Fast Boolean Array

In JavaScript, when working with large arrays of boolean values, a common challenge is efficiently indexing and retrieving these values. Using a regular JavaScript array to store booleans is straightforward, but it is memory-inefficient. While booleans are conceptually 1-bit values, JavaScript engines, like V8 (in Chrome and Node.js), allocate 1 byte (8 bits) per boolean for optimization purposes. This can waste a significant amount of memory when dealing with large arrays.

Fast Boolean Array solves this issue by utilizing bit manipulation to store booleans in a compact format. It uses a Uint8Array and stores each boolean as a single bit within the 8 bits of each byte. This allows you to index and retrieve boolean values by integers (e.g., the 0th boolean, 1st boolean, etc.) while only using a fraction of the memory.

For detailed benchmark results, see below.

Features

• Memory Efficiency: Stores booleans in bits rather than bytes, drastically reducing memory usage.
• Fast Set Performance: Up to 10x faster sets for fast data re-mapping.
• Familiar API: Map and Set like API for minimal learning curve. Intuitive helper functions, and works in for.. of.
• Array like interface: call .accessLikeArray() to access it like an arraysomeArray[index] (beware of the performance penalty caused by the Proxy)!

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Why Use Fast Boolean Array?

• Easy to Use: Familiar Map and Set like API for minimal learning curve.
• Scalable: Suitable for high-performance, memory-sensitive projects.

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Installation

Install the package via npm:

npm install fast-boolean-array --save-dev
pnpm install fast-boolean-array --save-dev

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Usage

Here's how to use the Fast Boolean Array:

import BooleanArray from "fast-boolean-array";
// const BooleanArray = require('fast-boolean-array'); commonjs works too.

// Create a new BooleanArray with the desired size
const booleans = new BooleanArray(2);

// Set a value at a specific index
booleans.set(0, true);
booleans.set(1, false);

// Retrieve it
console.log(booleans.get(0)); // Output: true
console.log(booleans.get(1)); // Output: false

booleans.set(3, true); // will not throw, but returns false as the boolean is not found
console.log(booleans.get(3)); // Output: false

booleans.setSafe(3, true); // will throw RangeError

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API

new BooleanArray(size)

Creates a new boolean array of the given size. All values are initialized to false.

• Parameters:
  • size (number): The number of booleans the array should hold.

set(index, value)

Sets the boolean value at the specified index.

• Parameters:
  • index (number): The position in the array to set the value.
  • value (boolean): The value to set (true or false).

get(index)

Gets the boolean value at the specified index.

• Parameters:

  • index (number): The position in the array to retrieve the value.

• Returns:

  • boolean: The value at the given index.

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Performance Breakdown

Our benchmark compares the performance of our Fast Boolean Array library against Vanilla JavaScript arrays in terms of get and set operations across varying numbers of Booleans. The results below reflect an updated benchmark algorithm that performs 1,000 runs for each x amount of Booleans to better simulate real-world scenarios.

Performance Breakdown

1 Boolean

Test	Time (ms)	Memory (Bytes)	Booleans
Set Vanilla Array	0.00236000	8	1
Set Fast Boolean Array	0.00423000	6	1
Get Vanilla Array	0.00053000	N/A	1
Get Fast Boolean Array	0.00291000	N/A	1

As useless as having just 1 boolean stored in an array might be, For 1 boolean, the Fast Boolean Array is 1.8x slower for Set and 5.5x slower for Get operations. Memory usage is nearly identical, with a small advantage for the Fast Boolean Array in terms of bytes.

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100 Booleans

Test	Time (ms)	Memory (Bytes)	Booleans
Set Vanilla Array	0.00332000	107	100
Set Fast Boolean Array	0.00824000	18	100
Get Vanilla Array	0.00149000	N/A	100
Get Fast Boolean Array	0.00581000	N/A	100

Observation: For 100 booleans, Fast Boolean Array is 2.5x slower in Set operations but 3.9x more memory efficient. However, Fast Boolean Array's' Get operation is 3.9x slower . compared to the Vanilla Array.

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1,000 Booleans

Test	Time (ms)	Memory (Bytes)	Booleans
Set Vanilla Array	0.09599000	1009	1000
Set Fast Boolean Array	0.04467000	130	1000
Get Vanilla Array	0.01261000	N/A	1000
Get Fast Boolean Array	0.05476000	N/A	1000

For 1,000 booleans, Fast Boolean Array is 2.1x faster for Set operations and uses 7.7x less memory. However, Fast Boolean Array's' Get operation is 4.3x slower . compared to the Vanilla Array.

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10,000 Booleans

Test	Time (ms)	Memory (Bytes)	Booleans
Set Vanilla Array	0.30075000	10009	10000
Set Fast Boolean Array	0.04225000	1256	10000
Get Vanilla Array	0.06054000	N/A	10000
Get Fast Boolean Array	0.12325000	N/A	10000

Observation: For 10,000 booleans, Fast Boolean Array is 7.1x faster in Set operations and uses 8x less memory. However, Fast Boolean Array's' Get operation is 2x slower . compared to the Vanilla Array.

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100,000 Booleans

Test	Time (ms)	Memory (Bytes)	Booleans
Set Vanilla Array	1.67949000	100011	100000
Set Fast Boolean Array	0.15400000	12506	100000
Get Vanilla Array	0.04920000	N/A	100000
Get Fast Boolean Array	0.07523000	N/A	100000

For 100,000 booleans, Fast Boolean Array is 10.9x faster in Set operations and uses 8x less memory. However, Fast Boolean Array's' Get operation is 1.5x slower .

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1,000,000 Booleans

Test	Time (ms)	Memory (Bytes)	Booleans
Set Vanilla Array	20.07889000	1000011	1000000
Set Fast Boolean Array	3.42817000	125007	1000000
Get Vanilla Array	0.49531000	N/A	1000000
Get Fast Boolean Array	0.74617000	N/A	1000000

For 1,000,000 booleans, the Fast Boolean Array is 5.9x faster for Set operations and uses 8x less memory. However, Fast Boolean Array's' Get operation is 1.5x slower .

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10,000,000 Booleans

Test	Time (ms)	Memory (Bytes)	Booleans
Set Vanilla Array	266.65778000	10000013	10000000
Set Fast Boolean Array	35.53492000	1250007	10000000
Get Vanilla Array	4.90792000	N/A	10000000
Get Fast Boolean Array	7.57038000	N/A	10000000

For 10,000,000 booleans, Fast Boolean Array is 7.5x faster for Set operations and uses 8x less memory. However, Fast Boolean Array's' Get operation is 1.5x slower .

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Summary

• The Fast Boolean Array is significantly more efficient in terms of memory usage and Set operation speeds, particularly as the number of booleans increases.
  • For example, as stated previously, at 10,000,000 booleans, it is 7.5x faster in Set operations and uses 8x less memory.
• The Get operation, however, tends to be slower on a Fast Boolean Array, with it being up to 1.5x slower compared to the regular vanilla boolean[] in larger datasets.

If memory efficiency and Set performance are priorities, the Fast Boolean Array is clearly advantageous, but if Get performance is more important, the Vanilla Array may still offer better results for certain use cases.

We are still working on improving the performance of the toArray function, but you can already use it today to convert back to a vanilla array, though generating one from scratch is currently more effecient.

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Contributing

Contributions are welcome! If you'd like to report a bug, suggest a feature, or submit a pull request, please visit the GitHub repository.

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License

This project is licensed under the MIT License. See the LICENSE file for details.

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Acknowledgements

Thank you to the open-source community for inspiration and support!