Thread: improvements in Unicode tables generation code

improvements in Unicode tables generation code

From
Peter Eisentraut
Date:
I have accumulated a few patches to improve the output of the scripts in 
src/backend/utils/mb/Unicode/ to be less non-standard-looking and fix a 
few other minor things in that area.

v1-0001-Make-Unicode-makefile-more-parallel-safe.patch

The makefile rule that calls UCS_to_most.pl was written incorrectly for 
parallel make.  The script writes all output files in one go, but the 
rule as written would call the command once for each output file in 
parallel.

v1-0002-Make-UCS_to_most.pl-process-encodings-in-sorted-o.patch

This mainly just helps eyeball the output while debugging the previous 
patch.

v1-0003-Remove-some-whitespace-in-generated-C-output.patch

Improve a small formatting issue in the output.

v1-0004-Simplify-code-generation-code.patch

This simplifies the code a bit, which helps with the next patch.

v1-0005-Fix-indentation-in-generated-output.patch

This changes the indentation in the output from two spaces to a tab.

I haven't included the actual output changes in the last patch, because 
they would be huge, but the idea should be clear.

All together, these make the output look closer to how pgindent would 
make it.

Attachment

Re: improvements in Unicode tables generation code

From
Kyotaro Horiguchi
Date:
At Tue, 22 Jun 2021 09:20:16 +0200, Peter Eisentraut <peter.eisentraut@enterprisedb.com> wrote in 
> I have accumulated a few patches to improve the output of the scripts
> in src/backend/utils/mb/Unicode/ to be less non-standard-looking and
> fix a few other minor things in that area.
> 
> v1-0001-Make-Unicode-makefile-more-parallel-safe.patch
> 
> The makefile rule that calls UCS_to_most.pl was written incorrectly
> for parallel make.  The script writes all output files in one go, but
> the rule as written would call the command once for each output file
> in parallel.

I was annoyed by that behavior but haven't found how to stop that.  It
looks to work. (But I haven't run it for me for the reason at the end
of this mail.)

> v1-0002-Make-UCS_to_most.pl-process-encodings-in-sorted-o.patch
> 
> This mainly just helps eyeball the output while debugging the previous
> patch.
> 
> v1-0003-Remove-some-whitespace-in-generated-C-output.patch
> 
> Improve a small formatting issue in the output.

These look just fine.

> v1-0004-Simplify-code-generation-code.patch
> 
> This simplifies the code a bit, which helps with the next patch.

This simplifies the code in exchange of allowing a comma after the
last element of array literals.  I'm fine with it as long as we allow
that style in the tree.

> v1-0005-Fix-indentation-in-generated-output.patch
> 
> This changes the indentation in the output from two spaces to a tab.
> 
> I haven't included the actual output changes in the last patch,
> because they would be huge, but the idea should be clear.
> 
> All together, these make the output look closer to how pgindent would
> make it.

I agree to the fix.

Mmm. (although, somewhat unrelated to this patch set) I tried this but
I found that www.unicode.org doesn't respond (for at least these
several days).  I'm not sure what is happening here.

> wget -O 8859-2.TXT --no-use-server-timestamps https://www.unicode.org/Public/MAPPINGS/ISO8859/8859-2.TXT
> --2021-06-22 17:09:34--  https://www.unicode.org/Public/MAPPINGS/ISO8859/8859-2.TXT
> Resolving www.unicode.org (www.unicode.org)... 66.34.208.12
> Connecting to www.unicode.org (www.unicode.org)|66.34.208.12|:443... 
(timeouts)


regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center



Re: improvements in Unicode tables generation code

From
Heikki Linnakangas
Date:
On 22/06/2021 10:20, Peter Eisentraut wrote:
> I have accumulated a few patches to improve the output of the scripts in
> src/backend/utils/mb/Unicode/ to be less non-standard-looking and fix a
> few other minor things in that area.
> 
> v1-0001-Make-Unicode-makefile-more-parallel-safe.patch
> 
> The makefile rule that calls UCS_to_most.pl was written incorrectly for
> parallel make.  The script writes all output files in one go, but the
> rule as written would call the command once for each output file in
> parallel.

This could use a comment. At a quick glance, I don't understand what all 
the $(wordlist ...) magic does.

Perhaps we should change the script or Makefile so that it doesn't 
create all the maps in one go?

> v1-0002-Make-UCS_to_most.pl-process-encodings-in-sorted-o.patch
> 
> This mainly just helps eyeball the output while debugging the previous
> patch.

+1

> v1-0003-Remove-some-whitespace-in-generated-C-output.patch
> 
> Improve a small formatting issue in the output.

I'm surprised the added \n in the perl code didn't result in extra 
newlines in the outputs.

> v1-0004-Simplify-code-generation-code.patch
> 
> This simplifies the code a bit, which helps with the next patch.

If we do that, let's add the trailing commas to the other arrays too, 
not just the combined maps.

No objection, but how does this help the next patch?

If we want to avoid the stray commas (and I think they are a little 
ugly, but that's a matter of taste), we could adopt the approach that 
print_radix_table() uses to avoid the comma. That seems simpler than 
what print_from_utf8_combined_map and print_to_utf8_combined_map are doing.

> v1-0005-Fix-indentation-in-generated-output.patch
> 
> This changes the indentation in the output from two spaces to a tab.
> 
> I haven't included the actual output changes in the last patch, because
> they would be huge, but the idea should be clear.
> 
> All together, these make the output look closer to how pgindent would
> make it.

Thanks!

- Heikki



Re: improvements in Unicode tables generation code

From
Kyotaro Horiguchi
Date:
At Tue, 22 Jun 2021 11:20:46 +0300, Heikki Linnakangas <hlinnaka@iki.fi> wrote in 
> On 22/06/2021 10:20, Peter Eisentraut wrote:
> > v1-0004-Simplify-code-generation-code.patch
> > This simplifies the code a bit, which helps with the next patch.
> 
> If we do that, let's add the trailing commas to the other arrays too,
> not just the combined maps.
> 
> No objection, but how does this help the next patch?
> 
> If we want to avoid the stray commas (and I think they are a little
> ugly, but that's a matter of taste), we could adopt the approach that
> print_radix_table() uses to avoid the comma. That seems simpler than
> what print_from_utf8_combined_map and print_to_utf8_combined_map are
> doing.

+1 for adopting the same method with print_radix_table *if* we do want
to avoid the stray commans.

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center



Re: improvements in Unicode tables generation code

From
Peter Eisentraut
Date:
On 22.06.21 10:20, Heikki Linnakangas wrote:
> On 22/06/2021 10:20, Peter Eisentraut wrote:
>> I have accumulated a few patches to improve the output of the scripts in
>> src/backend/utils/mb/Unicode/ to be less non-standard-looking and fix a
>> few other minor things in that area.
>>
>> v1-0001-Make-Unicode-makefile-more-parallel-safe.patch
>>
>> The makefile rule that calls UCS_to_most.pl was written incorrectly for
>> parallel make.  The script writes all output files in one go, but the
>> rule as written would call the command once for each output file in
>> parallel.
> 
> This could use a comment. At a quick glance, I don't understand what all 
> the $(wordlist ...) magic does.
> 
> Perhaps we should change the script or Makefile so that it doesn't 
> create all the maps in one go?

I agree, either comment it better or just write one file at a time. 
I'll take another look at that.

>> v1-0003-Remove-some-whitespace-in-generated-C-output.patch
>>
>> Improve a small formatting issue in the output.
> 
> I'm surprised the added \n in the perl code didn't result in extra 
> newlines in the outputs.

True, I'll have to check that again.  I suspect that \n actually belongs 
to patch 0004.

>> v1-0004-Simplify-code-generation-code.patch
>>
>> This simplifies the code a bit, which helps with the next patch.
> 
> If we do that, let's add the trailing commas to the other arrays too, 
> not just the combined maps.
> 
> No objection, but how does this help the next patch?

Mainly it just moves things around so that each print normally starts at 
the beginning of a line and concludes with a \n.



Re: improvements in Unicode tables generation code

From
Peter Eisentraut
Date:
On 23.06.21 10:55, Peter Eisentraut wrote:
>>> v1-0001-Make-Unicode-makefile-more-parallel-safe.patch
>>>
>>> The makefile rule that calls UCS_to_most.pl was written incorrectly for
>>> parallel make.  The script writes all output files in one go, but the
>>> rule as written would call the command once for each output file in
>>> parallel.
>>
>> This could use a comment. At a quick glance, I don't understand what 
>> all the $(wordlist ...) magic does.
>>
>> Perhaps we should change the script or Makefile so that it doesn't 
>> create all the maps in one go?
> 
> I agree, either comment it better or just write one file at a time. I'll 
> take another look at that.

Here is a patch that does it one file (pair) at a time.  The other rules 
besides UCS_to_most.pl actually had the same problem, since they produce 
two output files, so running in parallel called each script twice.  In 
this patch, all of that is heavily refactored and works correctly now. 
Note that UCS_to_most.pl already accepted a command-line argument to 
specify which encoding to work with.

Attachment

Re: improvements in Unicode tables generation code

From
Peter Eisentraut
Date:
On 20.07.21 13:57, Peter Eisentraut wrote:
>>> Perhaps we should change the script or Makefile so that it doesn't 
>>> create all the maps in one go?
>>
>> I agree, either comment it better or just write one file at a time. 
>> I'll take another look at that.
> 
> Here is a patch that does it one file (pair) at a time.  The other rules 
> besides UCS_to_most.pl actually had the same problem, since they produce 
> two output files, so running in parallel called each script twice.  In 
> this patch, all of that is heavily refactored and works correctly now. 
> Note that UCS_to_most.pl already accepted a command-line argument to 
> specify which encoding to work with.

Here is an updated patch with a thinko fix that made the previous patch 
not actually work.

Attachment

Re: improvements in Unicode tables generation code

From
Peter Eisentraut
Date:
On 28.09.21 10:25, Peter Eisentraut wrote:
> 
> On 20.07.21 13:57, Peter Eisentraut wrote:
>>>> Perhaps we should change the script or Makefile so that it doesn't 
>>>> create all the maps in one go?
>>>
>>> I agree, either comment it better or just write one file at a time. 
>>> I'll take another look at that.
>>
>> Here is a patch that does it one file (pair) at a time.  The other 
>> rules besides UCS_to_most.pl actually had the same problem, since they 
>> produce two output files, so running in parallel called each script 
>> twice.  In this patch, all of that is heavily refactored and works 
>> correctly now. Note that UCS_to_most.pl already accepted a 
>> command-line argument to specify which encoding to work with.
> 
> Here is an updated patch with a thinko fix that made the previous patch 
> not actually work.

I have committed this one and closed the CF entry.