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Core Calcite APIs and engine.
/*
* 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.calcite.util;
import org.apache.calcite.avatica.util.ByteString;
import org.apache.calcite.runtime.SqlFunctions;
import org.apache.calcite.sql.SqlCollation;
import org.apache.calcite.sql.SqlDialect;
import org.apache.calcite.sql.SqlUtil;
import org.apache.calcite.sql.dialect.AnsiSqlDialect;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import java.nio.ByteBuffer;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.IllegalCharsetNameException;
import java.nio.charset.UnsupportedCharsetException;
import java.util.List;
import java.util.Locale;
import java.util.Objects;
import javax.annotation.Nonnull;
import static org.apache.calcite.util.Static.RESOURCE;
/**
* A string, optionally with {@link Charset character set} and
* {@link SqlCollation}. It is immutable.
*/
public class NlsString implements Comparable, Cloneable {
//~ Instance fields --------------------------------------------------------
private static final LoadingCache, String>
DECODE_MAP =
CacheBuilder.newBuilder()
.softValues()
.build(
new CacheLoader, String>() {
public String load(@Nonnull Pair key) {
final Charset charset = key.right;
final CharsetDecoder decoder = charset.newDecoder();
final byte[] bytes = key.left.getBytes();
final ByteBuffer buffer = ByteBuffer.wrap(bytes);
try {
return decoder.decode(buffer).toString();
} catch (CharacterCodingException ex) {
throw RESOURCE.charsetEncoding(
//CHECKSTYLE: IGNORE 1
new String(bytes, Charset.defaultCharset()),
charset.name()).ex();
}
}
});
private final String stringValue;
private final ByteString bytesValue;
private final String charsetName;
private final Charset charset;
private final SqlCollation collation;
//~ Constructors -----------------------------------------------------------
/**
* Creates a string in a specified character set.
*
* @param bytesValue Byte array constant, must not be null
* @param charsetName Name of the character set, must not be null
* @param collation Collation, may be null
*
* @throws IllegalCharsetNameException If the given charset name is illegal
* @throws UnsupportedCharsetException If no support for the named charset
* is available in this instance of the Java virtual machine
* @throws RuntimeException If the given value cannot be represented in the
* given charset
*/
public NlsString(ByteString bytesValue, String charsetName,
SqlCollation collation) {
this(null, Objects.requireNonNull(bytesValue),
Objects.requireNonNull(charsetName), collation);
}
/**
* Easy constructor for Java string.
*
* @param stringValue String constant, must not be null
* @param charsetName Name of the character set, may be null
* @param collation Collation, may be null
*
* @throws IllegalCharsetNameException If the given charset name is illegal
* @throws UnsupportedCharsetException If no support for the named charset
* is available in this instance of the Java virtual machine
* @throws RuntimeException If the given value cannot be represented in the
* given charset
*/
public NlsString(String stringValue, String charsetName,
SqlCollation collation) {
this(Objects.requireNonNull(stringValue), null, charsetName, collation);
}
/** Internal constructor; other constructors must call it. */
private NlsString(String stringValue, ByteString bytesValue,
String charsetName, SqlCollation collation) {
if (charsetName != null) {
this.charsetName = charsetName.toUpperCase(Locale.ROOT);
this.charset = SqlUtil.getCharset(charsetName);
} else {
this.charsetName = null;
this.charset = null;
}
if ((stringValue != null) == (bytesValue != null)) {
throw new IllegalArgumentException("Specify stringValue or bytesValue");
}
if (bytesValue != null) {
if (charsetName == null) {
throw new IllegalArgumentException("Bytes value requires charset");
}
SqlUtil.validateCharset(bytesValue, charset);
} else {
// Java string can be malformed if LATIN1 is required.
if (this.charsetName != null
&& (this.charsetName.equals("LATIN1")
|| this.charsetName.equals("ISO-8859-1"))) {
if (!charset.newEncoder().canEncode(stringValue)) {
throw RESOURCE.charsetEncoding(stringValue, charset.name()).ex();
}
}
}
this.collation = collation;
this.stringValue = stringValue;
this.bytesValue = bytesValue;
}
//~ Methods ----------------------------------------------------------------
public Object clone() {
try {
return super.clone();
} catch (CloneNotSupportedException e) {
throw new AssertionError();
}
}
public int hashCode() {
return Objects.hash(stringValue, bytesValue, charsetName, collation);
}
public boolean equals(Object obj) {
return this == obj
|| obj instanceof NlsString
&& Objects.equals(stringValue, ((NlsString) obj).stringValue)
&& Objects.equals(bytesValue, ((NlsString) obj).bytesValue)
&& Objects.equals(charsetName, ((NlsString) obj).charsetName)
&& Objects.equals(collation, ((NlsString) obj).collation);
}
@Override public int compareTo(NlsString other) {
// TODO jvs 18-Jan-2006: Actual collation support. This just uses
// the default collation.
return getValue().compareTo(other.getValue());
}
public String getCharsetName() {
return charsetName;
}
public Charset getCharset() {
return charset;
}
public SqlCollation getCollation() {
return collation;
}
public String getValue() {
if (stringValue == null) {
assert bytesValue != null;
return DECODE_MAP.getUnchecked(Pair.of(bytesValue, charset));
}
return stringValue;
}
/**
* Returns a string the same as this but with spaces trimmed from the
* right.
*/
public NlsString rtrim() {
String trimmed = SqlFunctions.rtrim(getValue());
if (!trimmed.equals(getValue())) {
return new NlsString(trimmed, charsetName, collation);
}
return this;
}
/** As {@link #asSql(boolean, boolean, SqlDialect)} but with SQL standard
* dialect. */
public String asSql(boolean prefix, boolean suffix) {
return asSql(prefix, suffix, AnsiSqlDialect.DEFAULT);
}
/**
* Returns the string quoted for SQL, for example _ISO-8859-1'is it a
* plane? no it''s superman!'.
*
* @param prefix if true, prefix the character set name
* @param suffix if true, suffix the collation clause
* @param dialect Dialect
* @return the quoted string
*/
public String asSql(
boolean prefix,
boolean suffix,
SqlDialect dialect) {
StringBuilder ret = new StringBuilder();
dialect.quoteStringLiteral(ret, prefix ? charsetName : null, getValue());
// NOTE jvs 3-Feb-2005: see FRG-78 for why this should go away
if (false) {
if (suffix && (null != collation)) {
ret.append(" ");
ret.append(collation.toString());
}
}
return ret.toString();
}
/**
* Returns the string quoted for SQL, for example _ISO-8859-1'is it a
* plane? no it''s superman!'.
*/
public String toString() {
return asSql(true, true);
}
/**
* Concatenates some {@link NlsString} objects. The result has the charset
* and collation of the first element. The other elements must have matching
* (or null) charset and collation. Concatenates all at once, not pairwise,
* to avoid string copies.
*
* @param args array of {@link NlsString} to be concatenated
*/
public static NlsString concat(List args) {
if (args.size() < 2) {
return args.get(0);
}
String charSetName = args.get(0).charsetName;
SqlCollation collation = args.get(0).collation;
int length = args.get(0).getValue().length();
// sum string lengths and validate
for (int i = 1; i < args.size(); i++) {
final NlsString arg = args.get(i);
length += arg.getValue().length();
if (!((arg.charsetName == null)
|| arg.charsetName.equals(charSetName))) {
throw new IllegalArgumentException("mismatched charsets");
}
if (!((arg.collation == null)
|| arg.collation.equals(collation))) {
throw new IllegalArgumentException("mismatched collations");
}
}
StringBuilder sb = new StringBuilder(length);
for (NlsString arg : args) {
sb.append(arg.getValue());
}
return new NlsString(
sb.toString(),
charSetName,
collation);
}
/** Creates a copy of this {@code NlsString} with different content but same
* charset and collation. */
public NlsString copy(String value) {
return new NlsString(value, charsetName, collation);
}
/** Returns the value as a {@link ByteString}. */
public ByteString getValueBytes() {
return bytesValue;
}
}
// End NlsString.java
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