Implement set and get nthreads for magma interface

[rusydi]

This ticket implements the method to set and get the number of threads used to run some parallelized algorithms in Magma (e.g. Groebner bases).

CC: @slel

Component: interfaces: optional

Keywords: magma, threads

Author: Rusydi H. Makarim

Branch/Commit: 5860e68

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/26235

[rusydi]

Branch: u/ruhm/magma_threads

[rusydi]

Author: Rusydi H. Makarim

[rusydi]

New commits:

5860e68

initial commit

[rusydi]

Commit: 5860e68

[rusydi]

Changed keywords from none to magma, threads

[tscrim]

comment:3

LGTM.

[tscrim]

Reviewer: Travis Scrimshaw

[slel]

comment:4

It seems useless clutter to have each time two methods for the same thing.

The current proposition for this ticket is:

    def set_nthreads(self, n):
        """
        Set the number of threads used for parallelized algorithms in Magma.

        INPUT:

        - ``n`` - number of threads

        EXAMPLES::

            sage: magma.set_nthreads(2)                #optional - magma
            sage: magma.get_nthreads()                 #optional - magma
            2
        """
        self.SetNthreads(n)

    def SetNthreads(self, n):
        """
        Set the number of threads used for parallelized algorithms in Magma.

        INPUT:

        - ``n`` - number of threads

        .. note::

           This method is provided to be consistent with the Magma
           naming convention.

        EXAMPLES::

            sage: magma.SetNthreads(2)                 #optional - magma
            sage: magma.GetNthreads()                  #optional - magma
            2
        """
        self.eval('SetNthreads(%d)' % (n))

    def get_nthreads(self):
        """
        Get the number of threads used in Magma.

        EXAMPLES::

            sage: magma.set_nthreads(2)                #optional - magma
            sage: magma.get_nthreads()                 #optional - magma
            2
        """
        return self.GetNthreads()

    def GetNthreads(self):
        """
        Get the number of threads used in Magma.

        .. note::

           This method is provided to be consistent with the Magma
           naming convention.

        EXAMPLES::

            sage: magma.SetNthreads(2)                 #optional - magma
            sage: magma.GetNthreads()                  #optional - magma
            2
        """
        return int(self.eval('GetNthreads()'))

Among existing methods for the Magma class, one can find

• four examples with only Python-style names; they call the corresponding
  Magma function using self.eval(...):

    def set_seed(self, seed=None):
        self.eval('SetSeed(%d)' % seed)

    def cputime(self, t=None):
        if t:
            return float(self.eval('Cputime(%s)' % t))
        else:
            return float(self.eval('Cputime()'))

    def chdir(self, dir):
        self.eval('ChangeDirectory("%s")' % dir, strip=False)

    def version(self):
        t = tuple([int(n) for n in self.eval('GetVersion()').split()])
        return t, 'V%s.%s-%s' % t

• two examples with python-style names, which work like the four above,
  and are followed by synonyms with magma-style names:

    def attach(self, filename):
        self.eval('Attach("%s")' % filename)

    Attach = attach

    def attach_spec(self, filename):
        s = self.eval('AttachSpec("%s")' % filename)
        if s:
            raise RuntimeError(s.strip())

    AttachSpec = attach_spec

• two examples where there is each time two methods, with the two naming styles,
  one calling the other, much like the current proposition in this ticket:

    def set_verbose(self, type, level):
        self.SetVerbose(type, level)

    def SetVerbose(self, type, level):
        if level < 0:
            raise TypeError("level must be >= 0")
        self.eval('SetVerbose("%s",%d)' % (type, level))

    def get_verbose(self, type):
        return self.GetVerbose(type)

    def GetVerbose(self, type):
        return int(self.eval('GetVerbose("%s")' % type))

For the current ticket, I would suggest using synonyms rather than
defining two separate methods each time:

    def set_nthreads(self, n):
        """
        Set the number of threads used for parallelized algorithms in Magma.

        INPUT:

        - ``n`` - number of threads

        EXAMPLES::

            sage: magma.set_nthreads(2)                #optional - magma
            sage: magma.get_nthreads()                 #optional - magma
            2
        """
        self.eval('SetNthreads(%d)' % (n))

    SetNthreads = set_nthreads

    def get_nthreads(self):
        """
        Get the number of threads used in Magma.

        EXAMPLES::

            sage: magma.set_nthreads(2)                #optional - magma
            sage: magma.get_nthreads()                 #optional - magma
            2
        """
        return int(self.eval('GetNthreads()'))

    GetNthreads = get_nthreads

And I would suggest taking the opportunity to do the same for
set_verbose/SetVerbose and get_verbose/GetVerbose.

Or... this cleaning-up can all be done in a follow-up ticket --- possibly
a better idea, especially since this ticket already has positive_review.

[rusydi]

comment:5

Thanks for the remark. I will create a new ticket to deal with the cleaning up.

[rusydi]

comment:6

The ticket is #26259

[vbraun]

Changed branch from u/ruhm/magma_threads to 5860e68