49 lines
1.1 KiB
C++
49 lines
1.1 KiB
C++
|
|
#include "blockdevice.hpp"
|
|
|
|
namespace helos {
|
|
|
|
|
|
class SlicedBlockDevice: public BlockDevice {
|
|
public:
|
|
SlicedBlockDevice(BlockDevice *backing, uint64_t off, uint64_t cnt)
|
|
: backing(backing), off(off), cnt(cnt) {}
|
|
|
|
public:
|
|
virtual uint64_t BlockSize() const override {
|
|
return backing->BlockSize();
|
|
}
|
|
|
|
uint64_t Size() const override {
|
|
return cnt;
|
|
}
|
|
|
|
uint64_t SizeBytes() const override {
|
|
return backing->BlockSize() * cnt;
|
|
}
|
|
|
|
::helos::Permission DevicePermission() const override {
|
|
return backing->DevicePermission();
|
|
}
|
|
|
|
uint64_t ReadBlock(uint64_t blockOffset, void *data, uint64_t blockCount) const override {
|
|
return backing->ReadBlock(blockOffset + off, data, blockCount);
|
|
}
|
|
|
|
uint64_t WriteBlock(uint64_t blockOffset, const void *data, uint64_t blockCount) override {
|
|
return backing->WriteBlock(blockOffset + off, data, blockCount);
|
|
}
|
|
|
|
private:
|
|
BlockDevice *backing;
|
|
uint64_t off, cnt;
|
|
};
|
|
|
|
|
|
BlockDevice *BlockDevice::Slice(uint64_t blockOffset, uint64_t blockCount) {
|
|
return new SlicedBlockDevice(this, blockOffset, blockCount);
|
|
}
|
|
|
|
|
|
} // namespace helos
|