[CARBONDATA-3305] Added DDL to drop cache for a table

Added CarbonDropCacheCommand to drop all cache entries for a particular table.

usage: DROP METACACHE ON TABLE tableName
Dropping cache for child table is not supported, the table has to be parent table.
Running the above command will clear all the entries belonging to the table,
its index entries, its datamap entries and it's forward and reverse dictionary.

This closes #3138

core/src/main/java/org/apache/carbondata/core/cache/CarbonLRUCache.java

@@ -62,10 +62,13 @@ public final class CarbonLRUCache {
    */
   public CarbonLRUCache(String propertyName, String defaultPropertyName) {
     try {
-      lruCacheMemorySize = Integer
-          .parseInt(CarbonProperties.getInstance().getProperty(propertyName, defaultPropertyName));
+      lruCacheMemorySize = Long
+          .parseLong(CarbonProperties.getInstance().getProperty(propertyName, defaultPropertyName));
     } catch (NumberFormatException e) {
-      lruCacheMemorySize = Integer.parseInt(defaultPropertyName);
+      LOGGER.error(CarbonCommonConstants.CARBON_MAX_DRIVER_LRU_CACHE_SIZE
+          + " is not in a valid format. Falling back to default value: "
+          + CarbonCommonConstants.CARBON_MAX_LRU_CACHE_SIZE_DEFAULT);
+      lruCacheMemorySize = Long.parseLong(defaultPropertyName);
     }
     initCache();
     if (lruCacheMemorySize > 0) {
@@ -148,6 +151,17 @@ public void remove(String key) {
     }
   }
 
+  /**
+   * @param keys
+   */
+  public void removeAll(List<String> keys) {
+    synchronized (lruCacheMap) {
+      for (String key : keys) {
+        removeKey(key);
+      }
+    }
+  }
+
   /**
    * This method will remove the key from lru cache
    *
@@ -302,6 +316,9 @@ public Cacheable get(String key) {
    */
   public void clear() {
     synchronized (lruCacheMap) {
+      for (Cacheable cachebleObj : lruCacheMap.values()) {
+        cachebleObj.invalidate();
+      }
       lruCacheMap.clear();
     }
   }

docs/ddl-of-carbondata.md

@@ -1095,18 +1095,27 @@ Users can specify which columns to include and exclude for local dictionary gene
   about current cache used status in memory through the following command:
 
   ```sql
-  SHOW METADATA
+  SHOW METACACHE
   ``` 
 
   This shows the overall memory consumed in the cache by categories - index files, dictionary and 
   datamaps. This also shows the cache usage by all the tables and children tables in the current 
   database.
 
   ```sql
-  SHOW METADATA ON TABLE tableName
+  SHOW METACACHE ON TABLE tableName
   ```
 
   This shows detailed information on cache usage by the table `tableName` and its carbonindex files, 
   its dictionary files, its datamaps and children tables.
 
   This command is not allowed on child tables.
+
+  ```sql
+    DROP METACACHE ON TABLE tableName
+   ```
+
+  This clears any entry in cache by the table `tableName`, its carbonindex files, 
+  its dictionary files, its datamaps and children tables.
+
+  This command is not allowed on child tables.

integration/spark-common-test/src/test/scala/org/apache/carbondata/sql/commands/TestCarbonDropCacheCommand.scala

@@ -0,0 +1,200 @@
+/*
+ * 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.carbondata.sql.commands
+
+import java.util
+
+import scala.collection.JavaConverters._
+
+import org.apache.spark.sql.CarbonEnv
+import org.apache.spark.sql.catalyst.TableIdentifier
+import org.apache.spark.sql.catalyst.analysis.NoSuchTableException
+import org.apache.spark.sql.test.util.QueryTest
+import org.scalatest.BeforeAndAfterAll
+import org.apache.carbondata.core.cache.CacheProvider
+import org.apache.carbondata.core.constants.CarbonCommonConstants
+
+class TestCarbonDropCacheCommand extends QueryTest with BeforeAndAfterAll {
+
+  val dbName = "cache_db"
+
+  override protected def beforeAll(): Unit = {
+    sql(s"DROP DATABASE IF EXISTS $dbName CASCADE")
+    sql(s"CREATE DATABASE $dbName")
+    sql(s"USE $dbName")
+  }
+
+  override protected def afterAll(): Unit = {
+    sql(s"use default")
+    sql(s"DROP DATABASE $dbName CASCADE")
+  }
+
+
+  test("Test dictionary") {
+    val tableName = "t1"
+
+    sql(s"CREATE TABLE $tableName(empno int, empname String, designation String, " +
+        s"doj Timestamp, workgroupcategory int, workgroupcategoryname String, deptno int, " +
+        s"deptname String, projectcode int, projectjoindate Timestamp, projectenddate Timestamp," +
+        s"attendance int,utilization int, salary int) stored by 'carbondata' " +
+        s"TBLPROPERTIES('DICTIONARY_INCLUDE'='designation, workgroupcategoryname')")
+    sql(s"LOAD DATA INPATH '$resourcesPath/data.csv' INTO TABLE $tableName")
+    sql(s"LOAD DATA INPATH '$resourcesPath/data.csv' INTO TABLE $tableName")
+    sql(s"SELECT * FROM $tableName").collect()
+
+    val droppedCacheKeys = clone(CacheProvider.getInstance().getCarbonCache.getCacheMap.keySet())
+
+    sql(s"DROP METACACHE ON TABLE $tableName")
+
+    val cacheAfterDrop = clone(CacheProvider.getInstance().getCarbonCache.getCacheMap.keySet())
+    droppedCacheKeys.removeAll(cacheAfterDrop)
+
+    val tableIdentifier = new TableIdentifier(tableName, Some(dbName))
+    val carbonTable = CarbonEnv.getCarbonTable(tableIdentifier)(sqlContext.sparkSession)
+    val tablePath = carbonTable.getTablePath + CarbonCommonConstants.FILE_SEPARATOR
+    val dictIds = carbonTable.getAllDimensions.asScala.filter(_.isGlobalDictionaryEncoding)
+      .map(_.getColumnId).toArray
+
+    // Check if table index entries are dropped
+    assert(droppedCacheKeys.asScala.exists(key => key.startsWith(tablePath)))
+
+    // check if cache does not have any more table index entries
+    assert(!cacheAfterDrop.asScala.exists(key => key.startsWith(tablePath)))
+
+    // check if table dictionary entries are dropped
+    for (dictId <- dictIds) {
+      assert(droppedCacheKeys.asScala.exists(key => key.contains(dictId)))
+    }
+
+    // check if cache does not have any more table dictionary entries
+    for (dictId <- dictIds) {
+      assert(!cacheAfterDrop.asScala.exists(key => key.contains(dictId)))
+    }
+  }
+
+
+  test("Test preaggregate datamap") {
+    val tableName = "t2"
+
+    sql(s"CREATE TABLE $tableName(empno int, empname String, designation String, " +
+        s"doj Timestamp, workgroupcategory int, workgroupcategoryname String, deptno int, " +
+        s"deptname String, projectcode int, projectjoindate Timestamp, projectenddate Timestamp," +
+        s"attendance int, utilization int, salary int) stored by 'carbondata'")
+    sql(s"CREATE DATAMAP dpagg ON TABLE $tableName USING 'preaggregate' AS " +
+        s"SELECT AVG(salary), workgroupcategoryname from $tableName GROUP BY workgroupcategoryname")
+    sql(s"LOAD DATA INPATH '$resourcesPath/data.csv' INTO TABLE $tableName")
+    sql(s"SELECT * FROM $tableName").collect()
+    sql(s"SELECT AVG(salary), workgroupcategoryname from $tableName " +
+        s"GROUP BY workgroupcategoryname").collect()
+    val droppedCacheKeys = clone(CacheProvider.getInstance().getCarbonCache.getCacheMap.keySet())
+
+    sql(s"DROP METACACHE ON TABLE $tableName")
+
+    val cacheAfterDrop = clone(CacheProvider.getInstance().getCarbonCache.getCacheMap.keySet())
+    droppedCacheKeys.removeAll(cacheAfterDrop)
+
+    val tableIdentifier = new TableIdentifier(tableName, Some(dbName))
+    val carbonTable = CarbonEnv.getCarbonTable(tableIdentifier)(sqlContext.sparkSession)
+    val dbPath = CarbonEnv
+      .getDatabaseLocation(tableIdentifier.database.get, sqlContext.sparkSession)
+    val tablePath = carbonTable.getTablePath
+    val preaggPath = dbPath + CarbonCommonConstants.FILE_SEPARATOR + carbonTable.getTableName +
+                     "_" + carbonTable.getTableInfo.getDataMapSchemaList.get(0).getDataMapName +
+                     CarbonCommonConstants.FILE_SEPARATOR
+
+    // Check if table index entries are dropped
+    assert(droppedCacheKeys.asScala.exists(key => key.startsWith(tablePath)))
+
+    // check if cache does not have any more table index entries
+    assert(!cacheAfterDrop.asScala.exists(key => key.startsWith(tablePath)))
+
+    // Check if preaggregate index entries are dropped
+    assert(droppedCacheKeys.asScala.exists(key => key.startsWith(preaggPath)))
+
+    // check if cache does not have any more preaggregate index entries
+    assert(!cacheAfterDrop.asScala.exists(key => key.startsWith(preaggPath)))
+  }
+
+
+  test("Test bloom filter") {
+    val tableName = "t3"
+
+    sql(s"CREATE TABLE $tableName(empno int, empname String, designation String, " +
+        s"doj Timestamp, workgroupcategory int, workgroupcategoryname String, deptno int, " +
+        s"deptname String, projectcode int, projectjoindate Timestamp, projectenddate Timestamp," +
+        s"attendance int, utilization int, salary int) stored by 'carbondata'")
+    sql(s"CREATE DATAMAP dblom ON TABLE $tableName USING 'bloomfilter' " +
+        "DMPROPERTIES('INDEX_COLUMNS'='deptno')")
+    sql(s"LOAD DATA INPATH '$resourcesPath/data.csv' INTO TABLE $tableName")
+    sql(s"SELECT * FROM $tableName").collect()
+    sql(s"SELECT * FROM $tableName WHERE deptno=10").collect()
+
+    val droppedCacheKeys = clone(CacheProvider.getInstance().getCarbonCache.getCacheMap.keySet())
+
+    sql(s"DROP METACACHE ON TABLE $tableName")
+
+    val cacheAfterDrop = clone(CacheProvider.getInstance().getCarbonCache.getCacheMap.keySet())
+    droppedCacheKeys.removeAll(cacheAfterDrop)
+
+    val tableIdentifier = new TableIdentifier(tableName, Some(dbName))
+    val carbonTable = CarbonEnv.getCarbonTable(tableIdentifier)(sqlContext.sparkSession)
+    val tablePath = carbonTable.getTablePath
+    val bloomPath = tablePath + CarbonCommonConstants.FILE_SEPARATOR + "dblom" +
+                    CarbonCommonConstants.FILE_SEPARATOR
+
+    // Check if table index entries are dropped
+    assert(droppedCacheKeys.asScala.exists(key => key.startsWith(tablePath)))
+
+    // check if cache does not have any more table index entries
+    assert(!cacheAfterDrop.asScala.exists(key => key.startsWith(tablePath)))
+
+    // Check if bloom entries are dropped
+    assert(droppedCacheKeys.asScala.exists(key => key.contains(bloomPath)))
+
+    // check if cache does not have any more bloom entries
+    assert(!cacheAfterDrop.asScala.exists(key => key.contains(bloomPath)))
+  }
+
+
+  test("Test preaggregate datamap fail") {
+    val tableName = "t4"
+
+    sql(s"CREATE TABLE $tableName(empno int, empname String, designation String, " +
+        s"doj Timestamp, workgroupcategory int, workgroupcategoryname String, deptno int, " +
+        s"deptname String, projectcode int, projectjoindate Timestamp, projectenddate Timestamp," +
+        s"attendance int, utilization int, salary int) stored by 'carbondata'")
+    sql(s"CREATE DATAMAP dpagg ON TABLE $tableName USING 'preaggregate' AS " +
+        s"SELECT AVG(salary), workgroupcategoryname from $tableName GROUP BY workgroupcategoryname")
+    sql(s"LOAD DATA INPATH '$resourcesPath/data.csv' INTO TABLE $tableName")
+    sql(s"SELECT * FROM $tableName").collect()
+    sql(s"SELECT AVG(salary), workgroupcategoryname from $tableName " +
+        s"GROUP BY workgroupcategoryname").collect()
+
+    val fail_message = intercept[UnsupportedOperationException] {
+      sql(s"DROP METACACHE ON TABLE ${tableName}_dpagg")
+    }.getMessage
+    assert(fail_message.contains("Operation not allowed on child table."))
+  }
+
+
+  def clone(oldSet: util.Set[String]): util.HashSet[String] = {
+    val newSet = new util.HashSet[String]
+    newSet.addAll(oldSet)
+    newSet
+  }
+}

integration/spark-common-test/src/test/scala/org/apache/carbondata/sql/commands/TestCarbonShowCacheCommand.scala

@@ -128,7 +128,7 @@ class TestCarbonShowCacheCommand extends QueryTest with BeforeAndAfterAll {
     sql("use cache_empty_db").collect()
     val result1 = sql("show metacache").collect()
     assertResult(2)(result1.length)
-    assertResult(Row("cache_empty_db", "ALL", "0", "0", "0"))(result1(1))
+    assertResult(Row("cache_empty_db", "ALL", "0 bytes", "0 bytes", "0 bytes"))(result1(1))
 
     sql("use cache_db").collect()
     val result2 = sql("show metacache").collect()

integration/spark-common/src/main/scala/org/apache/carbondata/events/DropCacheEvents.scala

@@ -0,0 +1,28 @@
+/*
+ * 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.carbondata.events
+
+import org.apache.spark.sql.SparkSession
+
+import org.apache.carbondata.core.metadata.schema.table.CarbonTable
+
+case class DropCacheEvent(
+    carbonTable: CarbonTable,
+    sparkSession: SparkSession,
+    internalCall: Boolean)
+  extends Event with DropCacheEventInfo

integration/spark-common/src/main/scala/org/apache/carbondata/events/Events.scala

@@ -62,6 +62,13 @@ trait DropTableEventInfo {
   val ifExistsSet: Boolean
 }
 
+/**
+ * event for drop cache
+ */
+trait DropCacheEventInfo {
+  val carbonTable: CarbonTable
+}
+
 /**
  * event for alter_table_drop_column
  */

integration/spark2/src/main/scala/org/apache/spark/sql/CarbonEnv.scala

@@ -23,6 +23,7 @@ import org.apache.spark.sql.catalyst.TableIdentifier
 import org.apache.spark.sql.catalyst.analysis.NoSuchTableException
 import org.apache.spark.sql.catalyst.catalog.SessionCatalog
 import org.apache.spark.sql.events.{MergeBloomIndexEventListener, MergeIndexEventListener}
+import org.apache.spark.sql.execution.command.cache.DropCachePreAggEventListener
 import org.apache.spark.sql.execution.command.preaaggregate._
 import org.apache.spark.sql.execution.command.timeseries.TimeSeriesFunction
 import org.apache.spark.sql.hive._
@@ -185,6 +186,7 @@ object CarbonEnv {
       .addListener(classOf[AlterTableCompactionPostEvent], new MergeIndexEventListener)
       .addListener(classOf[AlterTableMergeIndexEvent], new MergeIndexEventListener)
       .addListener(classOf[BuildDataMapPostExecutionEvent], new MergeBloomIndexEventListener)
+      .addListener(classOf[DropCacheEvent], DropCachePreAggEventListener)
   }
 
   /**