| 50 | ReaderCache(uint32_t logPageSize, uint32_t logPageCount) : m_Cache(logPageCount), m_LogPageSize(logPageSize) {} |
| 51 | |
| 52 | void Read(ReaderT & reader, uint64_t pos, void * p, size_t size) |
| 53 | { |
| 54 | if (size == 0) |
| 55 | return; |
| 56 | ASSERT_LESS_OR_EQUAL(pos + size, reader.Size(), (pos, size, reader.Size())); |
| 57 | m_Stats.m_ReadSize(static_cast<uint32_t>(size)); |
| 58 | char * pDst = static_cast<char *>(p); |
| 59 | uint64_t pageNum = pos >> m_LogPageSize; |
| 60 | size_t const firstPageOffset = static_cast<size_t>(pos - (pageNum << m_LogPageSize)); |
| 61 | size_t const firstCopySize = std::min(size, PageSize() - firstPageOffset); |
| 62 | ASSERT_GREATER(firstCopySize, 0, ()); |
| 63 | memcpy(pDst, ReadPage(reader, pageNum) + firstPageOffset, firstCopySize); |
| 64 | size -= firstCopySize; |
| 65 | pos += firstCopySize; |
| 66 | pDst += firstCopySize; |
| 67 | ++pageNum; |
| 68 | while (size > 0) |
| 69 | { |
| 70 | size_t const copySize = std::min(size, PageSize()); |
| 71 | memcpy(pDst, ReadPage(reader, pageNum), copySize); |
| 72 | size -= copySize; |
| 73 | pos += copySize; |
| 74 | pDst += copySize; |
| 75 | ++pageNum; |
| 76 | } |
| 77 | } |
| 78 | |
| 79 | std::string GetStatsStr() const { return m_Stats.GetStatsStr(m_LogPageSize, m_Cache.GetCacheSize()); } |
| 80 | |