com.datastax.oss.driver.internal.core.type.codec.SetCodec Maven / Gradle / Ivy
The newest version!
/*
* 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 com.datastax.oss.driver.internal.core.type.codec;
import com.datastax.oss.driver.api.core.ProtocolVersion;
import com.datastax.oss.driver.api.core.type.DataType;
import com.datastax.oss.driver.api.core.type.SetType;
import com.datastax.oss.driver.api.core.type.codec.TypeCodec;
import com.datastax.oss.driver.api.core.type.reflect.GenericType;
import com.datastax.oss.driver.shaded.guava.common.base.Preconditions;
import com.datastax.oss.driver.shaded.guava.common.collect.Sets;
import edu.umd.cs.findbugs.annotations.NonNull;
import edu.umd.cs.findbugs.annotations.Nullable;
import java.nio.ByteBuffer;
import java.util.LinkedHashSet;
import java.util.Set;
import net.jcip.annotations.ThreadSafe;
@ThreadSafe
public class SetCodec implements TypeCodec> {
private final DataType cqlType;
private final GenericType> javaType;
private final TypeCodec elementCodec;
public SetCodec(DataType cqlType, TypeCodec elementCodec) {
this.cqlType = cqlType;
this.javaType = GenericType.setOf(elementCodec.getJavaType());
this.elementCodec = elementCodec;
Preconditions.checkArgument(cqlType instanceof SetType);
}
@NonNull
@Override
public GenericType> getJavaType() {
return javaType;
}
@NonNull
@Override
public DataType getCqlType() {
return cqlType;
}
@Override
public boolean accepts(@NonNull Object value) {
if (Set.class.isAssignableFrom(value.getClass())) {
// runtime type ok, now check element type
Set set = (Set) value;
return set.isEmpty() || elementCodec.accepts(set.iterator().next());
} else {
return false;
}
}
@Nullable
@Override
public ByteBuffer encode(
@Nullable Set value, @NonNull ProtocolVersion protocolVersion) {
// An int indicating the number of elements in the set, followed by the elements. Each element
// is a byte array representing the serialized value, preceded by an int indicating its size.
if (value == null) {
return null;
} else {
int i = 0;
ByteBuffer[] encodedElements = new ByteBuffer[value.size()];
int toAllocate = 4; // initialize with number of elements
for (ElementT element : value) {
if (element == null) {
throw new NullPointerException("Collection elements cannot be null");
}
ByteBuffer encodedElement;
try {
encodedElement = elementCodec.encode(element, protocolVersion);
} catch (ClassCastException e) {
throw new IllegalArgumentException("Invalid type for element: " + element.getClass());
}
if (encodedElement == null) {
throw new NullPointerException("Collection elements cannot encode to CQL NULL");
}
encodedElements[i++] = encodedElement;
toAllocate += 4 + encodedElement.remaining(); // the element preceded by its size
}
ByteBuffer result = ByteBuffer.allocate(toAllocate);
result.putInt(value.size());
for (ByteBuffer encodedElement : encodedElements) {
result.putInt(encodedElement.remaining());
result.put(encodedElement);
}
result.flip();
return result;
}
}
@Nullable
@Override
public Set decode(
@Nullable ByteBuffer bytes, @NonNull ProtocolVersion protocolVersion) {
if (bytes == null || bytes.remaining() == 0) {
return new LinkedHashSet<>(0);
} else {
ByteBuffer input = bytes.duplicate();
int size = input.getInt();
Set result = Sets.newLinkedHashSetWithExpectedSize(size);
for (int i = 0; i < size; i++) {
ElementT element;
int elementSize = input.getInt();
// Allow null elements on the decode path, because Cassandra might return such collections
// for some computed values in the future -- e.g. SELECT ttl(some_collection)
if (elementSize < 0) {
element = null;
} else {
ByteBuffer encodedElement = input.slice();
encodedElement.limit(elementSize);
element = elementCodec.decode(encodedElement, protocolVersion);
input.position(input.position() + elementSize);
}
result.add(element);
}
return result;
}
}
@NonNull
@Override
public String format(@Nullable Set value) {
if (value == null) {
return "NULL";
}
StringBuilder sb = new StringBuilder("{");
boolean first = true;
for (ElementT t : value) {
if (first) {
first = false;
} else {
sb.append(",");
}
sb.append(elementCodec.format(t));
}
sb.append("}");
return sb.toString();
}
@Nullable
@Override
public Set parse(@Nullable String value) {
if (value == null || value.isEmpty() || value.equalsIgnoreCase("NULL")) return null;
int idx = ParseUtils.skipSpaces(value, 0);
if (value.charAt(idx++) != '{')
throw new IllegalArgumentException(
String.format(
"Cannot parse set value from \"%s\", at character %d expecting '{' but got '%c'",
value, idx, value.charAt(idx)));
idx = ParseUtils.skipSpaces(value, idx);
if (value.charAt(idx) == '}') {
return new LinkedHashSet<>(0);
}
Set set = new LinkedHashSet<>();
while (idx < value.length()) {
int n;
try {
n = ParseUtils.skipCQLValue(value, idx);
} catch (IllegalArgumentException e) {
throw new IllegalArgumentException(
String.format(
"Cannot parse set value from \"%s\", invalid CQL value at character %d",
value, idx),
e);
}
set.add(elementCodec.parse(value.substring(idx, n)));
idx = n;
idx = ParseUtils.skipSpaces(value, idx);
if (value.charAt(idx) == '}') return set;
if (value.charAt(idx++) != ',')
throw new IllegalArgumentException(
String.format(
"Cannot parse set value from \"%s\", at character %d expecting ',' but got '%c'",
value, idx, value.charAt(idx)));
idx = ParseUtils.skipSpaces(value, idx);
}
throw new IllegalArgumentException(
String.format("Malformed set value \"%s\", missing closing '}'", value));
}
}