/*
* Copyright 2014 Goldman Sachs.
*
* Licensed 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 com.gs.collections.impl.lazy.parallel;
import java.io.IOException;
import java.util.Collections;
import java.util.Comparator;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.concurrent.Callable;
import java.util.concurrent.CompletionService;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorCompletionService;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
import com.gs.collections.api.LazyIterable;
import com.gs.collections.api.ParallelIterable;
import com.gs.collections.api.annotation.Beta;
import com.gs.collections.api.bag.MutableBag;
import com.gs.collections.api.bag.sorted.MutableSortedBag;
import com.gs.collections.api.block.function.Function;
import com.gs.collections.api.block.function.Function0;
import com.gs.collections.api.block.function.Function2;
import com.gs.collections.api.block.function.primitive.DoubleFunction;
import com.gs.collections.api.block.function.primitive.FloatFunction;
import com.gs.collections.api.block.function.primitive.IntFunction;
import com.gs.collections.api.block.function.primitive.LongFunction;
import com.gs.collections.api.block.predicate.Predicate;
import com.gs.collections.api.block.predicate.Predicate2;
import com.gs.collections.api.block.procedure.Procedure;
import com.gs.collections.api.block.procedure.Procedure2;
import com.gs.collections.api.list.MutableList;
import com.gs.collections.api.map.MapIterable;
import com.gs.collections.api.map.MutableMap;
import com.gs.collections.api.map.sorted.MutableSortedMap;
import com.gs.collections.api.set.MutableSet;
import com.gs.collections.api.set.sorted.MutableSortedSet;
import com.gs.collections.impl.Counter;
import com.gs.collections.impl.bag.mutable.HashBag;
import com.gs.collections.impl.bag.sorted.mutable.TreeBag;
import com.gs.collections.impl.block.factory.Comparators;
import com.gs.collections.impl.block.factory.Functions2;
import com.gs.collections.impl.block.factory.Predicates;
import com.gs.collections.impl.block.factory.Procedures;
import com.gs.collections.impl.block.procedure.CollectionAddProcedure;
import com.gs.collections.impl.block.procedure.DoubleSumResultHolder;
import com.gs.collections.impl.block.procedure.MapCollectProcedure;
import com.gs.collections.impl.block.procedure.MutatingAggregationProcedure;
import com.gs.collections.impl.block.procedure.NonMutatingAggregationProcedure;
import com.gs.collections.impl.block.procedure.checked.CheckedProcedure2;
import com.gs.collections.impl.list.mutable.CompositeFastList;
import com.gs.collections.impl.list.mutable.FastList;
import com.gs.collections.impl.map.mutable.ConcurrentHashMap;
import com.gs.collections.impl.map.mutable.ConcurrentHashMapUnsafe;
import com.gs.collections.impl.map.mutable.UnifiedMap;
import com.gs.collections.impl.map.sorted.mutable.TreeSortedMap;
import com.gs.collections.impl.set.mutable.SetAdapter;
import com.gs.collections.impl.set.mutable.UnifiedSet;
import com.gs.collections.impl.set.sorted.mutable.TreeSortedSet;
@Beta
public abstract class AbstractParallelIterable<T, B extends Batch<T>> implements ParallelIterable<T>
{
protected static <T> void forEach(final AbstractParallelIterable<T, ? extends RootBatch<T>> parallelIterable, final Procedure<? super T> procedure)
{
LazyIterable<Future<?>> futures = parallelIterable.split().collect(new Function<RootBatch<T>, Future<?>>()
{
public Future<?> valueOf(final RootBatch<T> chunk)
{
return parallelIterable.getExecutorService().submit(new Runnable()
{
public void run()
{
chunk.forEach(procedure);
}
});
}
});
// The call to toList() is important to stop the lazy evaluation and force all the Runnables to start executing.
MutableList<Future<?>> futuresList = futures.toList();
for (Future<?> future : futuresList)
{
try
{
future.get();
}
catch (InterruptedException e)
{
Thread.currentThread().interrupt();
throw new RuntimeException(e);
}
catch (ExecutionException e)
{
throw new RuntimeException(e);
}
}
}
protected static <T> boolean anySatisfy(AbstractParallelIterable<T, ? extends RootBatch<T>> parallelIterable, final Predicate<? super T> predicate)
{
final CompletionService<Boolean> completionService = new ExecutorCompletionService<Boolean>(parallelIterable.getExecutorService());
MutableSet<Future<Boolean>> futures = parallelIterable.split().collect(new Function<RootBatch<T>, Future<Boolean>>()
{
public Future<Boolean> valueOf(final RootBatch<T> batch)
{
return completionService.submit(new Callable<Boolean>()
{
public Boolean call()
{
return batch.anySatisfy(predicate);
}
});
}
}, UnifiedSet.<Future<Boolean>>newSet());
while (futures.notEmpty())
{
try
{
Future<Boolean> future = completionService.take();
if (future.get())
{
for (Future<Boolean> eachFuture : futures)
{
eachFuture.cancel(true);
}
return true;
}
futures.remove(future);
}
catch (InterruptedException e)
{
Thread.currentThread().interrupt();
throw new RuntimeException(e);
}
catch (ExecutionException e)
{
throw new RuntimeException(e);
}
}
return false;
}
protected static <T> boolean allSatisfy(AbstractParallelIterable<T, ? extends RootBatch<T>> parallelIterable, final Predicate<? super T> predicate)
{
final CompletionService<Boolean> completionService = new ExecutorCompletionService<Boolean>(parallelIterable.getExecutorService());
MutableSet<Future<Boolean>> futures = parallelIterable.split().collect(new Function<RootBatch<T>, Future<Boolean>>()
{
public Future<Boolean> valueOf(final RootBatch<T> batch)
{
return completionService.submit(new Callable<Boolean>()
{
public Boolean call()
{
return batch.allSatisfy(predicate);
}
});
}
}, UnifiedSet.<Future<Boolean>>newSet());
while (futures.notEmpty())
{
try
{
Future<Boolean> future = completionService.take();
if (!future.get())
{
for (Future<Boolean> eachFuture : futures)
{
eachFuture.cancel(true);
}
return false;
}
futures.remove(future);
}
catch (InterruptedException e)
{
Thread.currentThread().interrupt();
throw new RuntimeException(e);
}
catch (ExecutionException e)
{
throw new RuntimeException(e);
}
}
return true;
}
protected static <T> T detect(final AbstractParallelIterable<T, ? extends RootBatch<T>> parallelIterable, final Predicate<? super T> predicate)
{
LazyIterable<? extends RootBatch<T>> chunks = parallelIterable.split();
LazyIterable<Future<T>> futures = chunks.collect(new Function<RootBatch<T>, Future<T>>()
{
public Future<T> valueOf(final RootBatch<T> chunk)
{
return parallelIterable.getExecutorService().submit(new Callable<T>()
{
public T call()
{
return chunk.detect(predicate);
}
});
}
});
// The call to toList() is important to stop the lazy evaluation and force all the Runnables to start executing.
MutableList<Future<T>> futuresList = futures.toList();
for (Future<T> future : futuresList)
{
try
{
T eachResult = future.get();
if (eachResult != null)
{
for (Future<T> eachFutureToCancel : futuresList)
{
eachFutureToCancel.cancel(true);
}
return eachResult;
}
}
catch (InterruptedException e)
{
Thread.currentThread().interrupt();
throw new RuntimeException(e);
}
catch (ExecutionException e)
{
throw new RuntimeException(e);
}
}
return null;
}
public abstract ExecutorService getExecutorService();
public abstract int getBatchSize();
public abstract LazyIterable<B> split();
protected abstract boolean isOrdered();
protected <S, V> void collectCombine(Function<Batch<T>, V> function, Procedure2<S, V> combineProcedure, S state)
{
if (this.isOrdered())
{
this.collectCombineOrdered(function, combineProcedure, state);
}
else
{
this.collectCombineUnordered(function, combineProcedure, state);
}
}
private <S, V> void collectCombineOrdered(final Function<Batch<T>, V> function, Procedure2<S, V> combineProcedure, S state)
{
LazyIterable<? extends Batch<T>> chunks = this.split();
LazyIterable<Future<V>> futures = chunks.collect(new Function<Batch<T>, Future<V>>()
{
public Future<V> valueOf(final Batch<T> chunk)
{
return AbstractParallelIterable.this.getExecutorService().submit(new Callable<V>()
{
public V call()
{
return function.valueOf(chunk);
}
});
}
});
// The call to toList() is important to stop the lazy evaluation and force all the Runnables to start executing.
MutableList<Future<V>> futuresList = futures.toList();
for (Future<V> future : futuresList)
{
try
{
combineProcedure.value(state, future.get());
}
catch (InterruptedException e)
{
Thread.currentThread().interrupt();
throw new RuntimeException(e);
}
catch (ExecutionException e)
{
throw new RuntimeException(e);
}
}
}
private <S, V> void collectCombineUnordered(final Function<Batch<T>, V> function, Procedure2<S, V> combineProcedure, S state)
{
LazyIterable<? extends Batch<T>> chunks = this.split();
MutableList<Callable<V>> callables = chunks.collect(new Function<Batch<T>, Callable<V>>()
{
public Callable<V> valueOf(final Batch<T> chunk)
{
return new Callable<V>()
{
public V call()
{
return function.valueOf(chunk);
}
};
}
}).toList();
final ExecutorCompletionService<V> completionService = new ExecutorCompletionService<V>(this.getExecutorService());
callables.forEach(new Procedure<Callable<V>>()
{
public void value(Callable<V> callable)
{
completionService.submit(callable);
}
});
int numTasks = callables.size();
while (numTasks > 0)
{
try
{
Future<V> future = completionService.take();
combineProcedure.value(state, future.get());
numTasks--;
}
catch (InterruptedException e)
{
Thread.currentThread().interrupt();
throw new RuntimeException(e);
}
catch (ExecutionException e)
{
throw new RuntimeException(e);
}
}
}
private T collectReduce(Function<Batch<T>, T> map, Function2<T, T, T> function2)
{
return this.isOrdered()
? this.collectReduceOrdered(map, function2)
: this.collectReduceUnordered(map, function2);
}
private T collectReduceOrdered(final Function<Batch<T>, T> map, Function2<T, T, T> function2)
{
LazyIterable<? extends Batch<T>> chunks = this.split();
LazyIterable<Future<T>> futures = chunks.collect(new Function<Batch<T>, Future<T>>()
{
public Future<T> valueOf(final Batch<T> chunk)
{
return AbstractParallelIterable.this.getExecutorService().submit(new Callable<T>()
{
public T call()
{
return map.valueOf(chunk);
}
});
}
});
// The call to toList() is important to stop the lazy evaluation and force all the Runnables to start executing.
MutableList<Future<T>> futuresList = futures.toList();
try
{
T result = futuresList.getFirst().get();
for (int i = 1; i < futuresList.size(); i++)
{
T next = futuresList.get(i).get();
if (next != null)
{
if (result == null)
{
result = next;
}
else
{
result = function2.value(result, next);
}
}
}
if (result == null)
{
throw new NoSuchElementException();
}
return result;
}
catch (InterruptedException e)
{
Thread.currentThread().interrupt();
throw new RuntimeException(e);
}
catch (ExecutionException e)
{
if (e.getCause() instanceof NullPointerException)
{
throw (NullPointerException) e.getCause();
}
throw new RuntimeException(e);
}
}
private T collectReduceUnordered(final Function<Batch<T>, T> map, Function2<T, T, T> function2)
{
LazyIterable<? extends Batch<T>> chunks = this.split();
MutableList<Callable<T>> callables = chunks.collect(new Function<Batch<T>, Callable<T>>()
{
public Callable<T> valueOf(final Batch<T> chunk)
{
return new Callable<T>()
{
public T call()
{
return map.valueOf(chunk);
}
};
}
}).toList();
final ExecutorCompletionService<T> completionService = new ExecutorCompletionService<T>(this.getExecutorService());
callables.forEach(new Procedure<Callable<T>>()
{
public void value(Callable<T> callable)
{
completionService.submit(callable);
}
});
try
{
T result = completionService.take().get();
int numTasks = callables.size() - 1;
while (numTasks > 0)
{
T next = completionService.take().get();
if (next != null)
{
if (result == null)
{
result = next;
}
else
{
result = function2.value(result, next);
}
}
numTasks--;
}
if (result == null)
{
throw new NoSuchElementException();
}
return result;
}
catch (InterruptedException e)
{
Thread.currentThread().interrupt();
throw new RuntimeException(e);
}
catch (ExecutionException e)
{
if (e.getCause() instanceof NullPointerException)
{
throw (NullPointerException) e.getCause();
}
throw new RuntimeException(e);
}
}
@Override
public String toString()
{
return this.makeString("[", ", ", "]");
}
public String makeString()
{
return this.makeString(", ");
}
public String makeString(String separator)
{
return this.makeString("", separator, "");
}
public String makeString(String start, String separator, String end)
{
Appendable stringBuilder = new StringBuilder();
this.appendString(stringBuilder, start, separator, end);
return stringBuilder.toString();
}
public void appendString(Appendable appendable)
{
this.appendString(appendable, ", ");
}
public void appendString(Appendable appendable, String separator)
{
this.appendString(appendable, "", separator, "");
}
public void appendString(final Appendable appendable, String start, final String separator, String end)
{
try
{
appendable.append(start);
Function<Batch<T>, String> map = new Function<Batch<T>, String>()
{
public String valueOf(Batch<T> batch)
{
return batch.makeString(separator);
}
};
Procedure2<Appendable, String> reduce = new CheckedProcedure2<Appendable, String>()
{
private boolean first = true;
public void safeValue(Appendable accumulator, String each) throws IOException
{
if ("".equals(each))
{
return;
}
if (this.first)
{
this.first = false;
}
else
{
appendable.append(separator);
}
appendable.append(each);
}
};
this.collectCombine(map, reduce, appendable);
appendable.append(end);
}
catch (IOException e)
{
throw new RuntimeException(e);
}
}
public <P> void forEachWith(Procedure2<? super T, ? super P> procedure, P parameter)
{
this.forEach(Procedures.bind(procedure, parameter));
}
public <P> boolean anySatisfyWith(Predicate2<? super T, ? super P> predicate, P parameter)
{
return this.anySatisfy(Predicates.bind(predicate, parameter));
}
public <P> boolean allSatisfyWith(Predicate2<? super T, ? super P> predicate, P parameter)
{
return this.allSatisfy(Predicates.bind(predicate, parameter));
}
public boolean noneSatisfy(Predicate<? super T> predicate)
{
return this.allSatisfy(Predicates.not(predicate));
}
public <P> boolean noneSatisfyWith(Predicate2<? super T, ? super P> predicate, P parameter)
{
return this.noneSatisfy(Predicates.bind(predicate, parameter));
}
public <P> T detectWith(Predicate2<? super T, ? super P> predicate, P parameter)
{
return this.detect(Predicates.bind(predicate, parameter));
}
public T detectIfNone(Predicate<? super T> predicate, Function0<? extends T> function)
{
T result = this.detect(predicate);
return result == null ? function.value() : result;
}
public <P> T detectWithIfNone(Predicate2<? super T, ? super P> predicate, P parameter, Function0<? extends T> function)
{
return this.detectIfNone(Predicates.bind(predicate, parameter), function);
}
public Object[] toArray()
{
throw new UnsupportedOperationException(this.getClass().getSimpleName() + ".toArray() not implemented yet");
}
public <E> E[] toArray(E[] array)
{
throw new UnsupportedOperationException(this.getClass().getSimpleName() + ".toArray() not implemented yet");
}
public MutableList<T> toList()
{
Function<Batch<T>, FastList<T>> map = new Function<Batch<T>, FastList<T>>()
{
public FastList<T> valueOf(Batch<T> batch)
{
FastList<T> list = FastList.newList();
batch.forEach(CollectionAddProcedure.on(list));
return list;
}
};
Procedure2<MutableList<T>, FastList<T>> reduce = new Procedure2<MutableList<T>, FastList<T>>()
{
public void value(MutableList<T> accumulator, FastList<T> each)
{
accumulator.addAll(each);
}
};
MutableList<T> state = new CompositeFastList<T>();
this.collectCombine(map, reduce, state);
return state;
}
public MutableList<T> toSortedList()
{
return this.toList().toSortedList();
}
public MutableList<T> toSortedList(Comparator<? super T> comparator)
{
return this.toList().toSortedList(comparator);
}
public <V extends Comparable<? super V>> MutableList<T> toSortedListBy(Function<? super T, ? extends V> function)
{
return this.toSortedList(Comparators.byFunction(function));
}
public MutableSet<T> toSet()
{
ConcurrentHashMapUnsafe<T, Boolean> map = ConcurrentHashMapUnsafe.newMap();
Set<T> result = Collections.newSetFromMap(map);
this.forEach(CollectionAddProcedure.on(result));
return SetAdapter.adapt(map.keySet());
}
public MutableSortedSet<T> toSortedSet()
{
MutableSortedSet<T> result = TreeSortedSet.<T>newSet().asSynchronized();
this.forEach(CollectionAddProcedure.on(result));
return result;
}
public <V extends Comparable<? super V>> MutableSortedSet<T> toSortedSetBy(Function<? super T, ? extends V> function)
{
return this.toSortedSet(Comparators.byFunction(function));
}
public MutableBag<T> toBag()
{
MutableBag<T> result = HashBag.<T>newBag().asSynchronized();
this.forEach(CollectionAddProcedure.on(result));
return result;
}
public MutableSortedBag<T> toSortedBag()
{
MutableSortedBag<T> result = TreeBag.<T>newBag().asSynchronized();
this.forEach(CollectionAddProcedure.on(result));
return result;
}
public MutableSortedBag<T> toSortedBag(Comparator<? super T> comparator)
{
MutableSortedBag<T> result = TreeBag.newBag(comparator).asSynchronized();
this.forEach(CollectionAddProcedure.on(result));
return result;
}
public <V extends Comparable<? super V>> MutableSortedBag<T> toSortedBagBy(Function<? super T, ? extends V> function)
{
return this.toSortedBag(Comparators.byFunction(function));
}
public MutableSortedSet<T> toSortedSet(Comparator<? super T> comparator)
{
MutableSortedSet<T> result = TreeSortedSet.newSet(comparator).asSynchronized();
this.forEach(CollectionAddProcedure.on(result));
return result;
}
public <NK, NV> MutableMap<NK, NV> toMap(
Function<? super T, ? extends NK> keyFunction,
Function<? super T, ? extends NV> valueFunction)
{
MutableMap<NK, NV> map = UnifiedMap.<NK, NV>newMap().asSynchronized();
this.forEach(new MapCollectProcedure<T, NK, NV>(map, keyFunction, valueFunction));
return map;
}
public <NK, NV> MutableSortedMap<NK, NV> toSortedMap(
Function<? super T, ? extends NK> keyFunction,
Function<? super T, ? extends NV> valueFunction)
{
MutableSortedMap<NK, NV> sortedMap = TreeSortedMap.<NK, NV>newMap().asSynchronized();
this.forEach(new MapCollectProcedure<T, NK, NV>(sortedMap, keyFunction, valueFunction));
return sortedMap;
}
public <NK, NV> MutableSortedMap<NK, NV> toSortedMap(Comparator<? super NK> comparator,
Function<? super T, ? extends NK> keyFunction,
Function<? super T, ? extends NV> valueFunction)
{
MutableSortedMap<NK, NV> sortedMap = TreeSortedMap.<NK, NV>newMap(comparator).asSynchronized();
this.forEach(new MapCollectProcedure<T, NK, NV>(sortedMap, keyFunction, valueFunction));
return sortedMap;
}
public <K, V> MapIterable<K, V> aggregateBy(
Function<? super T, ? extends K> groupBy,
Function0<? extends V> zeroValueFactory,
Function2<? super V, ? super T, ? extends V> nonMutatingAggregator)
{
MutableMap<K, V> map = ConcurrentHashMapUnsafe.newMap();
this.forEach(new NonMutatingAggregationProcedure<T, K, V>(map, groupBy, zeroValueFactory, nonMutatingAggregator));
return map;
}
public <K, V> MapIterable<K, V> aggregateInPlaceBy(
Function<? super T, ? extends K> groupBy,
Function0<? extends V> zeroValueFactory,
Procedure2<? super V, ? super T> mutatingAggregator)
{
MutableMap<K, V> map = ConcurrentHashMapUnsafe.newMap();
this.forEach(new MutatingAggregationProcedure<T, K, V>(map, groupBy, zeroValueFactory, mutatingAggregator));
return map;
}
public int count(final Predicate<? super T> predicate)
{
Function<Batch<T>, Integer> map = new Function<Batch<T>, Integer>()
{
public Integer valueOf(Batch<T> batch)
{
return batch.count(predicate);
}
};
Procedure2<Counter, Integer> combineProcedure = new Procedure2<Counter, Integer>()
{
public void value(Counter counter, Integer eachCount)
{
counter.add(eachCount);
}
};
Counter state = new Counter();
this.collectCombineUnordered(map, combineProcedure, state);
return state.getCount();
}
public <P> int countWith(Predicate2<? super T, ? super P> predicate, P parameter)
{
return this.count(Predicates.bind(predicate, parameter));
}
public T min(final Comparator<? super T> comparator)
{
Function<Batch<T>, T> map = new Function<Batch<T>, T>()
{
public T valueOf(Batch<T> batch)
{
return batch.min(comparator);
}
};
return this.collectReduce(map, Functions2.min(comparator));
}
public T max(final Comparator<? super T> comparator)
{
Function<Batch<T>, T> map = new Function<Batch<T>, T>()
{
public T valueOf(Batch<T> batch)
{
return batch.max(comparator);
}
};
return this.collectReduce(map, Functions2.max(comparator));
}
public T min()
{
return this.min(Comparators.naturalOrder());
}
public T max()
{
return this.max(Comparators.naturalOrder());
}
public <V extends Comparable<? super V>> T minBy(final Function<? super T, ? extends V> function)
{
Function<Batch<T>, T> map = new Function<Batch<T>, T>()
{
public T valueOf(Batch<T> batch)
{
return batch.minBy(function);
}
};
return this.collectReduce(map, Functions2.minBy(function));
}
public <V extends Comparable<? super V>> T maxBy(final Function<? super T, ? extends V> function)
{
Function<Batch<T>, T> map = new Function<Batch<T>, T>()
{
public T valueOf(Batch<T> batch)
{
return batch.maxBy(function);
}
};
return this.collectReduce(map, Functions2.maxBy(function));
}
public long sumOfInt(final IntFunction<? super T> function)
{
LongFunction<Batch<T>> map = new LongFunction<Batch<T>>()
{
public long longValueOf(Batch<T> batch)
{
return batch.sumOfInt(function);
}
};
return this.sumOfLongOrdered(map);
}
public double sumOfFloat(final FloatFunction<? super T> function)
{
Function<Batch<T>, DoubleSumResultHolder> map = new Function<Batch<T>, DoubleSumResultHolder>()
{
public DoubleSumResultHolder valueOf(Batch<T> batch)
{
return batch.sumOfFloat(function);
}
};
return this.sumOfDoubleOrdered(map);
}
public long sumOfLong(final LongFunction<? super T> function)
{
LongFunction<Batch<T>> map = new LongFunction<Batch<T>>()
{
public long longValueOf(Batch<T> batch)
{
return batch.sumOfLong(function);
}
};
return this.sumOfLongOrdered(map);
}
public double sumOfDouble(final DoubleFunction<? super T> function)
{
Function<Batch<T>, DoubleSumResultHolder> map = new Function<Batch<T>, DoubleSumResultHolder>()
{
public DoubleSumResultHolder valueOf(Batch<T> batch)
{
return batch.sumOfDouble(function);
}
};
return this.sumOfDoubleOrdered(map);
}
private long sumOfLongOrdered(final LongFunction<Batch<T>> map)
{
LazyIterable<? extends Batch<T>> chunks = this.split();
LazyIterable<Future<Long>> futures = chunks.collect(new Function<Batch<T>, Future<Long>>()
{
public Future<Long> valueOf(final Batch<T> chunk)
{
return AbstractParallelIterable.this.getExecutorService().submit(new Callable<Long>()
{
public Long call()
{
return map.longValueOf(chunk);
}
});
}
});
// The call to toList() is important to stop the lazy evaluation and force all the Runnables to start executing.
MutableList<Future<Long>> futuresList = futures.toList();
try
{
long result = 0;
for (int i = 0; i < futuresList.size(); i++)
{
result += futuresList.get(i).get();
}
return result;
}
catch (InterruptedException e)
{
Thread.currentThread().interrupt();
throw new RuntimeException(e);
}
catch (ExecutionException e)
{
throw new RuntimeException(e);
}
}
private double sumOfDoubleOrdered(final Function<Batch<T>, DoubleSumResultHolder> map)
{
LazyIterable<? extends Batch<T>> chunks = this.split();
LazyIterable<Future<DoubleSumResultHolder>> futures = chunks.collect(new Function<Batch<T>, Future<DoubleSumResultHolder>>()
{
public Future<DoubleSumResultHolder> valueOf(final Batch<T> chunk)
{
return AbstractParallelIterable.this.getExecutorService().submit(new Callable<DoubleSumResultHolder>()
{
public DoubleSumResultHolder call()
{
return map.valueOf(chunk);
}
});
}
});
// The call to toList() is important to stop the lazy evaluation and force all the Runnables to start executing.
MutableList<Future<DoubleSumResultHolder>> futuresList = futures.toList();
try
{
double sum = 0.0d;
double compensation = 0.0d;
for (int i = 0; i < futuresList.size(); i++)
{
compensation += futuresList.get(i).get().getCompensation();
double adjustedValue = futuresList.get(i).get().getResult() - compensation;
double nextSum = sum + adjustedValue;
compensation = nextSum - sum - adjustedValue;
sum = nextSum;
}
return sum;
}
catch (InterruptedException e)
{
Thread.currentThread().interrupt();
throw new RuntimeException(e);
}
catch (ExecutionException e)
{
throw new RuntimeException(e);
}
}
public <V> MapIterable<V, T> groupByUniqueKey(final Function<? super T, ? extends V> function)
{
final MutableMap<V, T> result = ConcurrentHashMap.newMap();
this.forEach(new Procedure<T>()
{
public void value(T value)
{
V key = function.valueOf(value);
if (result.put(key, value) != null)
{
throw new IllegalStateException("Key " + key + " already exists in map!");
}
}
});
return result;
}
}