More obvious how to extend the code as it is all in one module.
Also add a new field to the standard object metadata tuple that may hold in the future other object metadata base don user-defined functions.
Adds support with test for tuplebuckets in Riak keys.
This exposed that there was no filter using the seglist on the in-mmemory keys. This means that if there is no filter applied in the fold_function, many false positives may emerge.
This is probably not a big performance benefit (and indeed for performance it may be better to apply during the leveled_pmem:merge_trees).
Some thought still required as to what is more likely to contribute to future bugs: an extra location using the hash matching found in leveled_sst, or the extra results in the query.
Which exposed it wasn't working. If there is no segment list passed - just a modification filter, you don't need to check the position list (as checking the position list returns an empty position so sipping all the matching results!)
Externally to leveled_sst all folds are actually managed through exapnd_list_by_pointer.
Make the API a bit clearer in this regards, and add specs to help dialyzer.
This also adds LowLastMod to the API for expanding pointers (although the leveled_penciller just defaults this to 0 for everything.
Although we are still pre-release in Leveled, for completeness it is a useful test of this code change to show that it can be done in a backwards compatible way.
So a boolean is added to indicate whether a file should index the modified date within the slot, and this can then be read when the file is opened.
Nothing happens with the boolean, yet.
An issue was spotted. If we use a segment filter in a query, and there are multiple matches within a given slot - only the first match is returned.
Tests didn't detect this. Now they do, and the issue is resolved.
Previously couldn't accumulate keys using check-blocks - so if a key was found in the first position, and there were other positions to check for other keys, those other positions wouldn't be checked.
