More work with nilmdb.stream_insert. Checks for overlap between
parser output and database intervals, and actually inserts the
data into pytables. Need to benchmark/figure out whether we can
use table.append rather than the row.append() nonsense -- it could
simplify things quite a bit.
Improve layout class and add tests to get more coverage. Better
error handling on invalid inputs (reports the reason for the error)
Replace layout.fillrow with layout.filltable, but turns out that we
can probably just remove it anyway.
Add nilmdb.Timer for simple timing tests
Move some duplicated test suite helper functions into a new file,
test_helper.py
Add class to test_interval.py to match the others
git-svn-id: https://bucket.mit.edu/svn/nilm/nilmdb@10661 ddd99763-3ecb-0310-9145-efcb8ce7c51f
