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Don’t use instantiateStreaming (#494)

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This commit is contained in:
Surma
2019-03-04 14:50:15 +00:00
committed by Jake Archibald
parent 7a6c6ec210
commit db76d4417c
1 changed files with 13 additions and 3 deletions
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16
src/codecs/rotate/processor.ts
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@@ -1,19 +1,29 @@
import wasmUrl from '../../../codecs/rotate/rotate.wasm'; import wasmUrl from '../../../codecs/rotate/rotate.wasm';
import { RotateOptions, RotateModuleInstance } from './processor-meta'; import { RotateOptions, RotateModuleInstance } from './processor-meta';
const instancePromise = (WebAssembly as any).instantiateStreaming(fetch(wasmUrl)); // We are loading a 500B module here. Loading the code to feature-detect
// `instantiateStreaming` probably takes longer to load than the time we save by
// using `instantiateStreaming` in the first place. So let’s just use
// `ArrayBuffer`s here.
const instancePromise = fetch(wasmUrl)
.then(r => r.arrayBuffer())
.then(buf => WebAssembly.instantiate(buf));
export async function rotate( export async function rotate(
data: ImageData, data: ImageData,
opts: RotateOptions, opts: RotateOptions,
): Promise<ImageData> { ): Promise<ImageData> {
const { instance } = (await instancePromise) as {instance: RotateModuleInstance}; const { instance } = (await instancePromise) as {
instance: RotateModuleInstance;
};
// Number of wasm memory pages (á 64KiB) needed to store the image twice. // Number of wasm memory pages (á 64KiB) needed to store the image twice.
const bytesPerImage = data.width * data.height * 4; const bytesPerImage = data.width * data.height * 4;
const numPagesNeeded = Math.ceil((bytesPerImage * 2 + 8) / (64 * 1024)); const numPagesNeeded = Math.ceil((bytesPerImage * 2 + 8) / (64 * 1024));
// Only count full pages, just to be safe. // Only count full pages, just to be safe.
const numPagesAvailable = Math.floor(instance.exports.memory.buffer.byteLength / (64 * 1024)); const numPagesAvailable = Math.floor(
instance.exports.memory.buffer.byteLength / (64 * 1024),
);
const additionalPagesToAllocate = numPagesNeeded - numPagesAvailable; const additionalPagesToAllocate = numPagesNeeded - numPagesAvailable;
if (additionalPagesToAllocate > 0) { if (additionalPagesToAllocate > 0) {