57 lines
1.4 KiB
TypeScript
57 lines
1.4 KiB
TypeScript
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/**
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* @packageDocumentation
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*
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* A [Hash Mapped Trie](https://en.wikipedia.org/wiki/Hash_array_mapped_trie) implementation for JavaScript.
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*
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* This is used by [@helia/unixfs](https://www.npmjs.com/package/@helia/unixfs) for it's HAMT-sharded directory implementation.
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*
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* @example
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*
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* ```TypeScript
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* import { createHAMT } from 'hamt-sharding'
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* import crypto from 'crypto-promise'
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*
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* // decide how to hash buffers made from keys, can return a Promise
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* const hashFn = async (buf) => {
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* return crypto
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* .createHash('sha256')
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* .update(buf)
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* .digest()
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* }
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*
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* const bucket = createHAMT({
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* hashFn: hashFn
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* })
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*
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* await bucket.put('key', 'value')
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*
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* const output = await bucket.get('key')
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* // output === 'value'
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* ```
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*/
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import { Bucket } from './bucket.js'
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import { wrapHash } from './consumable-hash.js'
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import type { BucketOptions, BucketPosition, BucketChild } from './bucket.js'
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interface UserBucketOptions {
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hashFn(value: Uint8Array): Promise<Uint8Array>
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bits?: number
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}
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export function createHAMT<T> (options: UserBucketOptions): Bucket<T> {
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if (options == null || options.hashFn == null) {
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throw new Error('please define an options.hashFn')
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}
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const bucketOptions = {
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bits: options.bits ?? 8,
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hash: wrapHash(options.hashFn)
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}
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return new Bucket<T>(bucketOptions)
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}
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export { Bucket }
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export type { BucketOptions, BucketPosition, BucketChild }
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