entry_info holds views, which may get invalidated when the containing
index blocks are removed. Current implementations of next_entry() keeps
the blocks in memory as long as the cursor is alive but that will
change in new implementations of the cursor.
Adjust the assumption of tests accordingly.
In preparation for supporting more than one algorithm for lookups in
the promoted index, extract relevant logic out of the index_reader
(which is a partition index cursor).
The clustered index cursor implementation is now hidden behind
abstract interface called clustered_index_cursor.
The current implementation is put into the
scanning_clustered_index_cursor. It's mostly code movement with minor
adjustments.
In order to encapsulate iteration over promoted index entries,
clustered_index_cursor::next_entry() was introduced.
No change in behavior intended in this patch.
The plan is to move the unstructured content of tests/ directory
into the following directories of test/:
test/lib - shared header and source files for unit tests
test/boost - boost unit tests
test/unit - non-boost unit tests
test/manual - tests intended to be run manually
test/resource - binary test resources and configuration files
In order to not break git bisect and preserve the file history,
first move most of the header files and resources.
Update paths to these files in .cc files, which are not moved.
