75 lines
2.5 KiB
JavaScript
75 lines
2.5 KiB
JavaScript
/*! Based on fetch-blob. MIT License. Jimmy Wärting <https://jimmy.warting.se/opensource> & David Frank */
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import { isFunction } from "./isFunction.js";
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const CHUNK_SIZE = 65536;
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async function* clonePart(part) {
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const end = part.byteOffset + part.byteLength;
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let position = part.byteOffset;
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while (position !== end) {
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const size = Math.min(end - position, CHUNK_SIZE);
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const chunk = part.buffer.slice(position, position + size);
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position += chunk.byteLength;
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yield new Uint8Array(chunk);
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}
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}
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async function* consumeNodeBlob(blob) {
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let position = 0;
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while (position !== blob.size) {
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const chunk = blob.slice(position, Math.min(blob.size, position + CHUNK_SIZE));
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const buffer = await chunk.arrayBuffer();
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position += buffer.byteLength;
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yield new Uint8Array(buffer);
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}
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}
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export async function* consumeBlobParts(parts, clone = false) {
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for (const part of parts) {
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if (ArrayBuffer.isView(part)) {
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if (clone) {
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yield* clonePart(part);
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}
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else {
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yield part;
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}
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}
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else if (isFunction(part.stream)) {
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yield* part.stream();
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}
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else {
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yield* consumeNodeBlob(part);
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}
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}
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}
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export function* sliceBlob(blobParts, blobSize, start = 0, end) {
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end !== null && end !== void 0 ? end : (end = blobSize);
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let relativeStart = start < 0
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? Math.max(blobSize + start, 0)
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: Math.min(start, blobSize);
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let relativeEnd = end < 0
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? Math.max(blobSize + end, 0)
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: Math.min(end, blobSize);
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const span = Math.max(relativeEnd - relativeStart, 0);
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let added = 0;
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for (const part of blobParts) {
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if (added >= span) {
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break;
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}
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const partSize = ArrayBuffer.isView(part) ? part.byteLength : part.size;
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if (relativeStart && partSize <= relativeStart) {
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relativeStart -= partSize;
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relativeEnd -= partSize;
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}
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else {
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let chunk;
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if (ArrayBuffer.isView(part)) {
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chunk = part.subarray(relativeStart, Math.min(partSize, relativeEnd));
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added += chunk.byteLength;
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}
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else {
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chunk = part.slice(relativeStart, Math.min(partSize, relativeEnd));
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added += chunk.size;
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}
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relativeEnd -= partSize;
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relativeStart = 0;
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yield chunk;
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}
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}
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}
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