Problem about message missing when write CJK string

[hicdre]

const SonicBoom = require('sonic-boom');
const sonic = new SonicBoom({ fd: process.stdout.fd }); 

sonic.write('测试一二三四五六七八九十\n');
sonic.write('零\n');  // this is missing in stdout

console.log('finish');

The problem is about line below

sonic-boom/index.js

Lines 164 to 165 in 7b4e25f

	const n = fs.writeSync(this.fd, this._writingBuf, 'utf8')
	this._len -= n

n is the byte length of this._writingBuf, but it may not equals the characters length of the string which actually encoded in utf16. So this._len would be less than zero. It will lead to message missing.

console.assert('测试一二三四五六七八九十\n'.length === 13);
console.assert(Buffer.from('测试一二三四五六七八九十\n', 'utf8').length === 37);

[ronag]

Good catch! @mcollina I don't see a good way to fix this without some form of perf regression. I think we have 2 options:

In write we:

1. Buffer.byteLength(str)
2. Always convert to Buffer in write.

[jsumners]

This module's readme clearly states it is a utf8 only stream module.

[ronag]

All strings in javascript are utf-16...

[jsumners]

All strings in javascript are utf-16...

So they are https://262.ecma-international.org/11.0/#sec-ecmascript-language-types-string-type

[hicdre]

pinojs/pino-pretty#324

[zbinlin]

Can you fix this issue? @mcollina @ronag @jsumners
I use Fastify v4, it will cause the log not to be flushed.

[mcollina]

That's unlikely to happen in the short term. I'd be happy to see a PR that fixes it (without regressing the throughput).

[mcollina]

Here is a PR with a partial fix: #154

[mcollina]

The next step would be to convert this._writingBuf from being a String to being a Buffer.

[jsumners]

For whomever tackles this by swapping out the String backing to a Buffer, keep in mind that there are multiple types of multi-byte utf-8 characters. See https://github.com/ldapjs/filter/blob/1423612281ccd43fb5f45dc9b534d91969d3cc6e/lib/utils/escape-filter-value.js for some code that covers 2 and 3 byte characters.