2020-08-11

The RFC, The URI, and The Tilde

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...

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2020-07-20

Special Care of Delphi 10.4

sillybug.jpg, Jul 2020

A regression in the Delphi 10.4 compiler was identified. Its optimizer wrongly deletes some code, in one very specific part of the framework.

sillybug.jpg, Jul 2020

As a result a GPF (Access violation) may be triggered with Delphi 10.4 in release mode - the debug mode (when optimization is disabled) has no problem. Thanks to great user feedback, we were able to circumvent it. But we should better stay in alert, like any mORMot, until Delphi 10.4 officially release a patch.

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2020-07-02

mORMot on GitHub Sponsors

We just enrolled on GitHub Sponsors!

Aim is to allow proper evolution of our Open Source project, especially the upcoming mORMot2.

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2020-06-05

SQlite3 Encryption Not Possible Any More Since 3.32.x

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.

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2020-05-07

New Multi-thread Friendly Memory Manager for FPC written in x86_64 assembly

As a gift to the FPC community, I just committed a new Memory Manager for FPC.
Check mormot.core.fpcx64mm.pas in our mORMot2 repository.
This is a stand-alone unit for FPC only.

It targets Windows and Linux multi-threaded Service applications - typically mORMot daemons.
It is written in almost pure x86_64 assembly, and some unique tricks in the Delphi/FPC Memory Manager world.

It is based on FastMM4 (not FastMM5), and we didn't follow the path of the FastMM4-AVX version - instead of AVX, we use plain good (non-temporal) SSE2 opcode, and we rely on the mremap API on Linux for very efficient reallocation. Using mremap is perhaps the biggest  benefit of this memory manager - it leverages a killer feature of the Linux kernel for sure. By the way, we directly call the Kernel without the need of the libc.

We tuned our x86_64 assembly a lot, and made it cross-platform (Windows and POSIX). We profiled the multi-threading, especially by adding some additional small blocks for GetMem (which is a less expensive notion of "arenas" as used in FastMM5 and most C allocators), introducing an innovatice and very efficient round-robin of tiny blocks (<128 bytes), and proper spinning for FreeMem and medium blocks.

It runs all our regression tests with huge performance and stability - including multi-threaded tests with almost no slow down: sleep is reported as less than 1 ms during a 1 minute test. It has also been validated on some demanding multi-threaded tasks.

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2020-03-30

Debriefing of mORMot2 Survey

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

Here are some insights.

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2020-03-28

Faster Double-To-Text Conversion

On server side, a lot of CPU is done processing conversions to or from text. Mainly JSON these days.

In mORMot, we take care a lot about performance, so we have rewritten most conversion functions to have something faster than the Delphi or FPC RTL can offer.
Only float to text conversion was not available. And RTL str/floattexttext performance, at least under Delphi, is not consistent among platforms.
So we just added a new Double-To-Text set of functions.

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2020-03-06

We Need U: Survey about mORMot 2.0

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  […]

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