32   std::size_t Read(FileOffset at, char *to, std::size_t minBytes,  in Read()  argument
34     if (enforceSequence_ && at != expect_) {  in Read()
36           static_cast<int>(at), static_cast<int>(minBytes),  in Read()
38     } else if (at < 0 || at + minBytes > bytes_) {  in Read()
40           static_cast<int>(at), static_cast<int>(minBytes),  in Read()
43     auto result{std::min<std::size_t>(maxBytes, bytes_ - at)};  in Read()
44     std::memcpy(to, &data_[at], result);  in Read()
45     expect_ = at + result;  in Read()
48   std::size_t Write(FileOffset at, const char *from, std::size_t bytes,  in Write()  argument
50     if (enforceSequence_ && at != expect_) {  in Write()
52           static_cast<int>(at), static_cast<int>(bytes),  in Write()
54     } else if (at < 0 || at + bytes > bytes_) {  in Write()
55       handler.SignalError("Write(%d,%d) is out of bounds", static_cast<int>(at),  in Write()
58     std::memcpy(&data_[at], from, bytes);  in Write()
59     expect_ = at + bytes;  in Write()
78 inline int ValueFor(int at) { return (at ^ (at >> 8)) & 0xff; }  in ValueFor()  argument
89   int at{0}, j{0};  in TEST()  local
90   while (at < bytes) {  in TEST()
91     auto chunk{ChunkSize(j, static_cast<int>(bytes - at))};  in TEST()
92     store.WriteFrame(at, chunk, handler);  in TEST()
95       to[k] = ValueFor(at + k);  in TEST()
97     at += chunk;  in TEST()
103   at = 0;  in TEST()
104   while (at < bytes) {  in TEST()
105     auto chunk{ChunkSize(j, static_cast<int>(bytes - at))};  in TEST()
106     std::size_t frame{store.ReadFrame(at, chunk, handler)};  in TEST()
108         << "Badly-sized ReadFrame at " << at << ", chunk=" << chunk << ", got "  in TEST()
113       auto expect{static_cast<char>(ValueFor(at + k))};  in TEST()
115           << "At " << at << '+' << k << '(' << (at + k) << "), read "  in TEST()
119     at += chunk;  in TEST()