The decompression of error-strings is only done if the string is accessed
via printing or via er.args. Tests are added for this feature to ensure
the decompression works.
The idea here is that there's a moderate amount of ROM used up by exception
text. Obviously we try to keep the messages short, and the code can enable
terse errors, but it still adds up. Listed below is the total string data
size for various ports:
bare-arm 2860
minimal 2876
stm32 8926 (PYBV11)
cc3200 3751
esp32 5721
This commit implements compression of these strings. It takes advantage of
the fact that these strings are all 7-bit ascii and extracts the top 128
frequently used words from the messages and stores them packed (dropping
their null-terminator), then uses (0x80 | index) inside strings to refer to
these common words. Spaces are automatically added around words, saving
more bytes. This happens transparently in the build process, mirroring the
steps that are used to generate the QSTR data. The MP_COMPRESSED_ROM_TEXT
macro wraps any literal string that should compressed, and it's
automatically decompressed in mp_decompress_rom_string.
There are many schemes that could be used for the compression, and some are
included in py/makecompresseddata.py for reference (space, Huffman, ngram,
common word). Results showed that the common-word compression gets better
results. This is before counting the increased cost of the Huffman
decoder. This might be slightly counter-intuitive, but this data is
extremely repetitive at a word-level, and the byte-level entropy coder
can't quite exploit that as efficiently. Ideally one would combine both
approaches, but for now the common-word approach is the one that is used.
For additional comparison, the size of the raw data compressed with gzip
and zlib is calculated, as a sort of proxy for a lower entropy bound. With
this scheme we come within 15% on stm32, and 30% on bare-arm (i.e. we use
x% more bytes than the data compressed with gzip -- not counting the code
overhead of a decoder, and how this would be hypothetically implemented).
The feature is disabled by default and can be enabled by setting
MICROPY_ROM_TEXT_COMPRESSION at the Makefile-level.
Instead of compiler-level if-logic. This is necessary to know what error
strings are included in the build at the preprocessor stage, so that string
compression can be implemented.
These were found by buiding the unix coverage variant on macOS (so clang
compiler). Mostly, these are fixing implicit cast of float/double to
mp_float_t which is one of those two and one mp_int_t to size_t fix for
good measure.
Implements Task and TaskQueue classes in C, using a pairing-heap data
structure. Using this reduces RAM use of each Task, and improves overall
performance of the uasyncio scheduler.
To enable lazy loading of submodules (among other things), which is very
useful for MicroPython libraries that want to have optional subcomponents.
Disabled explicitly on minimal ports.
This commit adds micropython.heap_locked() which returns the current
lock-depth of the heap, and can be used by Python code to check if the heap
is locked or not. This new function is configured via
MICROPY_PY_MICROPYTHON_HEAP_LOCKED and is disabled by default.
This commit also changes the return value of micropython.heap_unlock() so
it returns the current lock-depth as well.
This eliminates the need for the sizeof regex fixup by rearranging things a
bit. All other bitfields already use the parentheses around expressions
with sizeof, so one case is fixed by following this convention.
VM_MAX_STATE_ON_STACK is the only remaining problem and it can be worked
around by changing the order of the operands.
The double-% was added in 11de8399fe (Jun
2014) when such errors were formatted with printf. But then
55830dd9bf (Dec 2018) changed
mp_obj_new_exception_msg() to not format the message, as discussed
in #3004. So such error strings are no longer formatted and a % is just
that.
This string is recognised by uncrustify, to disable formatting in the
region marked by these comments. This is necessary in the qstrdef*.h files
to prevent modification of the strings within the Q(...). In other places
it is used to prevent excessive reformatting that would make the code less
readable.
Jim Mussared
David Lechner
Damien George
Andrew Leech
David Lechner
Tom Collins