The wterl:session_get function was fetching a value using a cursor, then
closing the cursor, and then trying to use the fetched value to create the
return binary. According to the WiredTiger documentation, this is a no-no
-- a value is good only until the next operation on the cursor used to
fetch it. We've been seeing occasional segmentation violations in the
memcpy for the fetched value, and this might explain it.
Make the unit tests call riak_kv_backend:standard_test like other
backends do for their unit tests. This is a little awkward at the
moment because riak_kv_backend.erl doesn't live in this repository, so
it requires temporarily copying it into src to run "rebar eunit".
The backend fold_objects was failing because it was trying to use
wterl:fold_keys/3, which doesn't fold over values. Add fold/3 to
wterl.erl to fix this.
Also clean up a few dialyzer warnings.
WiredTiger session count defaults to 50, but we need at least one per
vnode, so for now hard-code it to 100. Also ignore table creation
results in the kv backend because WiredTiger is currently producing a
strange error if the table already exists.
In order to reduce the number of wiredtiger session open/close calls,
open a session at startup and keep it in the kv backend state. This is
safe as far as using these sessions on scheduler threads goes because
the riak_kv_vnode fsm serializes all calls through the backend, so
we'll never have a case of multiple scheduler threads concurrently
trying to use the same session.
Add a temporary copy of riak_kv_backend, renamed to
temp_riak_kv_backend, to allow wterl to build on its own. This file
must be deleted when riak_kv_wterl_backend is moved to its proper
place in riak_kv.
Change cursor_{next,prev} to return {ok, Key, Value}. Add
cursor_{next,prev}_{key,value} functions to allow cursor movement
followed by fetch of either key or value. Add fold_keys function. Add
unit tests for these changes. Also specify "inorder" on the unit test
generator functions, since the tests they specified are intended to be
run that way.
Break the single wterl unit test into a series of tests separated by
function. Use eunit assert macros and add test setup and teardown
functions. Add descriptive messages for the tests for display under
"rebar -v eunit".
Add app, supervisor, and worker to open and cache the database
connection. Revert to using binaries for WT config in order to allow
wterl callers to use proplists for configuration. Change {error,
not_found} to not_found return values from wterl.
Add support for cursor.{next,prev,search,search_near,reset}.
Change table_create to no longer pass back the table name, WiredTiger's
model is that you pass in the object name each time (and the current
model means we can't drop the table before we run the tests).
Upgrade to the WiredTiger 1.0 release, there's a bug where static
libraries aren't created correctly, for now create shared libraries
for wterl.
not a pure integer).
Remove "exclusive" from the list of options, it's not in the 1.0 release.
Set the cache_size for the test, just to prove it works.
A number of changes:
* Added exported functions to close connections and sessions.
* Added exported functions to create and drop tables. Currently not
happy with the shape of these functions, though, as they treat
tables in Erlang just as strings, and they force users of sessions
to have to pass both sessions and tables into get/put/delete
operations. It might be better to take a table identifier as part of
the session creation function and store that identifier with the
session resource.
* Added implementations for key-value get, put, and delete.
* Added very minimal unit tests for the changes above.
