get-uri
Version:
Returns a `stream.Readable` from a URI string
36 lines • 1.29 kB
JavaScript
import createDebug from 'debug';
import { Readable } from 'stream';
import { createHash } from 'crypto';
import { dataUriToBuffer } from 'data-uri-to-buffer';
import NotModifiedError from './notmodified.js';
const debug = createDebug('get-uri:data');
class DataReadable extends Readable {
constructor(hash, buf) {
super();
this.push(buf);
this.push(null);
this.hash = hash;
}
}
/**
* Returns a Readable stream from a "data:" URI.
*/
export const data = async ({ href: uri }, { cache } = {}) => {
// need to create a SHA1 hash of the URI string, for cacheability checks
// in future `getUri()` calls with the same data URI passed in.
const shasum = createHash('sha1');
shasum.update(uri);
const hash = shasum.digest('hex');
debug('generated SHA1 hash for "data:" URI: %o', hash);
// check if the cache is the same "data:" URI that was previously passed in.
if (cache?.hash === hash) {
debug('got matching cache SHA1 hash: %o', hash);
throw new NotModifiedError();
}
else {
debug('creating Readable stream from "data:" URI buffer');
const { buffer } = dataUriToBuffer(uri);
return new DataReadable(hash, Buffer.from(buffer));
}
};
//# sourceMappingURL=data.js.map