Method WriteFilterToDisk

src/index/blockfilterindex.cpp:186–241

}

size_t BlockFilterIndex::WriteFilterToDisk(FlatFilePos& pos, const BlockFilter& filter)
{
    assert(filter.GetFilterType() == GetFilterType());

    uint64_t data_size{
        GetSerializeSize(filter.GetBlockHash()) +
        GetSerializeSize(filter.GetEncodedFilter())};

    // If writing the filter would overflow the file, flush and move to the next one.
    if (pos.nPos + data_size > MAX_FLTR_FILE_SIZE) {
        AutoFile last_file{m_filter_fileseq->Open(pos)};
        if (last_file.IsNull()) {
            LogError("Failed to open filter file %d", pos.nFile);
            return 0;
        }
        if (!last_file.Truncate(pos.nPos)) {
            LogError("Failed to truncate filter file %d", pos.nFile);
            return 0;
        }
        if (!last_file.Commit()) {
            LogError("Failed to commit filter file %d", pos.nFile);
            (void)last_file.fclose();
            return 0;
        }
        if (last_file.fclose() != 0) {
            LogError("Failed to close filter file %d after commit: %s", pos.nFile, SysErrorString(errno));
            return 0;
        }

        pos.nFile++;
        pos.nPos = 0;
    }

    // Pre-allocate sufficient space for filter data.
    bool out_of_space;
    m_filter_fileseq->Allocate(pos, data_size, out_of_space);
    if (out_of_space) {
        LogError("out of disk space");
        return 0;
    }

    AutoFile fileout{m_filter_fileseq->Open(pos)};
    if (fileout.IsNull()) {
        LogError("Failed to open filter file %d", pos.nFile);
        return 0;
    }

    fileout << filter.GetBlockHash() << filter.GetEncodedFilter();

    if (fileout.fclose() != 0) {
        LogError("Failed to close filter file %d: %s", pos.nFile, SysErrorString(errno));
        return 0;
    }

    return data_size;
}

std::optional<uint256> BlockFilterIndex::ReadFilterHeader(int height, const uint256& expected_block_hash)