suspect-devices/circuitpython/py/stream.c, branch type_hints

protocols: Allow them to be (optionally) type-safe

2019-12-04T15:29:57+00:00

Protocols are nice, but there is no way for C code to verify whether a type's "protocol" structure actually implements some particular protocol. As a result, you can pass an object that implements the "vfs" protocol to one that expects the "stream" protocol, and the opposite of awesomeness ensues. This patch adds an OPTIONAL (but enabled by default) protocol identifier as the first member of any protocol structure. This identifier is simply a unique QSTR chosen by the protocol designer and used by each protocol implementer. When checking for protocol support, instead of just checking whether the object's type has a non-NULL protocol field, use `mp_proto_get` which implements the protocol check when possible. The existing protocols are now named: protocol_framebuf protocol_i2c protocol_pin protocol_stream protocol_spi protocol_vfs (most of these are unused in CP and are just inherited from MP; vfs and stream are definitely used though) I did not find any crashing examples, but here's one to give a flavor of what is improved, using `micropython_coverage`. Before the change, the vfs "ioctl" protocol is invoked, and the result is not intelligible as json (but it could have resulted in a hard fault, potentially): >>> import uos, ujson >>> u = uos.VfsPosix('/tmp') >>> ujson.load(u) Traceback (most recent call last): File "", line 1, in ValueError: syntax error in JSON After the change, the vfs object is correctly detected as not supporting the stream protocol: >>> ujson.load(p) Traceback (most recent call last): File "", line 1, in OSError: stream operation not supported

In py/, must guard uses of RUN_BACKGROUND_TASKS

2019-09-12T02:15:10+00:00

stream_readall: This can be long-running, run background tasks

2019-09-10T01:14:02+00:00

While finding sources of clicks and buzzes in nrf i2sout, I identified this site as one which could be long running. Reproducer code was to play a 22.05kHz sample and repeatedly print `os.listdir('')`

Support print("", flush=True)

2019-02-16T00:53:19+00:00

Fixes #1127

CharacteristicBuffer: make it be a stream class; add locking

2019-01-20T00:45:35+00:00

UART changes: timeout in secs, write bytes, etc.

2018-12-03T17:04:32+00:00

Two fixes and translate more strings.

2018-08-09T20:29:30+00:00

* Fix finding translations with escaped characters. * Add back \r to translations since its needed by screen.

py/stream: Remove stray empty line at start of file.

2018-06-20T06:26:12+00:00

This was accidentally added in 6abede2ca9e221b6aefcaccbda0c89e367507df1

py/stream: Update comment for mp_stream_write_adaptor.

2018-06-20T05:56:32+00:00

py/stream: Introduce and use efficient mp_get_stream to access stream_p.

2018-06-18T02:35:56+00:00

The existing mp_get_stream_raise() helper does explicit checks that the input object is a real pointer object, has a non-NULL stream protocol, and has the desired stream C method (read/write/ioctl). In most cases it is not necessary to do these checks because it is guaranteed that the input object has the stream protocol and desired C methods. For example, native objects that use the stream wrappers (eg mp_stream_readinto_obj) in their locals dict always have the stream protocol (or else they shouldn't have these wrappers in their locals dict). This patch introduces an efficient mp_get_stream() which doesn't do any checks and just extracts the stream protocol struct. This should be used in all cases where the argument object is known to be a stream. The existing mp_get_stream_raise() should be used primarily to verify that an object does have the correct stream protocol methods. All uses of mp_get_stream_raise() in py/stream.c have been converted to use mp_get_stream() because the argument is guaranteed to be a proper stream object. This patch improves efficiency of stream operations and reduces code size.