Ujson should only worry about whitespace before JSON. This becomes apparent when you are using MP stream protocol to read directly from input buffers.
When you attempt to read(1) on a UART (and possibly other protocols) you have to wait for either the byte or the timeout.
Fixes:
- Waiting for a timeout after you have completed reading a correct and complete JSON off the input.
- Raising an OSError after reading a correct and complete JSON off the input.
- Eating more data than semantically owned off the input buffer.
- Blocking to start parsing JSON until the entire JSON body has been loaded into a potentially large, contiguous Python object.
Code you would write before:
```
line = board_busio_uart_port.read_line()
json_dict = json.loads(line)
```
or reaching for fixed buffers and swapping them around in Python.
Code that did not work before that does now:
```
json_dict = json.load(board_busio_uart_port)
```
- This removes the need for intermediate copies of data when reading JSON from micropython stream protocol inputs.
- It also increases total application speed by parsing JSON concurrently with receiving on boards that read from UART via DMA.
- It simplifies code that users write while improving their apps.
With this patch objects are only checked that they have the stream protocol
at the start of their use as a stream, and afterwards the efficient
mp_get_stream() helper is used to extract the stream protocol C methods.
This patch simplifies the str creation API to favour the common case of
creating a str object that is not forced to be interned. To force
interning of a new str the new mp_obj_new_str_via_qstr function is added,
and should only be used if warranted.
Apart from simplifying the mp_obj_new_str function (and making it have the
same signature as mp_obj_new_bytes), this patch also reduces code size by a
bit (-16 bytes for bare-arm and roughly -40 bytes on the bare-metal archs).
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.
- Changed: ValueError, TypeError, NotImplementedError
- OSError invocations unchanged, because the corresponding utility
function takes ints, not strings like the long form invocation.
- OverflowError, IndexError and RuntimeError etc. not changed for now
until we decide whether to add new utility functions.
This refactors ujson.loads(s) to behave as ujson.load(StringIO(s)).
Increase in code size is: 366 bytes for unix x86-64, 180 bytes for
stmhal, 84 bytes for esp8266.
This allows the mp_obj_t type to be configured to something other than a
pointer-sized primitive type.
This patch also includes additional changes to allow the code to compile
when sizeof(mp_uint_t) != sizeof(void*), such as using size_t instead of
mp_uint_t, and various casts.
Previous to this patch the printing mechanism was a bit of a tangled
mess. This patch attempts to consolidate printing into one interface.
All (non-debug) printing now uses the mp_print* family of functions,
mainly mp_printf. All these functions take an mp_print_t structure as
their first argument, and this structure defines the printing backend
through the "print_strn" function of said structure.
Printing from the uPy core can reach the platform-defined print code via
two paths: either through mp_sys_stdout_obj (defined pert port) in
conjunction with mp_stream_write; or through the mp_plat_print structure
which uses the MP_PLAT_PRINT_STRN macro to define how string are printed
on the platform. The former is only used when MICROPY_PY_IO is defined.
With this new scheme printing is generally more efficient (less layers
to go through, less arguments to pass), and, given an mp_print_t*
structure, one can call mp_print_str for efficiency instead of
mp_printf("%s", ...). Code size is also reduced by around 200 bytes on
Thumb2 archs.
Previous to this patch, a big-int, float or imag constant was interned
(made into a qstr) and then parsed at runtime to create an object each
time it was needed. This is wasteful in RAM and not efficient. Now,
these constants are parsed straight away in the parser and turned into
objects. This allows constants with large numbers of digits (so
addresses issue #1103) and takes us a step closer to #722.
This cleans up vstr so that it's a pure "variable buffer", and the user
can decide whether they need to add a terminating null byte. In most
places where vstr is used, the vstr did not need to be null terminated
and so this patch saves code size, a tiny bit of RAM, and makes vstr
usage more efficient. When null termination is needed it must be
done explicitly using vstr_null_terminate.
