Initial commit

1 files changed, 182 insertions, 0 deletions

diff --git a/vm.go b/vm.go
new file mode 100644
index 000000000..353f4f39e
--- /dev/null
+++ b/vm.go
@@ -0,0 +1,182 @@
+package main
+
+import (
+  "math"
+  "math/big"
+  "fmt"
+  "strconv"
+  _ "encoding/hex"
+)
+
+// Op codes
+const (
+  oSTOP       int = 0x00
+  oADD        int = 0x10
+  oSUB        int = 0x11
+  oMUL        int = 0x12
+  oDIV        int = 0x13
+  oSDIV       int = 0x14
+  oMOD        int = 0x15
+  oSMOD       int = 0x16
+  oEXP        int = 0x17
+  oNEG        int = 0x18
+  oLT         int = 0x20
+  oLE         int = 0x21
+  oGT         int = 0x22
+  oGE         int = 0x23
+  oEQ         int = 0x24
+  oNOT        int = 0x25
+  oSHA256     int = 0x30
+  oRIPEMD160  int = 0x31
+  oECMUL      int = 0x32
+  oECADD      int = 0x33
+  oSIGN       int = 0x34
+  oRECOVER    int = 0x35
+  oCOPY       int = 0x40
+  oST         int = 0x41
+  oLD         int = 0x42
+  oSET        int = 0x43
+  oJMP        int = 0x50
+  oJMPI       int = 0x51
+  oIND        int = 0x52
+  oEXTRO      int = 0x60
+  oBALANCE    int = 0x61
+  oMKTX       int = 0x70
+  oDATA       int = 0x80
+  oDATAN      int = 0x81
+  oMYADDRESS  int = 0x90
+  oSUICIDE    int = 0xff
+)
+
+type OpType int
+const (
+  tNorm = iota
+  tData
+  tExtro
+  tCrypto
+)
+type TxCallback func(opType OpType) bool
+
+type Vm struct {
+  // Memory stack
+  stack map[string]string
+  // Index ptr
+  iptr int
+  memory map[string]map[string]string
+}
+
+func NewVm() *Vm {
+  fmt.Println("init Ethereum VM")
+
+  stackSize := uint(256)
+  fmt.Println("stack size =", stackSize)
+
+  return &Vm{make(map[string]string), 0, make(map[string]map[string]string)}
+}
+
+func (vm *Vm) RunTransaction(tx *Transaction, cb TxCallback) {
+  fmt.Printf(`
+# processing Tx (%v)
+# fee = %f, ops = %d, sender = %s, value = %d
+`, tx.addr, float32(tx.fee) / 1e8, len(tx.data), tx.sender, tx.value)
+
+  vm.stack = make(map[string]string)
+  vm.stack["0"] = tx.sender
+  vm.stack["1"] = "100"  //int(tx.value)
+  vm.stack["1"] = "1000" //int(tx.fee)
+
+  //vm.memory[tx.addr] = make([]int, 256)
+  vm.memory[tx.addr] = make(map[string]string)
+
+  // Define instruction 'accessors' for the instruction, which makes it more readable
+  // also called register values, shorthanded as Rx/y/z. Memory address are shorthanded as Mx/y/z.
+  // Instructions are shorthanded as Ix/y/z
+  x := 0; y := 1; z := 2; //a := 3; b := 4; c := 5
+out:
+  for vm.iptr < len(tx.data) {
+    // The base big int for all calculations. Use this for any results.
+    base := new(big.Int)
+    // XXX Should Instr return big int slice instead of string slice?
+    op, args, _ := Instr(tx.data[vm.iptr])
+
+    fmt.Printf("%-3d %d %v\n", vm.iptr, op, args)
+
+    opType     := OpType(tNorm)
+    // Determine the op type (used for calculating fees by the block manager)
+    switch op {
+    case oEXTRO, oBALANCE:
+      opType = tExtro
+    case oSHA256, oRIPEMD160, oECMUL, oECADD: // TODO add rest
+      opType = tCrypto
+    }
+
+    // If the callback yielded a negative result abort execution
+    if !cb(opType) { break out }
+
+    nptr := vm.iptr
+    switch op {
+    case oSTOP:
+      fmt.Println("exiting (oSTOP), idx =", nptr)
+
+      break out
+    case oADD:
+      // (Rx + Ry) % 2 ** 256
+      base.Add(Big(vm.stack[args[ x ]]), Big(vm.stack[args[ y ]]))
+      base.Mod(base, big.NewInt(int64(math.Pow(2, 256))))
+      // Set the result to Rz
+      vm.stack[args[ z ]] = base.String()
+    case oSUB:
+      // (Rx - Ry) % 2 ** 256
+      base.Sub(Big(vm.stack[args[ x ]]), Big(vm.stack[args[ y ]]))
+      base.Mod(base, big.NewInt(int64(math.Pow(2, 256))))
+      // Set the result to Rz
+      vm.stack[args[ z ]] = base.String()
+    case oMUL:
+      // (Rx * Ry) % 2 ** 256
+      base.Mul(Big(vm.stack[args[ x ]]), Big(vm.stack[args[ y ]]))
+      base.Mod(base, big.NewInt(int64(math.Pow(2, 256))))
+      // Set the result to Rz
+      vm.stack[args[ z ]] = base.String()
+    case oDIV:
+      // floor(Rx / Ry)
+      base.Div(Big(vm.stack[args[ x ]]), Big(vm.stack[args[ y ]]))
+      // Set the result to Rz
+      vm.stack[args[ z ]] = base.String()
+    case oSET:
+      // Set the (numeric) value at Iy to Rx
+      vm.stack[args[ x ]] = args[ y ]
+    case oLD:
+      // Load the value at Mx to Ry
+      vm.stack[args[ y ]] = vm.memory[tx.addr][vm.stack[args[ x ]]]
+    case oLT:
+      cmp := Big(vm.stack[args[ x ]]).Cmp( Big(vm.stack[args[ y ]]) )
+      // Set the result as "boolean" value to Rz
+      if  cmp < 0 { // a < b
+        vm.stack[args[ z ]] = "1"
+      } else {
+        vm.stack[args[ z ]] = "0"
+      }
+    case oJMP:
+      // Set the instruction pointer to the value at Rx
+      ptr, _ := strconv.Atoi( vm.stack[args[ x ]] )
+      nptr = ptr
+    case oJMPI:
+      // Set the instruction pointer to the value at Ry if Rx yields true
+      if vm.stack[args[ x ]] != "0" {
+        ptr, _ := strconv.Atoi( vm.stack[args[ y ]] )
+        nptr = ptr
+      }
+    default:
+      fmt.Println("Error op", op)
+      break
+    }
+
+    if vm.iptr == nptr {
+      vm.iptr++
+    } else {
+      vm.iptr = nptr
+      fmt.Println("... JMP", nptr, "...")
+    }
+  }
+  fmt.Println("# finished processing Tx\n")
+}