LightProto

High-performance Protocol Buffers code generator for Java, optimized for serialization and deserialization speed.

Features

• Fastest Java Protobuf SerDe — Unsafe-based serialization bypasses Netty ByteBuf boundary checks
• 100% wire-compatible with proto2 and proto3 definitions
• Zero-copy deserialization using Netty ByteBuf (direct and heap memory)
• Zero heap allocations — reusable mutable objects, no Builder pattern overhead
• Lazy string/bytes deserialization — decoded only on access
• Optimized string handling — single-copy ASCII fast path via sun.misc.Unsafe
• No runtime dependencies — generated code is self-contained
• Maven and Gradle plugins for seamless build integration

Usage

Maven

Add the Maven plugin to your pom.xml:

<plugin>
    <groupId>io.streamnative.lightproto</groupId>
    <artifactId>lightproto-maven-plugin</artifactId>
    <version>0.5-SNAPSHOT</version>
    <executions>
        <execution>
            <goals>
                <goal>generate</goal>
            </goals>
        </execution>
    </executions>
</plugin>

Place .proto files in src/main/proto/ and LightProto will generate Java classes during the generate-sources phase.

Gradle

Add the plugin to your build.gradle:

plugins {
    id 'io.streamnative.lightproto' version '0.5-SNAPSHOT'
}

Or using the buildscript block:

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath 'io.streamnative.lightproto:lightproto-gradle-plugin:0.5-SNAPSHOT'
    }
}

apply plugin: 'io.streamnative.lightproto'

Place .proto files in src/main/proto/ and LightProto will generate Java classes automatically before compilation. Optional configuration:

lightproto {
    classPrefix = ''           // prefix for generated class names
    singleOuterClass = false   // wrap all messages in a single outer class
    protocVersion = '4.34.0'   // protoc compiler version
    // protocPath = '/usr/local/bin/protoc'  // use a local protoc binary
}

API Example

LightProto generates mutable, reusable objects instead of the Builder pattern used by Google Protobuf:

// Create and populate
MessageMetadata md = new MessageMetadata();
md.setProducerName("producer-1")
  .setSequenceId(12345)
  .setPublishTime(System.currentTimeMillis());
md.addProperty().setKey("key1").setValue("value1");

// Serialize to ByteBuf
ByteBuf buf = PooledByteBufAllocator.DEFAULT.buffer();
md.writeTo(buf);

// Deserialize from ByteBuf (zero-copy, lazy strings)
MessageMetadata parsed = new MessageMetadata();
parsed.parseFrom(buf, buf.readableBytes());

// Reuse the object for the next message
md.clear();
md.setProducerName("producer-2")...

Supported Features

Feature	proto2	proto3
Scalar fields (int32, int64, uint32, uint64, sint32, sint64, fixed32, fixed64, sfixed32, sfixed64, float, double, bool)	✅	✅
String fields	✅	✅
Bytes fields	✅	✅
Enum fields	✅	✅
Nested messages	✅	✅
optional fields (explicit presence)	✅	✅
required fields	✅	—
Implicit presence (no has*(), skip defaults)	—	✅
oneof	✅	✅
repeated fields	✅	✅
repeated packed encoding	✅	✅ (default)
map<K, V> fields	✅	✅
Nested enum / message definitions	✅	✅
Default values	✅	—
Multiple .proto files / import	✅	✅
service / RPC definitions	❌	❌
Extensions	❌	—
Any, Timestamp, well-known types	❌	❌
group (deprecated)	❌	—

Performance

Throughput Comparison (ops/μs, higher is better)

Benchmark	Google Protobuf	LightProto	Speedup
AddressBook (nested messages, strings)
Serialize	6.4	22.6	3.5x
Fill + Serialize	2.2	12.8	5.9x
Deserialize	3.8	19.2	5.1x
Simple (small numeric messages)
Serialize	30.8	245.6	8.0x
Deserialize	20.0	100.9	5.0x
Pulsar MessageMetadata (strings, properties, batch fields)
Serialize	2.8	10.9	3.8x
Deserialize	4.2	14.1	3.4x
Pulsar BaseCommand+Send (nested message, numerics)
Serialize	15.8	26.8	1.7x
Deserialize	12.8	40.3	3.2x

Speedup Chart

                        Speedup over Google Protobuf (x times faster)
                        1x    2x    3x    4x    5x    6x    7x    8x
                        |     |     |     |     |     |     |     |
AddressBook Ser         |████████████████████                       3.5x
AddressBook Fill+Ser    |██████████████████████████████████████████  5.9x
AddressBook Deser       |█████████████████████████████████          5.1x
                        |     |     |     |     |     |     |     |
Simple Ser              |█████████████████████████████████████████████████ 8.0x
Simple Deser            |█████████████████████████████████          5.0x
                        |     |     |     |     |     |     |     |
Pulsar MD Ser           |██████████████████████                     3.8x
Pulsar MD Deser         |███████████████████                        3.4x
                        |     |     |     |     |     |     |     |
Pulsar Cmd Ser          |████████                                   1.7x
Pulsar Cmd Deser        |█████████████████                          3.2x
                        |     |     |     |     |     |     |     |

Raw JMH Output

Click to expand full benchmark output

Benchmark                                                    Mode  Cnt    Score    Error   Units

-- AddressBook (nested messages with strings) --
ProtoBenchmark.protobufSerialize                            thrpt    3    6.422 ±  0.242  ops/us
ProtoBenchmark.protobufFillAndSerialize                     thrpt    3    2.190 ±  0.365  ops/us
ProtoBenchmark.protobufDeserialize                          thrpt    3    3.777 ±  0.253  ops/us
ProtoBenchmark.lightProtoSerialize                          thrpt    3   22.551 ±  0.355  ops/us
ProtoBenchmark.lightProtoFillAndSerialize                   thrpt    3   12.827 ±  2.816  ops/us
ProtoBenchmark.lightProtoDeserialize                        thrpt    3   19.166 ±  1.022  ops/us

-- Simple (small numeric messages) --
SimpleBenchmark.protobufSerialize                           thrpt    3   30.768 ± 14.107  ops/us
SimpleBenchmark.protobufDeserialize                         thrpt    3   19.988 ±  0.499  ops/us
SimpleBenchmark.lightProtoSerialize                         thrpt    3  245.575 ± 87.004  ops/us
SimpleBenchmark.lightProtoDeserialize                       thrpt    3  100.857 ±  2.221  ops/us
SimpleBenchmark.lightProtoDeserializeReadString             thrpt    3   54.111 ± 14.056  ops/us

-- Pulsar MessageMetadata (strings, repeated properties, batch fields) --
PulsarApiBenchmark.protobufSerializeMessageMetadata         thrpt    3    2.838 ±  0.580  ops/us
PulsarApiBenchmark.protobufDeserializeMessageMetadata       thrpt    3    4.176 ±  0.241  ops/us
PulsarApiBenchmark.lightProtoSerializeMessageMetadata       thrpt    3   10.852 ±  0.677  ops/us
PulsarApiBenchmark.lightProtoDeserializeMessageMetadata     thrpt    3   14.141 ±  8.862  ops/us

-- Pulsar BaseCommand + CommandSend (nested message, mostly numerics) --
PulsarApiBenchmark.protobufSerializeBaseCommand             thrpt    3   15.818 ±  4.591  ops/us
PulsarApiBenchmark.protobufDeserializeBaseCommand           thrpt    3   12.771 ±  3.192  ops/us
PulsarApiBenchmark.lightProtoSerializeBaseCommand           thrpt    3   26.814 ±  1.107  ops/us
PulsarApiBenchmark.lightProtoDeserializeBaseCommand         thrpt    3   40.296 ±  2.816  ops/us

Running Benchmarks

mvn -B install
java -jar benchmark/target/benchmarks.jar

License

Licensed under the Apache License, Version 2.0.