In general integer division is implemented using a form of long division, in binary. There is no base-10 arithmetic involved. It’s a relatively expensive operation which usually requires multiple clock cycles to complete, whereas dividing by a power of two (“bit shifting”) is trivial and can be done in hardware simply by routing the signals appropriately, without any logic gates.

The metric standard is to measure information in bits.

Bytes are a non-metric unit. Not a power-of-ten multiple of the metric base unit for information, the bit.

If you’re writing “1 million bytes” and not “8 million bits” then you’re not using metric.

If you aren’t using metric then the metric prefix definitions don’t apply.

There is plenty of precedent for the prefixes used in metric to refer to something other than an exact power of 1000 when not combined with a metric base unit. A microcomputer is not one one-thousandth of a computer. One thousand microscopes do not add up to one scope. Megastructures are not exactly one million times the size of ordinary structures. Etc.

Finally: This isn’t primarily about bit shifting, it’s about computers being based on binary representation and the fact that memory addresses are stored and communicated using whole numbers of bits, which naturally leads to memory sizes (for entire memory devices or smaller structures) which are powers of two. Though the fact that no one is going to do something as idiotic as introducing an expensive and completely unnecessary division by a power of ten for every memory access just so you can have 1000-byte MMU pages rather than 4096 also plays a part.

In what sense do you think this isn’t following the email standard? The plus sign is a valid character in the local part, and the standard doesn’t say how it should be interpreted (it could be a significant part of the name; it’s not proper to strip it out) or preclude multiple addresses from delivering to the same mailbox.

Unfortunately the feature is too well-known, and the mapping from the tagged address to the plain address is too transparent. Spammers will just remove the label. You need either a custom domain so you can use a different separator (‘+’ is the default but you can generally choose something else for your own server) or a way to generate random, opaque temporary addresses.

If you want to talk about non-compliant address handing, aside from not accepting valid addresses, the one that always bothers me is sites that capitalize or lowercase the local part of the address. Domain names are not case-sensitive, but the local part is. Changing the case could result in non-delivery or delivery to the wrong mailbox. Most servers are case-insensitive but senders shouldn’t assume that is always true.

CVS and E*Trade both refused to accept my fairly standard [email protected] address during initial registration, but had no issue changing to that address once the account was created. It would be nice if their internal teams communicated a bit better.

The full email address syntax described in the RFC cannot be precisely matched with a mere regular expression due to the support for nested comments. The need to track arbitrarily deep nesting state makes it a non-regular language.

If you remove the comments first the remainder can be parsed with a very complex regex, but it will be about a kilobyte long.

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So you’re not remapping the source ports to be unique? There’s no mechanism to avoid collisions when multiple clients use the same source port? Full Cone NAT implies that you have to remember the mapping (potentially indefinitely—if you ever reassign a given external IP:port combination to a different internal IP or port after it’s been used you’re not implementing Full Cone NAT), but not that the internal and external ports need to be identical. It would generally only be used when you have a large enough pool of external IP addresses available to assign a unique external IP:port for every internal IP:port. Which usually implies a unique external IP for each internal IP, as you can’t restrict the number of unique ports used by each client. This is why most routers only implement Symmetric NAT.

(If you do have sufficient external IPs the Linux kernel can do Full Cone NAT by translating only the IP addresses and not the ports, via SNAT/DNAT prefix mapping. The part it lacks, for very practical reasons, is support for attempting to create permanent unique mappings from a larger number of unconstrained internal IP:port combinations to a smaller number of external ones.)

I’m fairly certain that last one is UB in C. The result of an assignment operator is not an lvalue, and even if it were it’s UB (at least in C99) to modify the stored value of an object more than once between two adjacent sequence points. It might work in C++, though.

They should still be using the CPU’s built-in AES hardware acceleration, yes? It seems they have good reason not to trust the SSD to handle the encryption but that doesn’t mean it has to be entirely implemented in software. CPU-accelerated AES shouldn’t be that much slower.

MongoDB is under the Server Side Public License (SSPL) which is not an Open Source license.