58 lines
1.5 KiB
TypeScript
58 lines
1.5 KiB
TypeScript
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import type { ExtractionResult } from "@kreuzberg/wasm";
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import { extractBytes, initWasm } from "@kreuzberg/wasm";
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class ExtractionCache {
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private cache = new Map<string, ExtractionResult>();
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private fileHashes = new Map<File, string>();
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async getHash(file: File): Promise<string> {
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if (this.fileHashes.has(file)) {
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return this.fileHashes.get(file)!;
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}
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const buffer = await file.arrayBuffer();
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const hashBuffer = await crypto.subtle.digest("SHA-256", buffer);
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const hashArray = Array.from(new Uint8Array(hashBuffer));
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const hashStr = hashArray.map((b) => b.toString(16).padStart(2, "0")).join("");
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this.fileHashes.set(file, hashStr);
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return hashStr;
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}
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async extract(file: File): Promise<ExtractionResult> {
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const hash = await this.getHash(file);
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if (this.cache.has(hash)) {
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console.log("Cache hit for", file.name);
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return this.cache.get(hash)!;
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}
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console.log("Cache miss for", file.name);
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const bytes = new Uint8Array(await file.arrayBuffer());
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const result = await extractBytes(bytes, file.type);
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this.cache.set(hash, result);
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return result;
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}
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clear() {
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this.cache.clear();
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this.fileHashes.clear();
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}
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getSize() {
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return this.cache.size;
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}
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}
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async function demonstrateCaching() {
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await initWasm();
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const cache = new ExtractionCache();
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const _result = await cache.extract(new File([], "test.pdf"));
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console.log("Cache size:", cache.getSize());
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}
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demonstrateCaching().catch(console.error);
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