Summary:
WriteBatchWithIndex::GetFromBatchAndDB only works correctly for overwrite_key=false. Transactions use overwrite_key=true (since WriteBatchWithIndex::GetIteratorWithBase only works when overwrite_key=true). So currently, Transactions could return incorrectly merged results when calling Get/GetForUpdate().
Until a permanent fix can be put in place, Transaction::Get[ForUpdate] and WriteBatchWithIndex::GetFromBatch[AndDB] will now return MergeInProgress if the most recent write to a key in the batch is a Merge.
Test Plan: more tests
Reviewers: sdong, yhchiang, rven, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D47817
Summary: Fixed some bugs in using SingleDelete on a WriteBatchWithIndex and added some tests.
Test Plan: new tests
Reviewers: sdong, yhchiang, rven, kradhakrishnan, IslamAbdelRahman, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D47529
Summary:
This patch fixes#7460559. It introduces SingleDelete as a new database
operation. This operation can be used to delete keys that were never
overwritten (no put following another put of the same key). If an overwritten
key is single deleted the behavior is undefined. Single deletion of a
non-existent key has no effect but multiple consecutive single deletions are
not allowed (see limitations).
In contrast to the conventional Delete() operation, the deletion entry is
removed along with the value when the two are lined up in a compaction. Note:
The semantics are similar to @igor's prototype that allowed to have this
behavior on the granularity of a column family (
https://reviews.facebook.net/D42093 ). This new patch, however, is more
aggressive when it comes to removing tombstones: It removes the SingleDelete
together with the value whenever there is no snapshot between them while the
older patch only did this when the sequence number of the deletion was older
than the earliest snapshot.
Most of the complex additions are in the Compaction Iterator, all other changes
should be relatively straightforward. The patch also includes basic support for
single deletions in db_stress and db_bench.
Limitations:
- Not compatible with cuckoo hash tables
- Single deletions cannot be used in combination with merges and normal
deletions on the same key (other keys are not affected by this)
- Consecutive single deletions are currently not allowed (and older version of
this patch supported this so it could be resurrected if needed)
Test Plan: make all check
Reviewers: yhchiang, sdong, rven, anthony, yoshinorim, igor
Reviewed By: igor
Subscribers: maykov, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D43179
Summary:
This diff is a collection of cleanups that were initially part of D43179.
Additionally it adds a unified way of defining key-value maps that use a
Comparator for sorting (this was previously implemented in four different
places).
Test Plan: make clean check all
Reviewers: rven, anthony, yhchiang, sdong, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D45993
Summary:
Support RollbackToSavePoint() in WriteBatch and WriteBatchWithIndex. Support for partial transaction rollback is needed for MyRocks.
An alternate implementation of Transaction::RollbackToSavePoint() exists in D40869. However, the other implementation is messier because it is implemented outside of WriteBatch. This implementation is much cleaner and also exposes a potentially useful feature to WriteBatch.
Test Plan: Added unit tests
Reviewers: IslamAbdelRahman, kradhakrishnan, maykov, yoshinorim, hermanlee4, spetrunia, sdong, yhchiang
Reviewed By: yhchiang
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D42723
Summary:
[This is the resubmit of D39813. Tests were failing, so I reverted the diff. I found the bug and I'm now resubmitting]
If we don't do this, any calls to Entry() after WBWI mutation will result in undefined behavior. We need to re-fetch the offset from the skip list and regenerate the new pointer (because string's base pointer can change while mutating).
Test Plan: COMPILE_WITH_ASAN=1 make write_batch_with_index_test && ./write_batch_with_index_test
Reviewers: sdong
Reviewed By: sdong
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D39897
Summary: If we don't do this, any calls to Entry() after WBWI mutation will result in undefined behavior. We need to re-fetch the offset from the skip list and regenerate the new pointer (because string's base pointer can change while mutating).
Test Plan: COMPILE_WITH_ASAN=1 make write_batch_with_index_test && ./write_batch_with_index_test
Reviewers: sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D39813
Summary:
Added a couple functions to WriteBatchWithIndex to make it easier to query the value of a key including reading pending writes from a batch. (This is needed for transactions).
I created write_batch_with_index_internal.h to use to store an internal-only helper function since there wasn't a good place in the existing class hierarchy to store this function (and it didn't seem right to stick this function inside WriteBatchInternal::Rep).
Since I needed to access the WriteBatchEntryComparator, I moved some helper classes from write_batch_with_index.cc into write_batch_with_index_internal.h/.cc. WriteBatchIndexEntry, ReadableWriteBatch, and WriteBatchEntryComparator are all unchanged (just moved to a different file(s)).
Test Plan: Added new unit tests.
Reviewers: rven, yhchiang, sdong, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D38037
Summary: WriteBatch and WriteBatchWithIndex now both inherit from a common abstract base class. This makes it easier to write code that is agnostic toward the implementation of the particular write batch. In particular, I plan on utilizing this abstraction to allow transactions to support using either implementation of a write batch.
Test Plan: modified existing WriteBatchWithIndex tests to test new functions. Running all tests.
Reviewers: igor, rven, yhchiang, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D34017
Summary: I'm moving mongo to a single column family, so I need DeltaBase iterator with default column family.
Test Plan: Added unit test
Reviewers: sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D32589
Summary: Add an iterator that combines base_iterator of type Iterator* with delta iterator of type WBWIIterator*.
Test Plan: nothing yet. work in progress
Reviewers: ljin, igor
Reviewed By: igor
Subscribers: rven, yhchiang, leveldb
Differential Revision: https://reviews.facebook.net/D24741
Summary: Support SeekToFirst(), SeekToLast() and Prev() in WBWIIterator, returned by WriteBatchWithIndex::NewIterator().
Test Plan: Write unit test cases to cover the case.
Reviewers: ljin, igor
Reviewed By: igor
Subscribers: rven, yhchiang, leveldb
Differential Revision: https://reviews.facebook.net/D24765
Summary: With a new option, when accepting a new key, WriteBatchWithIndex will find an existing index of the same key, and replace the content of it.
Test Plan: Add a unit test case.
Reviewers: ljin, yhchiang, rven, igor
Reviewed By: igor
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D24753
Summary:
Previously, one single column family is given to WriteBatchWithIndex to index keys for all column families. An extra map from column family ID to comparator is maintained which can override the default comparator given in the constructor. A WriteBatchWithIndex::SetComparatorForCF() is added for user to add comparators per column family.
Also move more codes into anonymous namespace.
Test Plan: Add a unit test
Reviewers: ljin, igor
Reviewed By: igor
Subscribers: dhruba, leveldb, yhchiang
Differential Revision: https://reviews.facebook.net/D23355
Summary:
Add WriteBatchWithIndex so that a user can query data out of a WriteBatch, to support MongoDB's read-its-own-write.
WriteBatchWithIndex uses a skiplist to store the binary index. The index stores the offset of the entry in the write batch. When searching for a key, the key for the entry is read by read the entry from the write batch from the offset.
Define a new iterator class for querying data out of WriteBatchWithIndex. A user can create an iterator of the write batch for one column family, seek to a key and keep calling Next() to see next entries.
I will add more unit tests if people are OK about this API.
Test Plan:
make all check
Add unit tests.
Reviewers: yhchiang, igor, MarkCallaghan, ljin
Reviewed By: ljin
Subscribers: dhruba, leveldb, xjin
Differential Revision: https://reviews.facebook.net/D21381
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