@Override
public int compare(Value v1, Value v2) {
if ((v1 == POSITIVE_INFINITY && v2 == POSITIVE_INFINITY)
|| (v1 == NEGATIVE_INFINITY && v2 == NEGATIVE_INFINITY)) {
return 0;
} else if (v1 == POSITIVE_INFINITY) {
return 1;
} else if (v2 == POSITIVE_INFINITY) {
return -1;
} else if (v1 == NEGATIVE_INFINITY) {
return -1;
} else if (v2 == NEGATIVE_INFINITY) {
return 1;
} else {
Object o1 = v1.getObject();
Object o2 = v2.getObject();
if (o1 instanceof Number && o2 instanceof Number) {
return Numbers.compare((Number) o1, (Number) o2);
} else if (o1 instanceof Number) {
return -1;
} else if (o2 instanceof Number) {
return 1;
} else {
return o1.toString().compareToIgnoreCase(o2.toString());
}
}
}
@Override
public boolean equals(Object obj) {
if (obj instanceof Value) {
final Value other = (Value) obj;
return getObject().equals(other.getObject());
}
return false;
}
/**
* Return the optimized Value of {@code value}.
*
* @param value
* @return the optimized Value
*/
public static Value optimize(Value value) {
if (value.getType() == Type.TAG) {
return Value.wrap(Convert.javaToThrift(value.getObject().toString()));
}
return value;
}
/**
* A Value is an abstraction for a {@link TObject} that records type information and serves as the
* most basic element of data in Concourse. Values are logically sortable using weak typing and
* cannot exceed 2^32 bytes.
*
* <p>
*
* <h2>Storage Requirements</h2>
*
* Each Value requires at least {@value #CONSTANT_SIZE} bytes of space in addition to the following
* type specific requirements:
*
* <ul>
* <li>BOOLEAN requires an additional 1 byte
* <li>DOUBLE requires an additional 8 bytes
* <li>FLOAT requires an additional 4 bytes
* <li>INTEGER requires an additional 4 bytes
* <li>LONG requires an additional 8 bytes
* <li>LINK requires an additional 8 bytes
* <li>STRING requires an additional 14 bytes for every character (uses UTF8 encoding)
* </ul>
*
* @author jnelson
*/
@Immutable
public final class Value implements Byteable, Comparable<Value> {
/**
* Return the Value encoded in {@code bytes} so long as those bytes adhere to the format specified
* by the {@link #getBytes()} method. This method assumes that all the bytes in the {@code bytes}
* belong to the Value. In general, it is necessary to get the appropriate Value slice from the
* parent ByteBuffer using {@link ByteBuffers#slice(ByteBuffer, int, int)}.
*
* @param bytes
* @return the Value
*/
public static Value fromByteBuffer(ByteBuffer bytes) {
Type type = Type.values()[bytes.get()];
TObject data = extractTObjectAndCache(bytes, type);
return new Value(data, bytes);
}
/**
* Return the optimized Value of {@code value}.
*
* @param value
* @return the optimized Value
*/
public static Value optimize(Value value) {
if (value.getType() == Type.TAG) {
return Value.wrap(Convert.javaToThrift(value.getObject().toString()));
}
return value;
}
/**
* Return a Value that is backed by {@code data}.
*
* @param data
* @return the Value
*/
public static Value wrap(TObject data) {
return new Value(data);
}
/**
* Return the {@link TObject} of {@code type} represented by {@code bytes}. This method reads the
* remaining bytes from the current position into the returned TObject.
*
* @param bytes
* @param type
* @return the TObject
*/
private static TObject extractTObjectAndCache(ByteBuffer bytes, Type type) {
// Must allocate a heap buffer because TObject assumes it has a
// backing array and because of THRIFT-2104 that buffer must wrap a
// byte array in order to assume that the TObject does not lose data
// when transferred over the wire.
byte[] array = new byte[bytes.remaining()];
bytes.get(array); // We CANNOT simply slice {@code buffer} and use
// the slice's backing array because the backing
// array of the slice is the same as the
// original, which contains more data than we
// need for the quantity
return new TObject(ByteBuffer.wrap(array), type);
}
/**
* A constant representing the smallest possible Value. This should be used in normal operations,
* but should only be used to indicate an infinite range.
*/
public static Value NEGATIVE_INFINITY = Value.wrap(Convert.javaToThrift(Long.MIN_VALUE));
/**
* A constant representing the largest possible Value. This shouldn't be used in normal
* operations, but should only be used to indicate an infinite range.
*/
public static Value POSITIVE_INFINITY = Value.wrap(Convert.javaToThrift(Long.MAX_VALUE));
/** The minimum number of bytes needed to encode every Value. */
private static final int CONSTANT_SIZE = 1; // type(1)
/** A cached copy of the binary representation that is returned from {@link #getBytes()}. */
@Nullable private transient ByteBuffer bytes = null;
/**
* The underlying data represented by this Value. This representation is used when
* serializing/deserializing the data for RPC or disk and network I/O.
*/
private final TObject data;
/**
* The java representation of the underlying {@link #data}. This representation is used when
* interacting with other components in the JVM.
*/
@Nullable private transient Object object = null;
/**
* Construct a new instance.
*
* @param data
*/
private Value(TObject data) {
this(data, null);
}
/**
* Construct a new instance.
*
* @param data
* @param bytes
*/
private Value(TObject data, @Nullable ByteBuffer bytes) {
this.data = data;
this.bytes = bytes;
}
@Override
public int compareTo(Value other) {
return Sorter.INSTANCE.compare(this, other);
}
@Override
public boolean equals(Object obj) {
if (obj instanceof Value) {
final Value other = (Value) obj;
return getObject().equals(other.getObject());
}
return false;
}
/**
* Return a byte buffer that represents this Value with the following order:
*
* <ol>
* <li><strong>type</strong> - position 0
* <li><strong>data</strong> - position 1
* </ol>
*
* @return the ByteBuffer representation
*/
@Override
public ByteBuffer getBytes() {
if (bytes == null) {
bytes = ByteBuffer.allocate(size());
copyTo(bytes);
bytes.rewind();
}
return ByteBuffers.asReadOnlyBuffer(bytes);
}
/**
* Return the java object that is represented by this Value.
*
* @return the object representation
*/
public Object getObject() {
if (object == null) {
object = Convert.thriftToJava(data);
}
return object;
}
/**
* Return the TObject that is represented by this Value.
*
* @return the TObject representation
*/
public TObject getTObject() {
return data;
}
/**
* Return the {@link Type} that describes the underlying data represented by this Value.
*
* @return the type
*/
public Type getType() {
return data.getType();
}
@Override
public int hashCode() {
return getObject().hashCode();
}
@Override
public int size() {
return CONSTANT_SIZE + data.data.capacity();
}
@Override
public String toString() {
return getObject().toString() + " (" + getType() + ")";
}
@Override
public void copyTo(ByteBuffer buffer) {
buffer.put((byte) data.getType().ordinal());
buffer.put(data.bufferForData());
}
/**
* A {@link Comparator} that is used to sort Values using weak typing.
*
* @author jnelson
*/
public static enum Sorter implements Comparator<Value> {
INSTANCE;
@Override
public int compare(Value v1, Value v2) {
if ((v1 == POSITIVE_INFINITY && v2 == POSITIVE_INFINITY)
|| (v1 == NEGATIVE_INFINITY && v2 == NEGATIVE_INFINITY)) {
return 0;
} else if (v1 == POSITIVE_INFINITY) {
return 1;
} else if (v2 == POSITIVE_INFINITY) {
return -1;
} else if (v1 == NEGATIVE_INFINITY) {
return -1;
} else if (v2 == NEGATIVE_INFINITY) {
return 1;
} else {
Object o1 = v1.getObject();
Object o2 = v2.getObject();
if (o1 instanceof Number && o2 instanceof Number) {
return Numbers.compare((Number) o1, (Number) o2);
} else if (o1 instanceof Number) {
return -1;
} else if (o2 instanceof Number) {
return 1;
} else {
return o1.toString().compareToIgnoreCase(o2.toString());
}
}
}
}
}
