109 lines
2.9 KiB
JavaScript
109 lines
2.9 KiB
JavaScript
'use strict';
|
|
|
|
const stream = require('stream');
|
|
const Transform = stream.Transform;
|
|
|
|
/**
|
|
* Escapes dots in the beginning of lines. Ends the stream with <CR><LF>.<CR><LF>
|
|
* Also makes sure that only <CR><LF> sequences are used for linebreaks
|
|
*
|
|
* @param {Object} options Stream options
|
|
*/
|
|
class DataStream extends Transform {
|
|
constructor(options) {
|
|
super(options);
|
|
// init Transform
|
|
this.options = options || {};
|
|
this._curLine = '';
|
|
|
|
this.inByteCount = 0;
|
|
this.outByteCount = 0;
|
|
this.lastByte = false;
|
|
}
|
|
|
|
/**
|
|
* Escapes dots
|
|
*/
|
|
_transform(chunk, encoding, done) {
|
|
let chunks = [];
|
|
let chunklen = 0;
|
|
let i,
|
|
len,
|
|
lastPos = 0;
|
|
let buf;
|
|
|
|
if (!chunk || !chunk.length) {
|
|
return done();
|
|
}
|
|
|
|
if (typeof chunk === 'string') {
|
|
chunk = Buffer.from(chunk);
|
|
}
|
|
|
|
this.inByteCount += chunk.length;
|
|
|
|
for (i = 0, len = chunk.length; i < len; i++) {
|
|
if (chunk[i] === 0x2e) {
|
|
// .
|
|
if ((i && chunk[i - 1] === 0x0a) || (!i && (!this.lastByte || this.lastByte === 0x0a))) {
|
|
buf = chunk.slice(lastPos, i + 1);
|
|
chunks.push(buf);
|
|
chunks.push(Buffer.from('.'));
|
|
chunklen += buf.length + 1;
|
|
lastPos = i + 1;
|
|
}
|
|
} else if (chunk[i] === 0x0a) {
|
|
// .
|
|
if ((i && chunk[i - 1] !== 0x0d) || (!i && this.lastByte !== 0x0d)) {
|
|
if (i > lastPos) {
|
|
buf = chunk.slice(lastPos, i);
|
|
chunks.push(buf);
|
|
chunklen += buf.length + 2;
|
|
} else {
|
|
chunklen += 2;
|
|
}
|
|
chunks.push(Buffer.from('\r\n'));
|
|
lastPos = i + 1;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (chunklen) {
|
|
// add last piece
|
|
if (lastPos < chunk.length) {
|
|
buf = chunk.slice(lastPos);
|
|
chunks.push(buf);
|
|
chunklen += buf.length;
|
|
}
|
|
|
|
this.outByteCount += chunklen;
|
|
this.push(Buffer.concat(chunks, chunklen));
|
|
} else {
|
|
this.outByteCount += chunk.length;
|
|
this.push(chunk);
|
|
}
|
|
|
|
this.lastByte = chunk[chunk.length - 1];
|
|
done();
|
|
}
|
|
|
|
/**
|
|
* Finalizes the stream with a dot on a single line
|
|
*/
|
|
_flush(done) {
|
|
let buf;
|
|
if (this.lastByte === 0x0a) {
|
|
buf = Buffer.from('.\r\n');
|
|
} else if (this.lastByte === 0x0d) {
|
|
buf = Buffer.from('\n.\r\n');
|
|
} else {
|
|
buf = Buffer.from('\r\n.\r\n');
|
|
}
|
|
this.outByteCount += buf.length;
|
|
this.push(buf);
|
|
done();
|
|
}
|
|
}
|
|
|
|
module.exports = DataStream;
|