Constnium/node_modules/fetch-blob/from.js
2022-06-23 02:03:24 +02:00

106 lines
2.8 KiB
JavaScript

import { statSync, createReadStream, promises as fs } from 'node:fs'
import { basename } from 'node:path'
import DOMException from 'node-domexception'
import File from './file.js'
import Blob from './index.js'
const { stat } = fs
/**
* @param {string} path filepath on the disk
* @param {string} [type] mimetype to use
*/
const blobFromSync = (path, type) => fromBlob(statSync(path), path, type)
/**
* @param {string} path filepath on the disk
* @param {string} [type] mimetype to use
* @returns {Promise<Blob>}
*/
const blobFrom = (path, type) => stat(path).then(stat => fromBlob(stat, path, type))
/**
* @param {string} path filepath on the disk
* @param {string} [type] mimetype to use
* @returns {Promise<File>}
*/
const fileFrom = (path, type) => stat(path).then(stat => fromFile(stat, path, type))
/**
* @param {string} path filepath on the disk
* @param {string} [type] mimetype to use
*/
const fileFromSync = (path, type) => fromFile(statSync(path), path, type)
// @ts-ignore
const fromBlob = (stat, path, type = '') => new Blob([new BlobDataItem({
path,
size: stat.size,
lastModified: stat.mtimeMs,
start: 0
})], { type })
// @ts-ignore
const fromFile = (stat, path, type = '') => new File([new BlobDataItem({
path,
size: stat.size,
lastModified: stat.mtimeMs,
start: 0
})], basename(path), { type, lastModified: stat.mtimeMs })
/**
* This is a blob backed up by a file on the disk
* with minium requirement. Its wrapped around a Blob as a blobPart
* so you have no direct access to this.
*
* @private
*/
class BlobDataItem {
#path
#start
constructor (options) {
this.#path = options.path
this.#start = options.start
this.size = options.size
this.lastModified = options.lastModified
this.originalSize = options.originalSize === undefined
? options.size
: options.originalSize
}
/**
* Slicing arguments is first validated and formatted
* to not be out of range by Blob.prototype.slice
*/
slice (start, end) {
return new BlobDataItem({
path: this.#path,
lastModified: this.lastModified,
originalSize: this.originalSize,
size: end - start,
start: this.#start + start
})
}
async * stream () {
const { mtimeMs, size } = await stat(this.#path)
if (mtimeMs > this.lastModified || this.originalSize !== size) {
throw new DOMException('The requested file could not be read, typically due to permission problems that have occurred after a reference to a file was acquired.', 'NotReadableError')
}
yield * createReadStream(this.#path, {
start: this.#start,
end: this.#start + this.size - 1
})
}
get [Symbol.toStringTag] () {
return 'Blob'
}
}
export default blobFromSync
export { File, Blob, blobFrom, blobFromSync, fileFrom, fileFromSync }