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C is not Python II.

RaSPF, my C port of PySPF, is pret­ty much func­tion­al right now.

Here's what I mean:

  • It pass­es 75 in­­ter­­nal unit tests (ok, 74 , but that one is ar­guable).

  • It pass­es 137 of 145 tests of the SPF of­­fi­­cial test suit­­e.

  • It agrees with PySPF in 181 of the 183 cas­es of the lib­spf2 live DNS suit­­e.

  • It seg­­faults in none of the 326 test cas­es.

So, while there are still some cor­ner cas­es to de­bug, it's look­ing very good.

I even spent some time with val­grind to plug some leaks ( the in­ter­nal test suite runs al­most leak­less, the re­al app is a sieve ;-)

All in al­l, if I can spend a lit­tle while with it dur­ing the week, I should be able to make a re­lease that ac­tu­al­ly work­s.

Then, I can re­write my SPF plug­in for qmail, which was what sent me in this mon­th-log tan­gen­t.

As a lan­guage wars com­par­ison:

  • The sloc­­count of raspf is 2557 (or 2272 if we use the ragel gram­­mar source in­­stead of the gen­er­at­ed file)

  • The sloc­­count of PySPF is 993.

So, a 2.6:1 or 2.28:1 code ra­tio.

How­ev­er, I used 4 non-­s­tan­dard C li­braries: bstr­lib, udns, and helpers for hash­es and ex­cep­tion­s, which add an­oth­er 5794 LOC­s.

So, it could be ar­gued as a 8:1 ra­tio, too, but my C code is prob­a­bly ver­bose in ex­treme, and many C lines are not re­al­ly "log­ic" but dec­la­ra­tions and such.

Al­so, I did not write PySPF, so his code may be more con­cise, but I tried my best to copy the flow as much as pos­si­ble line-per-­line.

In short, you need to write, ac­cord­ing to this case, be­tween 2 and 8 times more code than you do in Python.

That's a bit much!

Kay / 2007-03-06 20:40:


did you explore if PyPy could help you with its translation into C code?

Roberto Alsina / 2007-03-06 21:34:

No, I didn't. Do you think it may work?

Jason / 2007-03-06 23:08:

My impression is that PyPy-generated C code is at best a vehicle for executing Python quickly. You wouldn't want to do anything else with it, like read it.

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