Java tutorial
/* * 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.pig.tools.pigstats; import java.io.IOException; import java.util.Iterator; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.Path; import org.apache.pig.LoadFunc; import org.apache.pig.PigException; import org.apache.pig.backend.executionengine.ExecException; import org.apache.pig.backend.hadoop.datastorage.ConfigurationUtil; import org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POStore; import org.apache.pig.classification.InterfaceAudience; import org.apache.pig.classification.InterfaceStability; import org.apache.pig.data.Tuple; import org.apache.pig.impl.PigContext; import org.apache.pig.impl.io.ReadToEndLoader; /** * This class encapsulates the runtime statistics of an user specified output. */ @InterfaceAudience.Public @InterfaceStability.Evolving public final class OutputStats { private String name; private String location; private long bytes; private long records; private boolean success; private POStore store = null; private Configuration conf; private static final Log LOG = LogFactory.getLog(OutputStats.class); public OutputStats(String location, long bytes, long records, boolean success) { this.location = location; this.bytes = bytes; this.records = records; this.success = success; try { this.name = new Path(location).getName(); } catch (Exception e) { // location is a mal formatted URL this.name = location; } } public String getName() { return name; } public String getLocation() { return location; } public long getBytes() { return bytes; } public void setBytes(long bytes) { this.bytes = bytes; } public long getRecords() { return records; } public void setRecords(long records) { this.records = records; } public long getNumberRecords() { return records; } public String getFunctionName() { return (store == null) ? null : store.getSFile().getFuncSpec().getClassName(); } public boolean isSuccessful() { return success; } public void setSuccessful(boolean success) { this.success = success; } public String getAlias() { return (store == null) ? null : store.getAlias(); } public POStore getPOStore() { return store; } public Configuration getConf() { return conf; } public String getDisplayString() { StringBuilder sb = new StringBuilder(); if (success) { sb.append("Successfully stored "); if (records >= 0) { sb.append(records).append(" records "); } else { sb.append("records "); } if (bytes > 0) { sb.append("(").append(bytes).append(" bytes) "); } sb.append("in: \"").append(location).append("\"\n"); } else { sb.append("Failed to produce result in \"").append(location).append("\"\n"); } return sb.toString(); } public void setPOStore(POStore store) { this.store = store; } public void setConf(Configuration conf) { this.conf = conf; } public Iterator<Tuple> iterator() throws IOException { final LoadFunc p; PigContext pigContext = ScriptState.get().getPigContext(); if (pigContext == null || store == null) { throw new IllegalArgumentException(); } try { LoadFunc originalLoadFunc = (LoadFunc) PigContext .instantiateFuncFromSpec(store.getSFile().getFuncSpec()); p = (LoadFunc) new ReadToEndLoader(originalLoadFunc, ConfigurationUtil.toConfiguration(pigContext.getProperties()), store.getSFile().getFileName(), 0); } catch (Exception e) { int errCode = 2088; String msg = "Unable to get results for: " + store.getSFile(); throw new ExecException(msg, errCode, PigException.BUG, e); } return new Iterator<Tuple>() { Tuple t; boolean atEnd; @Override public boolean hasNext() { if (atEnd) return false; try { if (t == null) t = p.getNext(); if (t == null) atEnd = true; } catch (Exception e) { LOG.error(e); t = null; atEnd = true; throw new Error(e); } return !atEnd; } @Override public Tuple next() { Tuple next = t; if (next != null) { t = null; return next; } try { next = p.getNext(); } catch (Exception e) { LOG.error(e); } if (next == null) atEnd = true; return next; } @Override public void remove() { throw new RuntimeException("Removal not supported"); } }; } }