AbstractComposite.java

package me.prettyprint.hector.api.beans;

import static me.prettyprint.hector.api.ddl.ComparatorType.ASCIITYPE;
import static me.prettyprint.hector.api.ddl.ComparatorType.BYTESTYPE;
import static me.prettyprint.hector.api.ddl.ComparatorType.INTEGERTYPE;
import static me.prettyprint.hector.api.ddl.ComparatorType.LEXICALUUIDTYPE;
import static me.prettyprint.hector.api.ddl.ComparatorType.LONGTYPE;
import static me.prettyprint.hector.api.ddl.ComparatorType.TIMEUUIDTYPE;
import static me.prettyprint.hector.api.ddl.ComparatorType.UTF8TYPE;
import static me.prettyprint.hector.api.ddl.ComparatorType.UUIDTYPE;
import static me.prettyprint.hector.api.ddl.ComparatorType.FLOATTYPE;

import java.math.BigInteger;
import java.nio.ByteBuffer;
import java.nio.charset.CharacterCodingException;
import java.util.AbstractList;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import me.prettyprint.cassandra.serializers.AsciiSerializer;
import me.prettyprint.cassandra.serializers.BigIntegerSerializer;
import me.prettyprint.cassandra.serializers.ByteBufferSerializer;
import me.prettyprint.cassandra.serializers.LongSerializer;
import me.prettyprint.cassandra.serializers.SerializerTypeInferer;
import me.prettyprint.cassandra.serializers.StringSerializer;
import me.prettyprint.cassandra.serializers.UUIDSerializer;
import me.prettyprint.cassandra.serializers.FloatSerializer;
import me.prettyprint.cassandra.utils.ByteBufferOutputStream;
import me.prettyprint.hector.api.Serializer;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.Charsets;
import com.google.common.collect.BiMap;
import com.google.common.collect.ImmutableBiMap;
import com.google.common.collect.ImmutableClassToInstanceMap;

/**
 * Parent class of Composite and DynamicComposite. Acts as a list of objects
 * that get serialized into a composite column name. Unless
 * setAutoDeserialize(true) is called, it's going to try to match serializers to
 * Cassandra comparator types.
 * 
 * @author edanuff
 */
@SuppressWarnings("rawtypes")
public abstract class AbstractComposite extends AbstractList<Object> implements
    Comparable<AbstractComposite> {

  public static Logger log = LoggerFactory.getLogger(AbstractComposite.class);

  public enum ComponentEquality {
    LESS_THAN_EQUAL((byte) -1), EQUAL((byte) 0), GREATER_THAN_EQUAL((byte) 1);

    private final byte equality;

    ComponentEquality(byte equality) {
      this.equality = equality;
    }

    public byte toByte() {
      return equality;
    }

    public static ComponentEquality fromByte(byte equality) {
      if (equality > 0) {
        return GREATER_THAN_EQUAL;
      }
      if (equality < 0) {
        return LESS_THAN_EQUAL;
      }
      return EQUAL;
    }
  }

  public static final BiMap<Class<? extends Serializer>, String> DEFAULT_SERIALIZER_TO_COMPARATOR_MAPPING = new ImmutableBiMap.Builder<Class<? extends Serializer>, String>()
      .put(AsciiSerializer.class,
          AsciiSerializer.get().getComparatorType().getTypeName())
      .put(BigIntegerSerializer.class,
          BigIntegerSerializer.get().getComparatorType().getTypeName())
      .put(ByteBufferSerializer.class,
          ByteBufferSerializer.get().getComparatorType().getTypeName())
      .put(LongSerializer.class,
          LongSerializer.get().getComparatorType().getTypeName())
      .put(StringSerializer.class,
          StringSerializer.get().getComparatorType().getTypeName())
      .put(FloatSerializer.class,
          FloatSerializer.get().getComparatorType().getTypeName())
      .put(UUIDSerializer.class,
          UUIDSerializer.get().getComparatorType().getTypeName()).build();

  static final ImmutableClassToInstanceMap<Serializer> SERIALIZERS = new ImmutableClassToInstanceMap.Builder<Serializer>()
      .put(AsciiSerializer.class, AsciiSerializer.get())
      .put(BigIntegerSerializer.class, BigIntegerSerializer.get())
      .put(ByteBufferSerializer.class, ByteBufferSerializer.get())
      .put(FloatSerializer.class, FloatSerializer.get())
      .put(LongSerializer.class, LongSerializer.get())
      .put(StringSerializer.class, StringSerializer.get())
      .put(UUIDSerializer.class, UUIDSerializer.get()).build();

  public static final BiMap<Byte, String> DEFAULT_ALIAS_TO_COMPARATOR_MAPPING = new ImmutableBiMap.Builder<Byte, String>()
      .put((byte) 'a', ASCIITYPE.getTypeName())
      .put((byte) 'b', BYTESTYPE.getTypeName())
      .put((byte) 'f', FLOATTYPE.getTypeName())
      .put((byte) 'i', INTEGERTYPE.getTypeName())
      .put((byte) 'x', LEXICALUUIDTYPE.getTypeName())
      .put((byte) 'l', LONGTYPE.getTypeName())
      .put((byte) 't', TIMEUUIDTYPE.getTypeName())
      .put((byte) 's', UTF8TYPE.getTypeName())
      .put((byte) 'u', UUIDTYPE.getTypeName()).build();

  BiMap<Class<? extends Serializer>, String> serializerToComparatorMapping = DEFAULT_SERIALIZER_TO_COMPARATOR_MAPPING;

  BiMap<Byte, String> aliasToComparatorMapping = DEFAULT_ALIAS_TO_COMPARATOR_MAPPING;

  final boolean dynamic;

  List<Serializer<?>> serializersByPosition = null;
  List<String> comparatorsByPosition = null;

  public class Component<T> {
    final Serializer<T> serializer;
    final T value;
    final ByteBuffer bytes;
    final String comparator;
    final ComponentEquality equality;

    public Component(T value, ByteBuffer bytes, Serializer<T> serializer,
        String comparator, ComponentEquality equality) {
      this.serializer = serializer;
      this.value = value;
      this.bytes = bytes;
      this.comparator = comparator;
      this.equality = equality;
    }

    public Serializer<T> getSerializer() {
      return serializer;
    }

    @SuppressWarnings("unchecked")
    public <A> A getValue(Serializer<A> s) {
      if (s == null) {
        s = (Serializer<A>) serializer;
      }
      if ((value == null) && (bytes != null) && (s != null)) {
        ByteBuffer cb = bytes.duplicate();
        return s.fromByteBuffer(cb);
      }
      if (value instanceof ByteBuffer) {
        return (A) ((ByteBuffer) value).duplicate();
      }
      return (A) value;
    }

    public T getValue() {
      return getValue(serializer);
    }

    @SuppressWarnings("unchecked")
    public <A> ByteBuffer getBytes(Serializer<A> s) {
      if (bytes == null) {
        if (value instanceof ByteBuffer) {
          return ((ByteBuffer) value).duplicate();
        }

        if (value == null) {
          return null;
        }

        if (s == null) {
          s = (Serializer<A>) serializer;
        }
        if (s != null) {
          return s.toByteBuffer((A) value).duplicate();
        }

      }

      return bytes.duplicate();
    }

    public ByteBuffer getBytes() {
      return getBytes(serializer);
    }

    public String getComparator() {
      return comparator;
    }

    public ComponentEquality getEquality() {
      return equality;
    }

    @Override
    public String toString() {
      return "Component [" + getValue() + "]";
    }
  }

  List<Component<?>> components = new ArrayList<Component<?>>();
  ComponentEquality equality = ComponentEquality.EQUAL;

  ByteBuffer serialized = null;

  public AbstractComposite(boolean dynamic) {
    this.dynamic = dynamic;
  }

  public AbstractComposite(boolean dynamic, Object... o) {
    this.dynamic = dynamic;
    this.addAll(Arrays.asList(o));
  }

  public AbstractComposite(boolean dynamic, List<?> l) {
    this.dynamic = dynamic;
    this.addAll(l);
  }

  public List<Component<?>> getComponents() {
    return components;
  }

  public void setComponents(List<Component<?>> components) {
    serialized = null;
    this.components = components;
  }

  public Map<Class<? extends Serializer>, String> getSerializerToComparatorMapping() {
    return serializerToComparatorMapping;
  }

  public void setSerializerToComparatorMapping(
      Map<Class<? extends Serializer>, String> serializerToComparatorMapping) {
    serialized = null;
    this.serializerToComparatorMapping = new ImmutableBiMap.Builder<Class<? extends Serializer>, String>()
        .putAll(serializerToComparatorMapping).build();
  }

  public Map<Byte, String> getAliasesToComparatorMapping() {
    return aliasToComparatorMapping;
  }

  public void setAliasesToComparatorMapping(
      Map<Byte, String> aliasesToComparatorMapping) {
    serialized = null;
    aliasToComparatorMapping = new ImmutableBiMap.Builder<Byte, String>()
        .putAll(aliasesToComparatorMapping).build();
  }

  public boolean isDynamic() {
    return dynamic;
  }

  public List<Serializer<?>> getSerializersByPosition() {
    return serializersByPosition;
  }

  public void setSerializersByPosition(List<Serializer<?>> serializersByPosition) {
    this.serializersByPosition = serializersByPosition;
  }

  public void setSerializersByPosition(Serializer<?>... serializers) {
    serializersByPosition = Arrays.asList(serializers);
  }

  public void setSerializerByPosition(int index, Serializer<?> s) {
    if (serializersByPosition == null) {
      serializersByPosition = new ArrayList<Serializer<?>>();
    }
    while (serializersByPosition.size() <= index) {
      serializersByPosition.add(null);
    }
    serializersByPosition.set(index, s);
  }

  public List<String> getComparatorsByPosition() {
    return comparatorsByPosition;
  }

  public void setComparatorsByPosition(List<String> comparatorsByPosition) {
    this.comparatorsByPosition = comparatorsByPosition;
  }

  public void setComparatorsByPosition(String... comparators) {
    comparatorsByPosition = Arrays.asList(comparators);
  }

  public void setComparatorByPosition(int index, String c) {
    if (comparatorsByPosition == null) {
      comparatorsByPosition = new ArrayList<String>();
    }
    while (comparatorsByPosition.size() <= index) {
      comparatorsByPosition.add(null);
    }
    comparatorsByPosition.set(index, c);
  }

  @Override
  public int compareTo(AbstractComposite o) {
    return serialize().compareTo(o.serialize());
  }

  private String comparatorForSerializer(Serializer<?> s) {
    String comparator = serializerToComparatorMapping.get(s.getClass());
    if (comparator != null) {
      return comparator;
    }
    return BYTESTYPE.getTypeName();
  }

  private Serializer<?> serializerForComparator(String c) {
    int p = c.indexOf('(');
    if (p >= 0) {
      c = c.substring(0, p);
    }
    if (LEXICALUUIDTYPE.getTypeName().equals(c)
        || TIMEUUIDTYPE.getTypeName().equals(c)) {
      return UUIDSerializer.get();
    }

    Serializer<?> s = SERIALIZERS.getInstance(serializerToComparatorMapping
        .inverse().get(c));
    if (s != null) {
      return s;
    }
    return ByteBufferSerializer.get();
  }

  private Serializer<?> serializerForPosition(int i) {
    if (serializersByPosition == null) {
      return null;
    }
    if (i >= serializersByPosition.size()) {
      return null;
    }
    return serializersByPosition.get(i);
  }

  private Serializer<?> getSerializer(int i, String c) {
    Serializer<?> s = serializerForPosition(i);
    if (s != null) {
      return s;
    }
    return serializerForComparator(c);
  }

  private String comparatorForPosition(int i) {
    if (comparatorsByPosition == null) {
      return null;
    }
    if (i >= comparatorsByPosition.size()) {
      return null;
    }
    return comparatorsByPosition.get(i);
  }

  private String getComparator(int i, ByteBuffer bb) {
    String name = comparatorForPosition(i);
    if (name != null) {
      return name;
    }
    if (!dynamic) {
      if (bb.hasRemaining()) {
        return BYTESTYPE.getTypeName();
      } else {
        return null;
      }
    }
    if (bb.hasRemaining()) {
      try {
        int header = getShortLength(bb);
        if ((header & 0x8000) == 0) {
          
          name = Charsets.UTF_8.newDecoder().decode(getBytes(bb, header).duplicate()).toString();
        } else {
          byte a = (byte) (header & 0xFF);
          name = aliasToComparatorMapping.get(a);
          if (name == null) {
            a = (byte) Character.toLowerCase((char) a);
            name = aliasToComparatorMapping.get(a);
            if (name != null) {
              name += "(reversed=true)";
            }
          }
        }
      } catch (CharacterCodingException e) {
        throw new RuntimeException(e);
      }
    }
    if ((name != null) && (name.length() == 0)) {
      name = null;
    }
    return name;
  }

  @Override
  public void clear() {
    serialized = null;
    components = new ArrayList<Component<?>>();
  }

  @Override
  public int size() {
    return components.size();
  }

  @SuppressWarnings("unchecked")
  public <T> AbstractComposite addComponent(int index, T element, ComponentEquality equality) {
    serialized = null;

    if (element instanceof Component) {
      components.add(index, (Component<?>) element);
      return this;
    }
    
    Serializer s = serializerForPosition(index);
    if (s == null) {
      s = SerializerTypeInferer.getSerializer(element);
    }
    String c = comparatorForPosition(index);
    if (c == null) {
      c = comparatorForSerializer(s);
    }
    components.add(index, new Component(element, null, s, c,
        equality));
    setSerializerByPosition(index, s);
    return this;
  }
    
  public <T> AbstractComposite addComponent(T value, Serializer<T> s) {

    addComponent(value, s, comparatorForSerializer(s));

    return this;

  }

  public <T> AbstractComposite addComponent(T value, Serializer<T> s,
      String comparator) {

    addComponent(value, s, comparator, ComponentEquality.EQUAL);

    return this;

  }

  public <T> AbstractComposite addComponent(T value, Serializer<T> s,
      String comparator, ComponentEquality equality) {

    addComponent(-1, value, s, comparator, equality);

    return this;

  }

  @SuppressWarnings("unchecked")
  public <T> AbstractComposite addComponent(int index, T value,
      Serializer<T> s, String comparator, ComponentEquality equality) {
    serialized = null;

    if (value == null) {
        throw new NullPointerException("Unable able to add null component");
    }
        
    if (index < 0) {
      index = components.size();
    }

    while (components.size() < index) {
      components.add(null);
    }
    components.add(index, new Component(value, null, s, comparator, equality));

    return this;

  }

  private static Object mapIfNumber(Object o) {
    if ((o instanceof Byte) || (o instanceof Integer) || (o instanceof Short)) {
      return BigInteger.valueOf(((Number) o).longValue());
    }
    return o;
  }

  @SuppressWarnings({ "unchecked" })
  private static Collection<?> flatten(Collection<?> c) {
    if (c instanceof AbstractComposite) {
      return ((AbstractComposite) c).getComponents();
    }
    boolean hasCollection = false;
    for (Object o : c) {
      if (o instanceof Collection) {
        hasCollection = true;
        break;
      }
    }
    if (!hasCollection) {
      return c;
    }
    List newList = new ArrayList();
    for (Object o : c) {
      if (o instanceof Collection) {
        newList.addAll(flatten((Collection) o));
      } else {
        newList.add(o);
      }
    }
    return newList;
  }

  /**
   * For education purposes, when addAll is called, it ultimately
   * ends up calling add(int,Object). The call stack using JDK7
   * is the following.
   * 1. addAll
   * 2. AbstractCollection<E>.addAll(Collection<Object>)
   * 3. AbstractList<E>.add(E)
   * 4. AbstractComposite.add(int,Object)
   * 
   * What happens is AbstractList<E>.add(E) does this add(size(),E).
   * Neither java.util.AbstractList or java.util.AbstractCollection 
   * provide storage in the base class. It expects the subclass to
   * provide the storage.
   */
  @Override
  public boolean addAll(Collection<? extends Object> c) {
    return super.addAll(flatten(c));
  }

  @Override
  public boolean containsAll(Collection<?> c) {
    return super.containsAll(flatten(c));
  }

  @Override
  public boolean removeAll(Collection<?> c) {
    return super.removeAll(flatten(c));
  }

  @Override
  public boolean retainAll(Collection<?> c) {
    return super.retainAll(flatten(c));
  }
  
  /**
   * Method is similar to addAll(Collection<? extends Object>) in that
   * it ends up calling AbstractComposite.add(int,Object).
   */
  @Override
  public boolean addAll(int i, Collection<? extends Object> c) {
    return super.addAll(i, flatten(c));
  }
	
	/**
	 * add(int,Object) is the primary method that adds elements
	 * to the list. All other add methods end up here.
	 */
  @Override
  public void add(int index, Object element) {    
    element = mapIfNumber(element);
    addComponent(index, element, ComponentEquality.EQUAL);
  }  

	/**
	 * remove(int) is the primary method that removes elements
	 * from the list. All other remove methods end up calling
	 * AbstractComposite.remove(int).
	 */
  @Override
  public Object remove(int index) {
    serialized = null;
    Component prev = components.remove(index);
    if (prev != null) {
      return prev.getValue();
    }
    return null;
  }

  public <T> AbstractComposite setComponent(int index, T value, Serializer<T> s) {

    setComponent(index, value, s, comparatorForSerializer(s));

    return this;

  }

  public <T> AbstractComposite setComponent(int index, T value,
      Serializer<T> s, String comparator) {

    setComponent(index, value, s, comparator, ComponentEquality.EQUAL);

    return this;

  }

  @SuppressWarnings("unchecked")
  public <T> AbstractComposite setComponent(int index, T value,
      Serializer<T> s, String comparator, ComponentEquality equality) {
    serialized = null;

    while (components.size() <= index) {
      components.add(null);
    }
    components.set(index, new Component(value, null, s, comparator, equality));

    return this;

  }

  @SuppressWarnings("unchecked")
  @Override
  public Object set(int index, Object element) {
    serialized = null;

    if (element instanceof Component) {
      Component prev = components.set(index, (Component<?>) element);
      if (prev != null) {
        return prev.getValue();
      }
      return null;
    }

    element = mapIfNumber(element);
    Serializer s = serializerForPosition(index);
    if (s == null) {
      s = SerializerTypeInferer.getSerializer(element);
    }
    String c = comparatorForPosition(index);
    if (c == null) {
      c = comparatorForSerializer(s);
    }
    Component prev = components.set(index, new Component(element, null, s, c,
        ComponentEquality.EQUAL));
    if (prev != null) {
      return prev.getValue();
    }
    return null;
  }

  @Override
  public Object get(int i) {
    Component c = components.get(i);
    if (c != null) {
      return c.getValue();
    }
    return null;
  }

  public <T> T get(int i, Serializer<T> s) throws ClassCastException {
    T value = null;
    Component<?> c = components.get(i);
    if (c != null) {
      value = c.getValue(s);
    }
    return value;
  }

  public Component getComponent(int i) {
    if (i >= components.size()) {
      return null;
    }
    Component c = components.get(i);
    return c;
  }

  public Iterator<Component<?>> componentsIterator() {
    return components.iterator();
  }

  @SuppressWarnings("unchecked")
  public ByteBuffer serialize() {
    if (serialized != null) {
      return serialized.duplicate();
    }

    ByteBufferOutputStream out = new ByteBufferOutputStream();

    int i = 0;
    for (Component c : components) {
      Serializer<?> s = serializerForPosition(i);
      ByteBuffer cb = c.getBytes(s);
      if (cb == null) {
        cb = ByteBuffer.allocate(0);
      }

      if (dynamic) {
        String comparator = comparatorForPosition(i);
        if (comparator == null) {
          comparator = c.getComparator();
        }
        if (comparator == null) {
          comparator = BYTESTYPE.getTypeName();
        }
        int p = comparator.indexOf("(reversed=true)");
        boolean desc = false;
        if (p >= 0) {
          comparator = comparator.substring(0, p);
          desc = true;
        }
        if (aliasToComparatorMapping.inverse().containsKey(comparator)) {
          byte a = aliasToComparatorMapping.inverse().get(comparator);
          if (desc) {
            a = (byte) Character.toUpperCase((char) a);
          }
          out.writeShort((short) (0x8000 | a));
        } else {
          out.writeShort((short) comparator.length());
          out.write(comparator.getBytes(Charsets.UTF_8));
        }
        // if (comparator.equals(BYTESTYPE.getTypeName()) && (cb.remaining() ==
        // 0)) {
        // log.warn("Writing zero-length BytesType, probably an error");
        // }
      }
      out.writeShort((short) cb.remaining());
      out.write(cb.slice());
      if ((i == (components.size() - 1))
          && (equality != ComponentEquality.EQUAL)) {
        out.write(equality.toByte());
      } else {
        out.write(c.getEquality().toByte());
      }
      i++;
    }

    serialized = out.getByteBuffer();
    return serialized.duplicate();
  }

  @SuppressWarnings("unchecked")
  public void deserialize(ByteBuffer b) {
    serialized = b.duplicate();
    components = new ArrayList<Component<?>>();

    String comparator = null;
    int i = 0;
    while ((comparator = getComparator(i, b)) != null) {
      ByteBuffer data = getWithShortLength(b);
      if (data != null) {
        Serializer<?> s = getSerializer(i, comparator);
        ComponentEquality equality = ComponentEquality.fromByte(b.get());
        components.add(new Component(null, data.slice(), s, comparator,
            equality));
      } else {
        throw new RuntimeException("Missing component data in composite type");
      }
      i++;
    }

  }

  protected static int getShortLength(ByteBuffer bb) {
    int length = (bb.get() & 0xFF) << 8;
    return length | (bb.get() & 0xFF);
  }

  protected static ByteBuffer getBytes(ByteBuffer bb, int length) {
    ByteBuffer copy = bb.duplicate();
    copy.limit(copy.position() + length);
    bb.position(bb.position() + length);
    return copy;
  }

  protected static ByteBuffer getWithShortLength(ByteBuffer bb) {
    int length = getShortLength(bb);
    return getBytes(bb, length);
  }

  public ComponentEquality getEquality() {
    return equality;
  }

  public void setEquality(ComponentEquality equality) {
    serialized = null;
    this.equality = equality;
  }

}