Method partialLoadFromFile

Core/MMKV_IO.cpp:157–202

read from last m_position

// read from last m_position
void MMKV::partialLoadFromFile() {
    if (!m_file->isFileValid()) {
        return;
    }
    m_metaInfo->read(m_metaFile->getMemory());

    size_t oldActualSize = m_actualSize;
    m_actualSize = readActualSize();
    auto fileSize = m_file->getFileSize();
    MMKVDebug("loading [%s] with file size %zu, oldActualSize %zu, newActualSize %zu", m_mmapID.c_str(), fileSize,
              oldActualSize, m_actualSize);

    if (m_actualSize > 0) {
        if (m_actualSize < fileSize && m_actualSize + Fixed32Size <= fileSize) {
            if (m_actualSize > oldActualSize) {
                auto position = oldActualSize;
                size_t addedSize = m_actualSize - position;
                auto basePtr = (uint8_t *) m_file->getMemory() + Fixed32Size;
                // incremental update crc digest
                m_crcDigest = (uint32_t) CRC32(m_crcDigest, basePtr + position, (z_size_t) addedSize);
                if (m_crcDigest == m_metaInfo->m_crcDigest) {
                    MMBuffer inputBuffer(basePtr, m_actualSize, MMBufferNoCopy);
#ifndef MMKV_DISABLE_CRYPT
                    if (m_crypter) {
                        MiniPBCoder::greedyDecodeMap(*m_dicCrypt, inputBuffer, m_crypter, position);
                    } else
#endif
                    {
                        MiniPBCoder::greedyDecodeMap(*m_dic, inputBuffer, position);
                    }
                    m_output->seek(addedSize);
                    m_hasFullWriteback = false;

                    [[maybe_unused]] auto count = m_crypter ? m_dicCrypt->size() : m_dic->size();
                    MMKVDebug("partial loaded [%s] with %zu values", m_mmapID.c_str(), count);
                    return;
                } else {
                    MMKVError("m_crcDigest[%u] != m_metaInfo->m_crcDigest[%u]", m_crcDigest, m_metaInfo->m_crcDigest);
                }
            }
        }
    }
    // something is wrong, do a full load
    clearMemoryCache();
    loadFromFile();
}

static bool deleteOrRenameFile(const MMKVPath_t &src) {
    if (!deleteFile(src)) {