Re: [pgadmin4][patch] Initial patch to decouple from ACI Tree

Hi Hackers,
Any other comment about this patch?

Thanks
Joao

On Tue, Apr 10, 2018 at 12:00 PM Joao De Almeida Pereira <
jdealmeidapereira(at)pivotal(dot)io> wrote:

> Hello Khushboo
>
> On Mon, Apr 9, 2018 at 1:59 AM Khushboo Vashi <
> khushboo(dot)vashi(at)enterprisedb(dot)com> wrote:
>
>> Hi Joao,
>>
>> I have reviewed your patch and have some suggestions.
>>
>> On Sat, Apr 7, 2018 at 12:43 AM, Joao De Almeida Pereira <
>> jdealmeidapereira(at)pivotal(dot)io> wrote:
>>
>>> Hello Murtuza/Dave,
>>> Yes now the extracted functions are spread into different files. The
>>> intent would be to make the files as small as possible, and also to group
>>> and name them in a way that would be easy to understand what each file is
>>> doing without the need of opening it.
>>> As a example:
>>> static/js/backup will contain all the backup related functionality
>>> inside of this folder we can see the file:
>>>
>> menu_utils.js At this moment in time we decided to group all the
>>> functions that are related to the menu, but we can split that also if we
>>> believe it is easier to see.
>>>
>> It's really very good to see the separated code for backup module. As we
>> have done for backup, we would like do it for other PG utilities like
>> restore, maintenance etc.
>> Considering this, we should separate the code in a way that some of the
>> common functionalities can be used for other modules like menu (as you
>> have mentioned above), dialogue factory etc.
>> Also, I think these functionalities should be in their respective static
>> folder instead of pgadmin/static.
>>
>
> About the location of the files. The move of the files to
> pgadmin/static/js was made on purpose in order to clearly separate
> Javascript from python code.
> The rational behind it was
> - Create a clear separation between the backend and frontend
> - Having Javascript code concentrated in a single place, hopefully, will
> encourage to developers to look for a functionality, that is already
> implemented in another modules, because they are right there. (When we
> started this journey we realized that the 'nodes' have a big groups of code
> that could be shared, but because the Javascript is spread everywhere it is
> much harder to look for it)
>
>
> There are some drawbacks of this separation:
> - When creating a new module we will need to put the javascript in a
> separate location from the backend code
>
>
>>
>>
>>> static/js/datagrid folder contains all the datagrid related
>>> functionality
>>>
>> Same as backup module, this should be in it's respective static/js
>> folder.
>>
>>> Inside of the folder we can see the files:
>>> get_panel_title.js is responsible for retrieving the name of the panel
>>> show_data.js is responsible for showing the datagrid
>>> show_query_tool.js is responsible for showing the query tool
>>>
>>> Does this structure make sense?
>>> Can you give an example of a comment that you think is missing and that
>>> could help?
>>>
>>> As a personal note, unless the algorithm is very obscure or very
>>> complicated, I believe that if the code needs comments it is a signal that
>>> something needs to change in terms of naming, structure of the part in
>>> question. This being said, I am open to add some comments that might help
>>> people.
>>>
>> You are right, with the help of naming convention and structure of the
>> code, any one can get the idea about the code. But it is very useful to
>> understand the code
>> very easily with the proper comments especially when there are multiple
>> developers working on a single project.
>>
>> I found some of the places where it would be great to have comments.
>>
>> - treeMenu: new tree.Tree() in a browser.js
>> - tree.js (especially Tree class)
>>
> About the comment point I need a more clear understanding on what kind of
> comments you are looking for. Because when you read the function names you
> understand the intent, what they are doing. The parameters also explain
> what you need to pass into them.
>
> If what you are looking for in these comments is the reasoning being the
> change itself, then that should be present in the commit message. Specially
> because this is going to be a very big patch with a very big number of
> changes.
>
>>
>> Thanks
>>> Joao
>>> ​
>>>
>>> Thanks,
>> Khushboo
>>
>>>
>>> On Fri, Apr 6, 2018 at 4:48 AM Murtuza Zabuawala <
>>> murtuza(dot)zabuawala(at)enterprisedb(dot)com> wrote:
>>>
>>>> Hi Joao,
>>>>
>>>> Patch looks good and working as expected.
>>>>
>>>> I also agree with Dave, Can we please add some comments in each file
>>>> which can help us to understand the flow, I'm saying because now the code
>>>> is segregated in so many separate files it will be hard to keep track of
>>>> the flow from one file to another when debugging.
>>>>
>>>>
>>>> --
>>>> Regards,
>>>> Murtuza Zabuawala
>>>> EnterpriseDB: http://www.enterprisedb.com
>>>> The Enterprise PostgreSQL Company
>>>>
>>>>
>>>> On Thu, Apr 5, 2018 at 7:08 PM, Joao De Almeida Pereira <
>>>> jdealmeidapereira(at)pivotal(dot)io> wrote:
>>>>
>>>>> Hi Khushboo,
>>>>> Attached you can find both patches rebased
>>>>>
>>>>> Thanks
>>>>>
>>>>>
>>>>> On Thu, Apr 5, 2018 at 6:31 AM Khushboo Vashi <
>>>>> khushboo(dot)vashi(at)enterprisedb(dot)com> wrote:
>>>>>
>>>>>> Hi Joao,
>>>>>>
>>>>>> Can you please rebase the second patch?
>>>>>>
>>>>>> Thanks,
>>>>>> Khushboo
>>>>>>
>>>>>>
>>>>>> On Tue, Apr 3, 2018 at 12:15 AM, Joao De Almeida Pereira <
>>>>>> jdealmeidapereira(at)pivotal(dot)io> wrote:
>>>>>>
>>>>>>> Hi Hackers,
>>>>>>>
>>>>>>> Attached you can find the patch that will start to decouple pgAdmin
>>>>>>> from ACITree library.
>>>>>>> This patch is intended to be merged after 3.0, because we do not
>>>>>>> want to cause any entropy or delay the release, but we want to start the
>>>>>>> discussion and show some code.
>>>>>>>
>>>>>>> This job that we started is a massive tech debt chore that will take
>>>>>>> some time to finalize and we would love the help of the community to do it.
>>>>>>>
>>>>>>> *Summary of the patch:*
>>>>>>> 0001 patch:
>>>>>>> - Creates a new tree that will allow us to create a separation
>>>>>>> between the application and ACI Tree
>>>>>>> - Creates a Fake Tree (Test double, for reference on the available
>>>>>>> test doubles: https://martinfowler.com/bliki/TestDouble.html) that
>>>>>>> can be used to inplace to replace the ACITree and also encapsulate the new
>>>>>>> tree behavior on our tests
>>>>>>> - Adds tests for all the tree functionalities
>>>>>>>
>>>>>>> 0002 patch:
>>>>>>> - Extracts, refactors, adds tests and remove dependency from ACI
>>>>>>> Tree on:
>>>>>>> - getTreeNodeHierarchy
>>>>>>> - on backup.js: menu_enabled, menu_enabled_server,
>>>>>>> start_backup_global_server, backup_objects
>>>>>>> - on datagrid.js: show_data_grid, get_panel_title, show_query_tool
>>>>>>> - Start using sprintf-js as Underscore.String is deprecating sprintf
>>>>>>> function
>>>>>>>
>>>>>>> This patch represents only 10 calls to ACITree.itemData out of 176
>>>>>>> that are spread around our code
>>>>>>>
>>>>>>>
>>>>>>> *In Depth look on the process behind the patch:*
>>>>>>>
>>>>>>> We started writing this patch with the idea that we need to decouple
>>>>>>> pgAdmin4 from ACITree, because ACITree is no longer supported, the
>>>>>>> documentation is non existent and ACITree is no longer being actively
>>>>>>> developed.
>>>>>>>
>>>>>>> Our process:
>>>>>>> 1. We "randomly" selected a function that is part of the ACITree.
>>>>>>> From this point we decided to replace that function with our own version.
>>>>>>> The function that we choose was "itemData".
>>>>>>> The function gives us all the "data" that a specific node of the
>>>>>>> tree find.
>>>>>>> Given in order to replace the tree we would need to have a function
>>>>>>> that would give us the same information. We had 2 options:
>>>>>>> a) Create a tree with a function called itemData
>>>>>>> Pros:
>>>>>>> - At first view this was the simpler solution
>>>>>>> - Would keep the status quo
>>>>>>> Cons:
>>>>>>> - Not a OOP approach
>>>>>>> - Not very flexible
>>>>>>> b) Create a tree that would return a node given an ID and then the
>>>>>>> node would be responsible for giving it's data.
>>>>>>> Pros:
>>>>>>> - OOP Approach
>>>>>>> - More flexible and we do not need to bring the tree around, just a
>>>>>>> node
>>>>>>> Cons:
>>>>>>> - Break the current status quo
>>>>>>>
>>>>>>> Given these 2 options we decided to go for a more OOP approach
>>>>>>> creating a Tree and a TreeNode classes, that in the future will be renamed
>>>>>>> to ACITreeWrapper and TreeNode.
>>>>>>>
>>>>>>> 2. After we decided on the starting point we searched for
>>>>>>> occurrences of the function "itemData" and we found out that there were 303
>>>>>>> occurrences of "itemData" in the code and roughly 176 calls to the function
>>>>>>> itself (some of the hits were variable names).
>>>>>>>
>>>>>>> 3. We selected the first file on the search and found the function
>>>>>>> that was responsible for calling the itemData function.
>>>>>>>
>>>>>>> 4. Extracted the function to a separate file
>>>>>>>
>>>>>>> 5. Wrap this function with tests
>>>>>>>
>>>>>>> 6. Refactor the function to ES6, give more declarative names to
>>>>>>> variables and break the functions into smaller chunks
>>>>>>>
>>>>>>> 7. When all the tests were passing we replaced ACITree with our Tree
>>>>>>>
>>>>>>> 8. We ensured that all tests were passing
>>>>>>>
>>>>>>> 9. Remove function from the original file and use the new function
>>>>>>>
>>>>>>> 10. Ensure everything still works
>>>>>>>
>>>>>>> 11. Find the next function and execute from step 4 until all the
>>>>>>> functions are replaced, refactored and tested.
>>>>>>>
>>>>>>> As you can see by the process this is a pretty huge undertake,
>>>>>>> because of the number of calls to the function. This is just the first step
>>>>>>> on the direction of completely isolating the ACITree so that we can solve
>>>>>>> the problem with a large number of elements on the tree.
>>>>>>>
>>>>>>> *What is on our radar that we need to address:*
>>>>>>> - Finish the complete decoupling of the ACITree
>>>>>>> - Performance of the current tree implementation
>>>>>>> - Tweak the naming of the Tree class to explicitly tell us this is
>>>>>>> to use only with ACITree.
>>>>>>>
>>>>>>>
>>>>>>> Thanks
>>>>>>> Joao
>>>>>>>
>>>>>>>
>>>>>>
>>>>