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https://github.com/harttle/liquidjs.git
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Max MedveandGitHub
3a0d80d1f4
The Tokenizer constructor calls createTrie(operators) and createTrie(literalValues) on every instantiation, and liquidjs builds a fresh Tokenizer per output/tag while parsing. On typical templates this rebuilt the same prefix-tries dozens of times and showed up as a large share of parse CPU in profiling. Memoize createTrie with a module-level WeakMap keyed on the input object. The inputs (operators, literalValues) are stable references and the trie is only ever read afterward (via matchTrie), never mutated, so caching by reference is behavior-preserving. WeakMap (not Map) lets short-lived, per-instance operator objects and their tries be garbage collected.
44 lines
1.1 KiB
TypeScript
44 lines
1.1 KiB
TypeScript
import { isWord } from '../util/character'
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interface TrieInput<T> {
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[key: string]: T
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}
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export type Trie<T> = {
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data?: T
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end?: true
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needBoundary?: true
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} & Record<string, any>
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// Tries are built once per input object and reused: the Tokenizer rebuilds them
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// on every instantiation, but `input` (operators/literalValues) is a stable
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// reference. WeakMap-keying by `input` lets short-lived operator objects (and
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// their tries) be garbage collected. The returned trie is treated as read-only
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// by callers (matchTrie only reads it); do not mutate it.
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const trieCache = new WeakMap<TrieInput<any>, Trie<any>>()
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export function createTrie<T = any> (input: TrieInput<T>): Trie<T> {
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const cached = trieCache.get(input)
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if (cached) return cached
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const trie: Trie<T> = {}
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for (const [name, data] of Object.entries(input)) {
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let node = trie
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for (let i = 0; i < name.length; i++) {
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const c = name[i]
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node[c] = node[c] || {}
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if (i === name.length - 1 && isWord(name[i])) {
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node[c].needBoundary = true
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}
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node = node[c]
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}
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node.data = data
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node.end = true
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}
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trieCache.set(input, trie)
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return trie
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}
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