| 78 | return total > 0 ? total : (_error == 0 ? 0 : -1); |
| 79 | } |
| 80 | total += n; |
| 81 | } |
| 82 | return total; |
| 83 | } |
| 84 | |
| 85 | ssize_t KittyIOFile::pread(kt_off64_t offset, void *buffer, size_t len) |
| 86 | { |
| 87 | _error = 0; |
| 88 | |
| 89 | if (_fd < 0) |
| 90 | return -1; |
| 91 | |
| 92 | char *ptr = static_cast<char *>(buffer); |
| 93 | size_t total = 0; |
| 94 | |
| 95 | while (total < len) |
| 96 | { |
| 97 | size_t toRead = std::min(len - total, KT_IO_CHUNK_SIZE); |
| 98 | ssize_t n = KT_EINTR_RETRY(kt_pread64(_fd, ptr + total, toRead, (kt_off64_t)(offset + total))); |
| 99 | if (n <= 0) |
| 100 | { |
| 101 | _error = (n < 0) ? errno : 0; |
| 102 | return total > 0 ? total : (_error == 0 ? 0 : -1); |
| 103 | } |
| 104 | total += n; |
| 105 | } |
| 106 | return total; |
| 107 | } |
| 108 | |