1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
|
'use strict'
const EE = require('events')
const Yallist = require('yallist')
const EOF = Symbol('EOF')
const MAYBE_EMIT_END = Symbol('maybeEmitEnd')
const EMITTED_END = Symbol('emittedEnd')
const CLOSED = Symbol('closed')
const READ = Symbol('read')
const FLUSH = Symbol('flush')
const doIter = process.env._MP_NO_ITERATOR_SYMBOLS_ !== '1'
const ASYNCITERATOR = doIter && Symbol.asyncIterator || Symbol('asyncIterator not implemented')
const ITERATOR = doIter && Symbol.iterator || Symbol('iterator not implemented')
const FLUSHCHUNK = Symbol('flushChunk')
const SD = require('string_decoder').StringDecoder
const ENCODING = Symbol('encoding')
const DECODER = Symbol('decoder')
const FLOWING = Symbol('flowing')
const RESUME = Symbol('resume')
const BUFFERLENGTH = Symbol('bufferLength')
const BUFFERPUSH = Symbol('bufferPush')
const BUFFERSHIFT = Symbol('bufferShift')
const OBJECTMODE = Symbol('objectMode')
// Buffer in node 4.x < 4.5.0 doesn't have working Buffer.from
// or Buffer.alloc, and Buffer in node 10 deprecated the ctor.
// .M, this is fine .\^/M..
let B = Buffer
/* istanbul ignore next */
if (!B.alloc) {
B = require('safe-buffer').Buffer
}
module.exports = class MiniPass extends EE {
constructor (options) {
super()
this[FLOWING] = false
this.pipes = new Yallist()
this.buffer = new Yallist()
this[OBJECTMODE] = options && options.objectMode || false
if (this[OBJECTMODE])
this[ENCODING] = null
else
this[ENCODING] = options && options.encoding || null
if (this[ENCODING] === 'buffer')
this[ENCODING] = null
this[DECODER] = this[ENCODING] ? new SD(this[ENCODING]) : null
this[EOF] = false
this[EMITTED_END] = false
this[CLOSED] = false
this.writable = true
this.readable = true
this[BUFFERLENGTH] = 0
}
get bufferLength () { return this[BUFFERLENGTH] }
get encoding () { return this[ENCODING] }
set encoding (enc) {
if (this[OBJECTMODE])
throw new Error('cannot set encoding in objectMode')
if (this[ENCODING] && enc !== this[ENCODING] &&
(this[DECODER] && this[DECODER].lastNeed || this[BUFFERLENGTH]))
throw new Error('cannot change encoding')
if (this[ENCODING] !== enc) {
this[DECODER] = enc ? new SD(enc) : null
if (this.buffer.length)
this.buffer = this.buffer.map(chunk => this[DECODER].write(chunk))
}
this[ENCODING] = enc
}
setEncoding (enc) {
this.encoding = enc
}
write (chunk, encoding, cb) {
if (this[EOF])
throw new Error('write after end')
if (typeof encoding === 'function')
cb = encoding, encoding = 'utf8'
if (!encoding)
encoding = 'utf8'
// fast-path writing strings of same encoding to a stream with
// an empty buffer, skipping the buffer/decoder dance
if (typeof chunk === 'string' && !this[OBJECTMODE] &&
// unless it is a string already ready for us to use
!(encoding === this[ENCODING] && !this[DECODER].lastNeed)) {
chunk = B.from(chunk, encoding)
}
if (B.isBuffer(chunk) && this[ENCODING])
chunk = this[DECODER].write(chunk)
try {
return this.flowing
? (this.emit('data', chunk), this.flowing)
: (this[BUFFERPUSH](chunk), false)
} finally {
this.emit('readable')
if (cb)
cb()
}
}
read (n) {
try {
if (this[BUFFERLENGTH] === 0 || n === 0 || n > this[BUFFERLENGTH])
return null
if (this[OBJECTMODE])
n = null
if (this.buffer.length > 1 && !this[OBJECTMODE]) {
if (this.encoding)
this.buffer = new Yallist([
Array.from(this.buffer).join('')
])
else
this.buffer = new Yallist([
B.concat(Array.from(this.buffer), this[BUFFERLENGTH])
])
}
return this[READ](n || null, this.buffer.head.value)
} finally {
this[MAYBE_EMIT_END]()
}
}
[READ] (n, chunk) {
if (n === chunk.length || n === null)
this[BUFFERSHIFT]()
else {
this.buffer.head.value = chunk.slice(n)
chunk = chunk.slice(0, n)
this[BUFFERLENGTH] -= n
}
this.emit('data', chunk)
if (!this.buffer.length && !this[EOF])
this.emit('drain')
return chunk
}
end (chunk, encoding, cb) {
if (typeof chunk === 'function')
cb = chunk, chunk = null
if (typeof encoding === 'function')
cb = encoding, encoding = 'utf8'
if (chunk)
this.write(chunk, encoding)
if (cb)
this.once('end', cb)
this[EOF] = true
this.writable = false
if (this.flowing)
this[MAYBE_EMIT_END]()
}
// don't let the internal resume be overwritten
[RESUME] () {
this[FLOWING] = true
this.emit('resume')
if (this.buffer.length)
this[FLUSH]()
else if (this[EOF])
this[MAYBE_EMIT_END]()
else
this.emit('drain')
}
resume () {
return this[RESUME]()
}
pause () {
this[FLOWING] = false
}
get flowing () {
return this[FLOWING]
}
[BUFFERPUSH] (chunk) {
if (this[OBJECTMODE])
this[BUFFERLENGTH] += 1
else
this[BUFFERLENGTH] += chunk.length
return this.buffer.push(chunk)
}
[BUFFERSHIFT] () {
if (this.buffer.length) {
if (this[OBJECTMODE])
this[BUFFERLENGTH] -= 1
else
this[BUFFERLENGTH] -= this.buffer.head.value.length
}
return this.buffer.shift()
}
[FLUSH] () {
do {} while (this[FLUSHCHUNK](this[BUFFERSHIFT]()))
if (!this.buffer.length && !this[EOF])
this.emit('drain')
}
[FLUSHCHUNK] (chunk) {
return chunk ? (this.emit('data', chunk), this.flowing) : false
}
pipe (dest, opts) {
if (dest === process.stdout || dest === process.stderr)
(opts = opts || {}).end = false
const p = { dest: dest, opts: opts, ondrain: _ => this[RESUME]() }
this.pipes.push(p)
dest.on('drain', p.ondrain)
this[RESUME]()
return dest
}
addListener (ev, fn) {
return this.on(ev, fn)
}
on (ev, fn) {
try {
return super.on(ev, fn)
} finally {
if (ev === 'data' && !this.pipes.length && !this.flowing)
this[RESUME]()
else if (ev === 'end' && this[EMITTED_END]) {
super.emit('end')
this.removeAllListeners('end')
}
}
}
get emittedEnd () {
return this[EMITTED_END]
}
[MAYBE_EMIT_END] () {
if (!this[EMITTED_END] && this.buffer.length === 0 && this[EOF]) {
this.emit('end')
this.emit('prefinish')
this.emit('finish')
if (this[CLOSED])
this.emit('close')
}
}
emit (ev, data) {
if (ev === 'data') {
if (!data)
return
if (this.pipes.length)
this.pipes.forEach(p => p.dest.write(data) || this.pause())
} else if (ev === 'end') {
if (this[EMITTED_END] === true)
return
this[EMITTED_END] = true
this.readable = false
if (this[DECODER]) {
data = this[DECODER].end()
if (data) {
this.pipes.forEach(p => p.dest.write(data))
super.emit('data', data)
}
}
this.pipes.forEach(p => {
p.dest.removeListener('drain', p.ondrain)
if (!p.opts || p.opts.end !== false)
p.dest.end()
})
} else if (ev === 'close') {
this[CLOSED] = true
// don't emit close before 'end' and 'finish'
if (!this[EMITTED_END])
return
}
const args = new Array(arguments.length)
args[0] = ev
args[1] = data
if (arguments.length > 2) {
for (let i = 2; i < arguments.length; i++) {
args[i] = arguments[i]
}
}
try {
return super.emit.apply(this, args)
} finally {
if (ev !== 'end')
this[MAYBE_EMIT_END]()
else
this.removeAllListeners('end')
}
}
// const all = await stream.collect()
collect () {
return new Promise((resolve, reject) => {
const buf = []
this.on('data', c => buf.push(c))
this.on('end', () => resolve(buf))
this.on('error', reject)
})
}
// for await (let chunk of stream)
[ASYNCITERATOR] () {
const next = () => {
const res = this.read()
if (res !== null)
return Promise.resolve({ done: false, value: res })
if (this[EOF])
return Promise.resolve({ done: true })
let resolve = null
let reject = null
const onerr = er => {
this.removeListener('data', ondata)
this.removeListener('end', onend)
reject(er)
}
const ondata = value => {
this.removeListener('error', onerr)
this.removeListener('end', onend)
this.pause()
resolve({ value: value, done: !!this[EOF] })
}
const onend = () => {
this.removeListener('error', onerr)
this.removeListener('data', ondata)
resolve({ done: true })
}
return new Promise((res, rej) => {
reject = rej
resolve = res
this.once('error', onerr)
this.once('end', onend)
this.once('data', ondata)
})
}
return { next }
}
// for (let chunk of stream)
[ITERATOR] () {
const next = () => {
const value = this.read()
const done = value === null
return { value, done }
}
return { next }
}
}
|