go-ethereum/core/vm/memory.go
2015-03-27 14:22:38 +01:00

84 lines
1.6 KiB
Go

package vm
import (
"fmt"
"github.com/ethereum/go-ethereum/common"
)
type Memory struct {
store []byte
}
func NewMemory() *Memory {
return &Memory{nil}
}
func (m *Memory) Set(offset, size uint64, value []byte) {
// If the length of the store is 0 this is a complete failure
// memory size is set prior to calling this method so enough size
// should always be available.
if len(m.store) == 0 {
panic("INVALID memory: store empty")
}
value = common.RightPadBytes(value, int(size))
totSize := offset + size
lenSize := int64(len(m.store) - 1)
if totSize > lenSize {
// Calculate the diff between the sizes
diff := totSize - lenSize
if diff > 0 {
// Create a new empty slice and append it
newSlice := make([]byte, diff-1)
// Resize slice
m.store = append(m.store, newSlice...)
}
}
copy(m.store[offset:offset+size], value)
}
func (m *Memory) Resize(size uint64) {
if uint64(m.Len()) < size {
m.store = append(m.store, make([]byte, size-uint64(m.Len()))...)
}
}
func (self *Memory) Get(offset, size int64) (cpy []byte) {
if size == 0 {
return nil
}
if len(self.store) > int(offset) {
cpy = make([]byte, size)
copy(cpy, self.store[offset:offset+size])
return
}
return
}
func (m *Memory) Len() int {
return len(m.store)
}
func (m *Memory) Data() []byte {
return m.store
}
func (m *Memory) Print() {
fmt.Printf("### mem %d bytes ###\n", len(m.store))
if len(m.store) > 0 {
addr := 0
for i := 0; i+32 <= len(m.store); i += 32 {
fmt.Printf("%03d: % x\n", addr, m.store[i:i+32])
addr++
}
} else {
fmt.Println("-- empty --")
}
fmt.Println("####################")
}