := range m.Inputs {
- types[i] = input.Type.String()
- i++
- }
- out += "(" + strings.Join(types, ",") + ")"
-
- return
-}
-
-func (m Method) Id() []byte {
- return crypto.Sha3([]byte(m.String()))[:4]
-}
-
-// Argument holds the name of the argument and the corresponding type.
-// Types are used when packing and testing arguments.
-type Argument struct {
- Name string
- Type Type
-}
-
-func (a *Argument) UnmarshalJSON(data []byte) error {
- var extarg struct {
- Name string
- Type string
- }
- err := json.Unmarshal(data, &extarg)
- if err != nil {
- return fmt.Errorf("argument json err: %v", err)
- }
-
- a.Type, err = NewType(extarg.Type)
- if err != nil {
- return err
- }
- a.Name = extarg.Name
-
- return nil
-}
+// Executer is an executer method for performing state executions. It takes one
+// argument which is the input data and expects output data to be returned as
+// multiple 32 byte word length concatenated slice
+type Executer func(datain []byte) []byte
// The ABI holds information about a contract's context and available
// invokable methods. It will allow you to type check function calls and
@@ -97,6 +39,18 @@ type ABI struct {
Methods map[string]Method
}
+// JSON returns a parsed ABI interface and error if it failed.
+func JSON(reader io.Reader) (ABI, error) {
+ dec := json.NewDecoder(reader)
+
+ var abi ABI
+ if err := dec.Decode(&abi); err != nil {
+ return ABI{}, err
+ }
+
+ return abi, nil
+}
+
// tests, tests whether the given input would result in a successful
// call. Checks argument list count and matches input to `input`.
func (abi ABI) pack(name string, args ...interface{}) ([]byte, error) {
@@ -145,6 +99,55 @@ func (abi ABI) Pack(name string, args ...interface{}) ([]byte, error) {
return packed, nil
}
+// toGoType parses the input and casts it to the proper type defined by the ABI
+// argument in t.
+func toGoType(t Argument, input []byte) interface{} {
+ switch t.Type.T {
+ case IntTy:
+ return common.BytesToBig(input)
+ case UintTy:
+ return common.BytesToBig(input)
+ case BoolTy:
+ return common.BytesToBig(input).Uint64() > 0
+ case AddressTy:
+ return common.BytesToAddress(input)
+ case HashTy:
+ return common.BytesToHash(input)
+ }
+ return nil
+}
+
+// Call executes a call and attemps to parse the return values and returns it as
+// an interface. It uses the executer method to perform the actual call since
+// the abi knows nothing of the lower level calling mechanism.
+//
+// Call supports all abi types and includes multiple return values. When only
+// one item is returned a single interface{} will be returned, if a contract
+// method returns multiple values an []interface{} slice is returned.
+func (abi ABI) Call(executer Executer, name string, args ...interface{}) interface{} {
+ callData, err := abi.Pack(name, args...)
+ if err != nil {
+ glog.V(logger.Debug).Infoln("pack error:", err)
+ return nil
+ }
+
+ output := executer(callData)
+
+ method := abi.Methods[name]
+ ret := make([]interface{}, int(math.Max(float64(len(method.Outputs)), float64(len(output)/32))))
+ for i := 0; i < len(ret); i += 32 {
+ index := i / 32
+ ret[index] = toGoType(method.Outputs[index], output[i:i+32])
+ }
+
+ // return single interface
+ if len(ret) == 1 {
+ return ret[0]
+ }
+
+ return ret
+}
+
func (abi *ABI) UnmarshalJSON(data []byte) error {
var methods []Method
if err := json.Unmarshal(data, &methods); err != nil {
@@ -158,14 +161,3 @@ func (abi *ABI) UnmarshalJSON(data []byte) error {
return nil
}
-
-func JSON(reader io.Reader) (ABI, error) {
- dec := json.NewDecoder(reader)
-
- var abi ABI
- if err := dec.Decode(&abi); err != nil {
- return ABI{}, err
- }
-
- return abi, nil
-}