> On March 7, 2016, 8:42 a.m., Yi Pan (Data Infrastructure) wrote: > > samza-api/src/main/java/org/apache/samza/storage/kv/KeyValueIterator.java, > > line 27 > > <https://reviews.apache.org/r/41068/diff/2/?file=1272213#file1272213line27> > > > > I recommend to drop this seekToLast() for now. Based on your use case > > description, to achieve the backward traverse, you would need both > > seekToLast() and previous() in the iterator. Adding seekToLast() only won't > > be sufficient.
Agreed. The latest diff has this change. - Amit ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/41068/#review122271 ----------------------------------------------------------- On March 9, 2016, 12:26 a.m., Amit Yadav wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/41068/ > ----------------------------------------------------------- > > (Updated March 9, 2016, 12:26 a.m.) > > > Review request for samza and Yi Pan (Data Infrastructure). > > > Repository: samza > > > Description > ------- > > Added Seek functionality to KeyValueStore and KeyValueStoreIterator. The > following alternatives were considered > > 1. Create a 'SeekingKeyValueIterator' and 'SeekingKeyValueStore' - Have a > completely separate classes which extends their existing > counterparts. This solution is appealing as it provides separation of > concerns. However, this also requires creating a complete > hierarchy of all the classes which are implementing the > KeyValueStore/Iterator interface. Therefore the effort to value didnt > made much sense. > > 2. Use the existing 'range' functionality - This solution requires a new > iterator to be created which could supply the 'end' > key for the range. We could make this user configurable, however this > assumes that the user can somehow come up with an > end key in all the cases. This assumption may not be true all the times. > Also, I feel this is more of a workaround then > a real solution, more of range degenerated to a seekTo functionality and > therefore is not a clean interaface. > > 3. Add seek functionality to existing interfaces and classes :- In the end, > this is what I implemented since it is the cleanest solution > in amongst all the options. This also requires minimum changes. The > downside of this approach is that not al stores can support seek > to a particular key (especially, the one derived from java iterators). > > > Diffs > ----- > > samza-api/src/main/java/org/apache/samza/storage/kv/KeyValueIterator.java > 854ebbfa640e96a87977ae25b67736ef57fadd8e > samza-api/src/main/java/org/apache/samza/storage/kv/KeyValueStore.java > b1fea7bc38d1a44e7bba6bdeb638dc33c0936c6f > > samza-kv-inmemory/src/main/scala/org/apache/samza/storage/kv/inmemory/InMemoryKeyValueStore.scala > 72f25a354eaa98e8df379d07d9cc8613dfafd13a > > samza-kv-rocksdb/src/main/scala/org/apache/samza/storage/kv/RocksDbKeyValueStore.scala > d614f8a58882628129ec30c0fe8800395d60ed99 > samza-kv/src/main/scala/org/apache/samza/storage/kv/CachedStore.scala > c28f8db8cb59bd5415e78535877acc1e5bee0f67 > > samza-kv/src/main/scala/org/apache/samza/storage/kv/CachedStoreMetrics.scala > a11b5fe4f91259228eb262cfbc1d36f2cba4e08d > > samza-kv/src/main/scala/org/apache/samza/storage/kv/KeyValueStorageEngine.scala > e5a66a4770b9553a1cc48fbb505f52d123c6c754 > > samza-kv/src/main/scala/org/apache/samza/storage/kv/KeyValueStorageEngineMetrics.scala > 233fba91caf041bfb78189efef00ce8fc56f9f15 > > samza-kv/src/main/scala/org/apache/samza/storage/kv/KeyValueStoreMetrics.scala > 967d5097253640ee41ee84e551e15fa2285c00e2 > samza-kv/src/main/scala/org/apache/samza/storage/kv/LoggedStore.scala > 7bba6ff37d8266674e7f15c10c7c146f4a41fc91 > > samza-kv/src/main/scala/org/apache/samza/storage/kv/LoggedStoreMetrics.scala > 743151a310792d4a6ff48ea102e796eb9f630bba > > samza-kv/src/main/scala/org/apache/samza/storage/kv/NullSafeKeyValueStore.scala > 3de257c3117c16b7cfdb7a3d7bb28d5cddc7c10a > > samza-kv/src/main/scala/org/apache/samza/storage/kv/SerializedKeyValueStore.scala > 8e183efcdec6fd3f921fc2bfe1971c95715930ed > > samza-kv/src/main/scala/org/apache/samza/storage/kv/SerializedKeyValueStoreMetrics.scala > 841e4a236da99cbfe121054654c648887f39c3f6 > samza-kv/src/test/scala/org/apache/samza/storage/kv/MockKeyValueStore.scala > 595dd0df6fde50f91ab5a046a193559326f2a1d5 > > Diff: https://reviews.apache.org/r/41068/diff/ > > > Testing > ------- > > > Thanks, > > Amit Yadav > >
