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| -rw-r--r-- | node_modules/undici/lib/fileapi/util.js | 392 |
1 files changed, 392 insertions, 0 deletions
diff --git a/node_modules/undici/lib/fileapi/util.js b/node_modules/undici/lib/fileapi/util.js new file mode 100644 index 0000000..1d10899 --- /dev/null +++ b/node_modules/undici/lib/fileapi/util.js @@ -0,0 +1,392 @@ +'use strict' + +const { + kState, + kError, + kResult, + kAborted, + kLastProgressEventFired +} = require('./symbols') +const { ProgressEvent } = require('./progressevent') +const { getEncoding } = require('./encoding') +const { DOMException } = require('../fetch/constants') +const { serializeAMimeType, parseMIMEType } = require('../fetch/dataURL') +const { types } = require('util') +const { StringDecoder } = require('string_decoder') +const { btoa } = require('buffer') + +/** @type {PropertyDescriptor} */ +const staticPropertyDescriptors = { + enumerable: true, + writable: false, + configurable: false +} + +/** + * @see https://w3c.github.io/FileAPI/#readOperation + * @param {import('./filereader').FileReader} fr + * @param {import('buffer').Blob} blob + * @param {string} type + * @param {string?} encodingName + */ +function readOperation (fr, blob, type, encodingName) { + // 1. If fr’s state is "loading", throw an InvalidStateError + // DOMException. + if (fr[kState] === 'loading') { + throw new DOMException('Invalid state', 'InvalidStateError') + } + + // 2. Set fr’s state to "loading". + fr[kState] = 'loading' + + // 3. Set fr’s result to null. + fr[kResult] = null + + // 4. Set fr’s error to null. + fr[kError] = null + + // 5. Let stream be the result of calling get stream on blob. + /** @type {import('stream/web').ReadableStream} */ + const stream = blob.stream() + + // 6. Let reader be the result of getting a reader from stream. + const reader = stream.getReader() + + // 7. Let bytes be an empty byte sequence. + /** @type {Uint8Array[]} */ + const bytes = [] + + // 8. Let chunkPromise be the result of reading a chunk from + // stream with reader. + let chunkPromise = reader.read() + + // 9. Let isFirstChunk be true. + let isFirstChunk = true + + // 10. In parallel, while true: + // Note: "In parallel" just means non-blocking + // Note 2: readOperation itself cannot be async as double + // reading the body would then reject the promise, instead + // of throwing an error. + ;(async () => { + while (!fr[kAborted]) { + // 1. Wait for chunkPromise to be fulfilled or rejected. + try { + const { done, value } = await chunkPromise + + // 2. If chunkPromise is fulfilled, and isFirstChunk is + // true, queue a task to fire a progress event called + // loadstart at fr. + if (isFirstChunk && !fr[kAborted]) { + queueMicrotask(() => { + fireAProgressEvent('loadstart', fr) + }) + } + + // 3. Set isFirstChunk to false. + isFirstChunk = false + + // 4. If chunkPromise is fulfilled with an object whose + // done property is false and whose value property is + // a Uint8Array object, run these steps: + if (!done && types.isUint8Array(value)) { + // 1. Let bs be the byte sequence represented by the + // Uint8Array object. + + // 2. Append bs to bytes. + bytes.push(value) + + // 3. If roughly 50ms have passed since these steps + // were last invoked, queue a task to fire a + // progress event called progress at fr. + if ( + ( + fr[kLastProgressEventFired] === undefined || + Date.now() - fr[kLastProgressEventFired] >= 50 + ) && + !fr[kAborted] + ) { + fr[kLastProgressEventFired] = Date.now() + queueMicrotask(() => { + fireAProgressEvent('progress', fr) + }) + } + + // 4. Set chunkPromise to the result of reading a + // chunk from stream with reader. + chunkPromise = reader.read() + } else if (done) { + // 5. Otherwise, if chunkPromise is fulfilled with an + // object whose done property is true, queue a task + // to run the following steps and abort this algorithm: + queueMicrotask(() => { + // 1. Set fr’s state to "done". + fr[kState] = 'done' + + // 2. Let result be the result of package data given + // bytes, type, blob’s type, and encodingName. + try { + const result = packageData(bytes, type, blob.type, encodingName) + + // 4. Else: + + if (fr[kAborted]) { + return + } + + // 1. Set fr’s result to result. + fr[kResult] = result + + // 2. Fire a progress event called load at the fr. + fireAProgressEvent('load', fr) + } catch (error) { + // 3. If package data threw an exception error: + + // 1. Set fr’s error to error. + fr[kError] = error + + // 2. Fire a progress event called error at fr. + fireAProgressEvent('error', fr) + } + + // 5. If fr’s state is not "loading", fire a progress + // event called loadend at the fr. + if (fr[kState] !== 'loading') { + fireAProgressEvent('loadend', fr) + } + }) + + break + } + } catch (error) { + if (fr[kAborted]) { + return + } + + // 6. Otherwise, if chunkPromise is rejected with an + // error error, queue a task to run the following + // steps and abort this algorithm: + queueMicrotask(() => { + // 1. Set fr’s state to "done". + fr[kState] = 'done' + + // 2. Set fr’s error to error. + fr[kError] = error + + // 3. Fire a progress event called error at fr. + fireAProgressEvent('error', fr) + + // 4. If fr’s state is not "loading", fire a progress + // event called loadend at fr. + if (fr[kState] !== 'loading') { + fireAProgressEvent('loadend', fr) + } + }) + + break + } + } + })() +} + +/** + * @see https://w3c.github.io/FileAPI/#fire-a-progress-event + * @see https://dom.spec.whatwg.org/#concept-event-fire + * @param {string} e The name of the event + * @param {import('./filereader').FileReader} reader + */ +function fireAProgressEvent (e, reader) { + // The progress event e does not bubble. e.bubbles must be false + // The progress event e is NOT cancelable. e.cancelable must be false + const event = new ProgressEvent(e, { + bubbles: false, + cancelable: false + }) + + reader.dispatchEvent(event) +} + +/** + * @see https://w3c.github.io/FileAPI/#blob-package-data + * @param {Uint8Array[]} bytes + * @param {string} type + * @param {string?} mimeType + * @param {string?} encodingName + */ +function packageData (bytes, type, mimeType, encodingName) { + // 1. A Blob has an associated package data algorithm, given + // bytes, a type, a optional mimeType, and a optional + // encodingName, which switches on type and runs the + // associated steps: + + switch (type) { + case 'DataURL': { + // 1. Return bytes as a DataURL [RFC2397] subject to + // the considerations below: + // * Use mimeType as part of the Data URL if it is + // available in keeping with the Data URL + // specification [RFC2397]. + // * If mimeType is not available return a Data URL + // without a media-type. [RFC2397]. + + // https://datatracker.ietf.org/doc/html/rfc2397#section-3 + // dataurl := "data:" [ mediatype ] [ ";base64" ] "," data + // mediatype := [ type "/" subtype ] *( ";" parameter ) + // data := *urlchar + // parameter := attribute "=" value + let dataURL = 'data:' + + const parsed = parseMIMEType(mimeType || 'application/octet-stream') + + if (parsed !== 'failure') { + dataURL += serializeAMimeType(parsed) + } + + dataURL += ';base64,' + + const decoder = new StringDecoder('latin1') + + for (const chunk of bytes) { + dataURL += btoa(decoder.write(chunk)) + } + + dataURL += btoa(decoder.end()) + + return dataURL + } + case 'Text': { + // 1. Let encoding be failure + let encoding = 'failure' + + // 2. If the encodingName is present, set encoding to the + // result of getting an encoding from encodingName. + if (encodingName) { + encoding = getEncoding(encodingName) + } + + // 3. If encoding is failure, and mimeType is present: + if (encoding === 'failure' && mimeType) { + // 1. Let type be the result of parse a MIME type + // given mimeType. + const type = parseMIMEType(mimeType) + + // 2. If type is not failure, set encoding to the result + // of getting an encoding from type’s parameters["charset"]. + if (type !== 'failure') { + encoding = getEncoding(type.parameters.get('charset')) + } + } + + // 4. If encoding is failure, then set encoding to UTF-8. + if (encoding === 'failure') { + encoding = 'UTF-8' + } + + // 5. Decode bytes using fallback encoding encoding, and + // return the result. + return decode(bytes, encoding) + } + case 'ArrayBuffer': { + // Return a new ArrayBuffer whose contents are bytes. + const sequence = combineByteSequences(bytes) + + return sequence.buffer + } + case 'BinaryString': { + // Return bytes as a binary string, in which every byte + // is represented by a code unit of equal value [0..255]. + let binaryString = '' + + const decoder = new StringDecoder('latin1') + + for (const chunk of bytes) { + binaryString += decoder.write(chunk) + } + + binaryString += decoder.end() + + return binaryString + } + } +} + +/** + * @see https://encoding.spec.whatwg.org/#decode + * @param {Uint8Array[]} ioQueue + * @param {string} encoding + */ +function decode (ioQueue, encoding) { + const bytes = combineByteSequences(ioQueue) + + // 1. Let BOMEncoding be the result of BOM sniffing ioQueue. + const BOMEncoding = BOMSniffing(bytes) + + let slice = 0 + + // 2. If BOMEncoding is non-null: + if (BOMEncoding !== null) { + // 1. Set encoding to BOMEncoding. + encoding = BOMEncoding + + // 2. Read three bytes from ioQueue, if BOMEncoding is + // UTF-8; otherwise read two bytes. + // (Do nothing with those bytes.) + slice = BOMEncoding === 'UTF-8' ? 3 : 2 + } + + // 3. Process a queue with an instance of encoding’s + // decoder, ioQueue, output, and "replacement". + + // 4. Return output. + + const sliced = bytes.slice(slice) + return new TextDecoder(encoding).decode(sliced) +} + +/** + * @see https://encoding.spec.whatwg.org/#bom-sniff + * @param {Uint8Array} ioQueue + */ +function BOMSniffing (ioQueue) { + // 1. Let BOM be the result of peeking 3 bytes from ioQueue, + // converted to a byte sequence. + const [a, b, c] = ioQueue + + // 2. For each of the rows in the table below, starting with + // the first one and going down, if BOM starts with the + // bytes given in the first column, then return the + // encoding given in the cell in the second column of that + // row. Otherwise, return null. + if (a === 0xEF && b === 0xBB && c === 0xBF) { + return 'UTF-8' + } else if (a === 0xFE && b === 0xFF) { + return 'UTF-16BE' + } else if (a === 0xFF && b === 0xFE) { + return 'UTF-16LE' + } + + return null +} + +/** + * @param {Uint8Array[]} sequences + */ +function combineByteSequences (sequences) { + const size = sequences.reduce((a, b) => { + return a + b.byteLength + }, 0) + + let offset = 0 + + return sequences.reduce((a, b) => { + a.set(b, offset) + offset += b.byteLength + return a + }, new Uint8Array(size)) +} + +module.exports = { + staticPropertyDescriptors, + readOperation, + fireAProgressEvent +} |