Python/Harmattan/Performance Considerations for Python Apps - Revision history

imported_>wmoreira: Performance Considerations for Python Apps moved to Python/Harmattan/Performance Considerations for Python Apps

2011-11-24T17:52:31Z

Performance Considerations for Python Apps moved to Python/Harmattan/Performance Considerations for Python Apps

← Older revision	Revision as of 17:52, 24 November 2011
(No difference)

imported_>caco3: /* ShedSkin */

2010-11-22T19:00:13Z

ShedSkin

← Older revision		Revision as of 19:00, 22 November 2010
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	ShedSkin is a tool to convert a restricted subset of python into C++.		ShedSkin is a tool to convert a restricted subset of python into C++.
	This then can get compiled and used as a module in python.		This then can get compiled and used as a module in python.
	~~Test~~ have shown that there are great speed improvements possible.		Tests have shown that there are great speed improvements possible.
			You dont need any knowledge in C or how to use gcc.
	{{main\|ShedSkin}}		{{main\|ShedSkin}}

imported_>caco3: /* ShedSkin */

2010-11-22T18:59:35Z

ShedSkin

← Older revision		Revision as of 18:59, 22 November 2010
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	==== ShedSkin ====		==== ShedSkin ====

	ShedSkin is a tool to convert a restricted subset of python into C++.		ShedSkin is a tool to convert a restricted subset of python into C++.
	This then can get compiled and used as a module in python.		This then can get compiled and used as a module in python.

imported_>caco3: /* ShedSkin */

2010-11-22T18:58:16Z

ShedSkin

← Older revision		Revision as of 18:58, 22 November 2010
Line 38:		Line 38:
	ShedSkin is a tool to convert a restricted subset of python into C++.		ShedSkin is a tool to convert a restricted subset of python into C++.
	This then can get compiled and used as a module in python.		This then can get compiled and used as a module in python.

	Test have shown that there are great speed improvements possible.		Test have shown that there are great speed improvements possible.
	{{main\|ShedSkin}}		{{main\|ShedSkin}}

imported_>caco3: /* Shedskin */

2010-11-22T18:57:55Z

Shedskin

← Older revision		Revision as of 18:57, 22 November 2010
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	Do these work with Arm?		Do these work with Arm?

	==== ~~Shedskin~~ ====		==== ShedSkin ====

	~~Converts~~ a restricted subset of python into C++		ShedSkin is a tool to convert a restricted subset of python into C++.
			This then can get compiled and used as a module in python.

	??		Test have shown that there are great speed improvements possible.
			{{main\|ShedSkin}}

	==== Delegating to C with CTypes/SWIG ====		==== Delegating to C with CTypes/SWIG ====

imported_>amigadave: add link

2010-10-21T10:27:34Z

add link

← Older revision		Revision as of 10:27, 21 October 2010
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	The standard response of "it depends". For a graphical application not doing too much processing a user will probably not notice it is written in Python. Compare that to an experiment by epage in writing a GST video filter in Python that at best ran at 2 seconds per frame.		The standard response of "it depends". For a graphical application not doing too much processing a user will probably not notice it is written in Python. Compare that to an experiment by epage in writing a GST video filter in Python that at best ran at 2 seconds per frame.

			== Further reading ==

			* [[PyQt Tips and Tricks]] - similar guide for PyQt

	[[Category:Python]]		[[Category:Python]]

imported_>amigadave: wikify slightly, use


2010-10-07T09:26:21Z
wikify slightly, use <code>
Show changes



imported_>epage: /* Splitting a call between multiple callbacks */
2010-06-16T14:48:45Z
Splitting a call between multiple callbacks

				
				
				
				
				
				← Older revision
				Revision as of 14:48, 16 June 2010
				
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epage's approach[https://garage.maemo.org/plugins/ggit/browse.php/?p=gc-dialer;a=blob;f=src/gtk_toolbox.py;h=17dc166b5c37c5d15efc6eb7baef52b3250544ac;hb=a0b504bcfb10c73989fbb8578f073e81f4f7edbd]: epage's approach[https://garage.maemo.org/plugins/ggit/browse.php/?p=gc-dialer;a=blob;f=src/gtk_toolbox.py;h=17dc166b5c37c5d15efc6eb7baef52b3250544ac;hb=a0b504bcfb10c73989fbb8578f073e81f4f7edbd]:
<source lang="python">
  def make_idler(func):   def make_idler(func):
          """           """
Line 138:
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                          return False                           return False
          return decorated_func           return decorated_func
</source>



Example Example
<source lang="python">
  @make_idler   @make_idler
  def func(self):   def func(self):
Line 153:
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  callback = make_idler(func)   callback = make_idler(func)
  gobject.idle_add(callback)   gobject.idle_add(callback)
</source>



== Memory Usage == == Memory Usage ==



imported_>epage: /* Startup */
2010-05-21T01:22:12Z
Startup

				
				
				
				
				
				← Older revision
				Revision as of 01:22, 21 May 2010
				
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* When a script is run by giving its name on the command line, the bytecode for the script is never written to a ‘.pyc’ or ‘.pyo’ file. Thus, the startup time of a script may be reduced by moving most of its code to a module and having a small bootstrap script that imports that module. It is also possible to name a ‘.pyc’ or ‘.pyo’ file directly on the command line. * When a script is run by giving its name on the command line, the bytecode for the script is never written to a ‘.pyc’ or ‘.pyo’ file. Thus, the startup time of a script may be reduced by moving most of its code to a module and having a small bootstrap script that imports that module. It is also possible to name a ‘.pyc’ or ‘.pyo’ file directly on the command line.
* The module ‘compileall’{} can create ‘.pyc’ files (or ‘.pyo’ files when -O is used) for all modules in a directory. * The module ‘compileall’{} can create ‘.pyc’ files (or ‘.pyo’ files when -O is used) for all modules in a directory.

=== Delayed work ===

With Dialcentral, epage found that caching off results from a good number of "re.compile" at object creation time (which occurs in a background thread) saved a significant amount on startup.  Even with profiling until the background thread is finished showed a speed up.  epage suspects this is due to fewer class variable assignments / queries which might be more expensive then the equivalent on a instance.

Sadly this was done earlier in the Dialcentral release cycle and no performance numbers are available to back up these claims.  It was considered significant enough at the time to make the code slightly uglier.



=== Perceived Startup Performance === === Perceived Startup Performance ===



imported_>epage: /* Responsiveness */
2010-05-20T13:25:06Z
Responsiveness

				
				
				
				
				
				← Older revision
				Revision as of 13:25, 20 May 2010
				
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== Responsiveness == == Responsiveness ==



==== Thread per Logical Unit ==== === Thread per Logical Unit ===



The One Ring has separate threads for its DBus logic and its networking logic.  it does this separation through a worker thread that the DBus thread posts tasks to.  Results come as callbacks in the DBus thread. The One Ring has separate threads for its DBus logic and its networking logic.  it does this separation through a worker thread that the DBus thread posts tasks to.  Results come as callbacks in the DBus thread.
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See [https://garage.maemo.org/plugins/ggit/browse.php/?p=theonering;a=blob;f=src/util/go_utils.py;h=20ccac19201a4eae1b019fe2861e120b92010f55;hb=835f22ccd4b8e357bcbbc364d451e98721401e72 AsyncLinearExecutor] and some [https://garage.maemo.org/plugins/ggit/browse.php/?p=theonering;a=blob;f=src/channel/call.py;h=aefc59861a1cede286d4094bf8fc35101f2ff19d;hb=835f22ccd4b8e357bcbbc364d451e98721401e72 example code] See [https://garage.maemo.org/plugins/ggit/browse.php/?p=theonering;a=blob;f=src/util/go_utils.py;h=20ccac19201a4eae1b019fe2861e120b92010f55;hb=835f22ccd4b8e357bcbbc364d451e98721401e72 AsyncLinearExecutor] and some [https://garage.maemo.org/plugins/ggit/browse.php/?p=theonering;a=blob;f=src/channel/call.py;h=aefc59861a1cede286d4094bf8fc35101f2ff19d;hb=835f22ccd4b8e357bcbbc364d451e98721401e72 example code]



==== Splitting a call between multiple callbacks ==== === Splitting a call between multiple callbacks ===



See [http://talk.maemo.org/showpost.php?p=623199&postcount=18 Khertan's approach] See [http://talk.maemo.org/showpost.php?p=623199&postcount=18 Khertan's approach]

← Older revision		Revision as of 14:48, 16 June 2010
Line 122:		Line 122:

	epage's approach[https://garage.maemo.org/plugins/ggit/browse.php/?p=gc-dialer;a=blob;f=src/gtk_toolbox.py;h=17dc166b5c37c5d15efc6eb7baef52b3250544ac;hb=a0b504bcfb10c73989fbb8578f073e81f4f7edbd]:		epage's approach[https://garage.maemo.org/plugins/ggit/browse.php/?p=gc-dialer;a=blob;f=src/gtk_toolbox.py;h=17dc166b5c37c5d15efc6eb7baef52b3250544ac;hb=a0b504bcfb10c73989fbb8578f073e81f4f7edbd]:
			<source lang="python">
	def make_idler(func):		def make_idler(func):
	"""		"""
Line 138:		Line 139:
	return False		return False
	return decorated_func		return decorated_func
			</source>

	Example		Example
			<source lang="python">
	@make_idler		@make_idler
	def func(self):		def func(self):
Line 153:		Line 156:
	callback = make_idler(func)		callback = make_idler(func)
	gobject.idle_add(callback)		gobject.idle_add(callback)
			</source>

	== Memory Usage ==		== Memory Usage ==

← Older revision		Revision as of 01:22, 21 May 2010
Line 98:		Line 98:
	* When a script is run by giving its name on the command line, the bytecode for the script is never written to a ‘.pyc’ or ‘.pyo’ file. Thus, the startup time of a script may be reduced by moving most of its code to a module and having a small bootstrap script that imports that module. It is also possible to name a ‘.pyc’ or ‘.pyo’ file directly on the command line.		* When a script is run by giving its name on the command line, the bytecode for the script is never written to a ‘.pyc’ or ‘.pyo’ file. Thus, the startup time of a script may be reduced by moving most of its code to a module and having a small bootstrap script that imports that module. It is also possible to name a ‘.pyc’ or ‘.pyo’ file directly on the command line.
	* The module ‘compileall’{} can create ‘.pyc’ files (or ‘.pyo’ files when -O is used) for all modules in a directory.		* The module ‘compileall’{} can create ‘.pyc’ files (or ‘.pyo’ files when -O is used) for all modules in a directory.

			=== Delayed work ===

			With Dialcentral, epage found that caching off results from a good number of "re.compile" at object creation time (which occurs in a background thread) saved a significant amount on startup. Even with profiling until the background thread is finished showed a speed up. epage suspects this is due to fewer class variable assignments / queries which might be more expensive then the equivalent on a instance.

			Sadly this was done earlier in the Dialcentral release cycle and no performance numbers are available to back up these claims. It was considered significant enough at the time to make the code slightly uglier.

	=== Perceived Startup Performance ===		=== Perceived Startup Performance ===

← Older revision		Revision as of 13:25, 20 May 2010
Line 105:		Line 105:
	== Responsiveness ==		== Responsiveness ==

	==== Thread per Logical Unit ====		=== Thread per Logical Unit ===

	The One Ring has separate threads for its DBus logic and its networking logic. it does this separation through a worker thread that the DBus thread posts tasks to. Results come as callbacks in the DBus thread.		The One Ring has separate threads for its DBus logic and its networking logic. it does this separation through a worker thread that the DBus thread posts tasks to. Results come as callbacks in the DBus thread.
Line 111:		Line 111:
	See [https://garage.maemo.org/plugins/ggit/browse.php/?p=theonering;a=blob;f=src/util/go_utils.py;h=20ccac19201a4eae1b019fe2861e120b92010f55;hb=835f22ccd4b8e357bcbbc364d451e98721401e72 AsyncLinearExecutor] and some [https://garage.maemo.org/plugins/ggit/browse.php/?p=theonering;a=blob;f=src/channel/call.py;h=aefc59861a1cede286d4094bf8fc35101f2ff19d;hb=835f22ccd4b8e357bcbbc364d451e98721401e72 example code]		See [https://garage.maemo.org/plugins/ggit/browse.php/?p=theonering;a=blob;f=src/util/go_utils.py;h=20ccac19201a4eae1b019fe2861e120b92010f55;hb=835f22ccd4b8e357bcbbc364d451e98721401e72 AsyncLinearExecutor] and some [https://garage.maemo.org/plugins/ggit/browse.php/?p=theonering;a=blob;f=src/channel/call.py;h=aefc59861a1cede286d4094bf8fc35101f2ff19d;hb=835f22ccd4b8e357bcbbc364d451e98721401e72 example code]

	==== Splitting a call between multiple callbacks ====		=== Splitting a call between multiple callbacks ===

	See [http://talk.maemo.org/showpost.php?p=623199&postcount=18 Khertan's approach]		See [http://talk.maemo.org/showpost.php?p=623199&postcount=18 Khertan's approach]