| /** |
| * 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. |
| */ |
| #include "hadoop/Pipes.hh" |
| #include "hadoop/TemplateFactory.hh" |
| #include "hadoop/StringUtils.hh" |
| #include "hadoop/SerialUtils.hh" |
| |
| #include <stdio.h> |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| |
| const std::string WORDCOUNT = "WORDCOUNT"; |
| const std::string INPUT_WORDS = "INPUT_WORDS"; |
| const std::string OUTPUT_WORDS = "OUTPUT_WORDS"; |
| |
| class WordCountMap: public HadoopPipes::Mapper { |
| public: |
| HadoopPipes::TaskContext::Counter* inputWords; |
| |
| WordCountMap(HadoopPipes::TaskContext& context) { |
| inputWords = context.getCounter(WORDCOUNT, INPUT_WORDS); |
| } |
| |
| void map(HadoopPipes::MapContext& context) { |
| std::vector<std::string> words = |
| HadoopUtils::splitString(context.getInputValue(), " "); |
| for(unsigned int i=0; i < words.size(); ++i) { |
| context.emit(words[i], "1"); |
| } |
| context.incrementCounter(inputWords, words.size()); |
| } |
| }; |
| |
| class WordCountReduce: public HadoopPipes::Reducer { |
| public: |
| HadoopPipes::TaskContext::Counter* outputWords; |
| |
| WordCountReduce(HadoopPipes::TaskContext& context) { |
| outputWords = context.getCounter(WORDCOUNT, OUTPUT_WORDS); |
| } |
| |
| void reduce(HadoopPipes::ReduceContext& context) { |
| int sum = 0; |
| while (context.nextValue()) { |
| sum += HadoopUtils::toInt(context.getInputValue()); |
| } |
| context.emit(context.getInputKey(), HadoopUtils::toString(sum)); |
| context.incrementCounter(outputWords, 1); |
| } |
| }; |
| |
| class WordCountReader: public HadoopPipes::RecordReader { |
| private: |
| int64_t bytesTotal; |
| int64_t bytesRead; |
| FILE* file; |
| public: |
| WordCountReader(HadoopPipes::MapContext& context) { |
| std::string filename; |
| HadoopUtils::StringInStream stream(context.getInputSplit()); |
| HadoopUtils::deserializeString(filename, stream); |
| struct stat statResult; |
| stat(filename.c_str(), &statResult); |
| bytesTotal = statResult.st_size; |
| bytesRead = 0; |
| file = fopen(filename.c_str(), "rt"); |
| HADOOP_ASSERT(file != NULL, "failed to open " + filename); |
| } |
| |
| ~WordCountReader() { |
| fclose(file); |
| } |
| |
| virtual bool next(std::string& key, std::string& value) { |
| key = HadoopUtils::toString(ftell(file)); |
| int ch = getc(file); |
| bytesRead += 1; |
| value.clear(); |
| while (ch != -1 && ch != '\n') { |
| value += ch; |
| ch = getc(file); |
| bytesRead += 1; |
| } |
| return ch != -1; |
| } |
| |
| /** |
| * The progress of the record reader through the split as a value between |
| * 0.0 and 1.0. |
| */ |
| virtual float getProgress() { |
| if (bytesTotal > 0) { |
| return (float)bytesRead / bytesTotal; |
| } else { |
| return 1.0f; |
| } |
| } |
| }; |
| |
| class WordCountWriter: public HadoopPipes::RecordWriter { |
| private: |
| FILE* file; |
| public: |
| WordCountWriter(HadoopPipes::ReduceContext& context) { |
| const HadoopPipes::JobConf* job = context.getJobConf(); |
| int part = job->getInt("mapreduce.task.partition"); |
| std::string outDir = job->get("mapreduce.task.output.dir"); |
| // remove the file: schema substring |
| std::string::size_type posn = outDir.find(":"); |
| HADOOP_ASSERT(posn != std::string::npos, |
| "no schema found in output dir: " + outDir); |
| outDir.erase(0, posn+1); |
| mkdir(outDir.c_str(), 0777); |
| std::string outFile = outDir + "/part-" + HadoopUtils::toString(part); |
| file = fopen(outFile.c_str(), "wt"); |
| HADOOP_ASSERT(file != NULL, "can't open file for writing: " + outFile); |
| } |
| |
| ~WordCountWriter() { |
| fclose(file); |
| } |
| |
| void emit(const std::string& key, const std::string& value) { |
| fprintf(file, "%s -> %s\n", key.c_str(), value.c_str()); |
| } |
| }; |
| |
| int main(int argc, char *argv[]) { |
| return HadoopPipes::runTask(HadoopPipes::TemplateFactory<WordCountMap, |
| WordCountReduce, void, void, WordCountReader, |
| WordCountWriter>()); |
| } |
| |