@httpland/range-request-middleware/esm/ranges/utils.js

HTTP range request middleware

// Copyright 2023-latest the httpland authors. All rights reserved. MIT license.
// This module is browser compatible.
import { concat, isString, stringifyContentRange, } from "../deps.js";
/** Deserialize {@link MultipartByteranges} into multipart/byterages bytestream. */
export function multipartByteranges(args) {
    const { content, contentType, ranges, boundary, rangeUnit } = args;
    const size = content.byteLength;
    const boundaryDelimiter = "--" + boundary;
    const endDelimiter = boundaryDelimiter + "--";
    const encoder = new TextEncoder();
    const contentTypeStr = `Content-Type: ${contentType}`;
    const contents = ranges
        .map(bodyParts)
        .flat()
        .map((buffer) => new Uint8Array(buffer))
        .concat(encoder.encode(endDelimiter));
    const buffer = join(contents, encoder.encode("\n")).buffer;
    return buffer;
    function bodyParts(inclRange) {
        const contentRangeStr = stringifyContentRange({
            rangeUnit,
            ...inclRange,
            completeLength: size,
        });
        return [
            boundaryDelimiter,
            contentTypeStr,
            `Content-Range: ${contentRangeStr}`,
            "",
            content.slice(inclRange.firstPos, inclRange.lastPos + 1),
        ].map(toBuffer);
    }
}
export function join(list, separator) {
    return list.reduce((acc, cur, i) => {
        if (!i)
            return concat(acc, cur);
        return concat(acc, separator, cur);
    }, new Uint8Array());
}
export function toBuffer(input) {
    return isString(input) ? new TextEncoder().encode(input) : input;
}