content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to you under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.calcite.avatica.remote;
  
  import org.apache.calcite.avatica.AvaticaConnection;
  import org.apache.calcite.avatica.AvaticaStatement;
  import org.apache.calcite.avatica.ConnectionConfig;
  import org.apache.calcite.avatica.ConnectionPropertiesImpl;
  import org.apache.calcite.avatica.ConnectionSpec;
  import org.apache.calcite.avatica.Meta;
  import org.apache.calcite.avatica.jdbc.JdbcMeta;
  import org.apache.calcite.avatica.server.AvaticaJsonHandler;
  import org.apache.calcite.avatica.server.HttpServer;
  import org.apache.calcite.avatica.server.Main;
  import org.apache.calcite.avatica.server.Main.HandlerFactory;
  
  import com.google.common.cache.Cache;
  
  import org.eclipse.jetty.server.handler.AbstractHandler;
  import org.junit.AfterClass;
  import org.junit.BeforeClass;
  import org.junit.Test;
  
  import java.lang.reflect.Field;
  import java.lang.reflect.Method;
  import java.net.MalformedURLException;
  import java.net.URI;
  import java.net.URISyntaxException;
  import java.net.URL;
  import java.sql.Connection;
  import java.sql.DriverManager;
  import java.sql.ResultSet;
  import java.sql.SQLException;
  import java.sql.Statement;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.List;
  import java.util.Map;
  import java.util.Random;
  
  import static org.hamcrest.CoreMatchers.is;
  import static org.hamcrest.MatcherAssert.assertThat;
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertFalse;
  import static org.junit.Assert.assertTrue;
  
  /**
   * Tests that verify that the Driver still functions when requests are randomly bounced between
   * more than one server.
   */
  public class AlternatingRemoteMetaTest {
    private static final ConnectionSpec CONNECTION_SPEC = ConnectionSpec.HSQLDB;
  
    private static String url;
  
    static {
      try {
        // Force DriverManager initialization before we hit AlternatingDriver->Driver.<clinit>
        // Otherwise Driver.<clinit> -> DriverManager.registerDriver -> scan service provider files
        // causes a deadlock; see [CALCITE-1060]
        DriverManager.getDrivers();
        DriverManager.registerDriver(new AlternatingDriver());
      } catch (SQLException e) {
        throw new RuntimeException(e);
      }
    }
  
    // Keep a reference to the servers we start to clean them up after
    private static final List<HttpServer> ACTIVE_SERVERS = new ArrayList<>();
  
    /** Factory that provides a {@link JdbcMeta}. */
    public static class FullyRemoteJdbcMetaFactory implements Meta.Factory {
  
      private static JdbcMeta instance = null;
  
      private static JdbcMeta getInstance() {
        if (instance == null) {
          try {
            instance = new JdbcMeta(CONNECTION_SPEC.url, CONNECTION_SPEC.username,
                CONNECTION_SPEC.password);
          } catch (SQLException e) {
            throw new RuntimeException(e);
          }
        }
        return instance;
      }
  
      @Override public Meta create(List<String> args) {
        return getInstance();
      }
    }
  
    /**
     * AvaticaHttpClient implementation that randomly chooses among the provided URLs.
     */
    public static class AlternatingAvaticaHttpClient implements AvaticaHttpClient {
      private final List<AvaticaHttpClientImpl> clients;
      private final Random r = new Random();
  
      public AlternatingAvaticaHttpClient(List<URL> urls) {
        //System.out.println("Constructing clients for " + urls);
        clients = new ArrayList<>(urls.size());
        for (URL url : urls) {
          clients.add(new AvaticaHttpClientImpl(url));
        }
      }
  
      public byte[] send(byte[] request) {
        AvaticaHttpClientImpl client = clients.get(r.nextInt(clients.size()));
        //System.out.println("URL: " + client.url);
        return client.send(request);
      }
  
    }
  
    /**
     * Driver implementation {@link AlternatingAvaticaHttpClient}.
     */
    public static class AlternatingDriver extends Driver {
  
      public static final String PREFIX = "jdbc:avatica:remote-alternating:";
  
      @Override protected String getConnectStringPrefix() {
        return PREFIX;
      }
  
      @Override public Meta createMeta(AvaticaConnection connection) {
        final ConnectionConfig config = connection.config();
        final Service service = new RemoteService(getHttpClient(connection, config));
        connection.setService(service);
        return new RemoteMeta(connection, service);
      }
  
      @Override AvaticaHttpClient getHttpClient(AvaticaConnection connection,
          ConnectionConfig config) {
        return new AlternatingAvaticaHttpClient(parseUrls(config.url()));
      }
  
      List<URL> parseUrls(String urlStr) {
        final List<URL> urls = new ArrayList<>();
        final char comma = ',';
  
        int prevIndex = 0;
        int index = urlStr.indexOf(comma);
        if (-1 == index) {
          try {
            return Collections.singletonList(new URI(urlStr).toURL());
          } catch (MalformedURLException | URISyntaxException e) {
            throw new RuntimeException(e);
          }
        }
  
        // String split w/o regex
        while (-1 != index) {
          try {
            urls.add(new URI(urlStr.substring(prevIndex, index)).toURL());
          } catch (MalformedURLException | URISyntaxException e) {
            throw new RuntimeException(e);
          }
          prevIndex = index + 1;
          index = urlStr.indexOf(comma, prevIndex);
        }
  
        // Get the last one
        try {
          urls.add(new URI(urlStr.substring(prevIndex)).toURL());
        } catch (MalformedURLException | URISyntaxException e) {
          throw new RuntimeException(e);
        }
  
        return urls;
      }
  
    }
  
    @BeforeClass
    public static void beforeClass() throws Exception {
      final String[] mainArgs = new String[] { FullyRemoteJdbcMetaFactory.class.getName() };
  
      // Bind to '0' to pluck an ephemeral port instead of expecting a certain one to be free
  
      StringBuilder sb = new StringBuilder();
      for (int i = 0; i < 2; i++) {
        if (sb.length() > 0) {
          sb.append(",");
        }
        HttpServer jsonServer = Main.start(mainArgs, 0, new HandlerFactory() {
          @Override public AbstractHandler createHandler(Service service) {
            return new AvaticaJsonHandler(service);
          }
        });
        ACTIVE_SERVERS.add(jsonServer);
        sb.append("http://localhost:").append(jsonServer.getPort());
      }
  
      url = AlternatingDriver.PREFIX + "url=" + sb.toString();
    }
  
    @AfterClass public static void afterClass() throws Exception {
      for (HttpServer server : ACTIVE_SERVERS) {
        if (server != null) {
          server.stop();
        }
      }
    }
  
    private static Meta getMeta(AvaticaConnection conn) throws Exception {
      Field f = AvaticaConnection.class.getDeclaredField("meta");
      f.setAccessible(true);
      return (Meta) f.get(conn);
    }
  
    private static Meta.ExecuteResult prepareAndExecuteInternal(AvaticaConnection conn,
        final AvaticaStatement statement, String sql, int maxRowCount) throws Exception {
      Method m =
          AvaticaConnection.class.getDeclaredMethod("prepareAndExecuteInternal",
              AvaticaStatement.class, String.class, long.class);
      m.setAccessible(true);
      return (Meta.ExecuteResult) m.invoke(conn, statement, sql, maxRowCount);
    }
  
    private static Connection getConnection(JdbcMeta m, String id) throws Exception {
      Field f = JdbcMeta.class.getDeclaredField("connectionCache");
      f.setAccessible(true);
      //noinspection unchecked
      Cache<String, Connection> connectionCache = (Cache<String, Connection>) f.get(m);
      return connectionCache.getIfPresent(id);
    }
  
    @Test public void testRemoteExecuteMaxRowCount() throws Exception {
      ConnectionSpec.getDatabaseLock().lock();
      try (AvaticaConnection conn = (AvaticaConnection) DriverManager.getConnection(url)) {
        final AvaticaStatement statement = conn.createStatement();
        prepareAndExecuteInternal(conn, statement,
            "select * from (values ('a', 1), ('b', 2))", 0);
        ResultSet rs = statement.getResultSet();
        int count = 0;
        while (rs.next()) {
          count++;
        }
        assertEquals("Check maxRowCount=0 and ResultSets is 0 row", count, 0);
        assertEquals("Check result set meta is still there",
            rs.getMetaData().getColumnCount(), 2);
        rs.close();
        statement.close();
        conn.close();
      } finally {
        ConnectionSpec.getDatabaseLock().unlock();
      }
    }
  
    /** Test case for
     * <a href="https://issues.apache.org/jira/browse/CALCITE-780">[CALCITE-780]
     * HTTP error 413 when sending a long string to the Avatica server</a>. */
    @Test public void testRemoteExecuteVeryLargeQuery() throws Exception {
      ConnectionSpec.getDatabaseLock().lock();
      try {
        // Before the bug was fixed, a value over 7998 caused an HTTP 413.
        // 16K bytes, I guess.
        checkLargeQuery(8);
        checkLargeQuery(240);
        checkLargeQuery(8000);
        checkLargeQuery(240000);
      } finally {
        ConnectionSpec.getDatabaseLock().unlock();
      }
    }
  
    private void checkLargeQuery(int n) throws Exception {
      try (AvaticaConnection conn = (AvaticaConnection) DriverManager.getConnection(url)) {
        final AvaticaStatement statement = conn.createStatement();
        final String frenchDisko = "It said human existence is pointless\n"
            + "As acts of rebellious solidarity\n"
            + "Can bring sense in this world\n"
            + "La resistance!\n";
        final String sql = "select '"
            + longString(frenchDisko, n)
            + "' as s from (values 'x')";
        prepareAndExecuteInternal(conn, statement, sql, -1);
        ResultSet rs = statement.getResultSet();
        int count = 0;
        while (rs.next()) {
          count++;
        }
        assertThat(count, is(1));
        rs.close();
        statement.close();
        conn.close();
      }
    }
  
    /** Creates a string of exactly {@code length} characters by concatenating
     * {@code fragment}. */
    private static String longString(String fragment, int length) {
      assert fragment.length() > 0;
      final StringBuilder buf = new StringBuilder();
      while (buf.length() < length) {
        buf.append(fragment);
      }
      buf.setLength(length);
      return buf.toString();
    }
  
    @Test public void testRemoteConnectionProperties() throws Exception {
      ConnectionSpec.getDatabaseLock().lock();
      try (AvaticaConnection conn = (AvaticaConnection) DriverManager.getConnection(url)) {
        String id = conn.id;
        final Map<String, ConnectionPropertiesImpl> m = ((RemoteMeta) getMeta(conn)).propsMap;
        assertFalse("remote connection map should start ignorant", m.containsKey(id));
        // force creating a connection object on the remote side.
        try (Statement stmt = conn.createStatement()) {
          assertTrue("creating a statement starts a local object.", m.containsKey(id));
          assertTrue(stmt.execute("select count(1) from EMP"));
        }
        Connection remoteConn = getConnection(FullyRemoteJdbcMetaFactory.getInstance(), id);
        final boolean defaultRO = remoteConn.isReadOnly();
        final boolean defaultAutoCommit = remoteConn.getAutoCommit();
        final String defaultCatalog = remoteConn.getCatalog();
        final String defaultSchema = remoteConn.getSchema();
        conn.setReadOnly(!defaultRO);
        assertTrue("local changes dirty local state", m.get(id).isDirty());
        assertEquals("remote connection has not been touched", defaultRO, remoteConn.isReadOnly());
        conn.setAutoCommit(!defaultAutoCommit);
        assertEquals("remote connection has not been touched",
            defaultAutoCommit, remoteConn.getAutoCommit());
  
        // further interaction with the connection will force a sync
        try (Statement stmt = conn.createStatement()) {
          assertEquals(!defaultAutoCommit, remoteConn.getAutoCommit());
          assertFalse("local values should be clean", m.get(id).isDirty());
        }
      } finally {
        ConnectionSpec.getDatabaseLock().unlock();
      }
    }
  
    @Test public void testQuery() throws Exception {
      ConnectionSpec.getDatabaseLock().lock();
      try (AvaticaConnection conn = (AvaticaConnection) DriverManager.getConnection(url);
          Statement statement = conn.createStatement()) {
        assertFalse(statement.execute("SET SCHEMA \"SCOTT\""));
        assertFalse(
            statement.execute(
                "CREATE TABLE \"FOO\"(\"KEY\" INTEGER NOT NULL, \"VALUE\" VARCHAR(10))"));
        assertFalse(statement.execute("SET TABLE \"FOO\" READONLY FALSE"));
  
        final int numRecords = 1000;
        for (int i = 0; i < numRecords; i++) {
          assertFalse(statement.execute("INSERT INTO \"FOO\" VALUES(" + i + ", '" + i + "')"));
        }
  
        // Make sure all the records are there that we expect
        ResultSet results = statement.executeQuery("SELECT count(KEY) FROM FOO");
        assertTrue(results.next());
        assertEquals(1000, results.getInt(1));
        assertFalse(results.next());
  
        results = statement.executeQuery("SELECT KEY, VALUE FROM FOO ORDER BY KEY ASC");
        for (int i = 0; i < numRecords; i++) {
          assertTrue(results.next());
          assertEquals(i, results.getInt(1));
          assertEquals(Integer.toString(i), results.getString(2));
        }
      } finally {
        ConnectionSpec.getDatabaseLock().unlock();
      }
    }
  
    @Test public void testSingleUrlParsing() throws Exception {
      AlternatingDriver d = new AlternatingDriver();
      List<URL> urls = d.parseUrls("http://localhost:1234");
      assertEquals(Arrays.asList(new URI("http://localhost:1234").toURL()), urls);
    }
  
    @Test public void testMultipleUrlParsing() throws Exception {
      AlternatingDriver d = new AlternatingDriver();
      List<URL> urls = d.parseUrls("http://localhost:1234,http://localhost:2345,"
          + "http://localhost:3456");
      List<URL> expectedUrls = Arrays.asList(new URI("http://localhost:1234").toURL(),
          new URI("http://localhost:2345").toURL(), new URI("http://localhost:3456").toURL());
      assertEquals(expectedUrls, urls);
    }
  }
  
  // End AlternatingRemoteMetaTest.java
  