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The latest revision of Delphi, named Delphi 11 Alexandria, is out.
A lot of new features, some enhanced platforms. Nice!
But it is also for us the opportunity to come back to some breaking changes, which appeared in Delphi 10.4 earlier this year, and are now "officially" part of Delphi 11.

The main breaking change of Delphi 10.4 and later, as reported by mORMot users, is the new lifetime of local variables.
TL&LR: a local variable which is not explicitly declared, but returned by a function may be released as soon as it is not used any more, whereas in the original implementation, it was allocated as a regular local variable, and we could expect its lifetime to remain active up to the end of the function. With Delphi 10.4, it is not the case any more: the compiler could release/clear the local variable sooner, to reduce the allocation pressure.

Idea behind this change is that it may have better register allocation within the function, so it "may" theoretically result in faster code. Not convinced about it, anyway - we will discuss that.
The main thing is that it could break existing code, because it breaks the Delphi compiler expectation since decades.
Some perfectly fine working code would end to work as expected. We have identified several use cases with mORMot which are affected by this change. Since it seems there will be no coming back from Delphi point of view, it is worth a blog article.

Debug information can be generated by compilers, to contain symbols and source code lines. This is very handy to have a meaningful stack trace on any problems like exceptions, at runtime.

The problem is that debug information can be huge. New code style with generics tends to increase this size into a bloated way...
On Delphi, mormot2tests generates a 4MB .map file;
on FPC, mormot2tests outputs a 20MB .dbg file in DWARF.

For Delphi, we propose our own binary .mab format which reduces this 4MB .map file into a 290KB .mab file since mORMot 1.
Now mORMot 2 can reduce a FPC debug file of 20MB into a 322KB .mab file!
And this .mab information can just be appended to the executable for single-file distribution, if needed, during the build. No need to distribute two files, potentially with synchronization issues.

The .zip format is from last century, back to the early DOS days, but can still be found everywhere. It is even hidden when you run a .docx document, a .jar application, or any Android app!
It is therefore (ab)used not only as archive format, but as application file format / container - even if in this respect using SQLite3 may have much more sense.

We recently enhanced our mormot.core.zip.pas unit:

• to support Zip64,
• with enhanced .zip read/write,
• to have a huge performance boost during its process,
• and to integrate better with signed executables.

Last week, I committed new ASM implementations of our AES-PRNG, AES-CTR and AES-GCM for mORMot 2.
They handle eight 128-bit at once in an interleaved fashion, as permitted by the CTR chaining mode. The aes-ni opcodes (aesenc aesenclast) are used for AES process, and the GMAC of the AES-GCM mode is computed using the pclmulqdq opcode.

Resulting performance is amazing: on my simple Core i3, I reach 2.6 GB/s for aes-128-ctr, and 1.5 GB/s for aes-128-gcm for instance - the first being actually faster than OpenSSL!

One proposal for mORMot 2. What if we renamed the RawUTF8 type into Utf8? With a default compatibility redirection if PUREMORMOT2 is not defined, of course. The "Raw" prefix came from early mORMot code, which used TRichView as reference for the UTF-8 encoding... but it is clearly an  […]

EKON 24 just finished. "The conference for Delphi & more" was fully online this year, due to the viral context... But this was a great event, and I am very happy to have been part of it. Please find the slides on my two sessions: mORMot 2 Performance: from Delphi to AVX2 Of course,  […]

For several reasons, only plain ASCII characters are accepted in Web URIs. Other characters should be escaped with % and the hexadecimal value of its code.

The tilde character ~ is not needed to be escaped... at least in theory... because in practice most code expects it...

A journey into confusing RFCs...

About latest SQlite3 3.32.xxx there is a big problem with codecs.

Critical changes to the public SQLite code were introduced on Feb 7, 2020: “Simplify the code by removing the unsupported and undocumented SQLITE_HAS_CODEC compile-time option”. With the release of SQLite version 3.32.0 on May 22, 2020 these changes finally took officially effect, although they weren't officially announced.

As a sad and unexpected consequence, we are NOT ANY MORE able to compile the new SQlite3 amalgamation with our encryption patch.

Thanks you all for have posted your feedback on our mORMot2 Survey!

Here are some insights.

First of all, if it was not clear enough: Delphi will continue to be supported in mORMot 2.0. Some people reported that our previous article may have been misleading. But perhaps not all versions. For sure, Delphi 5 and Kylix will not be supported in mORMot 2. It is also possible that it would not  […]