hash-code-string

Overview

hash-code-string is a small utility package to convert long strings into shorter, hash-like strings. It provides functions to create hashes, encode them in a URL-safe base64 format, and decode them back into bytes, or a 32 bit number if desired. Limited to 32 bits of uniqueness. No dependencies, the hashing code is 5 lines. Assumes environment has Uint8Array, Math.imul, and btoa.

Installation

``sh npm install hash-code-string`

`sh pnpm install hash-code-string`

`Usage`

`javascript import { hashString, hashToNum32 } from 'hash-code-string';

// Example usage const longString = "This is a long string that needs to be hashed"; const hash = hashString(longString); console.log(Hash: ${hash}); // Hash: g3g2qw

const decodedHash = hashToNum32(hash); console.log(Decoded Hash: ${decodedHash}); // Decoded Hash: -1422493565`

`API`

`$3`


Creates a hash code number from a string similar to Java's String.hashCode method.
Parameters:
* str: The input string to hash.
Returns:
A 32-bit integer hash code.
$3

Splits a 32-bit number into an array of 4 bytes.
Parameters:
* num: The 32-bit integer to split.
Returns:
A Uint8Array containing 4 bytes.
$3

Converts an array of byte values to a string.
Parameters:
* bytes: An array of bytes.
Returns:
A string representing the byte values.
$3

Encodes a string into a URL-safe base64 format.
Parameters:
* str: The input string to encode.
Returns:
A URL-safe base64 encoded string.
$3

Creates a hash of the input string and encodes it in URL-safe base64 format.
Parameters:
* str: The input string to hash and encode.
Returns:
A URL-safe base64 encoded hash string.
$3

Decodes a URL-safe base64 string.
Parameters:
* str: The URL-safe base64 string to decode.
Returns:
The decoded string.
$3

Converts a string to an array of character codes.
Parameters:
* str: The input string.
Returns:
An array of character codes.
$3

Converts the first 4 elements of a byte array back to a 32-bit number.
Parameters:
* bytes: An array of bytes.
Returns:
A 32-bit integer.
Example

`javascript const str = "example"; const hash = hashString(str); console.log(hash); // Output: URL-safe base64 encoded hash

const decoded = decode64(hash); console.log(decoded); // Output: decoded hash string

const charCodes = stringToCodes(decoded); console.log(charCodes); // Output: Array of character codes

const num = bytesToNum32(charCodes); console.log(num); // Output: 32-bit number``

Contributing

Contributions are welcome! Please open an issue or submit a pull request on GitHub.

License

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