Re: SVN: PCSWMM Use

[David Chapman]

On 9/14/2021 9:26 AM, Jason Kimmet wrote:

(snipped to avoid top-posting)


*From:* David Chapman 
*Sent:* Thursday, September 9, 2021 4:29 PM
*To:* Jason Kimmet ; 
users@subversion.apache.org 

*Subject:* Re: SVN: PCSWMM Use
On 9/9/2021 1:53 PM, Jason Kimmet wrote:

Subversion Users,

We are working on a large stormwater modeling program where we will 
be keeping track of a lot of PCSWMM file type models. We are 
exploring version management options and have come across the SVN 
community. I understand this is great for text-style files, however, 
I would like to know if you have seen users utilize this for 
engineering plans such as PCSWMM?


Many version control systems, Subversion included, work best when the 
new version of a file looks much the same as the previous version.  
Otherwise you could be storing multiple full versions of the files.


Some features of Subversion (like "show lines that changed") aren't 
available for binary files, but if the changes in a binary file are 
limited to specific sections, you still get space-saving benefits in 
the repository; see 
http://help.collab.net/index.jsp?topic=/faq/svnbinary.html 
 
and 
https://svnbook.red-bean.com/en/1.7/svn.forcvs.binary-and-trans.html 
 
(both links are old, but binary file handling shouldn't be worse now 
than then).


A quick search didn't tell me anything about the PCSWMM format; how 
much of a file changes between model runs?  Is it text or binary?  Are 
the files very large (gigabytes or more)?  Are they inputs to 
software, or outputs?  Generally it is assumed that output files can 
be recreated given the full input configuration, so program outputs 
are often left out of the repository.

--
 David chapmandcchap...@acm.org  
 Chapman Consulting -- San Jose, CA
 EDA Software Developer, Expert Witness
 www.chapman-consulting-sj.com  

 2018-2019 Chair, IEEE Consultants' Network of Silicon Valley



David,

PCSWMM files normally won't exceed 1 gigabyte. Rest of answers:

  * how much of a file changes between model runs?

Really depends … ranging from if perhaps a global model parameter edit 
is done during an iteration, or just changes to a study area like a 
detention pond.


  * Are the files text or binary?

Text

  * Are they inputs to software, or outputs?

Input file gets modified during design/analysis by the modeler.


Hopefully, this helps. thanks,

**

*Jason Kimmet*
www.allworldpm.com 



You should be able to use Subversion.  My normal use case is for much 
smaller files (software source code) but all you need is disk space, and 
any version control software will have to deal with the differences 
between file versions.  I presume that users are not typing a gigabyte 
each time, and that the PCSWMM files are assembled by a tool from other 
data.  In theory you could store the inputs to whatever tool is 
generating a particular PCSWMM file version, but that may be too much of 
a change from your present workflow.


The fact that they are text files is good too.  I work in the 
semiconductor industry, and the binary files our tools generate (GDS and 
OASIS format, in case anyone cares) tend to have major differences 
between versions.  We'd end up storing the entire file each time, even 
if the files are functionally equivalent - in large part, the formats 
are order independent, and tool A's ordering convention tends to differ 
from Tool B's convention.  That is a problem when a chip-level GDS file 
can be a terabyte in size!


--
David Chapman  dcchap...@acm.org
Chapman Consulting -- San Jose, CA
   

Re: SVN: PCSWMM Use

[Jason Kimmet]

David,

PCSWMM files normally won't exceed 1 gigabyte. Rest of answers:

 *   how much of a file changes between model runs?

Really depends … ranging from if perhaps a global model parameter edit is done 
during an iteration, or just changes to a study area like a detention pond.

 *   Are the files text or binary?

Text

 *   Are they inputs to software, or outputs?

Input file gets modified during design/analysis by the modeler.


Hopefully, this helps. thanks,



Jason Kimmet
www.allworldpm.com


From: David Chapman 
Sent: Thursday, September 9, 2021 4:29 PM
To: Jason Kimmet ; users@subversion.apache.org 

Subject: Re: SVN: PCSWMM Use

On 9/9/2021 1:53 PM, Jason Kimmet wrote:
Subversion Users,

We are working on a large stormwater modeling program where we will be keeping 
track of a lot of PCSWMM file type models. We are exploring version management 
options and have come across the SVN community. I understand this is great for 
text-style files, however, I would like to know if you have seen users utilize 
this for engineering plans such as PCSWMM?

Many version control systems, Subversion included, work best when the new 
version of a file looks much the same as the previous version.  Otherwise you 
could be storing multiple full versions of the files.

Some features of Subversion (like "show lines that changed") aren't available 
for binary files, but if the changes in a binary file are limited to specific 
sections, you still get space-saving benefits in the repository; see 
http://help.collab.net/index.jsp?topic=/faq/svnbinary.html
 and 
https://svnbook.red-bean.com/en/1.7/svn.forcvs.binary-and-trans.html
 (both links are old, but binary file handling shouldn't be worse now than 
then).

A quick search didn't tell me anything about the PCSWMM format; how much of a 
file changes between model runs?  Is it text or binary?  Are the files very 
large (gigabytes or more)?  Are they inputs to software, or outputs?  Generally 
it is assumed that output files can be recreated given the full input 
configuration, so program outputs are often left out of the repository.
--

David Chapman  dcchap...@acm.org
Chapman Consulting -- San Jose, CA
EDA Software Developer, Expert Witness

www.chapman-consulting-sj.com
2018-2019 Chair, IEEE Consultants' Network of Silicon Valley