PATCH: Debugger Redesign

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.enterprisedb.com>

*http://www.linkedin.com/in/asheshvashi*