# Trivially Copyable Objects in Java

DevFeed: [Trivially Copyable Objects in Java](<https://devfeed.tech/articles/trivially-copyable-objects-in-java-30748.md>)

Original publisher: [Read original article](<http://blog.vanillajava.blog/2024/12/trivially-copyable-objects-in-java.html>)

Author: Peter Lawrey (noreply@blogger.com)

Published: 2024-12-09T15:38:00Z

Content type: tutorial

Language: en

Sources: [Vanilla Java](<https://devfeed.tech/sources/vanilla-java.md>)

Topics: [Java](<https://devfeed.tech/topics/java.md>), [Low Latency](<https://devfeed.tech/topics/low-latency.md>), [real-time](<https://devfeed.tech/topics/real-time.md>), [C++](<https://devfeed.tech/topics/c-plus-plus.md>), [systems](<https://devfeed.tech/topics/systems.md>)

Tags: [benchmarks](<https://devfeed.tech/tags/benchmarks.md>), [c-plus-plus](<https://devfeed.tech/tags/c-plus-plus.md>), [ecosystem](<https://devfeed.tech/tags/ecosystem.md>), [high-performance](<https://devfeed.tech/tags/high-performance.md>), [java](<https://devfeed.tech/tags/java.md>), [jvm](<https://devfeed.tech/tags/jvm.md>), [latency](<https://devfeed.tech/tags/latency.md>), [low-latency](<https://devfeed.tech/tags/low-latency.md>), [opinion](<https://devfeed.tech/tags/opinion.md>), [performance](<https://devfeed.tech/tags/performance.md>), [real-time](<https://devfeed.tech/tags/real-time.md>)

## AI overview

This article explains how Java objects composed only of fixed-size primitive fields can emulate C++ trivially copyable objects for more efficient serialization. It describes reducing object graph traversal, reflection, and per-field copying through bulk memory operations, and discusses using Chronicle Bytes when strict trivial copyability is unnecessary. The approach trades flexibility for lower latency and higher throughput in latency-sensitive systems.

## Source excerpt

TL;DR Problem: Java's standard serialisation can be slow due to scattered object fields and reflection-based overhead. Approach: Emulate C++-style trivially copyable objects by restricting fields to primitives, enabling bulk memory copies. Result: Near C++-like serialisation performance, dramatically reducing latency and improving throughput. Trade-offs: Requires careful design, limited flexibility, and testing for JVM compatibility. Outcome: Low-latency systems with high performance, suitable for financial data feeds, real-time analytics, and other latency-sensitive domains. Introduction For low-latency systems, every microsecond has tangible business impact. In high-frequency trading, real-time analytics, and similarly time-sensitive workloads, even minor inefficiencies in serialisation and deserialisation can degrade throughput and responsiveness. The seemingly mundane act of converting objects into bytes and back often becomes a performance bottleneck. This article explores how we can emulate a C++-like concept of Trivially Copyable Objects within Java to achieve far more efficient serialisation. By ensuring objects contain only fixed-size primitives, we can sidestep the traditional overheads of object graph traversal, reflection, and per-field copying. Instead, we can treat them as contiguous memory blocks, dramatically reducing the time taken to read and write data. We shall also consider how to get very close to this performance using Chronicle Bytes without strictly requiring trivial copyability. This technique blends the low-level efficiency with the safety and familiarity of Java's ecosystem. The Core Challenge of Java Serialisation Most Java object graphs are composed of references linking scattered heap allocations. Serialising such objects typically involves visiting numerous memory locations, reading each field individually, and writing them out one at a time. This is akin to foraging around a warehouse for individual items whenever you need to pack a