| /* |
| * Copyright 2009-2013 by The Regents of the University of California |
| * Licensed 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 from |
| * |
| * 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 edu.uci.ics.hyracks.storage.am.lsm.invertedindex.tokenizers; |
| |
| import java.io.IOException; |
| |
| import edu.uci.ics.hyracks.data.std.primitive.UTF8StringPointable; |
| import edu.uci.ics.hyracks.data.std.util.GrowableArray; |
| import edu.uci.ics.hyracks.dataflow.common.data.util.StringUtils; |
| |
| public class UTF8NGramToken extends AbstractUTF8Token implements INGramToken { |
| |
| public final static char PRECHAR = '#'; |
| |
| public final static char POSTCHAR = '$'; |
| |
| protected int numPreChars; |
| protected int numPostChars; |
| |
| public UTF8NGramToken(byte tokenTypeTag, byte countTypeTag) { |
| super(tokenTypeTag, countTypeTag); |
| } |
| |
| @Override |
| public int getNumPostChars() { |
| return numPreChars; |
| } |
| |
| @Override |
| public int getNumPreChars() { |
| return numPostChars; |
| } |
| |
| @Override |
| public void serializeToken(GrowableArray out) throws IOException { |
| handleTokenTypeTag(out.getDataOutput()); |
| int tokenUTF8LenOff = out.getLength(); |
| |
| // regular chars |
| int numRegChars = tokenLength - numPreChars - numPostChars; |
| |
| // assuming pre and post char need 1-byte each in utf8 |
| int tokenUTF8Len = numPreChars + numPostChars; |
| |
| // Write dummy UTF length which will be correctly set later. |
| out.getDataOutput().writeShort(0); |
| |
| // pre chars |
| for (int i = 0; i < numPreChars; i++) { |
| StringUtils.writeCharAsModifiedUTF8(PRECHAR, out.getDataOutput()); |
| } |
| |
| int pos = start; |
| for (int i = 0; i < numRegChars; i++) { |
| char c = Character.toLowerCase(UTF8StringPointable.charAt(data, pos)); |
| tokenUTF8Len += StringUtils.writeCharAsModifiedUTF8(c, out.getDataOutput()); |
| pos += UTF8StringPointable.charSize(data, pos); |
| } |
| |
| // post chars |
| for (int i = 0; i < numPostChars; i++) { |
| StringUtils.writeCharAsModifiedUTF8(POSTCHAR, out.getDataOutput()); |
| } |
| |
| // Set UTF length of token. |
| out.getByteArray()[tokenUTF8LenOff] = (byte) ((tokenUTF8Len >>> 8) & 0xFF); |
| out.getByteArray()[tokenUTF8LenOff + 1] = (byte) ((tokenUTF8Len >>> 0) & 0xFF); |
| } |
| |
| public void setNumPrePostChars(int numPreChars, int numPostChars) { |
| this.numPreChars = numPreChars; |
| this.numPostChars = numPostChars; |
| } |
| } |