Current File : //opt/alt/alt-nodejs14/root/usr/lib/node_modules/npm/node_modules.bundled/byline/lib/byline.js
// Copyright (C) 2011-2015 John Hewson
//
// 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.
var stream = require('stream'),
util = require('util'),
timers = require('timers');
// convinience API
module.exports = function(readStream, options) {
return module.exports.createStream(readStream, options);
};
// basic API
module.exports.createStream = function(readStream, options) {
if (readStream) {
return createLineStream(readStream, options);
} else {
return new LineStream(options);
}
};
// deprecated API
module.exports.createLineStream = function(readStream) {
console.log('WARNING: byline#createLineStream is deprecated and will be removed soon');
return createLineStream(readStream);
};
function createLineStream(readStream, options) {
if (!readStream) {
throw new Error('expected readStream');
}
if (!readStream.readable) {
throw new Error('readStream must be readable');
}
var ls = new LineStream(options);
readStream.pipe(ls);
return ls;
}
//
// using the new node v0.10 "streams2" API
//
module.exports.LineStream = LineStream;
function LineStream(options) {
stream.Transform.call(this, options);
options = options || {};
// use objectMode to stop the output from being buffered
// which re-concatanates the lines, just without newlines.
this._readableState.objectMode = true;
this._lineBuffer = [];
this._keepEmptyLines = options.keepEmptyLines || false;
this._lastChunkEndedWithCR = false;
// take the source's encoding if we don't have one
var self = this;
this.on('pipe', function(src) {
if (!self.encoding) {
// but we can't do this for old-style streams
if (src instanceof stream.Readable) {
self.encoding = src._readableState.encoding;
}
}
});
}
util.inherits(LineStream, stream.Transform);
LineStream.prototype._transform = function(chunk, encoding, done) {
// decode binary chunks as UTF-8
encoding = encoding || 'utf8';
if (Buffer.isBuffer(chunk)) {
if (encoding == 'buffer') {
chunk = chunk.toString(); // utf8
encoding = 'utf8';
}
else {
chunk = chunk.toString(encoding);
}
}
this._chunkEncoding = encoding;
// see: http://www.unicode.org/reports/tr18/#Line_Boundaries
var lines = chunk.split(/\r\n|[\n\v\f\r\x85\u2028\u2029]/g);
// don't split CRLF which spans chunks
if (this._lastChunkEndedWithCR && chunk[0] == '\n') {
lines.shift();
}
if (this._lineBuffer.length > 0) {
this._lineBuffer[this._lineBuffer.length - 1] += lines[0];
lines.shift();
}
this._lastChunkEndedWithCR = chunk[chunk.length - 1] == '\r';
this._lineBuffer = this._lineBuffer.concat(lines);
this._pushBuffer(encoding, 1, done);
};
LineStream.prototype._pushBuffer = function(encoding, keep, done) {
// always buffer the last (possibly partial) line
while (this._lineBuffer.length > keep) {
var line = this._lineBuffer.shift();
// skip empty lines
if (this._keepEmptyLines || line.length > 0 ) {
if (!this.push(this._reencode(line, encoding))) {
// when the high-water mark is reached, defer pushes until the next tick
var self = this;
timers.setImmediate(function() {
self._pushBuffer(encoding, keep, done);
});
return;
}
}
}
done();
};
LineStream.prototype._flush = function(done) {
this._pushBuffer(this._chunkEncoding, 0, done);
};
// see Readable::push
LineStream.prototype._reencode = function(line, chunkEncoding) {
if (this.encoding && this.encoding != chunkEncoding) {
return new Buffer(line, chunkEncoding).toString(this.encoding);
}
else if (this.encoding) {
// this should be the most common case, i.e. we're using an encoded source stream
return line;
}
else {
return new Buffer(line, chunkEncoding);
}
};
Mini Shell