Example usage for com.google.common.collect Iterators transform

Introduction

In this page you can find the example usage for com.google.common.collect Iterators transform.

Prototype

public static <F, T> Iterator<T> transform(final Iterator<F> fromIterator,
        final Function<? super F, ? extends T> function)

Source Link

Document

Returns an iterator that applies function to each element of fromIterator .

Usage

From source file:org.apache.kylin.storage.gtrecord.StorageResponseGTScatter.java

@Override
public Iterator<GTRecord> iterator() {
    Iterator<PartitionResultIterator> iterators = Iterators.transform(blocks,
            new Function<byte[], PartitionResultIterator>() {
                public PartitionResultIterator apply(byte[] input) {
                    return new PartitionResultIterator(input, info, columns);
                }//w  ww  .  ja  va  2s  .  co m
            });

    if (!needSorted) {
        logger.debug("Using Iterators.concat to pipeline partition results");
        return Iterators.concat(iterators);
    }

    List<PartitionResultIterator> partitionResults = Lists.newArrayList(iterators);
    if (partitionResults.size() == 1) {
        return partitionResults.get(0);
    }
    logger.debug("Using SortMergedPartitionResultIterator to merge {} partition results",
            partitionResults.size());
    return new SortMergedPartitionResultIterator(partitionResults, info, GTRecord.getComparator(groupByDims));
}

From source file:com.yammer.collections.transforming.TransformingCollection.java

@SuppressWarnings("NullableProblems")
@Override
public Iterator<F> iterator() {
    return Iterators.transform(backingCollection.iterator(), fromFunction);
}

From source file:org.apache.gobblin.util.request_allocation.PriorityIterableBasedRequestAllocator.java

@Override
public AllocatedRequestsIterator<T> allocateRequests(Iterator<? extends Requestor<T>> requestors,
        ResourcePool resourcePool) {//  w w  w . jav a 2 s. com
    final ConcurrentBoundedPriorityIterable<T> iterable = new ConcurrentBoundedPriorityIterable<>(
            this.configuration.getPrioritizer(), this.configuration.getResourceEstimator(),
            this.configuration.getStoreRejectedRequestsSetting(), resourcePool);

    final Iterator<T> joinIterator = getJoinIterator(requestors, iterable);

    if (this.configuration.getAllowedThreads() <= 1) {
        while (joinIterator.hasNext()) {
            iterable.add(joinIterator.next());
        }
    } else {

        IteratorExecutor<Void> executor = new IteratorExecutor<>(
                Iterators.transform(joinIterator, new Function<T, Callable<Void>>() {
                    @Override
                    public Callable<Void> apply(final T input) {
                        return new Callable<Void>() {
                            @Override
                            public Void call() throws Exception {
                                iterable.add(input);
                                return null;
                            }
                        };
                    }
                }), this.configuration.getAllowedThreads(),
                ExecutorsUtils.newThreadFactory(Optional.of(log), Optional.of("request-allocator-%d")));

        try {
            List<Either<Void, ExecutionException>> results = executor.executeAndGetResults();
            IteratorExecutor.logFailures(results, log, 10);
        } catch (InterruptedException ie) {
            log.error("Request allocation was interrupted.");
            return new AllocatedRequestsIteratorBase<>(
                    Iterators.<AllocatedRequestsIteratorBase.RequestWithResourceRequirement<T>>emptyIterator(),
                    resourcePool);
        }
    }

    iterable.logStatistics(Optional.of(this.log));

    //Get all requests rejected/dropped
    getRejectedAndDroppedRequests(iterable);

    return new AllocatedRequestsIteratorBase<>(iterable.iterator(), resourcePool);
}

From source file:de.cosmocode.palava.ipc.xml.rpc.adapters.MapAdapter.java

@Override
public Map<String, Object> decode(Value input) {
    Preconditions.checkNotNull(input, "Input");
    @SuppressWarnings("unchecked")
    final JAXBElement<Struct> element = JAXBElement.class.cast(input.getContent().get(0));
    final List<Member> members = element.getValue().getMember();
    return new AbstractMap<String, Object>() {

        @Override/*from w w  w .  j  ava2  s.co  m*/
        public Set<Entry<String, Object>> entrySet() {
            return new AbstractSet<Entry<String, Object>>() {

                @Override
                public Iterator<Entry<String, Object>> iterator() {
                    return Iterators
                            .unmodifiableIterator(Iterators.transform(members.iterator(), entryDecoder));
                }

                @Override
                public int size() {
                    return members.size();
                }

            };
        }

    };
}

From source file:com.davidbracewell.math.linear.VectorMap.java

@Override
public Set<Integer> keySet() {
    return new AbstractSet<Integer>() {

        @Override//from   w  w w.  j av  a2  s . co  m
        public Iterator<Integer> iterator() {
            return Iterators.transform(vector.nonZeroIterator(), new Function<DoubleEntry, Integer>() {
                @Nullable
                @Override
                public Integer apply(@Nullable DoubleEntry input) {
                    return input == null ? null : input.index;
                }
            });
        }

        @Override
        public int size() {
            return vector.size();
        }

    };
}

From source file:nz.ac.massey.cs.guery.impl.BreadthFirstPathFinder.java

private Iterator<Path<V, E>> findDirectLinks(final GraphAdapter<V, E> g, V start, int minLength,
        boolean outgoing, Predicate<E> filter, boolean computeAll) {
    Iterator<Path<V, E>> nullIter = null;
    if (minLength == 0) {
        Path<V, E> path = new LREmptyPath(start);
        nullIter = (Iterator<Path<V, E>>) Iterators.singletonIterator(path);
    }/*w  ww .ja v a 2 s.  com*/
    Iterator<E> edges = outgoing ? g.getOutEdges(start, filter) : g.getInEdges(start, filter);
    Iterator<Path<V, E>> paths = Iterators.transform(edges, new Function<E, Path<V, E>>() {
        @Override
        public Path<V, E> apply(E e) {
            return new SingletonPath<V, E>(e, g);
        }
    });

    return nullIter == null ? paths : Iterators.concat(nullIter, paths);

}

From source file:org.apache.accumulo.core.util.shell.commands.TablesCommand.java

@SuppressWarnings("unchecked")
@Override//from www  .  j a v  a 2  s  .  c  om
public int execute(final String fullCommand, final CommandLine cl, final Shell shellState)
        throws AccumuloException, AccumuloSecurityException, IOException, NamespaceNotFoundException {

    final String namespace = cl.hasOption(OptUtil.namespaceOpt().getOpt())
            ? OptUtil.getNamespaceOpt(cl, shellState)
            : null;
    Map<String, String> tables = shellState.getConnector().tableOperations().tableIdMap();

    // filter only specified namespace
    tables = Maps.filterKeys(tables, new Predicate<String>() {
        @Override
        public boolean apply(String tableName) {
            return namespace == null || Tables.qualify(tableName).getFirst().equals(namespace);
        }
    });

    final boolean sortByTableId = cl.hasOption(sortByTableIdOption.getOpt());
    tables = new TreeMap<String, String>((sortByTableId ? MapUtils.invertMap(tables) : tables));

    Iterator<String> it = Iterators.transform(tables.entrySet().iterator(),
            new Function<Entry<String, String>, String>() {
                @Override
                public String apply(Map.Entry<String, String> entry) {
                    String tableName = String.valueOf(sortByTableId ? entry.getValue() : entry.getKey());
                    String tableId = String.valueOf(sortByTableId ? entry.getKey() : entry.getValue());
                    if (namespace != null)
                        tableName = Tables.qualify(tableName).getSecond();
                    if (cl.hasOption(tableIdOption.getOpt()))
                        return String.format(NAME_AND_ID_FORMAT, tableName, tableId);
                    else
                        return tableName;
                };
            });

    shellState.printLines(it, !cl.hasOption(disablePaginationOpt.getOpt()));
    return 0;
}

From source file:org.hashtrees.store.SimpleMemStore.java

public Iterator<Map.Entry<byte[], byte[]>> iterator() {
    return Iterators.transform(kvMap.entrySet().iterator(),
            new Function<Map.Entry<ByteBuffer, ByteBuffer>, Map.Entry<byte[], byte[]>>() {

                @Override//from   w w  w  .  ja va2 s  .c om
                public Entry<byte[], byte[]> apply(final Entry<ByteBuffer, ByteBuffer> input) {
                    return Maps.immutableEntry(input.getKey().array(), input.getValue().array());
                };
            });
}

From source file:de.cosmocode.collections.event.EventMap.java

@Override
public Set<K> keySet() {
    final Set<Entry<K, V>> entrySet = entrySet();
    // is ok, because the set returned by keySet() does not support add methods
    return new AbstractSet<K>() {

        @Override//from ww w.j av a 2s . c om
        public Iterator<K> iterator() {
            return Iterators.transform(entrySet.iterator(), getKey);
        }

        @Override
        public int size() {
            return entrySet.size();
        }

    };
}

From source file:org.fcrepo.kernel.impl.rdf.impl.VersionsRdfContext.java

private Iterator<Triple> versionTriples() throws RepositoryException {
    final Iterator<Version> allVersions = versionHistory.getAllVersions();
    return Iterators.concat(Iterators.transform(allVersions, version2triples));
}