org.deeplearning4j.text.tokenization.tokenizer.DefaultStreamTokenizer Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2015-2018 Skymind, Inc.
*
* This program and the accompanying materials are made available under the
* terms of the Apache License, Version 2.0 which is available at
* https://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.
*
* SPDX-License-Identifier: Apache-2.0
******************************************************************************/
package org.deeplearning4j.text.tokenization.tokenizer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.*;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;
/**
* Tokenizer based on the {@link java.io.StreamTokenizer}
* @author Adam Gibson
*
*/
public class DefaultStreamTokenizer implements Tokenizer {
private StreamTokenizer streamTokenizer;
private TokenPreProcess tokenPreProcess;
private List tokens = new ArrayList<>();
private AtomicInteger position = new AtomicInteger(0);
protected static final Logger log = LoggerFactory.getLogger(DefaultStreamTokenizer.class);
public DefaultStreamTokenizer(InputStream is) {
Reader r = new BufferedReader(new InputStreamReader(is));
streamTokenizer = new StreamTokenizer(r);
}
/**
* Checks, if underlying stream has any tokens left
*
* @return
*/
private boolean streamHasMoreTokens() {
if (streamTokenizer.ttype != StreamTokenizer.TT_EOF) {
try {
streamTokenizer.nextToken();
} catch (IOException e1) {
throw new RuntimeException(e1);
}
}
return streamTokenizer.ttype != StreamTokenizer.TT_EOF && streamTokenizer.ttype != -1;
}
/**
* Checks, if any prebuffered tokens left, otherswise checks underlying stream
* @return
*/
@Override
public boolean hasMoreTokens() {
log.info("Tokens size: [" + tokens.size() + "], position: [" + position.get() + "]");
if (!tokens.isEmpty())
return position.get() < tokens.size();
else
return streamHasMoreTokens();
}
/**
* Returns number of tokens
* PLEASE NOTE: this method effectively preloads all tokens. So use it with caution, since on large streams it will consume big amount of memory
*
* @return
*/
@Override
public int countTokens() {
return getTokens().size();
}
/**
* This method returns next token from prebuffered list of tokens or underlying InputStream
*
* @return next token as String
*/
@Override
public String nextToken() {
if (!tokens.isEmpty() && position.get() < tokens.size())
return tokens.get(position.getAndIncrement());
return nextTokenFromStream();
}
/**
* This method returns next token from underlying InputStream
*
* @return
*/
private String nextTokenFromStream() {
StringBuilder sb = new StringBuilder();
if (streamTokenizer.ttype == StreamTokenizer.TT_WORD) {
sb.append(streamTokenizer.sval);
} else if (streamTokenizer.ttype == StreamTokenizer.TT_NUMBER) {
sb.append(streamTokenizer.nval);
} else if (streamTokenizer.ttype == StreamTokenizer.TT_EOL) {
try {
while (streamTokenizer.ttype == StreamTokenizer.TT_EOL)
streamTokenizer.nextToken();
} catch (IOException e) {
throw new RuntimeException(e);
}
} else if (streamHasMoreTokens())
return nextTokenFromStream();
String ret = sb.toString();
if (tokenPreProcess != null)
ret = tokenPreProcess.preProcess(ret);
return ret;
}
/**
* Returns all tokens as list of Strings
*
* @return List of tokens
*/
@Override
public List getTokens() {
//List tokens = new ArrayList<>();
if (!tokens.isEmpty())
return tokens;
log.info("Starting prebuffering...");
while (streamHasMoreTokens()) {
tokens.add(nextTokenFromStream());
}
log.info("Tokens prefetch finished. Tokens size: [" + tokens.size() + "]");
return tokens;
}
@Override
public void setTokenPreProcessor(TokenPreProcess tokenPreProcessor) {
this.tokenPreProcess = tokenPreProcessor;
}
}