fe/src/test/java/org/apache/impala/common/AnalysisSessionFixture.java

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package org.apache.impala.common;

import org.apache.impala.analysis.ExprRewriterTest;
import org.apache.impala.catalog.Catalog;
import org.apache.impala.service.Frontend;
import org.apache.impala.testutil.ImpaladTestCatalog;
import org.apache.impala.testutil.TestUtils;
import org.apache.impala.thrift.TQueryCtx;
import org.apache.impala.thrift.TQueryOptions;

/**
 * Session fixture for analyzer tests. Holds state shared across test cases such
 * as the front-end, the user, the database, and query options. Queries created
 * from this fixture start with these defaults, but each query can change them
 * as needed for that particular test case.
 *
 * This fixture is analogous to a user session. Though, unlike a real session,
 * test can change the database, options and user per-query without changing
 * the session settings.
 *
 * The session fixture is created once per test file, then query fixtures perform
 * the work needed for each particular query. It is often helpful to wrap the
 * query fixtures in a function if the same setup is used over and over.
 * See {@link ExprRewriterTest} for  example usage.
 */
public class AnalysisSessionFixture {

  private final FrontendFixture feFixture_ = FrontendFixture.instance();
  // Query options to be used for all queries. Can be overridden per-query.
  private final TQueryOptions queryOptions_;
  // Default database for all queries.
  private String db_ = Catalog.DEFAULT_DB;
  // Default user for all queries.
  private String user_ = System.getProperty("user.name");

  public AnalysisSessionFixture() {
    queryOptions_ = new TQueryOptions();
  }

  public AnalysisSessionFixture setDB(String db) {
    db_ = db;
    return this;
  }

  public AnalysisSessionFixture setUser(String user) {
    user_ = user;
    return this;
  }

  public TQueryOptions options() { return queryOptions_; }
  public String db() { return db_; }
  public String user() { return user_; }
  public Frontend frontend() { return feFixture_.frontend(); }
  public ImpaladTestCatalog catalog() { return feFixture_.catalog(); }

  /**
   * Disable the optional expression rewrites.
   */
  public AnalysisSessionFixture disableExprRewrite() {
    queryOptions_.setEnable_expr_rewrites(false);
    return this;
  }

  public TQueryOptions cloneOptions() {
    return new TQueryOptions(queryOptions_);
  }

  public TQueryCtx queryContext() {
    return TestUtils.createQueryContext(db_, user_, cloneOptions());
  }

}