81 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			81 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
package vm
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import "fmt"
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type Memory struct {
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	store []byte
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}
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func NewMemory() *Memory {
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	return &Memory{nil}
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}
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func (m *Memory) Set(offset, size uint64, value []byte) {
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	// length of store may never be less than offset + size.
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	// The store should be resized PRIOR to setting the memory
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	if size > uint64(len(m.store)) {
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		panic("INVALID memory: store empty")
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	}
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	// It's possible the offset is greater than 0 and size equals 0. This is because
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	// the calcMemSize (common.go) could potentially return 0 when size is zero (NO-OP)
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	if size > 0 {
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		copy(m.store[offset:offset+size], value)
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	}
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}
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func (m *Memory) Resize(size uint64) {
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	if uint64(m.Len()) < size {
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		m.store = append(m.store, make([]byte, size-uint64(m.Len()))...)
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	}
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}
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func (self *Memory) Get(offset, size int64) (cpy []byte) {
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	if size == 0 {
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		return nil
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	}
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	if len(self.store) > int(offset) {
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		cpy = make([]byte, size)
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		copy(cpy, self.store[offset:offset+size])
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		return
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	}
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	return
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}
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func (self *Memory) GetPtr(offset, size int64) []byte {
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	if size == 0 {
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		return nil
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	}
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	if len(self.store) > int(offset) {
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		return self.store[offset : offset+size]
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	}
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	return nil
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}
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func (m *Memory) Len() int {
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	return len(m.store)
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}
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func (m *Memory) Data() []byte {
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	return m.store
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}
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func (m *Memory) Print() {
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	fmt.Printf("### mem %d bytes ###\n", len(m.store))
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	if len(m.store) > 0 {
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		addr := 0
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		for i := 0; i+32 <= len(m.store); i += 32 {
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			fmt.Printf("%03d: % x\n", addr, m.store[i:i+32])
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			addr++
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		}
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	} else {
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		fmt.Println("-- empty --")
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	}
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	fmt.Println("####################")
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}
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