[PATCH v6 02/11] stdio-common: Introduce buffers for implementing printf

[Florian Weimer]

* Noah Goldstein:

>> +/* Switch to the file buffer if possible.  If the file has write_ptr
>> +   == write_end, use the stage buffer instead.  */
>> +void
>> +__printf_buffer_to_file_switch (struct __printf_buffer_to_file *buf)
>> +{
>> +  if (buf->fp->_IO_write_ptr < buf->fp->_IO_write_end)
>> +    {
>
> Think maybe this should have a minimum bound so we don't end up
> in a situation where the strnlen / memcpy loop is only doing 1/2
> bytes at a time.
> Probably something like 32/64 would make sense.

I think this would only matter with setvbuf and a small buffer.  We can
use half of the staging buffer size (PRINTF_BUFFER_SIZE_TO_FILE_STAGE),
that would be your 64 number.

Thanks,
Florian