Заметки

The today’s hybrismart article is aimed to beginners (?).

I published a list of SAP hybris services which I’d call “essential”. There are some information on them as well, such as the operations they provide and other services they depend on.

In order to prioritize hundreds of services and come up with the list of essential services, I processed hybris sources to reveal the most requested beans. Any hybris developer uses (and combines) them in almost any custom code it creates.

https://hybrismart.com/2018/07/26/essential-hybris-services/

https://hybrismart.com/2018/07/26/essential-hybris-services/

For programmers who think they are able to explain any code in any programming language:

Proceed to this link and try to figure out what this code does and how. Yes, it is Haskell. Among all functional languages, Haskell is not completely dead. A great exercise for the brain on a quiet Sunday evening.

http://rextester.com/EAK40086

You probably noticed that there is no any breakthroughs on the e-reader markets for years. I have an idea) Let’s imagine you have a reader with the whole library already moved to the device and you can start reading any book immediately. For example, 30% of the any book content is available instantly for the user, and the remaining 70% needs activation to get access. The search works for all content. The simplest way of activating the remaining 70% is sending a simple text message to receive a personal single-use coupon. Possibly, you can buy (in advance) a number of universal activation single-use codes (which work with any book), and these coupons can be sold with the device as a package (extra $). The book library package is the updatable thing which can be sold as a package too. For example, if you are a software developer, you may decide to buy a reader with the IT books. You can update the device by loading new books to it, hundreds or thousands. I think it would be very convenient for anyone.

I can’t say how long this coupon will be. 10? 15? The device can be equipped with a barcode reader to enter it into the device faster. It can be used both for quick search (in a bookstore, you see a book and wants to buy it. The code is printed at the book or nearby) and as a coupon reader at the checkout (you pay at the checkout, and the book is yours. The bookstore gets their %).

As for security: The coupons are generated as unique per device. The library part of the device interface is one-directional, so you can’t retrieve books even if you try to hack it. The algorithm for coupon verification is in the firmware and unique per device (the algorithm itself can be simple, but the parameters it uses are unique per device). The same algorithm is used on the coupon generation service which is a black box for all except the manufacturer. The device parameters are known for the manufacturer, so the coupon generator and coupon verification module are synchronized by the public part of the device id. The public part of the device id is printed on the customer card which is used by the device owner to buy coupons. The private part is in the device and in the manufacturer database used for the generation, and it is protected and not retrievable. If you want to buy a coupon for a particular book or section and for a particular device, you need to enter these parameters into a code generation interface: public part of the device id and select the desired book or section. After payment is made, you will receive the coupon for the device. After you enter the coupon in the device, it will be decrypted and book id or section id will be used by firmware to grant access. These operations are performed each time you try to access books on the device. The coupons are stored in the device memory. If you need to replace device (warranty), the service center will generate a new set of coupons for a new device. This part of firmware shouldn’t be updatable too to avoid hacking the process.

What do you think?

Just watched. The genius of the Coen Brothers. The Big Lebowski is an absolute masterpiece! This year is its 20th anniversary, and I decided to rewatch it with the original English track. It’s like chalk and cheese, guys. Thanks Alex Exler for the tip today, it made my day.

https://www.imdb.com/title/tt0118715/

https://www.imdb.com/title/tt0118715/

This is the best lecture I’ve ever seen on how batteries work. Concepts, a bit of chemistry and physics, illustrated, in clear and simple language (the lecture is in Russian)

https://www.youtube.com/watch?v=g3FZsljHZqU

A new update on the hybris blog. A new set of groovy scripts. These scripts help to troubleshoot the hybris instance by injecting your code inside hybris on the fly. I’ve published some before, this is the part 6.

https://hybrismart.com/2018/07/20/useful-groovy-scripts-part-6/

https://hybrismart.com/2018/07/20/useful-groovy-scripts-part-6/

Two Chukchi hunters killed a walrus. The geologist sees them dragging the walrus by a tail and says, “Hi guys! Can’t you see the walrus’s tusk clings! It makes your job harder! Take it by the tusk, and things would be a lot easier for you.” The Chukchi hunters listened. They took the walrus by a tusk. It worked! After a while, one of them says, “That geologist is a smart guy. It is much easier to drag the walrus by a tusk.”. The second one replies: “Your geologist is an asshole! Look! We’ve come back to the sea!”

More: https://www.languagesoftheworld.info/russia-ukraine-and-the-caucasus/chukchis-russian-jokes-history.html

Yesterday I learned how IMAX works, the photo is from the Philadelphia Science Museum IMAX theatre.

Film platters weigh 250kg, the projector itself is about 1.5 tonnes. IMAX projectors are equipped with water-cooled xenon lamps. It was really interesting to see all this stuff in action.

I used to think that all IMAXes are digital, and it is so for years, but I learned that Digital IMAX has the same resolution as your domestic 1080P TV. Moreover, there are films which weren’t published for IMAX Digital, such as “Interstellar” or “Dark Night Returns”. The new generation is Laser 4k digital projectors which are rare, but they are much better in terms of quality and closer to 70mm IMAX.

For example, the majority of IMAX theaters are 70mm, some have Dual system (both digital and 70mm, rail system). https://en.wikipedia.org/wiki/List_of_IMAX_venues. In our area, there are two laser 4k projectors, in the National Air and Space Museum and in Steven F. Udvar-Hazy Center. In Moscow, there is only one, Formula Kino Kutuzovsky.

https://www.youtube.com/watch?v=_EaIQoIuSCc