`local-backend` — Default in-process `FingerprintBackend`

(no submodules)

Purpose

LocalBackend is the default implementation of the FingerprintBackend contract that hooks and components depend on. It composes AudioFingerprinter and FingerprintMatcher so callers get a single facade with the same shape the optional PythonBackend exposes from its gated subpath. The class owns no state apart from its two collaborator instances.

Features

Single facade for fingerprint(doc, opts?) and match(query, corpus).
AbortSignal and progress passthrough to the underlying fingerprinter.
Pure in-process: no I/O, no fetch, no server dependency.
Matches the FingerprintBackend interface byte-for-byte so it can be swapped at runtime via a hook prop.
Constructor takes no arguments — defaults rule.

Usage: Basic Example

import { LocalBackend } from "@suaveplan/react-audio-fingerprint/backends/local-backend";

const backend = new LocalBackend();
const fp = await backend.fingerprint(doc);

Usage: Advanced Example

Inject the backend into the hook explicitly to keep the default exporting tree shaken when a custom backend is in use:

import { LocalBackend } from "@suaveplan/react-audio-fingerprint/backends/local-backend";

const backend = new LocalBackend();
const controller = new AbortController();
const fp = await backend.fingerprint(doc, {
    signal: controller.signal,
    onProgress: ({ fraction }) => console.log(fraction),
});
const results = await backend.match(fp, corpus);

API Reference

class LocalBackend implements FingerprintBackend.
fingerprint(doc, opts?): Promise<Fingerprint>.
match(query, corpus): Promise<MatchResult[]>.

Implementation Notes

The class deliberately avoids exposing the underlying AudioFingerprinter and FingerprintMatcher instances so consumers cannot mutate them after construction — this preserves determinism and keeps the public surface stable across versions. There is no caching layer here; consumers wishing to cache fingerprint results between renders should do so at the hook layer, where the relationship to the React commit phase is explicit. Errors from the underlying components propagate unchanged; the backend deliberately does NOT re-wrap them so the original ReactAudioFingerprintError code surfaces to the caller.

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local-backend — Default in-process FingerprintBackend