When splitting windows into their own individual tables, do not wait for
empty tables to be read. Empty tables may never be read so waiting for
them can result in a deadlock.
This was found while writing a test case for in progress work and so a
test case for this condition will follow in a future commit.
This implements create empty for the window table reader and allows this
table read function to be used when it is specified. It will pass down
the create empty flag from the original window call into the storage
read function.
This also fixes the window table reader so it properly creates
individual tables for each window. Previously, it was constructing one
table for an entire series instead of one table per window.
Tests have been added to verify three edge case behaviors. The first is
the normal read operation where all values are present. The second is
when create empty is specified so null values may be created. The third
is with truncated boundaries to ensure that storage is read from and the
start and stop timestamps get correctly truncated.
Faith Chikwekwe
Brett Buddin
Jonathan A. Sternberg
jlapacik