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Lens Code Structure

  Here is some detail on how the Apache Lens modules are structured -

  * <<checkstyle>> - Has checkstyle rules imposed on the project.

  * <<lens-api>> - Lens API. Has API primarily for the clients.

  * <<lens-server-api>> - Lens API mainly for server extensions. This contains API for Service, Driver, LensEvent, QueryRewriter etc.

  * <<lens-cube>> - Cube data model and query rewriting from cube QL to HQL done here.

  * <<lens-storage-db>> - Storage definition for DBStorage and DBStorageHandler.

  * <<lens-query-lib>> - The Query lib containing some Serde or OutputFormatter implementations.

  * <<lens-driver-hive>> - Driver implementation for Hive as execution engine.

  * <<lens-driver-jdbc>> - Driver implementation for JDBC as execution engine.

  * <<lens-server>> - The server module - containing the service implementations, REST resources and HttpServer itself.

  * <<lens-client>> - Java client built on top of REST interface.

  * <<lens-cli>> - CLI built using spring shell and lens-client.

  * <<lens-examples>> - Examples containing example schema and queries.

  * <<lens-dist>> - Packaging for binary distribution of lens

  * <<lens-ml-lib>> - Wrapper over Spark ML lib where input to a model is output of a query.

  * <<lens-ml-dist>> - Packaging for ml-lib - which has server, client, spark libraries and ml-lib.

  * <<lens-regression>> - The regression test suite.