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/**
* DON'T depend on anything from the outside like `promiseTry`, as this module is part of a separate lazy-loaded chunk.
*
* Including anything from the main chunk would include the whole chunk by default.
* Even it it would be tree-shaken during build, it won't be tree-shaken in dev.
*
* In the future consider separating common utils into a separate shared chunk.
*/
import binary from "./harfbuzz-wasm";
import bindings from "./harfbuzz-bindings";
/**
* Lazy loads wasm and respective bindings for font subsetting based on the harfbuzzjs.
*/
let loadedWasm: ReturnType<typeof load> | null = null;
// TODO: consider adding support for fetching the wasm from an URL (external CDN, data URL, etc.)
const load = (): Promise<{
subset: (
fontBuffer: ArrayBuffer,
codePoints: ReadonlySet<number>,
) => Uint8Array;
}> => {
return new Promise(async (resolve, reject) => {
try {
const module = await WebAssembly.instantiate(binary);
const harfbuzzJsWasm = module.instance.exports;
// @ts-expect-error since `.buffer` is custom prop
const heapu8 = new Uint8Array(harfbuzzJsWasm.memory.buffer);
const hbSubset = {
subset: (fontBuffer: ArrayBuffer, codePoints: ReadonlySet<number>) => {
return bindings.subset(
harfbuzzJsWasm,
heapu8,
fontBuffer,
codePoints,
);
},
};
resolve(hbSubset);
} catch (e) {
reject(e);
}
});
};
// lazy load the default export
export default (): ReturnType<typeof load> => {
if (!loadedWasm) {
loadedWasm = load();
}
return loadedWasm;
};
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