| 13 | namespace rw_ops |
| 14 | { |
| 15 | void Reverse(Reader const & src, Writer & dest) |
| 16 | { |
| 17 | // Read from end, reverse and write directly. |
| 18 | |
| 19 | size_t const bufSz = 1024; |
| 20 | std::vector<uint8_t> buffer(bufSz); |
| 21 | |
| 22 | uint64_t pos = src.Size(); |
| 23 | while (pos > 0) |
| 24 | { |
| 25 | size_t const sz = pos > bufSz ? bufSz : static_cast<size_t>(pos); |
| 26 | ASSERT_GREATER_OR_EQUAL(pos, sz, ()); |
| 27 | |
| 28 | src.Read(pos - sz, &buffer[0], sz); |
| 29 | |
| 30 | std::reverse(buffer.begin(), buffer.begin() + sz); |
| 31 | |
| 32 | dest.Write(&buffer[0], sz); |
| 33 | |
| 34 | pos -= sz; |
| 35 | } |
| 36 | } |
| 37 | } // namespace rw_ops |