CommandArguments causes unnecessary array copies for large commands

Jedis Version

8.0.1

Java Version

Openjdk 25

Problem

When constructing large commands (ZADD, MSET, HMSET with hundreds of members), CommandArguments causes unnecessary array copies in two ways:

1. ArrayList reallocation

public CommandArguments(ProtocolCommand command) {
    args = new ArrayList<>(); // default capacity = 10
    args.add(command);
}

2. Raw defensive copy

public Raw(byte[] raw) {
    this.raw = Arrays.copyOf(raw, raw.length);
}

Raw is only used transiently: CommandArguments → Protocol.sendCommand() → RedisOutputStream → socket. After serialization it's never read again. For ZADD 500 members: 500 unnecessary arraycopy calls, ~16KB wasted.

Proposal

Fix 1: Add initial capacity constructor

public CommandArguments(ProtocolCommand command) {
    this(command, 10);
}

public CommandArguments(ProtocolCommand command, int initialCapacity) {
    args = new ArrayList<>(initialCapacity);
    args.add(command);
    keys = new ArrayList<>(DEFAULT_KEYS_CAPACITY);
    cachedHashSlots = null;
}

Fix 2: Remove defensive copy or add zero-copy path

public Raw(byte[] raw) {
    this.raw = raw;
}

Profiling Evidence

See attached async-profiler flame graph

server-alloc-20260911-114134.html