|
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182 |
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- 'use strict';
-
- module.exports = Transform;
-
- var Duplex = require('./_stream_duplex');
-
-
- var util = require('core-util-is');
- util.inherits = require('inherits');
-
-
- util.inherits(Transform, Duplex);
-
- function TransformState(stream) {
- this.afterTransform = function (er, data) {
- return afterTransform(stream, er, data);
- };
-
- this.needTransform = false;
- this.transforming = false;
- this.writecb = null;
- this.writechunk = null;
- this.writeencoding = null;
- }
-
- function afterTransform(stream, er, data) {
- var ts = stream._transformState;
- ts.transforming = false;
-
- var cb = ts.writecb;
-
- if (!cb) return stream.emit('error', new Error('no writecb in Transform class'));
-
- ts.writechunk = null;
- ts.writecb = null;
-
- if (data !== null && data !== undefined) stream.push(data);
-
- cb(er);
-
- var rs = stream._readableState;
- rs.reading = false;
- if (rs.needReadable || rs.length < rs.highWaterMark) {
- stream._read(rs.highWaterMark);
- }
- }
-
- function Transform(options) {
- if (!(this instanceof Transform)) return new Transform(options);
-
- Duplex.call(this, options);
-
- this._transformState = new TransformState(this);
-
- var stream = this;
-
-
- this._readableState.needReadable = true;
-
-
-
-
- this._readableState.sync = false;
-
- if (options) {
- if (typeof options.transform === 'function') this._transform = options.transform;
-
- if (typeof options.flush === 'function') this._flush = options.flush;
- }
-
-
- this.once('prefinish', function () {
- if (typeof this._flush === 'function') this._flush(function (er, data) {
- done(stream, er, data);
- });else done(stream);
- });
- }
-
- Transform.prototype.push = function (chunk, encoding) {
- this._transformState.needTransform = false;
- return Duplex.prototype.push.call(this, chunk, encoding);
- };
-
-
-
-
-
-
-
-
-
-
-
- Transform.prototype._transform = function (chunk, encoding, cb) {
- throw new Error('_transform() is not implemented');
- };
-
- Transform.prototype._write = function (chunk, encoding, cb) {
- var ts = this._transformState;
- ts.writecb = cb;
- ts.writechunk = chunk;
- ts.writeencoding = encoding;
- if (!ts.transforming) {
- var rs = this._readableState;
- if (ts.needTransform || rs.needReadable || rs.length < rs.highWaterMark) this._read(rs.highWaterMark);
- }
- };
-
-
-
-
- Transform.prototype._read = function (n) {
- var ts = this._transformState;
-
- if (ts.writechunk !== null && ts.writecb && !ts.transforming) {
- ts.transforming = true;
- this._transform(ts.writechunk, ts.writeencoding, ts.afterTransform);
- } else {
-
-
- ts.needTransform = true;
- }
- };
-
- function done(stream, er, data) {
- if (er) return stream.emit('error', er);
-
- if (data !== null && data !== undefined) stream.push(data);
-
-
-
- var ws = stream._writableState;
- var ts = stream._transformState;
-
- if (ws.length) throw new Error('Calling transform done when ws.length != 0');
-
- if (ts.transforming) throw new Error('Calling transform done when still transforming');
-
- return stream.push(null);
- }
|