rocksdb/table/cuckoo
Levi Tamasi 81388b36e0 Add support for wide-column point lookups (#10540)
Summary:
The patch adds a new API `GetEntity` that can be used to perform
wide-column point lookups. It also extends the `Get` code path and
the `MemTable` / `MemTableList` and `Version` / `GetContext` logic
accordingly so that wide-column entities can be served from both
memtables and SSTs. If the result of a lookup is a wide-column entity
(`kTypeWideColumnEntity`), it is passed to the application in deserialized
form; if it is a plain old key-value (`kTypeValue`), it is presented as a
wide-column entity with a single default (anonymous) column.
(In contrast, regular `Get` returns plain old key-values as-is, and
returns the value of the default column for wide-column entities, see
https://github.com/facebook/rocksdb/issues/10483 .)

The result of `GetEntity` is a self-contained `PinnableWideColumns` object.
`PinnableWideColumns` contains a `PinnableSlice`, which either stores the
underlying data in its own buffer or holds on to a cache handle. It also contains
a `WideColumns` instance, which indexes the contents of the `PinnableSlice`,
so applications can access the values of columns efficiently.

There are several pieces of functionality which are currently not supported
for wide-column entities: there is currently no `MultiGetEntity` or wide-column
iterator; also, `Merge` and `GetMergeOperands` are not supported, and there
is no `GetEntity` implementation for read-only and secondary instances.
We plan to implement these in future PRs.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10540

Test Plan: `make check`

Reviewed By: akankshamahajan15

Differential Revision: D38847474

Pulled By: ltamasi

fbshipit-source-id: 42311a34ccdfe88b3775e847a5e2a5296e002b5b
2022-08-19 11:51:12 -07:00
..
cuckoo_table_builder.cc Remove own ToString() (#9955) 2022-05-06 13:03:58 -07:00
cuckoo_table_builder.h
cuckoo_table_builder_test.cc
cuckoo_table_factory.cc
cuckoo_table_factory.h
cuckoo_table_reader.cc
cuckoo_table_reader.h
cuckoo_table_reader_test.cc Add support for wide-column point lookups (#10540) 2022-08-19 11:51:12 -07:00