| /** |
| * 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.mrql; |
| |
| import org.apache.mrql.gen.*; |
| import java.util.Iterator; |
| import javax.xml.parsers.SAXParserFactory; |
| import org.xml.sax.*; |
| import java.io.*; |
| import org.apache.hadoop.io.DataOutputBuffer; |
| import org.apache.flink.core.fs.FSDataInputStream; |
| |
| |
| /** Extract the XML elements tagged by tags from a data split of the input stream (fsin) |
| * and store them in a buffer (to be parsed by SAX). |
| */ |
| final public class FlinkXMLSplitter implements Iterator<DataOutputBuffer> { |
| boolean in_memory; |
| FSDataInputStream fsin; // for HDFS processing |
| BufferedReader in; // for in-memory processing |
| String[] tags; |
| long start; |
| long end; |
| long pos; |
| StringBuffer tagname = new StringBuffer(100); |
| String start_tagname; |
| final DataOutputBuffer buffer; |
| |
| FlinkXMLSplitter ( String[] tags, FSDataInputStream fsin, long start, long end ) { |
| in_memory = false; |
| this.tags = tags; |
| this.fsin = fsin; |
| this.start = start; |
| this.end = end; |
| pos = start; |
| this.buffer = new DataOutputBuffer(); |
| try { |
| fsin.seek(start); |
| } catch ( IOException e ) { |
| System.err.println("*** Cannot parse the data split: "+fsin); |
| } |
| } |
| |
| FlinkXMLSplitter ( String[] tags, String file ) { |
| in_memory = true; |
| try { |
| in = new BufferedReader(new InputStreamReader(new FileInputStream(file)), |
| 100000); |
| } catch ( Exception e ) { |
| throw new Error("Cannot open the file: "+file); |
| }; |
| this.tags = tags; |
| this.buffer = new DataOutputBuffer(); |
| } |
| |
| public boolean hasNext () { |
| try { |
| if (in_memory || pos < end) |
| if (skip()) |
| return store(); |
| return false; |
| } catch (Exception e) { |
| System.err.println(e); |
| return false; |
| } |
| } |
| |
| public DataOutputBuffer next () { |
| return buffer; |
| } |
| |
| public void remove () { } |
| |
| boolean is_start_tag () { |
| if (tags == null) |
| return true; |
| for (String tag: tags) |
| if (tag.contentEquals(tagname)) |
| return true; |
| return false; |
| } |
| |
| char read_tag () throws IOException { |
| tagname.setLength(0); |
| while (true) { |
| int b = in_memory ? in.read() : fsin.read(); |
| if (b == -1) |
| return ' '; |
| else if (!Character.isLetterOrDigit(b) && b != ':' && b != '_') |
| return (char)b; |
| tagname.append((char)b); |
| } |
| } |
| |
| /** skip until the beginning of a split element */ |
| boolean skip () throws IOException { |
| while (true) { |
| int b = in_memory ? in.read() : fsin.read(); |
| pos++; |
| if (b == -1 || (!in_memory && pos >= end)) |
| return false; |
| else if (b == '<') { |
| b = read_tag(); |
| pos += tagname.length()+1; |
| if (is_start_tag()) { |
| buffer.reset(); |
| buffer.write('<'); |
| for ( int i = 0; i < tagname.length(); i++ ) |
| buffer.write(tagname.charAt(i)); |
| buffer.write(b); |
| start_tagname = new String(tagname); |
| return true; |
| } |
| } |
| } |
| } |
| |
| /** store one split element into the buffer; may cross split boundaries */ |
| boolean store () throws IOException { |
| while (true) { |
| int b = in_memory ? in.read() : fsin.read(); |
| pos++; |
| if (b == -1) |
| return false; |
| if (b == '&') { // don't validate external XML entities |
| buffer.write('&');buffer.write('a');buffer.write('m');buffer.write('p');buffer.write(';'); |
| } else buffer.write(b); |
| if (b == '<') { |
| b = in_memory ? in.read() : fsin.read(); |
| pos++; |
| buffer.write(b); |
| if (b == '/') { |
| b = read_tag(); |
| pos += tagname.length()+1; |
| for ( int i = 0; i < tagname.length(); i++ ) |
| buffer.write(tagname.charAt(i)); |
| buffer.write(b); |
| if (start_tagname.contentEquals(tagname)) { |
| while (b != '>') { |
| b = fsin.read(); |
| pos++; |
| buffer.write(b); |
| }; |
| return true; |
| } |
| } |
| } |
| } |
| } |
| } |