Performance

Mutative is a high-performance immutable data structure library, it is up to 2x-6x faster than naive handcrafted reducer and up to 16x faster than Immer.

Mutative vs Reducer Performance​

Reducer by object​

• Naive handcrafted reducer

// baseState type: Record<string, { value: number }>
const state ={
...baseState,
 key0:{
...baseState.key0,
 value: i,
},
};

• Mutative

const state =create(baseState,(draft)=>{
 draft.key0.value = i;
});

[画像:Mutative vs Reducer benchmark by object]

Measure(seconds) to update the 1K-100K items object, lower is better(view source).

Mutative is up to 2x faster than naive handcrafted reducer for updating immutable objects.

Reducer by array​

• Naive handcrafted reducer

// baseState type: { value: number }[]

// slower 6x than Mutative
const state =[
{...baseState[0], value: i },
...baseState.slice(1, baseState.length),
];

// slower 2.5x than Mutative
// const state = baseState.map((item, index) =>
// index === 0 ? { ...item, value: i } : item
// );

// same performance as Mutative
// const state = [...baseState];
// state[0] = { ...baseState[0], value: i };

The actual difference depends on which spread operation syntax you use.

• Mutative

const state =create(baseState,(draft)=>{
 draft[0].value = i;
});

[画像:Mutative vs Reducer benchmark by array]

Measure(seconds) to update the 1K-100K items array, lower is better(view source).

Mutative is up to 6x faster than naive handcrafted reducer for updating immutable arrays.

Mutative vs Immer Performance​

Mutative passed all of Immer's test cases.

Measure(ops/sec) to update 50K arrays and 1K objects, bigger is better(view source). [Mutative v1.3.0 vs Immer v10.1.3]

[画像:Benchmark]

Naive handcrafted reducer - No Freeze x 4,777 ops/sec ±1.06% (94 runs sampled)
Mutative - No Freeze x 6,783 ops/sec ±0.71% (96 runs sampled)
Immer - No Freeze x 5.72 ops/sec ±0.39% (19 runs sampled)

Mutative - Freeze x 1,069 ops/sec ±0.75% (97 runs sampled)
Immer - Freeze x 392 ops/sec ±0.66% (92 runs sampled)

Mutative - Patches and No Freeze x 1,006 ops/sec ±1.73% (95 runs sampled)
Immer - Patches and No Freeze x 5.73 ops/sec ±0.16% (19 runs sampled)

Mutative - Patches and Freeze x 548 ops/sec ±1.06% (94 runs sampled)
Immer - Patches and Freeze x 287 ops/sec ±0.84% (93 runs sampled)

The fastest method is Mutative - No Freeze

Run yarn benchmark to measure performance.

OS: macOS 14.7, CPU: Apple M1 Max, Node.js: v22.11.0

Immer relies on auto-freeze to be enabled, if auto-freeze is disabled, Immer will have a huge performance drop and Mutative will have a huge performance lead, especially with large data structures it will have a performance lead of more than 50x.

So if you are using Immer, you will have to enable auto-freeze for performance. Mutative is disabled auto-freeze by default. With the default configuration of both, we can see the 17x performance gap between Mutative (6,783 ops/sec) and Immer (392 ops/sec).

Overall, Mutative has a huge performance lead over Immer in more performance testing scenarios. Run yarn performance to get all the performance results locally.

More Performance Testing Scenarios​

Mutative is up to 2.5X-82.9X faster than Immer:

[画像:Mutative vs Immer - All benchmark results by average multiplier]

view source.