Commit graph

163 commits

Author SHA1 Message Date
Leonard Lyubich
77e80f517f [] metabase: Store header value index in a tree leaf
In the previous implementation of the metabase, the unique value of the
header was assigned a bucket, the elements of which were leaves with a
key-address and an empty value. This approach was relatively efficient in
terms of write speed. However, a large number of buckets led to a rapid
increase in the database volume (~4GB for 100K objects with unique
attributes). An approach is presented with storing indexes on the value of
headers in the leaves of the tree, where the keys are the unique values ​​of
the header, and the values ​​are a serialized list of addresses (gob
encoding is temporarily used for serialization).

The new approach gave a good result in saving space (~350MB), however, it
significantly reduced the write speed with an increase in the number of
objects (~ 80x after 100K objects).

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2020-11-03 18:42:32 +03:00
Leonard Lyubich
e48f8a189e [] metabase: Replace exclusive select with the inclusive one
The previous metabase implementation took an exclusionary approach: filters
narrowed the set of all objects to those that match all filters. An
inclusive approach is presented. In it, when traversing the indexed headers,
the object becomes a candidate for selection. If at least one of the
subsequent filters is not passed, the object ceases to be a candidate. At
the end of the traversal, the remaining candidates are added to the
resulting sample. The borderline case of no filters is handled in a special
way: all stored objects are added to the resulting selection.

Presented inclusive approach showed better performance in most scenarios
(although not all).

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2020-11-03 18:42:32 +03:00
Leonard Lyubich
3bbf1d6a60 [] metabase: Do not select objects if there is no filterable attribute
In previous metabase implementation the absence of an attribute presented in
the search filter did not exclude the object from the result. Change this
behavior to exclude the object from the result.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2020-11-03 18:42:32 +03:00
Leonard Lyubich
d9a5007c72 [] metabase: Add unit test for a nonexistent attribute
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2020-11-03 18:42:32 +03:00
Leonard Lyubich
7704811654 [] metabase: Implement and useful test funcs for work with DB
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2020-11-03 18:42:32 +03:00
Leonard Lyubich
fc2038e929 [] metabase: Implement Path method
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2020-11-03 18:42:32 +03:00
Leonard Lyubich
c0aa892161 [] localstorage: Make local storage to use new metabase
Replace meta Bucket with meta.DB instance in local storage implementation.
Adopt all dependent components to new local storage.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2020-11-03 18:42:32 +03:00
Leonard Lyubich
a61f8d44d1 [] metabase: Implement benchmarking tests
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2020-11-03 18:42:32 +03:00
Leonard Lyubich
1db01725c9 [] metabase: Implement indexing by object properties
Process parent objects in Put method. Headers of parent object are stored as
regular leaf objects in metabase from now. Build indexes for ROOT, LEAF and
CHILDFREE properties.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2020-11-03 18:42:32 +03:00
Leonard Lyubich
20ed7c0d61 [] metabase: Implement Delete method
Implement Delete method on DB structure that adds deleted addresses to
tombstone index. Do not attach addresses from tombstone index to Select
result. Return error from Get method if address is presented in tombstone
index.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2020-10-29 17:34:41 +03:00
Leonard Lyubich
2d319aa29c [] metabase: Use static byte prefix for calculating non-empty keys
It is no longer necessary to make different prefixes to generate non-empty
keys for buckets.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2020-10-29 17:34:41 +03:00
Leonard Lyubich
5f78a18a4f [] metabase: Do not create leaves in indexed header bucket
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2020-10-29 17:34:41 +03:00
Leonard Lyubich
85aacbbb10 [] localstorage: Implement primary object metabase
Implement bolt-based metabase that is going to be used in local object
storage. Implement Put/Get/Select methods.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
2020-10-29 17:34:41 +03:00