Header files that are considered internal to the py core and should not
normally be included directly are:
py/nlr.h - internal nlr configuration and declarations
py/bc0.h - contains bytecode macro definitions
py/runtime0.h - contains basic runtime enums
Instead, the top-level header files to include are one of:
py/obj.h - includes runtime0.h and defines everything to use the
mp_obj_t type
py/runtime.h - includes mpstate.h and hence nlr.h, obj.h, runtime0.h,
and defines everything to use the general runtime support functions
Additional, specific headers (eg py/objlist.h) can be included if needed.
There were 2 bugs, now fixed by this patch:
- after deleting an element the len of the dict did not decrease by 1
- after deleting an element searching through the dict could lead to
a seg fault due to there being an MP_OBJ_SENTINEL in the ordered array
The internal map/set functions now use size_t exclusively for computing
addresses. size_t is enough to reach all of available memory when
computing addresses so is the right type to use. In particular, for
nanbox builds it saves quite a bit of code size and RAM compared to the
original use of mp_uint_t (which is 64-bits on nanbox builds).
Small hash tables (eg those used in user class instances that only have a
few members) now only use the minimum amount of memory necessary to hold
the key/value pairs. This can reduce performance for instances that have
many members (because then there are many reallocations/rehashings of the
table), but helps to conserve memory.
See issue #1760.
Map indicies are most commonly a qstr, and adding a fast-path for hashing
of a qstr increases overall performance of the runtime.
On pyboard there is a 4% improvement in the pystone benchmark for a cost
of 20 bytes of code size. It's about a 2% improvement on unix.
This change makes the code behave how it was supposed to work when first
written. The avail_slot variable is set to the first free slot when
looking for a key (which would come from deleting an entry). So it's
more efficient (for subsequent lookups) to insert a new key into such a
slot, rather than the very last slot that was searched.
Hashing is now done using mp_unary_op function with MP_UNARY_OP_HASH as
the operator argument. Hashing for int, str and bytes still go via
fast-path in mp_unary_op since they are the most common objects which
need to be hashed.
This lead to quite a bit of code cleanup, and should be more efficient
if anything. It saves 176 bytes code space on Thumb2, and 360 bytes on
x86.
The only loss is that the error message "unhashable type" is now the
more generic "unsupported type for __hash__".
Given that there's already support for "fixed table" maps, which are
essentially ordered maps, the implementation of OrderedDict just extends
"fixed table" maps by adding an "is ordered" flag and add/remove
operations, and reuses 95% of objdict code, just making methods tolerant
to both dict and OrderedDict.
Some things are missing so far, like CPython-compatible repr and comparison.
OrderedDict is Disabled by default; enabled on unix and stmhal ports.
This patch makes MICROPY_PY_BUILTINS_SET compile-time option fully
disable the builtin set object (when set to 0). This includes removing
set constructor/comprehension from the grammar, the compiler and the
emitters. Now, enabling set costs 8168 bytes on unix x64, and 3576
bytes on stmhal.
Damien George
Paul Sokolovsky
Alexander Steffen
Stephen Kyle