https://github.com/deno-library/crc32
https://github.com/deno-library/crc32
Last synced: 5 months ago
JSON representation
- Host: GitHub
- URL: https://github.com/deno-library/crc32
- Owner: deno-library
- License: mit
- Created: 2020-07-26T01:46:56.000Z (almost 5 years ago)
- Default Branch: master
- Last Pushed: 2024-11-18T03:03:24.000Z (6 months ago)
- Last Synced: 2024-11-18T04:18:25.884Z (6 months ago)
- Language: TypeScript
- Size: 19.5 KB
- Stars: 2
- Watchers: 2
- Forks: 2
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Funding: .github/FUNDING.yml
- License: LICENSE
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README
# crc32
[](https://jsr.io/@deno-library/crc32)
A TypeScript implementation of crc32, can be use for deno.
> CRC means 'Cyclic Redundancy Check' and is a way to checksum data. It is a simple algorithm based on polynomials and is used in such projects as gzip.
## Definition
```ts
crc32(arr: Uint8Array | string): string;
class Crc32Stream {
reset(): void;
append(arr: Uint8Array | string): string;
get crc32(): string;
}
hexToUint8Array(str: string): Uint8Array;
uint8ArrayToHex(bytes: Uint8Array): string;
```
## Usage
**basic**
```ts
import { crc32 } from "jsr:@deno-library/crc32";
//import { crc32 } from "https://deno.land/x/crc32/mod.ts";
const str = "deno";
const bytes = new TextEncoder().encode(str);
const crc32_deno = "fd6f8c63";
assert(crc32(str) === crc32_deno);
assert(crc32(bytes) === crc32_deno);
```
**Crc32Stream**
Used to calculate src32 value for large file
```ts
import { crc32 } from "jsr:@deno-library/crc32";
//import { Crc32Stream } from "https://deno.land/x/crc32/mod.ts";
const crc32_deno = "fd6f8c63";
const crc32Stream = new Crc32Stream();
crc32Stream.append("d"); // 98dd4acc === crc32("d")
crc32Stream.append("e"); // 7d90298b === crc32("de")
crc32Stream.append("n"); // 21f6953 === crc32("den")
const val = crc32Stream.append("o");
assertEquals(val, crc32_deno);
assertEquals(crc32Stream.crc32, crc32_deno);
assertEquals(crc32Stream.crc32, crc32_deno);
crc32Stream.reset();
crc32Stream.append("d"); // 98dd4acc === crc32("d")
crc32Stream.append("e"); // 7d90298b === crc32("de")
crc32Stream.append("n"); // 21f6953 === crc32("den")
const val = crc32Stream.append("o");
assertEquals(val, crc32_deno);
assertEquals(crc32Stream.crc32, crc32_deno);
assertEquals(crc32Stream.crc32, crc32_deno);
```
## Other methods
```ts
import { hexToUint8Array, uint8ArrayToHex } from "jsr:@deno-library/crc32";
const crc32_deno = "fd6f8c63";
// hexToUint8Array
const bytes = hexToUint8Array(crc32_deno);
assert(parseInt("fd", 16) === bytes[0]);
assert(parseInt("6f", 16) === bytes[1]);
assert(parseInt("8c", 16) === bytes[2]);
assert(parseInt("63", 16) === bytes[3]);
// uint8ArrayToHex
const bytes = new Uint8Array([
parseInt("fd", 16),
parseInt("6f", 16),
parseInt("8c", 16),
parseInt("63", 16),
]);
assert(uint8ArrayToHex(bytes) === crc32_deno);
```