Function chunk_is_postgres_chunk

src/backend/postmaster/syslogger.c:138–143

}

static bool chunk_is_postgres_chunk(PipeProtoHeader *hdr)
{
    return hdr->zero == 0 && hdr->pid != 0 && hdr->thid != 0 &&
		(hdr->log_format == 't' || hdr->log_format == 'c') &&
		(hdr->is_last == 't' || hdr->is_last == 'f');
}

/*
 * Flags set by interrupt handlers for later service in the main loop.