Examples with MapFn org.apache.crunch.MapFn used on opensource projects

Example 1 with MapFn

use of org.apache.crunch.MapFn in project crunch by cloudera.

the class TextFileReaderFactory method read.

@Override
public Iterator<T> read(FileSystem fs, Path path) {
    MapFn mapFn = null;
    if (String.class.equals(ptype.getTypeClass())) {
        mapFn = IdentityFn.getInstance();
    } else {
        // Check for a composite MapFn for the PType.
        // Note that this won't work for Avro-- need to solve that.
        MapFn input = ptype.getInputMapFn();
        if (input instanceof CompositeMapFn) {
            mapFn = ((CompositeMapFn) input).getSecond();
        }
    }
    mapFn.setConfigurationForTest(conf);
    mapFn.initialize();
    FSDataInputStream is = null;
    try {
        is = fs.open(path);
    } catch (IOException e) {
        LOG.info("Could not read path: " + path, e);
        return Iterators.emptyIterator();
    }
    final BufferedReader reader = new BufferedReader(new InputStreamReader(is));
    final MapFn<String, T> iterMapFn = mapFn;
    return new UnmodifiableIterator<T>() {

        private String nextLine;

        @Override
        public boolean hasNext() {
            try {
                return (nextLine = reader.readLine()) != null;
            } catch (IOException e) {
                LOG.info("Exception reading text file stream", e);
                return false;
            }
        }

        @Override
        public T next() {
            return iterMapFn.map(nextLine);
        }
    };
}

Example 2 with MapFn

use of org.apache.crunch.MapFn in project crunch by cloudera.

the class Writables method derived.

public static <S, T> PType<T> derived(Class<T> clazz, MapFn<S, T> inputFn, MapFn<T, S> outputFn, PType<S> base) {
    WritableType<S, ?> wt = (WritableType<S, ?>) base;
    MapFn input = new CompositeMapFn(wt.getInputMapFn(), inputFn);
    MapFn output = new CompositeMapFn(outputFn, wt.getOutputMapFn());
    return new WritableType(clazz, wt.getSerializationClass(), input, output, base.getSubTypes().toArray(new PType[0]));
}

Example 3 with MapFn

use of org.apache.crunch.MapFn in project crunch by cloudera.

the class AvroTypeSortTest method testSortAvroTypesBySelectedFields.

@Test
public void testSortAvroTypesBySelectedFields() throws Exception {
    MRPipeline pipeline = new MRPipeline(AvroTypeSortTest.class);
    Person ccc10 = createPerson("CCC", 10);
    Person bbb20 = createPerson("BBB", 20);
    Person aaa30 = createPerson("AAA", 30);
    writeAvroFile(Lists.newArrayList(ccc10, bbb20, aaa30), avroFile);
    PCollection<Person> unsorted = pipeline.read(At.avroFile(avroFile.getAbsolutePath(), records(Person.class)));
    // Sort by Name
    MapFn<Person, String> nameExtractor = new MapFn<Person, String>() {

        @Override
        public String map(Person input) {
            return input.getName().toString();
        }
    };
    PCollection<Person> sortedByName = unsorted.by(nameExtractor, strings()).groupByKey().ungroup().values();
    List<Person> sortedByNameList = Lists.newArrayList(sortedByName.materialize());
    assertEquals(3, sortedByNameList.size());
    assertEquals(aaa30, sortedByNameList.get(0));
    assertEquals(bbb20, sortedByNameList.get(1));
    assertEquals(ccc10, sortedByNameList.get(2));
    // Sort by Age
    MapFn<Person, Integer> ageExtractor = new MapFn<Person, Integer>() {

        @Override
        public Integer map(Person input) {
            return input.getAge();
        }
    };
    PCollection<Person> sortedByAge = unsorted.by(ageExtractor, ints()).groupByKey().ungroup().values();
    List<Person> sortedByAgeList = Lists.newArrayList(sortedByAge.materialize());
    assertEquals(3, sortedByAgeList.size());
    assertEquals(ccc10, sortedByAgeList.get(0));
    assertEquals(bbb20, sortedByAgeList.get(1));
    assertEquals(aaa30, sortedByAgeList.get(2));
    pipeline.done();
}

Example 4 with MapFn

use of org.apache.crunch.MapFn in project cdk-examples by cloudera.

the class CreateSessions method run.

@Override
public int run(String[] args) throws Exception {
    // Construct a local filesystem dataset repository rooted at /tmp/data
    DatasetRepository fsRepo = DatasetRepositories.open("repo:hdfs:/tmp/data");
    // Construct an HCatalog dataset repository using external Hive tables
    DatasetRepository hcatRepo = DatasetRepositories.open("repo:hive:/tmp/data");
    // Turn debug on while in development.
    getPipeline().enableDebug();
    getPipeline().getConfiguration().set("crunch.log.job.progress", "true");
    // Load the events dataset and get the correct partition to sessionize
    Dataset<StandardEvent> eventsDataset = fsRepo.load("events");
    Dataset<StandardEvent> partition;
    if (args.length == 0 || (args.length == 1 && args[0].equals("LATEST"))) {
        partition = getLatestPartition(eventsDataset);
    } else {
        partition = getPartitionForURI(eventsDataset, args[0]);
    }
    // Create a parallel collection from the working partition
    PCollection<StandardEvent> events = read(CrunchDatasets.asSource(partition, StandardEvent.class));
    // Process the events into sessions, using a combiner
    PCollection<Session> sessions = events.parallelDo(new DoFn<StandardEvent, Session>() {

        @Override
        public void process(StandardEvent event, Emitter<Session> emitter) {
            emitter.emit(Session.newBuilder().setUserId(event.getUserId()).setSessionId(event.getSessionId()).setIp(event.getIp()).setStartTimestamp(event.getTimestamp()).setDuration(0).setSessionEventCount(1).build());
        }
    }, Avros.specifics(Session.class)).by(new MapFn<Session, Pair<Long, String>>() {

        @Override
        public Pair<Long, String> map(Session session) {
            return Pair.of(session.getUserId(), session.getSessionId());
        }
    }, Avros.pairs(Avros.longs(), Avros.strings())).groupByKey().combineValues(new CombineFn<Pair<Long, String>, Session>() {

        @Override
        public void process(Pair<Pair<Long, String>, Iterable<Session>> pairIterable, Emitter<Pair<Pair<Long, String>, Session>> emitter) {
            String ip = null;
            long startTimestamp = Long.MAX_VALUE;
            long endTimestamp = Long.MIN_VALUE;
            int sessionEventCount = 0;
            for (Session s : pairIterable.second()) {
                ip = s.getIp();
                startTimestamp = Math.min(startTimestamp, s.getStartTimestamp());
                endTimestamp = Math.max(endTimestamp, s.getStartTimestamp() + s.getDuration());
                sessionEventCount += s.getSessionEventCount();
            }
            emitter.emit(Pair.of(pairIterable.first(), Session.newBuilder().setUserId(pairIterable.first().first()).setSessionId(pairIterable.first().second()).setIp(ip).setStartTimestamp(startTimestamp).setDuration(endTimestamp - startTimestamp).setSessionEventCount(sessionEventCount).build()));
        }
    }).parallelDo(new DoFn<Pair<Pair<Long, String>, Session>, Session>() {

        @Override
        public void process(Pair<Pair<Long, String>, Session> pairSession, Emitter<Session> emitter) {
            emitter.emit(pairSession.second());
        }
    }, Avros.specifics(Session.class));
    // Write the sessions to the "sessions" Dataset
    getPipeline().write(sessions, CrunchDatasets.asTarget(hcatRepo.load("sessions")), Target.WriteMode.APPEND);
    return run().succeeded() ? 0 : 1;
}