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node_modules/readable-stream/lib/_stream_writable.js
| 686 lines
| 19.8 KiB
| application/javascript
| JavascriptLexer
|
r789 | // Copyright Joyent, Inc. and other Node contributors. | ||
// | |||
// Permission is hereby granted, free of charge, to any person obtaining a | |||
// copy of this software and associated documentation files (the | |||
// "Software"), to deal in the Software without restriction, including | |||
// without limitation the rights to use, copy, modify, merge, publish, | |||
// distribute, sublicense, and/or sell copies of the Software, and to permit | |||
// persons to whom the Software is furnished to do so, subject to the | |||
// following conditions: | |||
// | |||
// The above copyright notice and this permission notice shall be included | |||
// in all copies or substantial portions of the Software. | |||
// | |||
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS | |||
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF | |||
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN | |||
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, | |||
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR | |||
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE | |||
// USE OR OTHER DEALINGS IN THE SOFTWARE. | |||
// A bit simpler than readable streams. | |||
// Implement an async ._write(chunk, encoding, cb), and it'll handle all | |||
// the drain event emission and buffering. | |||
'use strict'; | |||
/*<replacement>*/ | |||
var pna = require('process-nextick-args'); | |||
/*</replacement>*/ | |||
module.exports = Writable; | |||
/* <replacement> */ | |||
function WriteReq(chunk, encoding, cb) { | |||
this.chunk = chunk; | |||
this.encoding = encoding; | |||
this.callback = cb; | |||
this.next = null; | |||
} | |||
// It seems a linked list but it is not | |||
// there will be only 2 of these for each stream | |||
function CorkedRequest(state) { | |||
var _this = this; | |||
this.next = null; | |||
this.entry = null; | |||
this.finish = function () { | |||
onCorkedFinish(_this, state); | |||
}; | |||
} | |||
/* </replacement> */ | |||
/*<replacement>*/ | |||
var asyncWrite = !process.browser && ['v0.10', 'v0.9.'].indexOf(process.version.slice(0, 5)) > -1 ? setImmediate : pna.nextTick; | |||
/*</replacement>*/ | |||
/*<replacement>*/ | |||
var Duplex; | |||
/*</replacement>*/ | |||
Writable.WritableState = WritableState; | |||
/*<replacement>*/ | |||
var util = Object.create(require('core-util-is')); | |||
util.inherits = require('inherits'); | |||
/*</replacement>*/ | |||
/*<replacement>*/ | |||
var internalUtil = { | |||
deprecate: require('util-deprecate') | |||
}; | |||
/*</replacement>*/ | |||
/*<replacement>*/ | |||
var Stream = require('./internal/streams/stream'); | |||
/*</replacement>*/ | |||
/*<replacement>*/ | |||
var Buffer = require('safe-buffer').Buffer; | |||
var OurUint8Array = global.Uint8Array || function () {}; | |||
function _uint8ArrayToBuffer(chunk) { | |||
return Buffer.from(chunk); | |||
} | |||
function _isUint8Array(obj) { | |||
return Buffer.isBuffer(obj) || obj instanceof OurUint8Array; | |||
} | |||
/*</replacement>*/ | |||
var destroyImpl = require('./internal/streams/destroy'); | |||
util.inherits(Writable, Stream); | |||
function nop() {} | |||
function WritableState(options, stream) { | |||
Duplex = Duplex || require('./_stream_duplex'); | |||
options = options || {}; | |||
// Duplex streams are both readable and writable, but share | |||
// the same options object. | |||
// However, some cases require setting options to different | |||
// values for the readable and the writable sides of the duplex stream. | |||
// These options can be provided separately as readableXXX and writableXXX. | |||
var isDuplex = stream instanceof Duplex; | |||
// object stream flag to indicate whether or not this stream | |||
// contains buffers or objects. | |||
this.objectMode = !!options.objectMode; | |||
if (isDuplex) this.objectMode = this.objectMode || !!options.writableObjectMode; | |||
// the point at which write() starts returning false | |||
// Note: 0 is a valid value, means that we always return false if | |||
// the entire buffer is not flushed immediately on write() | |||
var hwm = options.highWaterMark; | |||
var writableHwm = options.writableHighWaterMark; | |||
var defaultHwm = this.objectMode ? 16 : 16 * 1024; | |||
if (hwm || hwm === 0) this.highWaterMark = hwm;else if (isDuplex && (writableHwm || writableHwm === 0)) this.highWaterMark = writableHwm;else this.highWaterMark = defaultHwm; | |||
// cast to ints. | |||
this.highWaterMark = Math.floor(this.highWaterMark); | |||
// if _final has been called | |||
this.finalCalled = false; | |||
// drain event flag. | |||
this.needDrain = false; | |||
// at the start of calling end() | |||
this.ending = false; | |||
// when end() has been called, and returned | |||
this.ended = false; | |||
// when 'finish' is emitted | |||
this.finished = false; | |||
// has it been destroyed | |||
this.destroyed = false; | |||
// should we decode strings into buffers before passing to _write? | |||
// this is here so that some node-core streams can optimize string | |||
// handling at a lower level. | |||
var noDecode = options.decodeStrings === false; | |||
this.decodeStrings = !noDecode; | |||
// Crypto is kind of old and crusty. Historically, its default string | |||
// encoding is 'binary' so we have to make this configurable. | |||
// Everything else in the universe uses 'utf8', though. | |||
this.defaultEncoding = options.defaultEncoding || 'utf8'; | |||
// not an actual buffer we keep track of, but a measurement | |||
// of how much we're waiting to get pushed to some underlying | |||
// socket or file. | |||
this.length = 0; | |||
// a flag to see when we're in the middle of a write. | |||
this.writing = false; | |||
// when true all writes will be buffered until .uncork() call | |||
this.corked = 0; | |||
// a flag to be able to tell if the onwrite cb is called immediately, | |||
// or on a later tick. We set this to true at first, because any | |||
// actions that shouldn't happen until "later" should generally also | |||
// not happen before the first write call. | |||
this.sync = true; | |||
// a flag to know if we're processing previously buffered items, which | |||
// may call the _write() callback in the same tick, so that we don't | |||
// end up in an overlapped onwrite situation. | |||
this.bufferProcessing = false; | |||
// the callback that's passed to _write(chunk,cb) | |||
this.onwrite = function (er) { | |||
onwrite(stream, er); | |||
}; | |||
// the callback that the user supplies to write(chunk,encoding,cb) | |||
this.writecb = null; | |||
// the amount that is being written when _write is called. | |||
this.writelen = 0; | |||
this.bufferedRequest = null; | |||
this.lastBufferedRequest = null; | |||
// number of pending user-supplied write callbacks | |||
// this must be 0 before 'finish' can be emitted | |||
this.pendingcb = 0; | |||
// emit prefinish if the only thing we're waiting for is _write cbs | |||
// This is relevant for synchronous Transform streams | |||
this.prefinished = false; | |||
// True if the error was already emitted and should not be thrown again | |||
this.errorEmitted = false; | |||
// count buffered requests | |||
this.bufferedRequestCount = 0; | |||
// allocate the first CorkedRequest, there is always | |||
// one allocated and free to use, and we maintain at most two | |||
this.corkedRequestsFree = new CorkedRequest(this); | |||
} | |||
WritableState.prototype.getBuffer = function getBuffer() { | |||
var current = this.bufferedRequest; | |||
var out = []; | |||
while (current) { | |||
out.push(current); | |||
current = current.next; | |||
} | |||
return out; | |||
}; | |||
(function () { | |||
try { | |||
Object.defineProperty(WritableState.prototype, 'buffer', { | |||
get: internalUtil.deprecate(function () { | |||
return this.getBuffer(); | |||
}, '_writableState.buffer is deprecated. Use _writableState.getBuffer ' + 'instead.', 'DEP0003') | |||
}); | |||
} catch (_) {} | |||
})(); | |||
// Test _writableState for inheritance to account for Duplex streams, | |||
// whose prototype chain only points to Readable. | |||
var realHasInstance; | |||
if (typeof Symbol === 'function' && Symbol.hasInstance && typeof Function.prototype[Symbol.hasInstance] === 'function') { | |||
realHasInstance = Function.prototype[Symbol.hasInstance]; | |||
Object.defineProperty(Writable, Symbol.hasInstance, { | |||
value: function (object) { | |||
if (realHasInstance.call(this, object)) return true; | |||
if (this !== Writable) return false; | |||
return object && object._writableState instanceof WritableState; | |||
} | |||
}); | |||
} else { | |||
realHasInstance = function (object) { | |||
return object instanceof this; | |||
}; | |||
} | |||
function Writable(options) { | |||
Duplex = Duplex || require('./_stream_duplex'); | |||
// Writable ctor is applied to Duplexes, too. | |||
// `realHasInstance` is necessary because using plain `instanceof` | |||
// would return false, as no `_writableState` property is attached. | |||
// Trying to use the custom `instanceof` for Writable here will also break the | |||
// Node.js LazyTransform implementation, which has a non-trivial getter for | |||
// `_writableState` that would lead to infinite recursion. | |||
if (!realHasInstance.call(Writable, this) && !(this instanceof Duplex)) { | |||
return new Writable(options); | |||
} | |||
this._writableState = new WritableState(options, this); | |||
// legacy. | |||
this.writable = true; | |||
if (options) { | |||
if (typeof options.write === 'function') this._write = options.write; | |||
if (typeof options.writev === 'function') this._writev = options.writev; | |||
if (typeof options.destroy === 'function') this._destroy = options.destroy; | |||
if (typeof options.final === 'function') this._final = options.final; | |||
} | |||
Stream.call(this); | |||
} | |||
// Otherwise people can pipe Writable streams, which is just wrong. | |||
Writable.prototype.pipe = function () { | |||
this.emit('error', new Error('Cannot pipe, not readable')); | |||
}; | |||
function writeAfterEnd(stream, cb) { | |||
var er = new Error('write after end'); | |||
// TODO: defer error events consistently everywhere, not just the cb | |||
stream.emit('error', er); | |||
pna.nextTick(cb, er); | |||
} | |||
// Checks that a user-supplied chunk is valid, especially for the particular | |||
// mode the stream is in. Currently this means that `null` is never accepted | |||
// and undefined/non-string values are only allowed in object mode. | |||
function validChunk(stream, state, chunk, cb) { | |||
var valid = true; | |||
var er = false; | |||
if (chunk === null) { | |||
er = new TypeError('May not write null values to stream'); | |||
} else if (typeof chunk !== 'string' && chunk !== undefined && !state.objectMode) { | |||
er = new TypeError('Invalid non-string/buffer chunk'); | |||
} | |||
if (er) { | |||
stream.emit('error', er); | |||
pna.nextTick(cb, er); | |||
valid = false; | |||
} | |||
return valid; | |||
} | |||
Writable.prototype.write = function (chunk, encoding, cb) { | |||
var state = this._writableState; | |||
var ret = false; | |||
var isBuf = !state.objectMode && _isUint8Array(chunk); | |||
if (isBuf && !Buffer.isBuffer(chunk)) { | |||
chunk = _uint8ArrayToBuffer(chunk); | |||
} | |||
if (typeof encoding === 'function') { | |||
cb = encoding; | |||
encoding = null; | |||
} | |||
if (isBuf) encoding = 'buffer';else if (!encoding) encoding = state.defaultEncoding; | |||
if (typeof cb !== 'function') cb = nop; | |||
if (state.ended) writeAfterEnd(this, cb);else if (isBuf || validChunk(this, state, chunk, cb)) { | |||
state.pendingcb++; | |||
ret = writeOrBuffer(this, state, isBuf, chunk, encoding, cb); | |||
} | |||
return ret; | |||
}; | |||
Writable.prototype.cork = function () { | |||
var state = this._writableState; | |||
state.corked++; | |||
}; | |||
Writable.prototype.uncork = function () { | |||
var state = this._writableState; | |||
if (state.corked) { | |||
state.corked--; | |||
if (!state.writing && !state.corked && !state.finished && !state.bufferProcessing && state.bufferedRequest) clearBuffer(this, state); | |||
} | |||
}; | |||
Writable.prototype.setDefaultEncoding = function setDefaultEncoding(encoding) { | |||
// node::ParseEncoding() requires lower case. | |||
if (typeof encoding === 'string') encoding = encoding.toLowerCase(); | |||
if (!(['hex', 'utf8', 'utf-8', 'ascii', 'binary', 'base64', 'ucs2', 'ucs-2', 'utf16le', 'utf-16le', 'raw'].indexOf((encoding + '').toLowerCase()) > -1)) throw new TypeError('Unknown encoding: ' + encoding); | |||
this._writableState.defaultEncoding = encoding; | |||
return this; | |||
}; | |||
function decodeChunk(state, chunk, encoding) { | |||
if (!state.objectMode && state.decodeStrings !== false && typeof chunk === 'string') { | |||
chunk = Buffer.from(chunk, encoding); | |||
} | |||
return chunk; | |||
} | |||
Object.defineProperty(Writable.prototype, 'writableHighWaterMark', { | |||
// making it explicit this property is not enumerable | |||
// because otherwise some prototype manipulation in | |||
// userland will fail | |||
enumerable: false, | |||
get: function () { | |||
return this._writableState.highWaterMark; | |||
} | |||
}); | |||
// if we're already writing something, then just put this | |||
// in the queue, and wait our turn. Otherwise, call _write | |||
// If we return false, then we need a drain event, so set that flag. | |||
function writeOrBuffer(stream, state, isBuf, chunk, encoding, cb) { | |||
if (!isBuf) { | |||
var newChunk = decodeChunk(state, chunk, encoding); | |||
if (chunk !== newChunk) { | |||
isBuf = true; | |||
encoding = 'buffer'; | |||
chunk = newChunk; | |||
} | |||
} | |||
var len = state.objectMode ? 1 : chunk.length; | |||
state.length += len; | |||
var ret = state.length < state.highWaterMark; | |||
// we must ensure that previous needDrain will not be reset to false. | |||
if (!ret) state.needDrain = true; | |||
if (state.writing || state.corked) { | |||
var last = state.lastBufferedRequest; | |||
state.lastBufferedRequest = { | |||
chunk: chunk, | |||
encoding: encoding, | |||
isBuf: isBuf, | |||
callback: cb, | |||
next: null | |||
}; | |||
if (last) { | |||
last.next = state.lastBufferedRequest; | |||
} else { | |||
state.bufferedRequest = state.lastBufferedRequest; | |||
} | |||
state.bufferedRequestCount += 1; | |||
} else { | |||
doWrite(stream, state, false, len, chunk, encoding, cb); | |||
} | |||
return ret; | |||
} | |||
function doWrite(stream, state, writev, len, chunk, encoding, cb) { | |||
state.writelen = len; | |||
state.writecb = cb; | |||
state.writing = true; | |||
state.sync = true; | |||
if (writev) stream._writev(chunk, state.onwrite);else stream._write(chunk, encoding, state.onwrite); | |||
state.sync = false; | |||
} | |||
function onwriteError(stream, state, sync, er, cb) { | |||
--state.pendingcb; | |||
if (sync) { | |||
// defer the callback if we are being called synchronously | |||
// to avoid piling up things on the stack | |||
pna.nextTick(cb, er); | |||
// this can emit finish, and it will always happen | |||
// after error | |||
pna.nextTick(finishMaybe, stream, state); | |||
stream._writableState.errorEmitted = true; | |||
stream.emit('error', er); | |||
} else { | |||
// the caller expect this to happen before if | |||
// it is async | |||
cb(er); | |||
stream._writableState.errorEmitted = true; | |||
stream.emit('error', er); | |||
// this can emit finish, but finish must | |||
// always follow error | |||
finishMaybe(stream, state); | |||
} | |||
} | |||
function onwriteStateUpdate(state) { | |||
state.writing = false; | |||
state.writecb = null; | |||
state.length -= state.writelen; | |||
state.writelen = 0; | |||
} | |||
function onwrite(stream, er) { | |||
var state = stream._writableState; | |||
var sync = state.sync; | |||
var cb = state.writecb; | |||
onwriteStateUpdate(state); | |||
if (er) onwriteError(stream, state, sync, er, cb);else { | |||
// Check if we're actually ready to finish, but don't emit yet | |||
var finished = needFinish(state); | |||
if (!finished && !state.corked && !state.bufferProcessing && state.bufferedRequest) { | |||
clearBuffer(stream, state); | |||
} | |||
if (sync) { | |||
/*<replacement>*/ | |||
asyncWrite(afterWrite, stream, state, finished, cb); | |||
/*</replacement>*/ | |||
} else { | |||
afterWrite(stream, state, finished, cb); | |||
} | |||
} | |||
} | |||
function afterWrite(stream, state, finished, cb) { | |||
if (!finished) onwriteDrain(stream, state); | |||
state.pendingcb--; | |||
cb(); | |||
finishMaybe(stream, state); | |||
} | |||
// Must force callback to be called on nextTick, so that we don't | |||
// emit 'drain' before the write() consumer gets the 'false' return | |||
// value, and has a chance to attach a 'drain' listener. | |||
function onwriteDrain(stream, state) { | |||
if (state.length === 0 && state.needDrain) { | |||
state.needDrain = false; | |||
stream.emit('drain'); | |||
} | |||
} | |||
// if there's something in the buffer waiting, then process it | |||
function clearBuffer(stream, state) { | |||
state.bufferProcessing = true; | |||
var entry = state.bufferedRequest; | |||
if (stream._writev && entry && entry.next) { | |||
// Fast case, write everything using _writev() | |||
var l = state.bufferedRequestCount; | |||
var buffer = new Array(l); | |||
var holder = state.corkedRequestsFree; | |||
holder.entry = entry; | |||
var count = 0; | |||
var allBuffers = true; | |||
while (entry) { | |||
buffer[count] = entry; | |||
if (!entry.isBuf) allBuffers = false; | |||
entry = entry.next; | |||
count += 1; | |||
} | |||
buffer.allBuffers = allBuffers; | |||
doWrite(stream, state, true, state.length, buffer, '', holder.finish); | |||
// doWrite is almost always async, defer these to save a bit of time | |||
// as the hot path ends with doWrite | |||
state.pendingcb++; | |||
state.lastBufferedRequest = null; | |||
if (holder.next) { | |||
state.corkedRequestsFree = holder.next; | |||
holder.next = null; | |||
} else { | |||
state.corkedRequestsFree = new CorkedRequest(state); | |||
} | |||
state.bufferedRequestCount = 0; | |||
} else { | |||
// Slow case, write chunks one-by-one | |||
while (entry) { | |||
var chunk = entry.chunk; | |||
var encoding = entry.encoding; | |||
var cb = entry.callback; | |||
var len = state.objectMode ? 1 : chunk.length; | |||
doWrite(stream, state, false, len, chunk, encoding, cb); | |||
entry = entry.next; | |||
state.bufferedRequestCount--; | |||
// if we didn't call the onwrite immediately, then | |||
// it means that we need to wait until it does. | |||
// also, that means that the chunk and cb are currently | |||
// being processed, so move the buffer counter past them. | |||
if (state.writing) { | |||
break; | |||
} | |||
} | |||
if (entry === null) state.lastBufferedRequest = null; | |||
} | |||
state.bufferedRequest = entry; | |||
state.bufferProcessing = false; | |||
} | |||
Writable.prototype._write = function (chunk, encoding, cb) { | |||
cb(new Error('_write() is not implemented')); | |||
}; | |||
Writable.prototype._writev = null; | |||
Writable.prototype.end = function (chunk, encoding, cb) { | |||
var state = this._writableState; | |||
if (typeof chunk === 'function') { | |||
cb = chunk; | |||
chunk = null; | |||
encoding = null; | |||
} else if (typeof encoding === 'function') { | |||
cb = encoding; | |||
encoding = null; | |||
} | |||
if (chunk !== null && chunk !== undefined) this.write(chunk, encoding); | |||
// .end() fully uncorks | |||
if (state.corked) { | |||
state.corked = 1; | |||
this.uncork(); | |||
} | |||
// ignore unnecessary end() calls. | |||
if (!state.ending && !state.finished) endWritable(this, state, cb); | |||
}; | |||
function needFinish(state) { | |||
return state.ending && state.length === 0 && state.bufferedRequest === null && !state.finished && !state.writing; | |||
} | |||
function callFinal(stream, state) { | |||
stream._final(function (err) { | |||
state.pendingcb--; | |||
if (err) { | |||
stream.emit('error', err); | |||
} | |||
state.prefinished = true; | |||
stream.emit('prefinish'); | |||
finishMaybe(stream, state); | |||
}); | |||
} | |||
function prefinish(stream, state) { | |||
if (!state.prefinished && !state.finalCalled) { | |||
if (typeof stream._final === 'function') { | |||
state.pendingcb++; | |||
state.finalCalled = true; | |||
pna.nextTick(callFinal, stream, state); | |||
} else { | |||
state.prefinished = true; | |||
stream.emit('prefinish'); | |||
} | |||
} | |||
} | |||
function finishMaybe(stream, state) { | |||
var need = needFinish(state); | |||
if (need) { | |||
prefinish(stream, state); | |||
if (state.pendingcb === 0) { | |||
state.finished = true; | |||
stream.emit('finish'); | |||
} | |||
} | |||
return need; | |||
} | |||
function endWritable(stream, state, cb) { | |||
state.ending = true; | |||
finishMaybe(stream, state); | |||
if (cb) { | |||
if (state.finished) pna.nextTick(cb);else stream.once('finish', cb); | |||
} | |||
state.ended = true; | |||
stream.writable = false; | |||
} | |||
function onCorkedFinish(corkReq, state, err) { | |||
var entry = corkReq.entry; | |||
corkReq.entry = null; | |||
while (entry) { | |||
var cb = entry.callback; | |||
state.pendingcb--; | |||
cb(err); | |||
entry = entry.next; | |||
} | |||
if (state.corkedRequestsFree) { | |||
state.corkedRequestsFree.next = corkReq; | |||
} else { | |||
state.corkedRequestsFree = corkReq; | |||
} | |||
} | |||
Object.defineProperty(Writable.prototype, 'destroyed', { | |||
get: function () { | |||
if (this._writableState === undefined) { | |||
return false; | |||
} | |||
return this._writableState.destroyed; | |||
}, | |||
set: function (value) { | |||
// we ignore the value if the stream | |||
// has not been initialized yet | |||
if (!this._writableState) { | |||
return; | |||
} | |||
// backward compatibility, the user is explicitly | |||
// managing destroyed | |||
this._writableState.destroyed = value; | |||
} | |||
}); | |||
Writable.prototype.destroy = destroyImpl.destroy; | |||
Writable.prototype._undestroy = destroyImpl.undestroy; | |||
Writable.prototype._destroy = function (err, cb) { | |||
this.end(); | |||
cb(err); | |||
}; |