homepage

Just for the record, I've compiled Raymond's roadmap version in Cython (with only slight changes to make 'self.maxsize' a Py_ssize_t and using an external .pxd for typing) and ran Serhiy's benchmark over it (Ubuntu 12.10, 64bit). This is what I get in Py3.4:
 0.022 untyped_cy(i)
 0.023 untyped_cy("spam", i)
 0.024 untyped_cy("spam", "spam", i)
 0.106 untyped_cy(a=i)
 0.133 untyped_cy(a="spam", b=i)
 0.152 untyped_cy(a="spam", b="spam", c=i)
 0.033 typed_cy(i)
 0.038 typed_cy("spam", i)
 0.039 typed_cy("spam", "spam", i)
 0.129 typed_cy(a=i)
 0.168 typed_cy(a="spam", b=i)
 0.183 typed_cy(a="spam", b="spam", c=i)
 0.143 untyped_py(i)
 0.234 untyped_py("spam", i)
 0.247 untyped_py("spam", "spam", i)
 0.368 untyped_py(a=i)
 0.406 untyped_py(a="spam", b=i)
 0.425 untyped_py(a="spam", b="spam", c=i)
 0.447 typed_py(i)
 0.469 typed_py("spam", i)
 0.480 typed_py("spam", "spam", i)
 0.745 typed_py(a=i)
 0.783 typed_py(a="spam", b=i)
 0.819 typed_py(a="spam", b="spam", c=i)
Looking at the factors, that's about the same speedup that the dedicated hand tuned C implementation presented according to Serhiy's own runs (he reported 10-25x). Makes me wonder why we should have two entirely separate implementations for this.
Here's the lru_cache_class.pxd file I used:
"""
cimport cython
cdef make_key(tuple args, dict kwds, bint typed, tuple kwd_mark)
@cython.final
@cython.internal
cdef class c_lru_cache:
 cdef dict cache
 cdef Py_ssize_t hits
 cdef Py_ssize_t misses
 cdef Py_ssize_t maxsize
 cdef bint typed
 cdef object user_function
 cdef object cache_info_type
 cdef tuple kwd_mark
 cdef list root
"""