|
| 1 | +'use strict' |
| 2 | +const { Minipass } = require('minipass') |
| 3 | +const TYPE = Symbol('type') |
| 4 | +const BUFFER = Symbol('buffer') |
| 5 | + |
| 6 | +class Blob { |
| 7 | + constructor (blobParts, options) { |
| 8 | + this[TYPE] = '' |
| 9 | + |
| 10 | + const buffers = [] |
| 11 | + let size = 0 |
| 12 | + |
| 13 | + if (blobParts) { |
| 14 | + const a = blobParts |
| 15 | + const length = Number(a.length) |
| 16 | + for (let i = 0; i < length; i++) { |
| 17 | + const element = a[i] |
| 18 | + const buffer = element instanceof Buffer ? element |
| 19 | + : ArrayBuffer.isView(element) |
| 20 | + ? Buffer.from(element.buffer, element.byteOffset, element.byteLength) |
| 21 | + : element instanceof ArrayBuffer ? Buffer.from(element) |
| 22 | + : element instanceof Blob ? element[BUFFER] |
| 23 | + : typeof element === 'string' ? Buffer.from(element) |
| 24 | + : Buffer.from(String(element)) |
| 25 | + size += buffer.length |
| 26 | + buffers.push(buffer) |
| 27 | + } |
| 28 | + } |
| 29 | + |
| 30 | + this[BUFFER] = Buffer.concat(buffers, size) |
| 31 | + |
| 32 | + const type = options && options.type !== undefined |
| 33 | + && String(options.type).toLowerCase() |
| 34 | + if (type && !/[^\u0020-\u007E]/.test(type)) { |
| 35 | + this[TYPE] = type |
| 36 | + } |
| 37 | + } |
| 38 | + |
| 39 | + get size () { |
| 40 | + return this[BUFFER].length |
| 41 | + } |
| 42 | + |
| 43 | + get type () { |
| 44 | + return this[TYPE] |
| 45 | + } |
| 46 | + |
| 47 | + text () { |
| 48 | + return Promise.resolve(this[BUFFER].toString()) |
| 49 | + } |
| 50 | + |
| 51 | + arrayBuffer () { |
| 52 | + const buf = this[BUFFER] |
| 53 | + const off = buf.byteOffset |
| 54 | + const len = buf.byteLength |
| 55 | + const ab = buf.buffer.slice(off, off + len) |
| 56 | + return Promise.resolve(ab) |
| 57 | + } |
| 58 | + |
| 59 | + stream () { |
| 60 | + return new Minipass().end(this[BUFFER]) |
| 61 | + } |
| 62 | + |
| 63 | + slice (start, end, type) { |
| 64 | + const size = this.size |
| 65 | + const relativeStart = start === undefined ? 0 |
| 66 | + : start < 0 ? Math.max(size + start, 0) |
| 67 | + : Math.min(start, size) |
| 68 | + const relativeEnd = end === undefined ? size |
| 69 | + : end < 0 ? Math.max(size + end, 0) |
| 70 | + : Math.min(end, size) |
| 71 | + const span = Math.max(relativeEnd - relativeStart, 0) |
| 72 | + |
| 73 | + const buffer = this[BUFFER] |
| 74 | + const slicedBuffer = buffer.slice( |
| 75 | + relativeStart, |
| 76 | + relativeStart + span |
| 77 | + ) |
| 78 | + const blob = new Blob([], { type }) |
| 79 | + blob[BUFFER] = slicedBuffer |
| 80 | + return blob |
| 81 | + } |
| 82 | + |
| 83 | + get [Symbol.toStringTag] () { |
| 84 | + return 'Blob' |
| 85 | + } |
| 86 | + |
| 87 | + static get BUFFER () { |
| 88 | + return BUFFER |
| 89 | + } |
| 90 | +} |
| 91 | + |
| 92 | +Object.defineProperties(Blob.prototype, { |
| 93 | + size: { enumerable: true }, |
| 94 | + type: { enumerable: true }, |
| 95 | +}) |
| 96 | + |
| 97 | +module.exports = Blob |
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