BlockInfo.cpp

#include <base/types.h>
#include <Common/Exception.h>
#include <IO/ReadBuffer.h>
#include <IO/WriteBuffer.h>
#include <IO/VarInt.h>
#include <IO/ReadHelpers.h>
#include <IO/WriteHelpers.h>
#include <Core/BlockInfo.h>


namespace DB
{

namespace ErrorCodes
{
    extern const int UNKNOWN_BLOCK_INFO_FIELD;
}


/// Write values in binary form. NOTE: You could use protobuf, but it would be overkill for this case.
void BlockInfo::write(WriteBuffer & out, UInt64 server_protocol_revision) const
{
/// Set of pairs `FIELD_NUM`, value in binary form. Then 0.
#define WRITE_FIELD(TYPE, NAME, DEFAULT, FIELD_NUM, MIN_PROTOCOL_REVISION) \
    if (server_protocol_revision >= (MIN_PROTOCOL_REVISION)) \
    { \
        writeVarUInt(FIELD_NUM, out); \
        writeBinary(NAME, out); \
    }

    APPLY_FOR_BLOCK_INFO_FIELDS(WRITE_FIELD)

#undef WRITE_FIELD
    writeVarUInt(0, out);
}

/// Read values in binary form.
void BlockInfo::read(ReadBuffer & in, UInt64 client_protocol_revision)
{
    UInt64 field_num = 0;

    while (true)
    {
        readVarUInt(field_num, in);
        if (field_num == 0)
            break;

        switch (field_num)
        {
#define READ_FIELD(TYPE, NAME, DEFAULT, FIELD_NUM, MIN_PROTOCOL_REVISION) \
    case FIELD_NUM: \
        if (client_protocol_revision >= (MIN_PROTOCOL_REVISION)) \
            readBinary(NAME, in); \
        break;

            APPLY_FOR_BLOCK_INFO_FIELDS(READ_FIELD)

        #undef READ_FIELD
            default:
                throw Exception(ErrorCodes::UNKNOWN_BLOCK_INFO_FIELD, "Unknown BlockInfo field number: {}", field_num);
        }
    }
}

}