@tokenizer/range/lib/range-request-factory.js

Range-request tokenizer adapter

import { RangeRequestTokenizer, roundRange } from './range-request-tokenizer.js';
import initDebug from 'debug';
const debug = initDebug('range-request-reader');
export class RangeRequestFactory {
    constructor(rangeRequestClient) {
        this.rangeRequestClient = rangeRequestClient;
        this.config = {
            avoidHeadRequests: false,
            initialChunkSize: 4 * 1024,
            minimumChunkSize: 1024
        };
    }
    async initTokenizer(config) {
        if (config) {
            this.config = { ...this.config, ...config };
        }
        const headRequestInfo = await this.getHeadRequestInfo();
        if (!headRequestInfo.acceptPartialRequests) {
            throw new Error('Server does not accept partial requests');
        }
        return new RangeRequestTokenizer(this.rangeRequestClient, {
            fileInfo: headRequestInfo,
            minimumChunkSize: this.config.minimumChunkSize,
            abortSignal: config?.abortSignal
        });
    }
    /**
     * Get file information, an HTTP-client may implement this doing a HEAD request
     * @return Promise with head-request-info, extending tokenizer file-info.
     */
    getHeadRequestInfo() {
        return this.config.avoidHeadRequests ?
            this.fetchFileInfoWithGetRequest() :
            this.fetchFileInfoWithHeadRequest();
    }
    async fetchFileInfoWithHeadRequest() {
        debug('_fetchSizeWithHeadRequest()');
        if (this.rangeRequestClient.getHeadInfo) {
            const info = await this.rangeRequestClient.getHeadInfo();
            if (info.size) {
                debug(`MIME-type=${info.mimeType}, content-length=${info.size}, accept-partial-requests=${info.acceptPartialRequests}`);
                return info;
            }
        }
        // Content-Length not provided by the server, fallback to
        // GET requests.
        debug('Content-Length not provided by the server, fallback to GET requests');
        return this.fetchFileInfoWithGetRequest();
    }
    async fetchFileInfoWithGetRequest() {
        const range = roundRange([0, this.config.initialChunkSize], this.config.minimumChunkSize);
        const response = await this.rangeRequestClient.getResponse('GET', range);
        debug(`_fetchSizeWithGetRequest response: contentRange=[${response.contentRange?.firstBytePosition}-${response.contentRange?.lastBytePosition}/${response.contentRange?.instanceLength}]`);
        if (!response.contentRange) {
            throw new Error('Failed to resolve content range (file size)');
        }
        return response;
    }
}
//# sourceMappingURL=range-request-factory.js.map