Re: PATCH: Debugger Redesign

Hi

First impressions - it already seems more stable than the old code,
and I only played with it for an hour or so on Mac so far. Nice work
:-)

I did find a few things in my initial testing that need some
attention. I didn't get the impression anything was particularly
serious or would be troublesome to fix though:

- The layout of the parameters dialogue needs work - the grid needs to
size to the dialogue.

- The checkboxes in the grid are jumbo sized. We have them in the Edit
Grid already - can the code be reused?

- The popup activity dialog is kinda annoying. Perhaps we could put a
progress indicator in the status bar? Low priority.

- When injecting new values into variables, if the value can't be
accepted (wrong datatype etc), then the grid should be reset to the
original value when the error message box is accepted.

- If a function is re-executed in the same session, the return value
isn't cleared from the Results grid.

- If a function is re-executed in the same session, the breakpoints
are cleared. This doesn't seem to happen with in-process debugging,
only direct.

- Aborting a direct debug session mid-function caused an indefinite(?)
hang with a busy cursor.

- The status messages in the status bar are a little confusing. I
think you need to add "Done." to the end of the string when an action
completes, otherwise it looks like things never complete until you
step or run.

If you can fix those issues (with the possible exception of the
progress indicator), I'll dive in a bit deeper. I don't want to go too
deep just yet in case you have to change more than I expect.

Thanks.

On Wed, Apr 10, 2013 at 12:10 PM, Ashesh Vashi
<ashesh.vashi@enterprisedb.com> wrote:
> Hi All,
>
>     We always wanted to redesign the plpgsql debugger in pgAdmin III from
> very long time due to very long list of bug
> Reports of the debugger. We were not able crack down variety of cases across
> the platforms.  For many cases - resolving
> On one platform, we ended up introducing other issues on another platforms.
> This inability of handling variety of cases
> Across platforms made us to redesign the debugger from the scratch.
>
> Let me list down few the limitations/flaws with the current implementation
> of the debugger:
> - Uses its own mechanism for making connection, querying (async/sync) &
> handing results instead of using the common
>   available classes, which are used by all other components in pgAdmin III.
>   i.e.
>     dbgConn, dbgResult, dbgPgThread, etc.
>
>   Because of this, the improvements in the existing infrastructure were
> never reflected in the debugger.
>   i.e.
>     The connection with debugger were never be created with the SSL support.
>     Because - dbgConn never supported the SSL.
>   This is also results for the many bugs.
>   i.e.
>     The dbgPgThread has its own mechanism to run queries asynchronously and
> resulted into many bugs. It generates few
>   events, which shouldn't be done after the completion of the debugger
> operations. And, that leads to crash.  Using
>   TestDestroy() function for JOINABLE threads were unnecessary and never
> required. But - it is using it.
>
> - A hidden windows is taking care of the events generated during the
> debugging the actual window. It could have been
>   Good, if all the tasks having intialited and handled from by this central
> mechanism, instead we do have different
>   places for handling both the direct/indirect debugging. And, that
> introduced a lot of issues. And, that made the
>   things very confusing even to understand the existing mechanism.
>
> And, many more.
>
> We had to made changes in the existing infrastructure/classes to use it with
> the debugger.
> * pgConn:
>   + Report error quietly (if told) while error found in execution, this
> allows these functions to be used from any
>     Thread. Otherwise, it used to throw an error.
>   + Set/Reset the PGcancel object before and after the query execution,
> which will be useful for us to use the new
>     Mechanism of libpq (of course, not very new) to cancel any query
> execution from in between.
>   + Allow new application name, while duplicating the connection
>   + Save the version and the features list, while duplicating the
> connection, this will avoid/reduce the duplicate calls
>     To the database server.
> * pgQueryThread:
>   + Allow to specify the custom notice processor and handler
>   + Allow to run multiple queries by creating queue
>   + Allow to use the EnterpriseDB's callable statement from the
> pgQueryThread (if available)
>   + Proper cancellation mechanism implementation
>   + Send a custom event to the caller (instead of standard event) for
> successful execution or on different errors
>     (but - not if it is explicitly cancelled by the user.) This allows us to
> send more information to the developer.
>   + Allows the developer to add a batch queries (which should run
> asynchronously) even after starting of the thread.
>   + Allow to use the PGparam now, to avoid generating the queries
> dynamically
>
> The new design is based on the MVC (Model-View-Controller) architecture.
> * Controller (dbgController)
>   - A central mechanism to handle all the operations.
> * View (frmDebugger - mostly reused)
>   - Responsible for presentation and interaction with the end-user
>   i.e.
>     code viewer, different variable windows, stack window, etc.
>   - It also controls other part of view.
> * Model (dbgModel)
>  - Handles/Contains all the data
>  - It contains the information about the target function/procedure.
>
> For any operation, View and Model will ask the Controller to handle it.
>
> Summary of the changes:
>
>  INSERTED|   DELETED| FILENAME                                    | SUMMARY
> ---------+----------+---------------------------------------------|----------------------------
>         3|         1| pgadmin/ctl/ctlSQLResult.cpp                | - Call
> cancel thread execution on exit, if already
>                                                                   | running
> for nice exit handling
>       196|        18| pgadmin/db/pgConn.cpp                       | -
> Set/Reset the PGcancel object
>                                                                   | - Saving
> settings and new application name, while
>                                                                   | cloning
>        31|        24| pgadmin/include/db/pgConn.h                 |
>       245|        33| pgadmin/include/db/pgQueryThread.h          |
>       647|       111| pgadmin/db/pgQueryThread.cpp                | -
> Multiple queries execution support (one-by-one)
>         8|         0| pgadmin/include/db/pgSet.h                  | -
> Introduce a new function GetCommandStatus for the
>                                                                   | result
>         0|         1| pgadmin/db/pgSet.cpp                        | -
> Removed unnecessary header inclusion
>         0|      1563| pgadmin/debugger/ctlCodeWindow.cpp          | -
> Omitted/Removed it completely
>         0|       250| pgadmin/include/debugger/ctlCodeWindow.h    |
>         9|         9| pgadmin/debugger/ctlMessageWindow.cpp       | -
> Standardize the function naming conversion with the
>                                                                   | other
> components
>         5|        12| pgadmin/include/debugger/ctlMessageWindow.h |
>        28|        27| pgadmin/debugger/ctlResultGrid.cpp          | - Using
> the standard querying mechanism (pgSet)
>                                                                   | instead
> of libpq's PGresult directly
>         4|         3| pgadmin/include/debugger/ctlResultGrid.h    |
>         4|         7| pgadmin/debugger/ctlStackWindow.cpp         | -
> Standardize the function naming conversion with the
>                                                                   | other
> components
>         2|         2| pgadmin/include/debugger/ctlStackWindow.h   |
>        50|        56| pgadmin/debugger/ctlTabWindow.cpp           | -
> Standardize the function naming conversion with the
>                                                                   | other
> components
>        20|        17| pgadmin/include/debugger/ctlTabWindow.h     |
>        60|        55| pgadmin/debugger/ctlVarWindow.cpp           | -
> Standardize the function naming conversion with the
>                                                                   | other
> components
>        17|        15| pgadmin/include/debugger/ctlVarWindow.h     |
>       819|         0| pgadmin/debugger/dbgController.cpp          | -
> Central of the debugger (it takes care of all the
>                                                                   |
> operations, the frmDebugger (view) and dbgModel
>                                                                   | (model)
> interact with it.
>       173|         0| pgadmin/include/debugger/dbgController.h    |
>         0|        21| pgadmin/debugger/dbgDbResult.cpp            | -
> Omitted/Removed it completely
>       703|         0| pgadmin/debugger/dbgEvents.cpp              | - Added
> new file, which contains all the event
>                                                                   | handling
> functions of the dbgController to reduce
>                                                                   | the size
> of dbgController and separating them from
>                                                                   | the
> direct operations
>        63|         0| pgadmin/debugger/dbgModel.cpp               | -
> Contains all the information regarding the
>                                                                   | target.
>       143|         0| pgadmin/include/debugger/dbgModel.h         |
>         0|       544| pgadmin/debugger/dbgPgConn.cpp              | -
> Omitted/Removed it completely
>         0|       363| pgadmin/debugger/dbgPgThread.cpp            | -
> Omitted/Removed it completely
>         0|       157| pgadmin/debugger/dbgResultset.cpp           | -
> Omitted/Removed it completely
>       536|       194| pgadmin/debugger/dbgTargetInfo.cpp          | - It
> fetches and saves the target information from
>                                                                   | the
> database server (it is no more using the
>                                                                   |
> deprecated pldbg_target_info function).
>       146|        75| pgadmin/include/debugger/dbgTargetInfo.h    |
>        44|       101| pgadmin/debugger/debugger.cpp               | -
> Debugger menu factory, modified accordingly new
>                                                                   | design
>       770|       682| pgadmin/debugger/dlgDirectDbg.cpp           | -
> Handles now only taking input from the end-user
>                                                                   | - It
> also takes care of converting an expression
>                                                                   | input to
> a proper value
>                                                                   | - It
> also allows the end-user to use the default
>                                                                   | value of
> an argument through UI.
>                                                                   | - It
> does not control the debugger execution any
>                                                                   | more
>        74|        48| pgadmin/include/debugger/dlgDirectDbg.h     |
>       734|       165| pgadmin/debugger/frmDebugger.cpp            | - Mostly
> reused
>                                                                   | - Works
> as presentation layer and takes input from
>                                                                   | from the
> end-user
>                                                                   | i.e.
> set/reset break-points, changing parameter
>                                                                   |
> values, showing the target code, showing
>                                                                   |
> current parameter values, etc.
>       114|        92| pgadmin/include/debugger/frmDebugger.h      |
>         3|         5| pgadmin/debugger/module.mk                  |
>         5|         1| pgadmin/dlg/dlgClasses.cpp                  | - Call
> cancel thread execution on exit, if already
>                                                                   | running
> for nice exit handling (ExecutionDialog)
>         4|         1| pgadmin/frm/frmEditGrid.cpp                 | - Call
> cancel thread execution on abort
>         2|         2| pgadmin/frm/frmQuery.cpp                    | -
> Modified to use new custom event on query
>                                                                   |
> execution completion
>         2|         1| pgadmin/include/frm/frmQuery.h              |
>         1|         1| pgadmin/include/db/module.mk                |
>        79|         0| pgadmin/include/db/pgQueryResultEvent.h     | -
> Introduced a new custom event for handling the
>                                                                   | query
> execution error/success (pgQueryThread)
>        14|        21| pgadmin/include/debugger/dbgBreakPoint.h    | -
> Reformatted the break-point according to new design
>         0|        38| pgadmin/include/debugger/dbgConnProp.h      | -
> Omitted/Removed it completely
>        57|        10| pgadmin/include/debugger/dbgConst.h         |
>         0|        53| pgadmin/include/debugger/dbgDbResult.h      | -
> Omitted/Removed it completely
>         0|        99| pgadmin/include/debugger/dbgPgConn.h        | -
> Omitted/Removed it completely
>         0|        95| pgadmin/include/debugger/dbgPgThread.h      | -
> Omitted/Removed it completely
>         0|        52| pgadmin/include/debugger/dbgResultset.h     | -
> Omitted/Removed it completely
>         2|         6| pgadmin/include/debugger/module.mk          |
>         3|         6| pgadmin/include/precomp.h                   |
>         7|        12| pgadmin/pgAdmin3.vcxproj                    | - Window
> build script changes
>        10|        28| pgadmin/pgAdmin3.vcxproj.filters            |
>         3|         3| pgadmin/ii/dlgDirectDbg.xrc                 | - Input
> Arguments dialog change (changed the
>                                                                   |
> dimensions.)
>        44|        44| pgadmin/ii/xrcDialogs.cpp                   |
>
>
> --
>
> Thanks & Regards,
>
> Ashesh Vashi
> EnterpriseDB INDIA: Enterprise PostgreSQL Company
>
>
> http://www.linkedin.com/in/asheshvashi
>
>
>
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