Benchmark: DataView set vs TypedArray

Script Preparation code:

var buffer = new ArrayBuffer(1024);
var array = new Uint32Array(buffer);
var view = new DataView(buffer);

Tests:

array[i] = i;
for (let i = 0; i < 256; i += 1) array[i] = i;
view.setUint32Array(i, i)
for (let i = 0; i < 1024; i += 4) view.setUint32(1, i);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
array[i] = i;
view.setUint32Array(i, i)

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one month ago)

User agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Mobile Safari/537.36

Browser/OS: Chrome Mobile 134 on Android

View result in a separate tab

Test name	Executions per second
array[i] = i;	950831.6 Ops/sec
view.setUint32Array(i, i)	827224.9 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated 6 months ago):

LLMs can make mistakes. Check important info.

### Benchmark Overview: DataView vs TypedArray

The benchmark defined here compares two variants of data manipulation in JavaScript: updating values in a TypedArray (`Uint32Array`) versus using a `DataView` to set values in an underlying `ArrayBuffer`. This benchmark focuses on understanding the performance characteristics of these two approaches for writing data, specifically in the context of handling binary data for high-performance applications.

### Components

1. **TypedArray (`Uint32Array`)**:
   - **Definition**: A `TypedArray` is a view on an `ArrayBuffer` that represents an array of a specific type, in this case, a 32-bit unsigned integer. The `Uint32Array` provides a fixed-size representation of integers, allowing optimized data access and manipulation.
   - **Benchmark Test**: The test case `for (let i = 0; i < 256; i += 1) array[i] = i;` measures performance by assigning values directly to each index of the `Uint32Array`.

2. **DataView**:
   - **Definition**: `DataView` provides a low-level interface for reading and writing multiple number types onto an `ArrayBuffer` without needing to specify a particular `TypedArray`. It allows developers to manage bytes explicitly, making it useful for binary data manipulation.
   - **Benchmark Test**: The test case `for (let i = 0; i < 1024; i += 4) view.setUint32(1, i);` sets unsigned 32-bit integers at specific offsets in the buffer, thereby utilizing the `DataView`'s set operation to examine its performance.

### Pros and Cons of Each Approach

#### TypedArray (Uint32Array)

**Pros**:
- **Type Safety**: Offers a strict and predictable structure for data.
- **Performance Optimization**: Generally faster for sequential memory access due to direct index-based updates.
- **Ease of Use**: Simple and clear API for manipulating large arrays of data.

**Cons**:
- **Fixed Data Type**: Less flexible in handling different data types compared to `DataView`.
- **Limited Control**: Does not allow for byte-level access or direct manipulation of data structures.

#### DataView

**Pros**:
- **Flexibility**: Can handle various data types and allows for reading and writing at specific byte offsets.
- **Byte Control**: Provides precise control over the structure of binary data, which is essential for applications that need to work with custom binary formats or protocols.

**Cons**:
- **Performance Overhead**: Generally slower than `TypedArray` for large sequential operations due to additional overhead when specifying offsets and reading/writing methods.
- **Complexity**: More complex API that might increase the risk of errors when managing byte offsets.

### Other Considerations

- **Access Patterns**: If you're performing a lot of aggregated writes at a fixed interval (like what is seen in benchmarks), `TypedArray` is likely to outperform due to its simpler structure and sequential optimization. For custom binary formats where flexibility is crucial (e.g., reading/writing network protocols, file formats), `DataView` provides the necessary capabilities.
  
- **Browser and Platform Variability**: Benchmark results might vary significantly across different JavaScript engines and browser implementations, as evidenced by the test results showing slight performance differences between `TypedArray` and `DataView` under the same browser conditions.

### Alternatives

- **ArrayBuffer**: While not a direct alternative for high-level operations, `ArrayBuffer` is the foundational object for the other two. It can be useful in scenarios where you need lower-level management of binary data.
  
- **Other TypedArrays**: Besides `Uint32Array`, there are various other `TypedArray` types (e.g., `Float32Array`, `Int16Array`) that could be used depending on the size and type of data you need to store.

- **WebAssembly**: For certain performance-critical applications, leveraging WebAssembly alongside JavaScript could provide more optimized data manipulation capabilities.

In conclusion, choosing between using a `TypedArray` or a `DataView` largely depends on your specific application requirements, emphasizing either performance or flexibility in data handling.

Related benchmarks:

DataView set vs TypedArray (version: 0)

Comparing performance of: array[i] = i; vs view.setUint32Array(i, i)

Created: 6 months ago by: Registered User

Jump to the latest result

array[i] = i;

view.setUint32Array(i, i)

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated 6 months ago):