Method get

src/storage/disk_array.cpp:85–103

}

void DiskArrayInternal::get(uint64_t idx, const Transaction* transaction,
    std::span<std::byte> val) {
    std::shared_lock sLck{diskArraySharedMtx};
    DASSERT(checkOutOfBoundAccess(transaction->getType(), idx));
    auto apCursor = getAPIdxAndOffsetInAP(storageInfo, idx);
    page_idx_t apPageIdx = getAPPageIdxNoLock(apCursor.pageIdx, transaction->getType());
    if (transaction->getType() != TransactionType::CHECKPOINT || !hasTransactionalUpdates ||
        apPageIdx > lastPageOnDisk ||
        !shadowFile->hasShadowPage(fileHandle.getFileIndex(), apPageIdx)) {
        fileHandle.optimisticReadPage(apPageIdx, [&](const uint8_t* frame) -> void {
            memcpy(val.data(), frame + apCursor.elemPosInPage, val.size());
        });
    } else {
        ShadowUtils::readShadowVersionOfPage(fileHandle, apPageIdx, *shadowFile,
            [&val, &apCursor](const uint8_t* frame) -> void {
                memcpy(val.data(), frame + apCursor.elemPosInPage, val.size());
            });
    }
}

void DiskArrayInternal::updatePage(uint64_t pageIdx, bool isNewPage,
    std::function<void(uint8_t*)> updateOp) {