kvm/vendor/github.com/pojntfx/go-nbd/pkg/backend/memory.go

56 lines
843 B
Go

package backend
import (
"io"
"sync"
)
type MemoryBackend struct {
memory []byte
lock sync.Mutex
}
func NewMemoryBackend(memory []byte) *MemoryBackend {
return &MemoryBackend{memory, sync.Mutex{}}
}
func (b *MemoryBackend) ReadAt(p []byte, off int64) (n int, err error) {
b.lock.Lock()
if off >= int64(len(b.memory)) {
return 0, io.EOF
}
n = copy(p, b.memory[off:off+int64(len(p))])
b.lock.Unlock()
return
}
func (b *MemoryBackend) WriteAt(p []byte, off int64) (n int, err error) {
b.lock.Lock()
if off >= int64(len(b.memory)) {
return 0, io.EOF
}
n = copy(b.memory[off:off+int64(len(p))], p)
if n < len(p) {
return n, io.ErrShortWrite
}
b.lock.Unlock()
return
}
func (b *MemoryBackend) Size() (int64, error) {
return int64(len(b.memory)), nil
}
func (b *MemoryBackend) Sync() error {
return nil
}