core: vm: extract stateDB and contract out

Extract stateDB and contract out from core/vm/evm to core/vm,
such that other vm type can use the common modules.

1 files changed, 50 insertions, 0 deletions

diff --git a/core/vm/sqlvm/sqlvm.go b/core/vm/sqlvm/sqlvm.go
new file mode 100644
index 000000000..258a65d01
--- /dev/null
+++ b/core/vm/sqlvm/sqlvm.go
@@ -0,0 +1,50 @@
+package sqlvm
+
+import (
+	"math/big"
+
+	"github.com/dexon-foundation/dexon/common"
+	"github.com/dexon-foundation/dexon/core/vm"
+	"github.com/dexon-foundation/dexon/crypto"
+	"github.com/dexon-foundation/dexon/params"
+)
+
+type SQLVM struct {
+	// Context provides auxiliary blockchain related information
+	vm.Context
+	// StateDB gives access to the underlying state
+	StateDB vm.StateDB
+	// Depth is the current call stack
+	depth int
+
+	// chainConfig contains information about the current chain
+	chainConfig *params.ChainConfig
+	// chain rules contains the chain rules for the current epoch
+	chainRules params.Rules
+	// abort is used to abort the SQLVM calling operations
+	// NOTE: must be set atomically
+	abort int32
+	// callGasTemp holds the gas available for the current call. This is needed because the
+	// available gas is calculated in gasCall* according to the 63/64 rule and later
+	// applied in opCall*.
+	callGasTemp uint64
+}
+
+func (sqlvm *SQLVM) Create(caller vm.ContractRef, code []byte, gas uint64,
+	value *big.Int) (ret []byte, contractAddr common.Address,
+	leftOverGas uint64, err error) {
+
+	contractAddr = crypto.CreateAddress(caller.Address(), sqlvm.StateDB.GetNonce(caller.Address()))
+	return sqlvm.create(caller, &vm.CodeAndHash{Code: code}, gas, value, contractAddr)
+}
+
+// create creates a new contract using code as deployment code.
+func (sqlvm *SQLVM) create(caller vm.ContractRef, codeAndHash *vm.CodeAndHash, gas uint64,
+	value *big.Int, address common.Address) ([]byte, common.Address, uint64, error) {
+	// Depth check execution. Fail if we're trying to execute above the
+	if sqlvm.depth > int(params.CallCreateDepth) {
+		return nil, common.Address{}, gas, vm.ErrDepth
+	}
+	// TODO (JM) implement create database contract function
+	return nil, common.Address{}, gas, nil
+}