send-mail/node_modules/nodemailer/lib/smtp-connection/data-stream.js

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2020-03-01 05:01:03 +07:00
'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;