undocumented exception in getsensor.get_acceleration()

[smmiller]

The doc strings in getsensor.r2py claim there are no exceptions for the get_acceleration() call. However, sometimes there is an exception (in sensorlib) when parsing json received from SL4A, such as the following:

Uncaught exception!

Following is a full traceback, and a user traceback.
The user traceback excludes non-user modules. The most recent call is displayed last.

Full debugging traceback:
"/storage/emulated/0/Android/data/com.sensibility_testbed/files/sl4a/seattle/seattle_repy/repyV2/emultimer.py", line 115, in wrapped_func
"poll.r2py", line 10, in acc
"getsensor.r2py", line 969, in get_acceleration
"sensorlib.r2py", line 111, in request_data
"/storage/emulated/0/Android/data/com.sensibility_testbed/files/extras/python/json/init.py", line 326, in loads
"/storage/emulated/0/Android/data/com.sensibility_testbed/files/extras/python/json/decoder.py", line 369, in decode

User traceback:
"poll.r2py", line 10, in acc
"getsensor.r2py", line 969, in get_acceleration
"sensorlib.r2py", line 111, in request_data
"/storage/emulated/0/Android/data/com.sensibility_testbed/files/extras/python/json/init.py", line 326, in loads
"/storage/emulated/0/Android/data/com.sensibility_testbed/files/extras/python/json/decoder.py", line 369, in decode

Exception (with type 'exceptions.ValueError'): Extra data: line 2 column 1 - line 4 column 1 (char 48 - 144)

[yyzhuang]

Thanks for reporting this. It seems to be a Python issue http://stackoverflow.com/questions/14150823/python-json-decode-valueerror-extra-data Though it's very unlikely, the accelerometer data could get mangled when transmitted over the loopback.. We didn't think this could happen but it actually did. It would be helpful to catch this and print out the data that caused the exception.

Anyways, we should add exception handling in getsensor.r2py.

[smmiller]

No problem. I'll wrap the call and update the issue with some accelerometer
data that causes this.

On Thu, Jul 30, 2015 at 10:39 PM, Yanyan Zhuang notifications@github.com
wrote:

Thanks for reporting this. It seems to be a Python issue
http://stackoverflow.com/questions/14150823/python-json-decode-valueerror-extra-data
Though it's very unlikely, the accelerometer data could get mangled when
transmitted over the loopback.. We didn't think this could happen but it
actually did. It would be helpful to catch this and print out the data that
caused the exception.

Anyways, we should add exception handling in getsensor.r2py.

—
Reply to this email directly or view it on GitHub
#7 (comment)
.

[yyzhuang]

I added this https://github.com/SensibilityTestbed/sensorlib/blob/master/getsensor.r2py#L965-L972 If other sensors have similar issue, we should log the data and see what happened.

[yyzhuang]

I made a slight change https://github.com/SensibilityTestbed/sensorlib/blob/master/getsensor.r2py#L968-L970 In the user program, you should catch the exception and then log to see what the data is. It's not a good idea to log data in the library. Thanks to Albert's elegant suggestion.

[smmiller]

Makes sense. Thanks for the update.

On Tue, Aug 11, 2015 at 12:26 PM, Yanyan Zhuang notifications@github.com
wrote:

I made a slight change
https://github.com/SensibilityTestbed/sensorlib/blob/master/getsensor.r2py#L968-L970
In the user program, you should catch the exception and then log to see
what the data is. It's not a good idea to log data in the library. Thanks
to Albert's elegant suggestion.

—
Reply to this email directly or view it on GitHub
#7 (comment)
.