Data Serialization for Games

Implement efficient serialization for low-latency game networking.

Format Comparison

Format	Size	Speed	Schema	Use Case
Protobuf	Small	Fast	Required	Most games
FlatBuffers	Small	Fastest	Required	Real-time
MsgPack	Small	Fast	Optional	Flexible
JSON	Large	Slow	None	Debug
Custom Binary	Smallest	Fastest	Custom	Ultra-low latency

Protocol Buffers

syntax = "proto3";

message PlayerState {
    uint32 player_id = 1;
    float x = 2;
    float y = 3;
    float z = 4;
    uint32 health = 5;
}

message GameUpdate {
    uint64 tick = 1;
    repeated PlayerState players = 2;
}

GameUpdate update;
update.set_tick(current_tick);
auto* player = update.add_players();
player->set_player_id(1);
player->set_x(pos.x);

std::string serialized;
update.SerializeToString(&serialized);

Custom Binary Format

struct PacketHeader {
    uint16_t type;
    uint16_t length;
    uint32_t sequence;
};

struct PlayerUpdate {
    uint32_t player_id;
    float position[3];
    uint16_t angle;  // Compressed rotation
    uint8_t flags;
};

void serialize(Buffer& buf, const PlayerUpdate& p) {
    buf.write_u32(htonl(p.player_id));
    for (int i = 0; i < 3; i++)
        buf.write_float(p.position[i]);
    buf.write_u16(htons(p.angle));
    buf.write_u8(p.flags);
}

Compression Techniques

Technique	Savings	Complexity
Delta	50-80%	Medium
Quantization	30-50%	Low
LZ4	50-70%	Low

Troubleshooting

Common Failure Modes

Error	Root Cause	Solution
Parse error	Version mismatch	Schema versioning
Large packets	No compression	Enable delta/LZ4
Slow parsing	JSON in hot path	Use binary format
Corruption	Byte order	Use htonl/ntohl

Debug Checklist

// Check serialized size
std::string data;
message.SerializeToString(&data);
std::cout << "Size: " << data.size() << " bytes\n";

// Validate roundtrip
Message parsed;
parsed.ParseFromString(data);
assert(parsed.id() == message.id());

Unit Test Template

TEST(Serialization, RoundTrip) {
    PlayerState original{1, 10.0f, 20.0f, 30.0f, 100};

    std::string data;
    original.SerializeToString(&data);

    PlayerState parsed;
    parsed.ParseFromString(data);

    EXPECT_EQ(original.player_id(), parsed.player_id());
    EXPECT_FLOAT_EQ(original.x(), parsed.x());
}

Resources

• assets/ - Schema templates
• references/ - Format benchmarks