Data Serialization for Games Skill

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

Agent Skills: Data Serialization for Games

Skill Files