org.h2.value.ValueStringFixed Maven / Gradle / Ivy
/*
* Copyright 2004-2018 H2 Group. Multiple-Licensed under the MPL 2.0,
* and the EPL 1.0 (http://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.value;
import java.util.Arrays;
import org.h2.engine.Mode;
import org.h2.engine.SysProperties;
import org.h2.util.StringUtils;
/**
* Implementation of the CHAR data type.
*/
public class ValueStringFixed extends ValueString {
/**
* Special value for the precision in {@link #get(String, int, Mode)} to indicate that the value
* should not be trimmed.
*/
public static final int PRECISION_DO_NOT_TRIM = Integer.MIN_VALUE;
/**
* Special value for the precision in {@link #get(String, int, Mode)} to indicate
* that the default behaviour should of trimming the value should apply.
*/
public static final int PRECISION_TRIM = -1;
private static final ValueStringFixed EMPTY = new ValueStringFixed("");
protected ValueStringFixed(String value) {
super(value);
}
private static String trimRight(String s) {
return trimRight(s, 0);
}
private static String trimRight(String s, int minLength) {
int endIndex = s.length() - 1;
int i = endIndex;
while (i >= minLength && s.charAt(i) == ' ') {
i--;
}
s = i == endIndex ? s : s.substring(0, i + 1);
return s;
}
private static String rightPadWithSpaces(String s, int length) {
int pad = length - s.length();
if (pad <= 0) {
return s;
}
char[] res = new char[length];
s.getChars(0, s.length(), res, 0);
Arrays.fill(res, s.length(), length, ' ');
return new String(res);
}
@Override
public int getType() {
return Value.STRING_FIXED;
}
/**
* Get or create a fixed length string value for the given string.
* Spaces at the end of the string will be removed.
*
* @param s the string
* @return the value
*/
public static ValueStringFixed get(String s) {
// Use the special precision constant PRECISION_TRIM to indicate
// default H2 behaviour of trimming the value.
return get(s, PRECISION_TRIM, null);
}
/**
* Get or create a fixed length string value for the given string.
*
* This method will use a {@link Mode}-specific conversion when mode is not
* null.
* Otherwise it will use the default H2 behaviour of trimming the given string if
* precision is not {@link #PRECISION_DO_NOT_TRIM}.
*
* @param s the string
* @param precision if the {@link Mode#padFixedLengthStrings} indicates that strings should
* be padded, this defines the overall length of the (potentially padded) string.
* If the special constant {@link #PRECISION_DO_NOT_TRIM} is used the value will
* not be trimmed.
* @param mode the database mode
* @return the value
*/
public static ValueStringFixed get(String s, int precision, Mode mode) {
// Should fixed strings be padded?
if (mode != null && mode.padFixedLengthStrings) {
if (precision == Integer.MAX_VALUE) {
// CHAR without a length specification is identical to CHAR(1)
precision = 1;
}
if (s.length() < precision) {
// We have to pad
s = rightPadWithSpaces(s, precision);
} else {
// We should trim, because inserting 'A ' into a CHAR(1) is possible!
s = trimRight(s, precision);
}
} else if (precision != PRECISION_DO_NOT_TRIM) {
// Default behaviour of H2
s = trimRight(s);
}
if (s.length() == 0) {
return EMPTY;
}
ValueStringFixed obj = new ValueStringFixed(StringUtils.cache(s));
if (s.length() > SysProperties.OBJECT_CACHE_MAX_PER_ELEMENT_SIZE) {
return obj;
}
return (ValueStringFixed) Value.cache(obj);
}
@Override
protected ValueString getNew(String s) {
return ValueStringFixed.get(s);
}
}