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.cassandra.cql3.terms;
  
  import static org.apache.cassandra.cql3.terms.Constants.UNSET_VALUE;
  
  import java.nio.ByteBuffer;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  import java.util.Objects;
  import java.util.Optional;
  import java.util.Set;
  import java.util.stream.Collectors;
  import java.util.stream.StreamSupport;
  
  import org.apache.cassandra.cql3.AssignmentTestable;
  import org.apache.cassandra.cql3.ColumnIdentifier;
  import org.apache.cassandra.cql3.ColumnSpecification;
  import org.apache.cassandra.cql3.Operation;
  import org.apache.cassandra.cql3.QueryOptions;
  import org.apache.cassandra.cql3.UpdateParameters;
  import org.apache.cassandra.db.DecoratedKey;
  import org.apache.cassandra.db.guardrails.Guardrails;
  import org.apache.cassandra.db.marshal.AbstractType;
  import org.apache.cassandra.db.marshal.MapType;
  import org.apache.cassandra.db.marshal.MultiElementType;
  import org.apache.cassandra.db.marshal.SetType;
  import org.apache.cassandra.db.rows.Cell;
  import org.apache.cassandra.db.rows.CellPath;
  import org.apache.cassandra.exceptions.InvalidRequestException;
  import org.apache.cassandra.schema.ColumnMetadata;
  import org.apache.cassandra.utils.ByteBufferUtil;
  
  /**
   * Static helper methods and classes for sets.
   */
  public final class Sets
  {
      private Sets() {}
  
      public static ColumnSpecification valueSpecOf(ColumnSpecification column)
      {
          return new ColumnSpecification(column.ksName, column.cfName, new ColumnIdentifier("value(" + column.name + ')', true), elementsType(column.type));
      }
  
      private static AbstractType<?> elementsType(AbstractType<?> type)
      {
          return ((SetType<?>) type.unwrap()).getElementsType();
      }
  
      /**
       * Tests that the set with the specified elements can be assigned to the specified column.
       *
       * @param receiver the receiving column
       * @param elements the set elements
       */
      public static AssignmentTestable.TestResult testSetAssignment(ColumnSpecification receiver,
                                                                    List<? extends AssignmentTestable> elements)
      {
          if (!(receiver.type instanceof SetType))
          {
              // We've parsed empty maps as a set literal to break the ambiguity so handle that case now
              if (receiver.type instanceof MapType && elements.isEmpty())
                  return AssignmentTestable.TestResult.WEAKLY_ASSIGNABLE;
  
              return AssignmentTestable.TestResult.NOT_ASSIGNABLE;
          }
  
          // If there is no elements, we can't say it's an exact match (an empty set if fundamentally polymorphic).
          if (elements.isEmpty())
              return AssignmentTestable.TestResult.WEAKLY_ASSIGNABLE;
  
          ColumnSpecification valueSpec = valueSpecOf(receiver);
          return AssignmentTestable.TestResult.testAll(receiver.ksName, valueSpec, elements);
      }
  
      /**
       * Create a <code>String</code> representation of the set containing the specified elements.
       *
       * @param elements the set elements
       * @return a <code>String</code> representation of the set
       */
      public static String setToString(List<?> elements)
      {
          return setToString(elements, Object::toString);
      }
  
      /**
       * Create a <code>String</code> representation of the set from the specified items associated to
       * the set elements.
       *
       * @param items items associated to the set elements
       * @param mapper the mapper used to map the items to the <code>String</code> representation of the set elements
       * @return a <code>String</code> representation of the set
       */
      public static <T> String setToString(Iterable<T> items, java.util.function.Function<T, String> mapper)
      {
          return StreamSupport.stream(items.spliterator(), false)
                              .map(mapper)
                              .collect(Collectors.joining(", ", "{", "}"));
      }
  
      /**
       * Returns the exact SetType from the items if it can be known.
       *
       * @param items the items mapped to the set elements
       * @param mapper the mapper used to retrieve the element types from the items
       * @return the exact SetType from the items if it can be known or <code>null</code>
       */
      public static <T> SetType<?> getExactSetTypeIfKnown(List<T> items,
                                                          java.util.function.Function<T, AbstractType<?>> mapper)
      {
          Optional<AbstractType<?>> type = items.stream().map(mapper).filter(Objects::nonNull).findFirst();
          return type.isPresent() ? SetType.getInstance(type.get(), false) : null;
      }
  
      public static <T> SetType<?> getPreferredCompatibleType(List<T> items,
                                                              java.util.function.Function<T, AbstractType<?>> mapper)
      {
          Set<AbstractType<?>> types = items.stream().map(mapper).filter(Objects::nonNull).collect(Collectors.toSet());
          AbstractType<?> type = AssignmentTestable.getCompatibleTypeIfKnown(types);
          return type == null ? null : SetType.getInstance(type, false);
      }
  
      public static class Literal extends Term.Raw
      {
          private final List<Term.Raw> elements;
  
          public Literal(List<Term.Raw> elements)
          {
              this.elements = elements;
          }
  
          public Term prepare(String keyspace, ColumnSpecification receiver) throws InvalidRequestException
          {
              validateAssignableTo(keyspace, receiver);
  
              // We've parsed empty maps as a set literal to break the ambiguity so
              // handle that case now
              if (receiver.type instanceof MapType && elements.isEmpty())
                  return new MultiElements.Value(((MapType<?, ?>) receiver.type), Collections.emptyList());
  
              ColumnSpecification valueSpec = Sets.valueSpecOf(receiver);
              List<Term> values = new ArrayList<>(elements.size());
              boolean allTerminal = true;
              for (Term.Raw rt : elements)
              {
                  Term t = rt.prepare(keyspace, valueSpec);
  
                  if (t.containsBindMarker())
                      throw new InvalidRequestException(String.format("Invalid set literal for %s: bind variables are not supported inside collection literals", receiver.name));
  
                  if (t instanceof Term.NonTerminal)
                      allTerminal = false;
  
                  values.add(t);
              }
              MultiElements.DelayedValue value = new MultiElements.DelayedValue((MultiElementType<?>) receiver.type.unwrap(), values);
              return allTerminal ? value.bind(QueryOptions.DEFAULT) : value;
          }
  
          private void validateAssignableTo(String keyspace, ColumnSpecification receiver) throws InvalidRequestException
          {
              AbstractType<?> type = receiver.type.unwrap();
  
              if (!(type instanceof SetType))
              {
                  // We've parsed empty maps as a set literal to break the ambiguity so
                  // handle that case now
                  if ((type instanceof MapType) && elements.isEmpty())
                      return;
  
                  throw new InvalidRequestException(String.format("Invalid set literal for %s of type %s", receiver.name, receiver.type.asCQL3Type()));
              }
  
              ColumnSpecification valueSpec = Sets.valueSpecOf(receiver);
              for (Term.Raw rt : elements)
              {
                  if (!rt.testAssignment(keyspace, valueSpec).isAssignable())
                      throw new InvalidRequestException(String.format("Invalid set literal for %s: value %s is not of type %s", receiver.name, rt, valueSpec.type.asCQL3Type()));
              }
          }
  
          public AssignmentTestable.TestResult testAssignment(String keyspace, ColumnSpecification receiver)
          {
              return testSetAssignment(receiver, elements);
          }
  
          @Override
          public AbstractType<?> getExactTypeIfKnown(String keyspace)
          {
              return getExactSetTypeIfKnown(elements, p -> p.getExactTypeIfKnown(keyspace));
          }
  
          @Override
          public AbstractType<?> getCompatibleTypeIfKnown(String keyspace)
          {
              return Sets.getPreferredCompatibleType(elements, p -> p.getCompatibleTypeIfKnown(keyspace));
          }
  
          public String getText()
          {
              return setToString(elements, Term.Raw::getText);
          }
      }
  
      public static class Setter extends Operation
      {
          public Setter(ColumnMetadata column, Term t)
          {
              super(column, t);
          }
  
          public void execute(DecoratedKey partitionKey, UpdateParameters params) throws InvalidRequestException
          {
              Term.Terminal value = t.bind(params.options);
              if (value == UNSET_VALUE)
                  return;
  
              // delete + add
              if (column.type.isMultiCell())
                  params.setComplexDeletionTimeForOverwrite(column);
              Adder.doAdd(value, column, params);
          }
      }
  
      public static class Adder extends Operation
      {
          public Adder(ColumnMetadata column, Term t)
          {
              super(column, t);
          }
  
          public void execute(DecoratedKey partitionKey, UpdateParameters params) throws InvalidRequestException
          {
              assert column.type.isMultiCell() : "Attempted to add items to a frozen set";
              Term.Terminal value = t.bind(params.options);
              if (value != UNSET_VALUE)
                  doAdd(value, column, params);
          }
  
          static void doAdd(Term.Terminal value, ColumnMetadata column, UpdateParameters params) throws InvalidRequestException
          {
              SetType<?> type = (SetType<?>) column.type;
  
              if (value == null)
              {
                  // for frozen sets, we're overwriting the whole cell
                  if (!type.isMultiCell())
                      params.addTombstone(column);
  
                  return;
              }
  
              List<ByteBuffer> elements = value.getElements();
  
              if (type.isMultiCell())
              {
                  if (elements.isEmpty())
                      return;
  
                  // Guardrails about collection size are only checked for the added elements without considering
                  // already existent elements. This is done so to avoid read-before-write, having additional checks
                  // during SSTable write.
                  Guardrails.itemsPerCollection.guard(type.collectionSize(elements), column.name.toString(), false, params.clientState);
  
                  int dataSize = 0;
                  for (ByteBuffer bb : elements)
                  {
                      if (bb == ByteBufferUtil.UNSET_BYTE_BUFFER)
                          continue;
  
                      Cell<?> cell = params.addCell(column, CellPath.create(bb), ByteBufferUtil.EMPTY_BYTE_BUFFER);
                      dataSize += cell.dataSize();
                  }
                  Guardrails.collectionSetSize.guard(dataSize, column.name.toString(), false, params.clientState);
              }
              else
              {
                  Guardrails.itemsPerCollection.guard(type.collectionSize(elements), column.name.toString(), false, params.clientState);
                  Cell<?> cell = params.addCell(column, value.get());
                  Guardrails.collectionSetSize.guard(cell.dataSize(), column.name.toString(), false, params.clientState);
              }
          }
      }
  
      // Note that this is reused for Map subtraction too (we subtract a set from a map)
      public static class Discarder extends Operation
      {
          public Discarder(ColumnMetadata column, Term t)
          {
              super(column, t);
          }
  
          public void execute(DecoratedKey partitionKey, UpdateParameters params) throws InvalidRequestException
          {
              assert column.type.isMultiCell() : "Attempted to remove items from a frozen set";
  
              Term.Terminal value = t.bind(params.options);
              if (value == null || value == UNSET_VALUE)
                  return;
  
              // This can be either a set or a single element
              List<ByteBuffer> toDiscard = value.getElements();
  
              for (ByteBuffer bb : toDiscard)
                  params.addTombstone(column, CellPath.create(bb));
          }
      }
  
      public static class ElementDiscarder extends Operation
      {
          public ElementDiscarder(ColumnMetadata column, Term k)
          {
              super(column, k);
          }
  
          public void execute(DecoratedKey partitionKey, UpdateParameters params) throws InvalidRequestException
          {
              assert column.type.isMultiCell() : "Attempted to delete a single element in a frozen set";
              Term.Terminal elt = t.bind(params.options);
              if (elt == null)
                  throw new InvalidRequestException("Invalid null set element");
  
              params.addTombstone(column, CellPath.create(elt.get()));
          }
      }
  }
  