Synopse Open Source

2013-05-21

Performance issue in NextGen ARC model

By AB4327-GANDI, 2013-05-21. Pascal Programming

Apart from being very slow during compilation, the Delphi NextGen compiler introduced a new memory model, named ARC.

We already spoke about ARC years ago, so please refer to our corresponding blog article for further information, especially about how Apple did introduce ARC to iOS instead of the Garbage Collector model.

About how ARC is to be used in the NextGen compiler, take a look at Marco's blog article, and its linked resources.

But the ARC model, as implemented by Embarcadero, has at least one huge performance issue, in the way weak references, and zeroing weak pointers have been implemented.
I do not speak about the general slow down introduced during every class/record initialization/finalization, which is noticeable, but not a big concern.

If you look at XE4 internals, you will discover a disappointing global lock introduced in the RTL.

2013-05-19

"The shorter code, the better?"

By AB4327-GANDI, 2013-05-19. Pascal Programming

One quick Sunday post, from a comment I wrote in a blog article.

I'm always wondering why a lot of programmers tend to implicitly assume that "the shorter source code, the better".

It is true when it means that with proper code refactoring, making small objects with dedicated methods, the code of your methods will be smaller.
It is true when you do not like to write as a "Copy & Paste" coder, without searching to put common code in shared places.

But is it true at the language level?
I mean, is it just because your ARC or GC model allow you not to manage the object memory, that it is always better?

Just some ideas...

2013-05-11

Delphi XE4 NextGen compiler: using byte instead of ansichar?

By AB4327-GANDI, 2013-05-11. Pascal Programming

When I first read the technical white paper covering all of the language changes in XE4 for mobile development (tied to the new ARM LLVM-based Delphi compiler), I have to confess I was pretty much confused.

Two great mORMot users just asked for XE4/iOS support of mORMot.

Win32/Win64 support for XE4 will be done as soon as we got a copy of it.
I suspect the code already works, since it was working as expected with XE3, and we rely on our own set of low-level functions for most internal work.

But iOS-targetting is more complex, due to the NextGen compiler, mainly.

2013-04-24

mORMots know how to swim like fishes

By AB4327-GANDI, 2013-04-24. Open Source › mORMot Framework

Another great video by warleyalex. This time, a full FishFacts demo in AJAX, using mORMot and its SQLite3 ORM as server. See it on YouTube! Feedback is welcome on our forum. Update: I've just uploaded the corresponding source code to our repository. See sample 19 - AJAX ExtJS FishFacts. You need to […]

2013-04-22

TDataSet... now I'm confused

By AB4327-GANDI, 2013-04-22. Pascal Programming

You perhaps know that I'm not a big fan of the TDataSet / RAD DB approach for end-user applications.
They are easy to define, almost no code to write, and you are able to publish a working solution very fast.

But it is a nightmare to debug and maintain. I prefer the new DataBinding feature, or... of course... ORM!
In mORMot, we have some auto-generated screens, and in our roadmap, we forcast to use some auto-binding features, using a KISS by-convention MVC pattern.

For some users, we made a ORM / TDataSet conversion unit.
And we discovered that TDataSet has a weird, and very misleading definition of its AsString property, for Unicode versions of Delphi.

2013-04-02

Two videos about EXTjs client of mORMot server

By AB4327-GANDI, 2013-04-02. Open Source › mORMot Framework

Two nice videos, posted by a framework user. The first one presents a remote RESTful access of a SQLite3 database, hosted by a mORMot server: After one post in the forum, warleyalex was able to easily add remote filtering of the request: In addition to the previous video about security (by which the […]

2013-03-28

Adding some generic-based methods to mORMot

By AB4327-GANDI, 2013-03-28. Open Source › mORMot Framework

We have just added a TSQLTable.ToObjectList<T: class>() method. I want to add some generics-based methods to mORMot, for newer versions of Delphi. What do you think of it? Have you some method prototypes to propose? My first concern is that FreePascal does not offer the same syntax. I suppose […]

2013-03-27

Introducing TSQLTable.Step() method

By AB4327-GANDI, 2013-03-27. Open Source › mORMot Framework

We have just added TSQLTable.Step(), FieldBuffer() and Field() methods, handling a cursor at TSQLTable level, with optional late-binding column access.

It allows to retrieve results from a TSQLTable / TSQLTableJSON result sets within a "cursor-like" orientation.
That is, no need to specify the row number, but write a simple while aList.Step do ... loop.

Of course, you should better use TSQLRecord.FillPrepare most of the time, and access the data from a TSQLRecord instance.
But it can be very useful, e.g. when working on a custom JOINed SQL statement.