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stream-transform

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Object transformations implementing the Node.js `stream.Transform` API

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var domain; // This constructor is used to store event handlers. Instantiating this is // faster than explicitly calling `Object.create(null)` to get a "clean" empty // object (tested with v8 v4.9). function EventHandlers() {} EventHandlers.prototype = Object.create(null); function EventEmitter() { EventEmitter.init.call(this); } // nodejs oddity // require('events') === require('events').EventEmitter EventEmitter.EventEmitter = EventEmitter; EventEmitter.usingDomains = false; EventEmitter.prototype.domain = undefined; EventEmitter.prototype._events = undefined; EventEmitter.prototype._maxListeners = undefined; // By default EventEmitters will print a warning if more than 10 listeners are // added to it. This is a useful default which helps finding memory leaks. EventEmitter.defaultMaxListeners = 10; EventEmitter.init = function() { this.domain = null; if (EventEmitter.usingDomains) { // if there is an active domain, then attach to it. if (domain.active && !(this instanceof domain.Domain)) { this.domain = domain.active; } } if (!this._events || this._events === Object.getPrototypeOf(this)._events) { this._events = new EventHandlers(); this._eventsCount = 0; } this._maxListeners = this._maxListeners || undefined; }; // Obviously not all Emitters should be limited to 10. This function allows // that to be increased. Set to zero for unlimited. EventEmitter.prototype.setMaxListeners = function setMaxListeners(n) { if (typeof n !== 'number' || n < 0 || isNaN(n)) throw new TypeError('"n" argument must be a positive number'); this._maxListeners = n; return this; }; function $getMaxListeners(that) { if (that._maxListeners === undefined) return EventEmitter.defaultMaxListeners; return that._maxListeners; } EventEmitter.prototype.getMaxListeners = function getMaxListeners() { return $getMaxListeners(this); }; // These standalone emit* functions are used to optimize calling of event // handlers for fast cases because emit() itself often has a variable number of // arguments and can be deoptimized because of that. These functions always have // the same number of arguments and thus do not get deoptimized, so the code // inside them can execute faster. function emitNone(handler, isFn, self) { if (isFn) handler.call(self); else { var len = handler.length; var listeners = arrayClone(handler, len); for (var i = 0; i < len; ++i) listeners[i].call(self); } } function emitOne(handler, isFn, self, arg1) { if (isFn) handler.call(self, arg1); else { var len = handler.length; var listeners = arrayClone(handler, len); for (var i = 0; i < len; ++i) listeners[i].call(self, arg1); } } function emitTwo(handler, isFn, self, arg1, arg2) { if (isFn) handler.call(self, arg1, arg2); else { var len = handler.length; var listeners = arrayClone(handler, len); for (var i = 0; i < len; ++i) listeners[i].call(self, arg1, arg2); } } function emitThree(handler, isFn, self, arg1, arg2, arg3) { if (isFn) handler.call(self, arg1, arg2, arg3); else { var len = handler.length; var listeners = arrayClone(handler, len); for (var i = 0; i < len; ++i) listeners[i].call(self, arg1, arg2, arg3); } } function emitMany(handler, isFn, self, args) { if (isFn) handler.apply(self, args); else { var len = handler.length; var listeners = arrayClone(handler, len); for (var i = 0; i < len; ++i) listeners[i].apply(self, args); } } EventEmitter.prototype.emit = function emit(type) { var er, handler, len, args, i, events, domain; var doError = (type === 'error'); events = this._events; if (events) doError = (doError && events.error == null); else if (!doError) return false; domain = this.domain; // If there is no 'error' event listener then throw. if (doError) { er = arguments[1]; if (domain) { if (!er) er = new Error('Uncaught, unspecified "error" event'); er.domainEmitter = this; er.domain = domain; er.domainThrown = false; domain.emit('error', er); } else if (er instanceof Error) { throw er; // Unhandled 'error' event } else { // At least give some kind of context to the user var err = new Error('Uncaught, unspecified "error" event. (' + er + ')'); err.context = er; throw err; } return false; } handler = events[type]; if (!handler) return false; var isFn = typeof handler === 'function'; len = arguments.length; switch (len) { // fast cases case 1: emitNone(handler, isFn, this); break; case 2: emitOne(handler, isFn, this, arguments[1]); break; case 3: emitTwo(handler, isFn, this, arguments[1], arguments[2]); break; case 4: emitThree(handler, isFn, this, arguments[1], arguments[2], arguments[3]); break; // slower default: args = new Array(len - 1); for (i = 1; i < len; i++) args[i - 1] = arguments[i]; emitMany(handler, isFn, this, args); } return true; }; function _addListener(target, type, listener, prepend) { var m; var events; var existing; if (typeof listener !== 'function') throw new TypeError('"listener" argument must be a function'); events = target._events; if (!events) { events = target._events = new EventHandlers(); target._eventsCount = 0; } else { // To avoid recursion in the case that type === "newListener"! Before // adding it to the listeners, first emit "newListener". if (events.newListener) { target.emit('newListener', type, listener.listener ? listener.listener : listener); // Re-assign `events` because a newListener handler could have caused the // this._events to be assigned to a new object events = target._events; } existing = events[type]; } if (!existing) { // Optimize the case of one listener. Don't need the extra array object. existing = events[type] = listener; ++target._eventsCount; } else { if (typeof existing === 'function') { // Adding the second element, need to change to array. existing = events[type] = prepend ? [listener, existing] : [existing, listener]; } else { // If we've already got an array, just append. if (prepend) { existing.unshift(listener); } else { existing.push(listener); } } // Check for listener leak if (!existing.warned) { m = $getMaxListeners(target); if (m && m > 0 && existing.length > m) { existing.warned = true; var w = new Error('Possible EventEmitter memory leak detected. ' + existing.length + ' ' + type + ' listeners added. ' + 'Use emitter.setMaxListeners() to increase limit'); w.name = 'MaxListenersExceededWarning'; w.emitter = target; w.type = type; w.count = existing.length; emitWarning(w); } } } return target; } function emitWarning(e) { typeof console.warn === 'function' ? console.warn(e) : console.log(e); } EventEmitter.prototype.addListener = function addListener(type, listener) { return _addListener(this, type, listener, false); }; EventEmitter.prototype.on = EventEmitter.prototype.addListener; EventEmitter.prototype.prependListener = function prependListener(type, listener) { return _addListener(this, type, listener, true); }; function _onceWrap(target, type, listener) { var fired = false; function g() { target.removeListener(type, g); if (!fired) { fired = true; listener.apply(target, arguments); } } g.listener = listener; return g; } EventEmitter.prototype.once = function once(type, listener) { if (typeof listener !== 'function') throw new TypeError('"listener" argument must be a function'); this.on(type, _onceWrap(this, type, listener)); return this; }; EventEmitter.prototype.prependOnceListener = function prependOnceListener(type, listener) { if (typeof listener !== 'function') throw new TypeError('"listener" argument must be a function'); this.prependListener(type, _onceWrap(this, type, listener)); return this; }; // emits a 'removeListener' event iff the listener was removed EventEmitter.prototype.removeListener = function removeListener(type, listener) { var list, events, position, i, originalListener; if (typeof listener !== 'function') throw new TypeError('"listener" argument must be a function'); events = this._events; if (!events) return this; list = events[type]; if (!list) return this; if (list === listener || (list.listener && list.listener === listener)) { if (--this._eventsCount === 0) this._events = new EventHandlers(); else { delete events[type]; if (events.removeListener) this.emit('removeListener', type, list.listener || listener); } } else if (typeof list !== 'function') { position = -1; for (i = list.length; i-- > 0;) { if (list[i] === listener || (list[i].listener && list[i].listener === listener)) { originalListener = list[i].listener; position = i; break; } } if (position < 0) return this; if (list.length === 1) { list[0] = undefined; if (--this._eventsCount === 0) { this._events = new EventHandlers(); return this; } else { delete events[type]; } } else { spliceOne(list, position); } if (events.removeListener) this.emit('removeListener', type, originalListener || listener); } return this; }; EventEmitter.prototype.removeAllListeners = function removeAllListeners(type) { var listeners, events; events = this._events; if (!events) return this; // not listening for removeListener, no need to emit if (!events.removeListener) { if (arguments.length === 0) { this._events = new EventHandlers(); this._eventsCount = 0; } else if (events[type]) { if (--this._eventsCount === 0) this._events = new EventHandlers(); else delete events[type]; } return this; } // emit removeListener for all listeners on all events if (arguments.length === 0) { var keys = Object.keys(events); for (var i = 0, key; i < keys.length; ++i) { key = keys[i]; if (key === 'removeListener') continue; this.removeAllListeners(key); } this.removeAllListeners('removeListener'); this._events = new EventHandlers(); this._eventsCount = 0; return this; } listeners = events[type]; if (typeof listeners === 'function') { this.removeListener(type, listeners); } else if (listeners) { // LIFO order do { this.removeListener(type, listeners[listeners.length - 1]); } while (listeners[0]); } return this; }; EventEmitter.prototype.listeners = function listeners(type) { var evlistener; var ret; var events = this._events; if (!events) ret = []; else { evlistener = events[type]; if (!evlistener) ret = []; else if (typeof evlistener === 'function') ret = [evlistener.listener || evlistener]; else ret = unwrapListeners(evlistener); } return ret; }; EventEmitter.listenerCount = function(emitter, type) { if (typeof emitter.listenerCount === 'function') { return emitter.listenerCount(type); } else { return listenerCount$1.call(emitter, type); } }; EventEmitter.prototype.listenerCount = listenerCount$1; function listenerCount$1(type) { var events = this._events; if (events) { var evlistener = events[type]; if (typeof evlistener === 'function') { return 1; } else if (evlistener) { return evlistener.length; } } return 0; } EventEmitter.prototype.eventNames = function eventNames() { return this._eventsCount > 0 ? Reflect.ownKeys(this._events) : []; }; // About 1.5x faster than the two-arg version of Array#splice(). function spliceOne(list, index) { for (var i = index, k = i + 1, n = list.length; k < n; i += 1, k += 1) list[i] = list[k]; list.pop(); } function arrayClone(arr, i) { var copy = new Array(i); while (i--) copy[i] = arr[i]; return copy; } function unwrapListeners(arr) { var ret = new Array(arr.length); for (var i = 0; i < ret.length; ++i) { ret[i] = arr[i].listener || arr[i]; } return ret; } var global$1 = (typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {}); var lookup = []; var revLookup = []; var Arr = typeof Uint8Array !== 'undefined' ? Uint8Array : Array; var inited = false; function init () { inited = true; var code = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'; for (var i = 0, len = code.length; i < len; ++i) { lookup[i] = code[i]; revLookup[code.charCodeAt(i)] = i; } revLookup['-'.charCodeAt(0)] = 62; revLookup['_'.charCodeAt(0)] = 63; } function toByteArray (b64) { if (!inited) { init(); } var i, j, l, tmp, placeHolders, arr; var len = b64.length; if (len % 4 > 0) { throw new Error('Invalid string. Length must be a multiple of 4') } // the number of equal signs (place holders) // if there are two placeholders, than the two characters before it // represent one byte // if there is only one, then the three characters before it represent 2 bytes // this is just a cheap hack to not do indexOf twice placeHolders = b64[len - 2] === '=' ? 2 : b64[len - 1] === '=' ? 1 : 0; // base64 is 4/3 + up to two characters of the original data arr = new Arr(len * 3 / 4 - placeHolders); // if there are placeholders, only get up to the last complete 4 chars l = placeHolders > 0 ? len - 4 : len; var L = 0; for (i = 0, j = 0; i < l; i += 4, j += 3) { tmp = (revLookup[b64.charCodeAt(i)] << 18) | (revLookup[b64.charCodeAt(i + 1)] << 12) | (revLookup[b64.charCodeAt(i + 2)] << 6) | revLookup[b64.charCodeAt(i + 3)]; arr[L++] = (tmp >> 16) & 0xFF; arr[L++] = (tmp >> 8) & 0xFF; arr[L++] = tmp & 0xFF; } if (placeHolders === 2) { tmp = (revLookup[b64.charCodeAt(i)] << 2) | (revLookup[b64.charCodeAt(i + 1)] >> 4); arr[L++] = tmp & 0xFF; } else if (placeHolders === 1) { tmp = (revLookup[b64.charCodeAt(i)] << 10) | (revLookup[b64.charCodeAt(i + 1)] << 4) | (revLookup[b64.charCodeAt(i + 2)] >> 2); arr[L++] = (tmp >> 8) & 0xFF; arr[L++] = tmp & 0xFF; } return arr } function tripletToBase64 (num) { return lookup[num >> 18 & 0x3F] + lookup[num >> 12 & 0x3F] + lookup[num >> 6 & 0x3F] + lookup[num & 0x3F] } function encodeChunk (uint8, start, end) { var tmp; var output = []; for (var i = start; i < end; i += 3) { tmp = (uint8[i] << 16) + (uint8[i + 1] << 8) + (uint8[i + 2]); output.push(tripletToBase64(tmp)); } return output.join('') } function fromByteArray (uint8) { if (!inited) { init(); } var tmp; var len = uint8.length; var extraBytes = len % 3; // if we have 1 byte left, pad 2 bytes var output = ''; var parts = []; var maxChunkLength = 16383; // must be multiple of 3 // go through the array every three bytes, we'll deal with trailing stuff later for (var i = 0, len2 = len - extraBytes; i < len2; i += maxChunkLength) { parts.push(encodeChunk(uint8, i, (i + maxChunkLength) > len2 ? len2 : (i + maxChunkLength))); } // pad the end with zeros, but make sure to not forget the extra bytes if (extraBytes === 1) { tmp = uint8[len - 1]; output += lookup[tmp >> 2]; output += lookup[(tmp << 4) & 0x3F]; output += '=='; } else if (extraBytes === 2) { tmp = (uint8[len - 2] << 8) + (uint8[len - 1]); output += lookup[tmp >> 10]; output += lookup[(tmp >> 4) & 0x3F]; output += lookup[(tmp << 2) & 0x3F]; output += '='; } parts.push(output); return parts.join('') } function read (buffer, offset, isLE, mLen, nBytes) { var e, m; var eLen = nBytes * 8 - mLen - 1; var eMax = (1 << eLen) - 1; var eBias = eMax >> 1; var nBits = -7; var i = isLE ? (nBytes - 1) : 0; var d = isLE ? -1 : 1; var s = buffer[offset + i]; i += d; e = s & ((1 << (-nBits)) - 1); s >>= (-nBits); nBits += eLen; for (; nBits > 0; e = e * 256 + buffer[offset + i], i += d, nBits -= 8) {} m = e & ((1 << (-nBits)) - 1); e >>= (-nBits); nBits += mLen; for (; nBits > 0; m = m * 256 + buffer[offset + i], i += d, nBits -= 8) {} if (e === 0) { e = 1 - eBias; } else if (e === eMax) { return m ? NaN : ((s ? -1 : 1) * Infinity) } else { m = m + Math.pow(2, mLen); e = e - eBias; } return (s ? -1 : 1) * m * Math.pow(2, e - mLen) } function write (buffer, value, offset, isLE, mLen, nBytes) { var e, m, c; var eLen = nBytes * 8 - mLen - 1; var eMax = (1 << eLen) - 1; var eBias = eMax >> 1; var rt = (mLen === 23 ? Math.pow(2, -24) - Math.pow(2, -77) : 0); var i = isLE ? 0 : (nBytes - 1); var d = isLE ? 1 : -1; var s = value < 0 || (value === 0 && 1 / value < 0) ? 1 : 0; value = Math.abs(value); if (isNaN(value) || value === Infinity) { m = isNaN(value) ? 1 : 0; e = eMax; } else { e = Math.floor(Math.log(value) / Math.LN2); if (value * (c = Math.pow(2, -e)) < 1) { e--; c *= 2; } if (e + eBias >= 1) { value += rt / c; } else { value += rt * Math.pow(2, 1 - eBias); } if (value * c >= 2) { e++; c /= 2; } if (e + eBias >= eMax) { m = 0; e = eMax; } else if (e + eBias >= 1) { m = (value * c - 1) * Math.pow(2, mLen); e = e + eBias; } else { m = value * Math.pow(2, eBias - 1) * Math.pow(2, mLen); e = 0; } } for (; mLen >= 8; buffer[offset + i] = m & 0xff, i += d, m /= 256, mLen -= 8) {} e = (e << mLen) | m; eLen += mLen; for (; eLen > 0; buffer[offset + i] = e & 0xff, i += d, e /= 256, eLen -= 8) {} buffer[offset + i - d] |= s * 128; } var toString = {}.toString; var isArray$1 = Array.isArray || function (arr) { return toString.call(arr) == '[object Array]'; }; var INSPECT_MAX_BYTES = 50; /** * If `Buffer.TYPED_ARRAY_SUPPORT`: * === true Use Uint8Array implementation (fastest) * === false Use Object implementation (most compatible, even IE6) * * Browsers that support typed arrays are IE 10+, Firefox 4+, Chrome 7+, Safari 5.1+, * Opera 11.6+, iOS 4.2+. * * Due to various browser bugs, sometimes the Object implementation will be used even * when the browser supports typed arrays. * * Note: * * - Firefox 4-29 lacks support for adding new properties to `Uint8Array` instances, * See: https://bugzilla.mozilla.org/show_bug.cgi?id=695438. * * - Chrome 9-10 is missing the `TypedArray.prototype.subarray` function. * * - IE10 has a broken `TypedArray.prototype.subarray` function which returns arrays of * incorrect length in some situations. * We detect these buggy browsers and set `Buffer.TYPED_ARRAY_SUPPORT` to `false` so they * get the Object implementation, which is slower but behaves correctly. */ Buffer.TYPED_ARRAY_SUPPORT = global$1.TYPED_ARRAY_SUPPORT !== undefined ? global$1.TYPED_ARRAY_SUPPORT : true; /* * Export kMaxLength after typed array support is determined. */ kMaxLength(); function kMaxLength () { return Buffer.TYPED_ARRAY_SUPPORT ? 0x7fffffff : 0x3fffffff } function createBuffer (that, length) { if (kMaxLength() < length) { throw new RangeError('Invalid typed array length') } if (Buffer.TYPED_ARRAY_SUPPORT) { // Return an augmented `Uint8Array` instance, for best performance that = new Uint8Array(length); that.__proto__ = Buffer.prototype; } else { // Fallback: Return an object instance of the Buffer class if (that === null) { that = new Buffer(length); } that.length = length; } return that } /** * The Buffer constructor returns instances of `Uint8Array` that have their * prototype changed to `Buffer.prototype`. Furthermore, `Buffer` is a subclass of * `Uint8Array`, so the returned instances will have all the node `Buffer` methods * and the `Uint8Array` methods. Square bracket notation works as expected -- it * returns a single octet. * * The `Uint8Array` prototype remains unmodified. */ function Buffer (arg, encodingOrOffset, length) { if (!Buffer.TYPED_ARRAY_SUPPORT && !(this instanceof Buffer)) { return new Buffer(arg, encodingOrOffset, length) } // Common case. if (typeof arg === 'number') { if (typeof encodingOrOffset === 'string') { throw new Error( 'If encoding is specified then the first argument must be a string' ) } return allocUnsafe(this, arg) } return from(this, arg, encodingOrOffset, length) } Buffer.poolSize = 8192; // not used by this implementation // TODO: Legacy, not needed anymore. Remove in next major version. Buffer._augment = function (arr) { arr.__proto__ = Buffer.prototype; return arr }; function from (that, value, encodingOrOffset, length) { if (typeof value === 'number') { throw new TypeError('"value" argument must not be a number') } if (typeof ArrayBuffer !== 'undefined' && value instanceof ArrayBuffer) { return fromArrayBuffer(that, value, encodingOrOffset, length) } if (typeof value === 'string') { return fromString(that, value, encodingOrOffset) } return fromObject(that, value) } /** * Functionally equivalent to Buffer(arg, encoding) but throws a TypeError * if value is a number. * Buffer.from(str[, encoding]) * Buffer.from(array) * Buffer.from(buffer) * Buffer.from(arrayBuffer[, byteOffset[, length]]) **/ Buffer.from = function (value, encodingOrOffset, length) { return from(null, value, encodingOrOffset, length) }; if (Buffer.TYPED_ARRAY_SUPPORT) { Buffer.prototype.__proto__ = Uint8Array.prototype; Buffer.__proto__ = Uint8Array; if (typeof Symbol !== 'undefined' && Symbol.species && Buffer[Symbol.species] === Buffer) ; } function assertSize (size) { if (typeof size !== 'number') { throw new TypeError('"size" argument must be a number') } else if (size < 0) { throw new RangeError('"size" argument must not be negative') } } function alloc (that, size, fill, encoding) { assertSize(size); if (size <= 0) { return createBuffer(that, size) } if (fill !== undefined) { // Only pay attention to encoding if it's a string. This // prevents accidentally sending in a number that would // be interpretted as a start offset. return typeof encoding === 'string' ? createBuffer(that, size).fill(fill, encoding) : createBuffer(that, size).fill(fill) } return createBuffer(that, size) } /** * Creates a new filled Buffer instance. * alloc(size[, fill[, encoding]]) **/ Buffer.alloc = function (size, fill, encoding) { return alloc(null, size, fill, encoding) }; function allocUnsafe (that, size) { assertSize(size); that = createBuffer(that, size < 0 ? 0 : checked(size) | 0); if (!Buffer.TYPED_ARRAY_SUPPORT) { for (var i = 0; i < size; ++i) { that[i] = 0; } } return that } /** * Equivalent to Buffer(num), by default creates a non-zero-filled Buffer instance. * */ Buffer.allocUnsafe = function (size) { return allocUnsafe(null, size) }; /** * Equivalent to SlowBuffer(num), by default creates a non-zero-filled Buffer instance. */ Buffer.allocUnsafeSlow = function (size) { return allocUnsafe(null, size) }; function fromString (that, string, encoding) { if (typeof encoding !== 'string' || encoding === '') { encoding = 'utf8'; } if (!Buffer.isEncoding(encoding)) { throw new TypeError('"encoding" must be a valid string encoding') } var length = byteLength(string, encoding) | 0; that = createBuffer(that, length); var actual = that.write(string, encoding); if (actual !== length) { // Writing a hex string, for example, that contains invalid characters will // cause everything after the first invalid character to be ignored. (e.g. // 'abxxcd' will be treated as 'ab') that = that.slice(0, actual); } return that } function fromArrayLike (that, array) { var length = array.length < 0 ? 0 : checked(array.length) | 0; that = createBuffer(that, length); for (var i = 0; i < length; i += 1) { that[i] = array[i] & 255; } return that } function fromArrayBuffer (that, array, byteOffset, length) { array.byteLength; // this throws if `array` is not a valid ArrayBuffer if (byteOffset < 0 || array.byteLength < byteOffset) { throw new RangeError('\'offset\' is out of bounds') } if (array.byteLength < byteOffset + (length || 0)) { throw new RangeError('\'length\' is out of bounds') } if (byteOffset === undefined && length === undefined) { array = new Uint8Array(array); } else if (length === undefined) { array = new Uint8Array(array, byteOffset); } else { array = new Uint8Array(array, byteOffset, length); } if (Buffer.TYPED_ARRAY_SUPPORT) { // Return an augmented `Uint8Array` instance, for best performance that = array; that.__proto__ = Buffer.prototype; } else { // Fallback: Return an object instance of the Buffer class that = fromArrayLike(that, array); } return that } function fromObject (that, obj) { if (internalIsBuffer(obj)) { var len = checked(obj.length) | 0; that = createBuffer(that, len); if (that.length === 0) { return that } obj.copy(that, 0, 0, len); return that } if (obj) { if ((typeof ArrayBuffer !== 'undefined' && obj.buffer instanceof ArrayBuffer) || 'length' in obj) { if (typeof obj.length !== 'number' || isnan(obj.length)) { return createBuffer(that, 0) } return fromArrayLike(that, obj) } if (obj.type === 'Buffer' && isArray$1(obj.data)) { return fromArrayLike(that, obj.data) } } throw new TypeError('First argument must be a string, Buffer, ArrayBuffer, Array, or array-like object.') } function checked (length) { // Note: cannot use `length < kMaxLength()` here because that fails when // length is NaN (which is otherwise coerced to zero.) if (length >= kMaxLength()) { throw new RangeError('Attempt to allocate Buffer larger than maximum ' + 'size: 0x' + kMaxLength().toString(16) + ' bytes') } return length | 0 } Buffer.isBuffer = isBuffer$1; function internalIsBuffer (b) { return !!(b != null && b._isBuffer) } Buffer.compare = function compare (a, b) { if (!internalIsBuffer(a) || !internalIsBuffer(b)) { throw new TypeError('Arguments must be Buffers') } if (a === b) return 0 var x = a.length; var y = b.length; for (var i = 0, len = Math.min(x, y); i < len; ++i) { if (a[i] !== b[i]) { x = a[i]; y = b[i]; break } } if (x < y) return -1 if (y < x) return 1 return 0 }; Buffer.isEncoding = function isEncoding (encoding) { switch (String(encoding).toLowerCase()) { case 'hex': case 'utf8': case 'utf-8': case 'ascii': case 'latin1': case 'binary': case 'base64': case 'ucs2': case 'ucs-2': case 'utf16le': case 'utf-16le': return true default: return false } }; Buffer.concat = function concat (list, length) { if (!isArray$1(list)) { throw new TypeError('"list" argument must be an Array of Buffers') } if (list.length === 0) { return Buffer.alloc(0) } var i; if (length === undefined) { length = 0; for (i = 0; i < list.length; ++i) { length += list[i].length; } } var buffer = Buffer.allocUnsafe(length); var pos = 0; for (i = 0; i < list.length; ++i) { var buf = list[i]; if (!internalIsBuffer(buf)) { throw new TypeError('"list" argument must be an Array of Buffers') } buf.copy(buffer, pos); pos += buf.length; } return buffer }; function byteLength (string, encoding) { if (internalIsBuffer(string)) { return string.length } if (typeof ArrayBuffer !== 'undefined' && typeof ArrayBuffer.isView === 'function' && (ArrayBuffer.isView(string) || string instanceof ArrayBuffer)) { return string.byteLength } if (typeof string !== 'string') { string = '' + string; } var len = string.length; if (len === 0) return 0 // Use a for loop to avoid recursion var loweredCase = false; for (;;) { switch (encoding) { case 'ascii': case 'latin1': case 'binary': return len case 'utf8': case 'utf-8': case undefined: return utf8ToBytes(string).length case 'ucs2': case 'ucs-2': case 'utf16le': case 'utf-16le': return len * 2 case 'hex': return len >>> 1 case 'base64': return base64ToBytes(string).length default: if (loweredCase) return utf8ToBytes(string).length // assume utf8 encoding = ('' + encoding).toLowerCase(); loweredCase = true; } } } Buffer.byteLength = byteLength; function slowToString (encoding, start, end) { var loweredCase = false; // No need to verify that "this.length <= MAX_UINT32" since it's a read-only // property of a typed array. // This behaves neither like String nor Uint8Array in that we set start/end // to their upper/lower bounds if the value passed is out of range. // undefined is handled specially as per ECMA-262 6th Edition, // Section 13.3.3.7 Runtime Semantics: KeyedBindingInitialization. if (start === undefined || start < 0) { start = 0; } // Return early if start > this.length. Done here to prevent potential uint32 // coercion fail below. if (start > this.length) { return '' } if (end === undefined || end > this.length) { end = this.length; } if (end <= 0) { return '' } // Force coersion to uint32. This will also coerce falsey/NaN values to 0. end >>>= 0; start >>>= 0; if (end <= start) { return '' } if (!encoding) encoding = 'utf8'; while (true) { switch (encoding) { case 'hex': return hexSlice(this, start, end) case 'utf8': case 'utf-8': return utf8Slice(this, start, end) case 'ascii': return asciiSlice(this, start, end) case 'latin1': case 'binary': return latin1Slice(this, start, end) case 'base64': return base64Slice(this, start, end) case 'ucs2': case 'ucs-2': case 'utf16le': case 'utf-16le': return utf16leSlice(this, start, end) default: if (loweredCase) throw new TypeError('Unknown encoding: ' + encoding) encoding = (encoding + '').toLowerCase(); loweredCase = true; } } } // The property is used by `Buffer.isBuffer` and `is-buffer` (in Safari 5-7) to detect // Buffer instances. Buffer.prototype._isBuffer = true; function swap (b, n, m) { var i = b[n]; b[n] = b[m]; b[m] = i; } Buffer.prototype.swap16 = function swap16 () { var len = this.length; if (len % 2 !== 0) { throw new RangeError('Buffer size must be a multiple of 16-bits') } for (var i = 0; i < len; i += 2) { swap(this, i, i + 1); } return this }; Buffer.prototype.swap32 = function swap32 () { var len = this.length; if (len % 4 !== 0) { throw new RangeError('Buffer size must be a multiple of 32-bits') } for (var i = 0; i < len; i += 4) { swap(this, i, i + 3); swap(this, i + 1, i + 2); } return this }; Buffer.prototype.swap64 = function swap64 () { var len = this.length; if (len % 8 !== 0) { throw new RangeError('Buffer size must be a multiple of 64-bits') } for (var i = 0; i < len; i += 8) { swap(this, i, i + 7); swap(this, i + 1, i + 6); swap(this, i + 2, i + 5); swap(this, i + 3, i + 4); } return this }; Buffer.prototype.toString = function toString () { var length = this.length | 0; if (length === 0) return '' if (arguments.length === 0) return utf8Slice(this, 0, length) return slowToString.apply(this, arguments) }; Buffer.prototype.equals = function equals (b) { if (!internalIsBuffer(b)) throw new TypeError('Argument must be a Buffer') if (this === b) return true return Buffer.compare(this, b) === 0 }; Buffer.prototype.inspect = function inspect () { var str = ''; var max = INSPECT_MAX_BYTES; if (this.length > 0) { str = this.toString('hex', 0, max).match(/.{2}/g).join(' '); if (this.length > max) str += ' ... '; } return '<Buffer ' + str + '>' }; Buffer.prototype.compare = function compare (target, start, end, thisStart, thisEnd) { if (!internalIsBuffer(target)) { throw new TypeError('Argument must be a Buffer') } if (start === undefined) { start = 0; } if (end === undefined) { end = target ? target.length : 0; } if (thisStart === undefined) { thisStart = 0; } if (thisEnd === undefined) { thisEnd = this.length; } if (start < 0 || end > target.length || thisStart < 0 || thisEnd > this.length) { throw new RangeError('out of range index') } if (thisStart >= thisEnd && start >= end) { return 0 } if (thisStart >= thisEnd) { return -1 } if (start >= end) { return 1 } start >>>= 0; end >>>= 0; thisStart >>>= 0; thisEnd >>>= 0; if (this === target) return 0 var x = thisEnd - thisStart; var y = end - start; var len = Math.min(x, y); var thisCopy = this.slice(thisStart, thisEnd); var targetCopy = target.slice(start, end); for (var i = 0; i < len; ++i) { if (thisCopy[i] !== targetCopy[i]) { x = thisCopy[i]; y = targetCopy[i]; break } } if (x < y) return -1 if (y < x) return 1 return 0 }; // Finds either the first index of `val` in `buffer` at offset >= `byteOffset`, // OR the last index of `val` in `buffer` at offset <= `byteOffset`. // // Arguments: // - buffer - a Buffer to search // - val - a string, Buffer, or number // - byteOffset - an index into `buffer`; will be clamped to an int32 // - encoding - an optional encoding, relevant is val is a string // - dir - true for indexOf, false for lastIndexOf function bidirectionalIndexOf (buffer, val, byteOffset, encoding, dir) { // Empty buffer means no match if (buffer.length === 0) return -1 // Normalize byteOffset if (typeof byteOffset === 'string') { encoding = byteOffset; byteOffset = 0; } else if (byteOffset > 0x7fffffff) { byteOffset = 0x7fffffff; } else if (byteOffset < -2147483648) { byteOffset = -2147483648; } byteOffset = +byteOffset; // Coerce to Number. if (isNaN(byteOffset)) { // byteOffset: it it's undefined, null, NaN, "foo", etc, search whole buffer byteOffset = dir ? 0 : (buffer.length - 1); } // Normalize byteOffset: negative offsets start from the end of the buffer if (byteOffset < 0) byteOffset = buffer.length + byteOffset; if (byteOffset >= buffer.length) { if (dir) return -1 else byteOffset = buffer.length - 1; } else if (byteOffset < 0) { if (dir) byteOffset = 0; else return -1 } // Normalize val if (typeof val === 'string') { val = Buffer.from(val, encoding); } // Finally, search either indexOf (if dir is true) or lastIndexOf if (internalIsBuffer(val)) { // Special case: looking for empty string/buffer always fails if (val.length === 0) { return -1 } return arrayIndexOf(buffer, val, byteOffset, encoding, dir) } else if (typeof val === 'number') { val = val & 0xFF; // Search for a byte value [0-255] if (Buffer.TYPED_ARRAY_SUPPORT && typeof Uint8Array.prototype.indexOf === 'function') { if (dir) { return Uint8Array.prototype.indexOf.call(buffer, val, byteOffset) } else { return Uint8Array.prototype.lastIndexOf.call(buffer, val, byteOffset) } } return arrayIndexOf(buffer, [ val ], byteOffset, encoding, dir) } throw new TypeError('val must be string, number or Buffer') } function arrayIndexOf (arr, val, byteOffset, encoding, dir) { var indexSize = 1; var arrLength = arr.length; var valLength = val.length; if (encoding !== undefined) { encoding = String(encoding).toLowerCase(); if (encoding === 'ucs2' || encoding === 'ucs-2' || encoding === 'utf16le' || encoding === 'utf-16le') { if (arr.length < 2 || val.length < 2) { return -1 } indexSize = 2; arrLength /= 2; valLength /= 2; byteOffset /= 2; } } function read (buf, i) { if (indexSize === 1) { return buf[i] } else { return buf.readUInt16BE(i * indexSize) } } var i; if (dir) { var foundIndex = -1; for (i = byteOffset; i < arrLength; i++) { if (read(arr, i) === read(val, foundIndex === -1 ? 0 : i - foundIndex)) { if (foundIndex === -1) foundIndex = i; if (i - foundIndex + 1 === valLength) return foundIndex * indexSize } else { if (foundIndex !== -1) i -= i - foundIndex; foundIndex = -1; } } } else { if (byteOffset + valLength > arrLength) byteOffset = arrLength - valLength; for (i = byteOffset; i >= 0; i--) { var found = true; for (var j = 0; j < valLength; j++) { if (read(arr, i + j) !== read(val, j)) { found = false; break } } if (found) return i } } return -1 } Buffer.prototype.includes = function includes (val, byteOffset, encoding) { return this.indexOf(val, byteOffset, encoding) !== -1 }; Buffer.prototype.indexOf = function indexOf (val, byteOffset, encoding) { return bidirectionalIndexOf(this, val, byteOffset, encoding, true) }; Buffer.prototype.lastIndexOf = function lastIndexOf (val, byteOffset, encoding) { return bidirectionalIndexOf(this, val, byteOffset, encoding, false) }; function hexWrite (buf, string, offset, length) { offset = Number(offset) || 0; var remaining = buf.length - offset; if (!length) { length = remaining; } else { length = Number(length); if (length > remaining) { length = remaining; } } // must be an even number of digits var strLen = string.length; if (strLen % 2 !== 0) throw new TypeError('Invalid hex string') if (length > strLen / 2) { length = strLen / 2; } for (var i = 0; i < length; ++i) { var parsed = parseInt(string.substr(i * 2, 2), 16); if (isNaN(parsed)) return i buf[offset + i] = parsed; } return i } function utf8Write (buf, string, offset, length) { return blitBuffer(utf8ToBytes(string, buf.length - offset), buf, offset, length) } function asciiWrite (buf, string, offset, length) { return blitBuffer(asciiToBytes(string), buf, offset, length) } function latin1Write (buf, string, offset, length) { return asciiWrite(buf, string, offset, length) } function base64Write (buf, string, offset, length) { return blitBuffer(base64ToBytes(string), buf, offset, length) } function ucs2Write (buf, string, offset, length) { return blitBuffer(utf16leToBytes(string, buf.length - offset), buf, offset, length) } Buffer.prototype.write = function write (string, offset, length, encoding) { // Buffer#write(string) if (offset === undefined) { encoding = 'utf8'; length = this.length; offset = 0; // Buffer#write(string, encoding) } else if (length === undefined && typeof offset === 'string') { encoding = offset; length = this.length; offset = 0; // Buffer#write(string, offset[, length][, encoding]) } else if (isFinite(offset)) { offset = offset | 0; if (isFinite(length)) { length = length | 0; if (encoding === undefined) encoding = 'utf8'; } else { encoding = length; length = undefined; } // legacy write(string, encoding, offset, length) - remove in v0.13 } else { throw new Error( 'Buffer.write(string, encoding, offset[, length]) is no longer supported' ) } var remaining = this.length - offset; if (length === undefined || length > remaining) length = remaining; if ((string.length > 0 && (length < 0 || offset < 0)) || offset > this.length) { throw new RangeError('Attempt to write outside buffer bounds') } if (!encoding) encoding = 'utf8'; var loweredCase = false; for (;;) { switch (encoding) { case 'hex': return hexWrite(this, string, offset, length) case 'utf8': case 'utf-8': return utf8Write(this, string, offset, length) case 'ascii': return asciiWrite(this, string, offset, length) case 'latin1': case 'binary': return latin1Write(this, string, offset, length) case 'base64': // Warning: maxLength not taken into account in base64Write return base64Write(this, string, offset, length) case 'ucs2': case 'ucs-2': case 'utf16le': case 'utf-16le': return ucs2Write(this, string, offset, length) default: if (loweredCase) throw new TypeError('Unknown encoding: ' + encoding) encoding = ('' + encoding).toLowerCase(); loweredCase = true; } } }; Buffer.prototype.toJSON = function toJSON () { return { type: 'Buffer', data: Array.prototype.slice.call(this._arr || this, 0) } }; function base64Slice (buf, start, end) { if (start === 0 && end === buf.length) { return fromByteArray(buf) } else { return fromByteArray(buf.slice(start, end)) } } function utf8Slice (buf, start, end) { end = Math.min(buf.length, end); var res = []; var i = start; while (i < end) { var firstByte = buf[i]; var codePoint = null; var bytesPerSequence = (firstByte > 0xEF) ? 4 : (firstByte > 0xDF) ? 3 : (firstByte > 0xBF) ? 2 : 1; if (i + bytesPerSequence <= end) { var secondByte, thirdByte, fourthByte, tempCodePoint; switch (bytesPerSequence) { case 1: if (firstByte < 0x80) { codePoint = firstByte; } break case 2: secondByte = buf[i + 1]; if ((secondByte & 0xC0) === 0x80) { tempCodePoint = (firstByte & 0x1F) << 0x6 | (secondByte & 0x3F); if (tempCodePoint > 0x7F) { codePoint = tempCodePoint; } } break case 3: secondByte = buf[i + 1]; thirdByte = buf[i + 2]; if ((secondByte & 0xC0) === 0x80 && (thirdByte & 0xC0) === 0x80) { tempCodePoint = (firstByte & 0xF) << 0xC | (secondByte & 0x3F) << 0x6 | (thirdByte & 0x3F); if (tempCodePoint > 0x7FF && (tempCodePoint < 0xD800 || tempCodePoint > 0xDFFF)) { codePoint = tempCodePoint; } } break case 4: secondByte = buf[i + 1]; thirdByte = buf[i + 2]; fourthByte = buf[i + 3]; if ((secondByte & 0xC0) === 0x80 && (thirdByte & 0xC0) === 0x80 && (fourthByte & 0xC0) === 0x80) { tempCodePoint = (firstByte & 0xF) << 0x12 | (secondByte & 0x3F) << 0xC | (thirdByte & 0x3F) << 0x6 | (fourthByte & 0x3F); if (tempCodePoint > 0xFFFF && tempCodePoint < 0x110000) { codePoint = tempCodePoint; } } } } if (codePoint === null) { // we did not generate a valid codePoint so insert a // replacement char (U+FFFD) and advance only 1 byte codePoint = 0xFFFD; bytesPerSequence = 1; } else if (codePoint > 0xFFFF) { // encode to utf16 (surrogate pair dance) codePoint -= 0x10000; res.push(codePoint >>> 10 & 0x3FF | 0xD800); codePoint = 0xDC00 | codePoint & 0x3FF; } res.push(codePoint); i += bytesPerSequence; } return decodeCodePointsArray(res) } // Based on http://stackoverflow.com/a/22747272/680742, the browser with // the lowest limit is Chrome, with 0x10000 args. // We go 1 magnitude less, for safety var MAX_ARGUMENTS_LENGTH = 0x1000; function decodeCodePointsArray (codePoints) { var len = codePoints.length; if (len <= MAX_ARGUMENTS_LENGTH) { return String.fromCharCode.apply(String, codePoints) // avoid extra slice() } // Decode in chunks to avoid "call stack size exceeded". var res = ''; var i = 0; while (i < len) { res += String.fromCharCode.apply( String, codePoints.slice(i, i += MAX_ARGUMENTS_LENGTH) ); } return res } function asciiSlice (buf, start, end) { var ret = ''; end = Math.min(buf.length, end); for (var i = start; i < end; ++i) { ret += String.fromCharCode(buf[i] & 0x7F); } return ret } function latin1Slice (buf, start, end) { var ret = ''; end = Math.min(buf.length, end); for (var i = start; i < end; ++i) { ret += String.fromCharCode(buf[i]); } return ret } function hexSlice (buf, start, end) { var len = buf.length; if (!start || start < 0) start = 0; if (!end || end < 0 || end > len) end = len; var out = ''; for (var i = start; i < end; ++i) { out += toHex(buf[i]); } return out } function utf16leSlice (buf, start, end) { var bytes = buf.slice(start, end); var res = ''; for (var i = 0; i < bytes.length; i += 2) { res += String.fromCharCode(bytes[i] + bytes[i + 1] * 256); } return res } Buffer.prototype.slice = function slice (start, end) { var len = this.length; start = ~~start; end = end === undefined ? len : ~~end; if (start < 0) { start += len; if (start < 0) start = 0; } else if (start > len) { start = len; } if (end < 0) { end += len; if (end < 0) end = 0; } else if (end > len) { end = len; } if (end < start) end = start; var newBuf; if (Buffer.TYPED_ARRAY_SUPPORT) { newBuf = this.subarray(start, end); newBuf.__proto__ = Buffer.prototype; } else { var sliceLen = end - start; newBuf = new Buffer(sliceLen, undefined); for (var i = 0; i < sliceLen; ++i) { newBuf[i] = this[i + start]; } } return newBuf }; /* * Need to make sure that buffer isn't trying to write out of bounds. */ function checkOffset (offset, ext, length) { if ((offset % 1) !== 0 || offset < 0) throw new RangeError('offset is not uint') if (offset + ext > length) throw new RangeError('Trying to access beyond buffer length') } Buffer.prototype.readUIntLE = function readUIntLE (offset, byteLength, noAssert) { offset = offset | 0; byteLength = byteLength | 0; if (!noAssert) checkOffset(offset, byteLength, this.length); var val = this[offset]; var mul = 1; var i = 0; while (++i < byteLength && (mul *= 0x100)) { val += this[offset + i] * mul; } return val }; Buffer.prototype.readUIntBE = function readUIntBE (offset, byteLength, noAssert) { offset = offset | 0; byteLength = byteLength | 0; if (!noAssert) { checkOffset(offset, byteLength, this.length); } var val = this[offset + --byteLength]; var mul = 1; while (byteLength > 0 && (mul *= 0x100)) { val += this[offset + --byteLength] * mul; } return val }; Buffer.prototype.readUInt8 = function readUInt8 (offset, noAssert) { if (!noAssert) checkOffset(offset, 1, this.length); return this[offset] }; Buffer.prototype.readUInt16LE = function readUInt16LE (offset, noAssert) { if (!noAssert) checkOffset(offset, 2, this.length); return this[offset] | (this[offset + 1] << 8) }; Buffer.prototype.readUInt16BE = function readUInt16BE (offset, noAssert) { if (!noAssert) checkOffset(offset, 2, this.length); return (this[offset] << 8) | this[offset + 1] }; Buffer.prototype.readUInt32LE = function readUInt32LE (offset, noAssert) { if (!noAssert) checkOffset(offset, 4, this.length); return ((this[offset]) | (this[offset + 1] << 8) | (this[offset + 2] << 16)) + (this[offset + 3] * 0x1000000) }; Buffer.prototype.readUInt32BE = function readUInt32BE (offset, noAssert) { if (!noAssert) checkOffset(offset, 4, this.length); return (this[offset] * 0x1000000) + ((this[offset + 1] << 16) | (this[offset + 2] << 8) | this[offset + 3]) }; Buffer.prototype.readIntLE = function readIntLE (offset, byteLength, noAssert) { offset = offset | 0; byteLength = byteLength | 0; if (!noAssert) checkOffset(offset, byteLength, this.length); var val = this[offset]; var mul = 1; var i = 0; while (++i < byteLength && (mul *= 0x100)) { val += this[offset + i] * mul; } mul *= 0x80; if (val >= mul) val -= Math.pow(2, 8 * byteLength); return val }; Buffer.prototype.readIntBE = function readIntBE (offset, byteLength, noAssert) { offset = offset | 0; byteLength = byteLength | 0; if (!noAssert) checkOffset(offset, byteLength, this.length); var i = byteLength; var mul = 1; var val = this[offset + --i]; while (i > 0 && (mul *= 0x100)) { val += this[offset + --i] * mul; } mul *= 0x80; if (val >= mul) val -= Math.pow(2, 8 * byteLength); return val }; Buffer.prototype.readInt8 = function readInt8 (offset, noAssert) { if (!noAssert) checkOffset(offset, 1, this.length); if (!(this[offset] & 0x80)) return (this[offset]) return ((0xff - this[offset] + 1) * -1) }; Buffer.prototype.readInt16LE = function readInt16LE (offset, noAssert) { if (!noAssert) checkOffset(offset, 2, this.length); var val = this[offset] | (this[offset + 1] << 8); re