Managing pure-python and C-ext code

Module openquake.hazardlib.speedups contains internal utilities for managing alternative implementation of the same functionality depending on their availability.

class openquake.hazardlib.speedups.SpeedupsRegistry

Speedups registry allows to manage alternative implementations of functions. Typical use case for it is something like this:

# in the module namespace

def do_foo(foo, bar):
    # code in pure python
    ...

def do_bar(baz, quux):
    # code in pure python
    ...

# in the end of the module

try:
    import _foobar_speedups
except ImportError:
    import warnings
    warnings.warn("foobar speedups are not available", RuntimeWarning)
else:
    from openquake.hazardlib import speedups

    def _c_do_foo(foo, bar):
        return _foobar_speedups.do_foo(foo, bar)
    speedups.register(do_foo, _c_do_foo)
    del _c_do_foo

    def _c_do_bar(baz, quux):
        return _foobar_speedups.do_foo(baz, quux)
    speedups.register(do_bar, _c_do_bar)
    del _c_do_bar

Global registry is being used here. All speedups are enabled by default. In order to disable them, use disable().

disable()

Set implementation to “original” for all the registered functions.

enable()

Set implementation to “alternative” for all the registered functions.

register(func, altfunc)

Add a function and its alternative implementation to the registry.

If registry is enabled, function code will be substituted by an alternative implementation immediately.

Parameters:

• func – A function object to patch.
• altfunc – An alternative implementation of the function. Must have the same signature and is supposed to behave exactly the same way as func.

openquake.hazardlib.speedups.disable = <bound method SpeedupsRegistry.disable of <openquake.hazardlib.speedups.SpeedupsRegistry object at 0x7f571b63c4d0>>

Global (default) registry disable().

openquake.hazardlib.speedups.enable = <bound method SpeedupsRegistry.enable of <openquake.hazardlib.speedups.SpeedupsRegistry object at 0x7f571b63c4d0>>

Global (default) registry enable().

openquake.hazardlib.speedups.register = <bound method SpeedupsRegistry.register of <openquake.hazardlib.speedups.SpeedupsRegistry object at 0x7f571b63c4d0>>

Global (default) registry register().