Hi,
In a recent change[1], the Buffer._charsWritten expected from following
code is changed from 6 to 4, this make me wonder what is the definition and
proper value for Buffer._charsWritten.
buf = new Buffer(9);
buf.write('123456', 'base64');
assert.equal(Buffer._charsWritten, 4);
buf.write('00010203040506070809', 'hex');
assert.equal(Buffer._charsWritten, 18);
According to the doc, "The number of characters written (which may be
different than the number of bytes written) is set in Buffer._charsWrittenand
will be overwritten the next time
buf.write() is called."
My understanding to "The number of characters written" is the number of
characters used in the input stream to be decoded into the buffer, and in
this case, 6 seems to be reasonable as used to decode 4 octets.
Theoretically, the proper base64 encoded input should have multiple of 4
characters, in this case, 2 paddings is probably needed. If we consider
multiple of 4 to be "non partial character", then the decoded octets would
be 3 instead of 4. But in this case, Buffer.write do return 4 and write 4
octets into the buffer.
So, is this a bug or there is a better explanation? Perhaps my
understanding is just wrong. Would you please shed the light on what should
be expected here?
Cheers,
Henry
[1]
https://github.com/joyent/node/commit/f101f7c9babb31f077c78b52de7cc45ad687f57e#test/simple/test-buffer.js
