/**
* 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.solr.util;
import org.apache.lucene.util.BytesRef;
import org.apache.noggit.CharArr;
public class ByteUtils {
/** Converts utf8 to utf16 and returns the number of 16 bit Java chars written.
* Full characters are read, even if this reads past the length passed (and can result in
* an ArrayOutOfBoundsException if invalid UTF8 is passed). Explicit checks for valid UTF8 are not performed.
* The char[] out should probably have enough room to hold the worst case of each byte becoming a Java char.
*/
public static int UTF8toUTF16(byte[] utf8, int offset, int len, char[] out, int out_offset) {
int out_start = out_offset;
final int limit = offset + len;
while (offset < limit) {
int b = utf8[offset++]&0xff;
if (b < 0xc0) {
assert b < 0x80;
out[out_offset++] = (char)b;
} else if (b < 0xe0) {
out[out_offset++] = (char)(((b&0x1f)<<6) + (utf8[offset++]&0x3f));
} else if (b < 0xf0) {
out[out_offset++] = (char)(((b&0xf)<<12) + ((utf8[offset]&0x3f)<<6) + (utf8[offset+1]&0x3f));
offset += 2;
} else {
assert b < 0xf8;
int ch = ((b&0x7)<<18) + ((utf8[offset]&0x3f)<<12) + ((utf8[offset+1]&0x3f)<<6) + (utf8[offset+2]&0x3f);
offset += 3;
if (ch < 0xffff) {
out[out_offset++] = (char)ch;
} else {
int chHalf = ch - 0x0010000;
out[out_offset++] = (char) ((chHalf >> 10) + 0xD800);
out[out_offset++] = (char) ((chHalf & 0x3FFL) + 0xDC00);
}
}
}
return out_offset - out_start;
}
/** Convert UTF8 bytes into UTF16 characters. */
public static void UTF8toUTF16(BytesRef utf8, CharArr out) {
// TODO: do in chunks if the input is large
out.reserve(utf8.length);
int n = UTF8toUTF16(utf8.bytes, utf8.offset, utf8.length, out.getArray(), out.getEnd());
out.setEnd(out.getEnd() + n);
}
/** Convert UTF8 bytes into a String */
public static String UTF8toUTF16(BytesRef utf8) {
char[] out = new char[utf8.length];
int n = UTF8toUTF16(utf8.bytes, utf8.offset, utf8.length, out, 0);
return new String(out,0,n);
}
}