Package com.landawn.abacus.util.stream
Class ByteStream
java.lang.Object
com.landawn.abacus.util.stream.ByteStream
- All Implemented Interfaces:
Immutable
,BaseStream<Byte,
,byte[], BytePredicate, ByteConsumer, ByteList, u.OptionalByte, IndexedByte, ByteIterator, ByteStream> Closeable
,AutoCloseable
- Direct Known Subclasses:
ByteStream.ByteStreamEx
The Stream will be automatically closed after execution(A terminal method is executed/triggered).
- See Also:
-
Nested Class Summary
Nested ClassesNested classes/interfaces inherited from interface com.landawn.abacus.util.stream.BaseStream
BaseStream.ParallelSettings, BaseStream.Splitor
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Method Summary
Modifier and TypeMethodDescription<SS extends BaseStream>
SS__
(Function<? super ByteStream, ? extends SS> transfer) Deprecated.abstract <E extends Exception>
booleanallMatch
(Throwables.BytePredicate<E> predicate) abstract <E extends Exception>
booleananyMatch
(Throwables.BytePredicate<E> predicate) abstract ByteStream
append
(byte... a) abstract ByteStream
appendIfEmpty
(byte... a) abstract IntStream
abstract u.OptionalDouble
average()
boxed()
void
close()
It will be called by terminal operations in final.collapse
(ByteBiPredicate collapsible) Merge series of adjacent elements which satisfy the given predicate using the merger function and return a new stream.abstract ByteStream
collapse
(ByteBiPredicate collapsible, ByteBinaryOperator mergeFunction) Merge series of adjacent elements which satisfy the given predicate using the merger function and return a new stream.abstract ByteStream
collapse
(ByteTriPredicate collapsible, ByteBinaryOperator mergeFunction) abstract <R> R
collect
(Supplier<R> supplier, ObjByteConsumer<? super R> accumulator) Only call this method when the returned typeR
is one types:Collection/Map/StringBuilder/Multiset/LongMultiset/Multimap/BooleanList/IntList/.../DoubleList
.abstract <R> R
collect
(Supplier<R> supplier, ObjByteConsumer<? super R> accumulator, BiConsumer<R, R> combiner) static ByteStream
concat
(byte[]... a) static ByteStream
concat
(ByteIterator... a) static ByteStream
concat
(ByteStream... a) static ByteStream
concat
(Collection<? extends ByteStream> c) static ByteStream
static ByteStream
concatIterators
(Collection<? extends ByteIterator> c) static ByteStream
defer
(Supplier<ByteStream> supplier) Lazy evaluation.elementAt
(long position) static ByteStream
empty()
abstract <E extends Exception>
u.OptionalBytefindAny
(Throwables.BytePredicate<E> predicate) abstract <E extends Exception>
u.OptionalBytefindFirst
(Throwables.BytePredicate<E> predicate) abstract <E extends Exception>
u.OptionalBytefindFirstOrAny
(Throwables.BytePredicate<E> predicateForFirst) Returns the first element matched bypredicateForFirst
if found or the first element if this stream is not empty Otherwise an emptyOptionalByte
will be returned.abstract <E extends Exception>
u.OptionalBytefindFirstOrLast
(Throwables.BytePredicate<E> predicateForFirst) Returns the first element matched bypredicateForFirst
if found or the last element if this stream is not empty Otherwise an emptyOptionalByte
will be returned.abstract <E extends Exception>
u.OptionalBytefindLast
(Throwables.BytePredicate<E> predicate) Consider using:stream.reversed().findFirst(predicate)
for better performance if possible.abstract ByteStream
flatmap
(ByteFunction<byte[]> mapper) abstract ByteStream
flatMap
(ByteFunction<? extends ByteStream> mapper) abstract IntStream
flatMapToInt
(ByteFunction<? extends IntStream> mapper) abstract <T> Stream<T>
flatmapToObj
(ByteFunction<? extends Collection<? extends T>> mapper) abstract <T> Stream<T>
flatMapToObj
(ByteFunction<? extends Stream<? extends T>> mapper) static ByteStream
flatten
(byte[][] a) static ByteStream
flatten
(byte[][][] a) static ByteStream
flatten
(byte[][] a, boolean vertically) static ByteStream
flatten
(byte[][] a, byte valueForNone, boolean vertically) abstract <T> Stream<T>
flattMapToObj
(ByteFunction<T[]> mapper) abstract <E extends Exception>
voidforEach
(Throwables.ByteConsumer<E> action) abstract <E extends Exception>
voidforEachIndexed
(Throwables.IndexedByteConsumer<E> action) static ByteStream
groupTo
(Throwables.ByteFunction<? extends K, E> keyMapper, Collector<? super Byte, ?, D> downstream) groupTo
(Throwables.ByteFunction<? extends K, E> keyMapper, Collector<? super Byte, ?, D> downstream, Supplier<? extends M> mapFactory) boolean
static ByteStream
iterate
(byte init, BytePredicate hasNext, ByteUnaryOperator f) static ByteStream
iterate
(byte init, ByteUnaryOperator f) static ByteStream
iterate
(byte init, BooleanSupplier hasNext, ByteUnaryOperator f) static ByteStream
iterate
(BooleanSupplier hasNext, ByteSupplier next) iterator()
Remember to close this Stream after the iteration is done, if needed.join
(CharSequence delimiter) abstract u.OptionalByte
kthLargest
(int k) abstract ByteStream
map
(ByteUnaryOperator mapper) abstract ByteStream
mapPartial
(ByteFunction<u.OptionalByte> mapper) Note: copied from StreamEx: https://github.com/amaembo/streamexabstract IntStream
mapToInt
(ByteToIntFunction mapper) abstract <T> Stream<T>
mapToObj
(ByteFunction<? extends T> mapper) abstract u.OptionalByte
max()
static ByteStream
merge
(byte[] a, byte[] b, byte[] c, ByteBiFunction<MergeResult> nextSelector) static ByteStream
merge
(byte[] a, byte[] b, ByteBiFunction<MergeResult> nextSelector) static ByteStream
merge
(ByteIterator a, ByteIterator b, ByteIterator c, ByteBiFunction<MergeResult> nextSelector) static ByteStream
merge
(ByteIterator a, ByteIterator b, ByteBiFunction<MergeResult> nextSelector) static ByteStream
merge
(ByteStream a, ByteStream b, ByteBiFunction<MergeResult> nextSelector) static ByteStream
merge
(ByteStream a, ByteStream b, ByteStream c, ByteBiFunction<MergeResult> nextSelector) static ByteStream
merge
(Collection<? extends ByteStream> c, ByteBiFunction<MergeResult> nextSelector) abstract ByteStream
mergeWith
(ByteStream b, ByteBiFunction<MergeResult> nextSelector) abstract u.OptionalByte
min()
abstract <E extends Exception>
booleannoneMatch
(Throwables.BytePredicate<E> predicate) static ByteStream
of
(byte... a) static ByteStream
of
(byte[] a, int startIndex, int endIndex) static ByteStream
of
(ByteIterator iterator) static ByteStream
static ByteStream
of
(InputStream is) static ByteStream
of
(InputStream is, boolean closeReaderAferExecution) static ByteStream
static ByteStream
static ByteStream
of
(ByteBuffer buf) static ByteStream
of
(Collection<Byte> c) static ByteStream
ofNullable
(Byte e) parallel()
Consider usingsps(Function)
if only next operation need to be parallelized.parallel
(int maxThreadNum) Consider usingsps(int, Function)
if only next operation need to be parallelized.parallel
(int maxThreadNum, BaseStream.Splitor splitor) Returns an equivalent stream that is parallel.parallel
(int maxThreadNum, BaseStream.Splitor splitor, Executor executor) stream.parallel(maxThreadNum, splitor, executor).map(f).filter(p)...; // Replace above line of code with "sps" if only "f" need to be parallelized.// Replace above line of code with "sps" if only "f" need to be parallelized.stream.parallel(parallelSettings).map(f).filter(p)...; // Replace above line of code with "sps" if only "f" need to be parallelized.parallel
(BaseStream.Splitor splitor) stream.parallel(executor).map(f).filter(p)...; // Replace above line of code with "sps" if only "f" need to be parallelized.static ByteStream
parallelMerge
(Collection<? extends ByteStream> c, ByteBiFunction<MergeResult> nextSelector) All the elements from each inputCollection/Iterator/Stream
will be merged into two queues by multiple threads.static ByteStream
parallelMerge
(Collection<? extends ByteStream> c, ByteBiFunction<MergeResult> nextSelector, int maxThreadNum) All the elements from each inputCollection/Iterator/Stream
will be merged into two queues by multiple threads.peek
(ByteConsumer action) abstract ByteStream
prepend
(byte... a) void
println()
<SS extends BaseStream>
SSpsp
(Function<? super ByteStream, ? extends SS> ops) Temporarily switch the stream to sequence stream for operationops
and then switch back to parallel stream with samemaxThreadNum/splitor/asyncExecutor
.static ByteStream
random()
static ByteStream
range
(byte startInclusive, byte endExclusive) static ByteStream
range
(byte startInclusive, byte endExclusive, byte by) static ByteStream
rangeClosed
(byte startInclusive, byte endInclusive) static ByteStream
rangeClosed
(byte startInclusive, byte endInclusive, byte by) abstract ByteStream
rangeMap
(ByteBiPredicate sameRange, ByteBinaryOperator mapper) Note: copied from StreamEx: https://github.com/amaembo/streamex
Returns a stream consisting of results of applying the given function to the ranges created from the source elements.abstract <T> Stream<T>
rangeMapToObj
(ByteBiPredicate sameRange, ByteBiFunction<? extends T> mapper) Note: copied from StreamEx: https://github.com/amaembo/streamex
Returns a stream consisting of results of applying the given function to the ranges created from the source elements.rateLimited
(double permitsPerSecond) rateLimited
(RateLimiter rateLimiter) abstract byte
reduce
(byte identity, ByteBinaryOperator op) abstract u.OptionalByte
static ByteStream
repeat
(byte element, long n) abstract ByteStream
scan
(byte init, ByteBinaryOperator accumulator) Returns aStream
produced by iterative application of a accumulation function to an initial elementinit
and next element of the current stream.abstract ByteStream
scan
(byte init, ByteBinaryOperator accumulator, boolean initIncluded) abstract ByteStream
scan
(ByteBinaryOperator accumulator) Returns aStream
produced by iterative application of a accumulation function to an initial elementinit
and next element of the current stream.shuffled()
This method only runs sequentially, even in parallel stream and all elements will be loaded to memory.skipUntil
(BytePredicate predicate) sliding
(int windowSize) slidingToList
(int windowSize) <SS extends BaseStream>
SSsps
(int maxThreadNum, Function<? super ByteStream, ? extends SS> ops) Temporarily switch the stream to parallel stream for operationops
and then switch back to sequence stream.<SS extends BaseStream>
SSsps
(Function<? super ByteStream, ? extends SS> ops) Temporarily switch the stream to parallel stream for operationops
and then switch back to sequence stream.abstract int
sum()
abstract ByteSummaryStatistics
abstract Pair<ByteSummaryStatistics,
u.Optional<Map<Percentage, Byte>>> throwIfEmpty
(Supplier<? extends RuntimeException> exceptionSupplier) byte[]
toArray()
abstract ByteList
toMap
(Throwables.ByteFunction<? extends K, E> keyMapper, Throwables.ByteFunction<? extends V, E2> valueMapper) toMap
(Throwables.ByteFunction<? extends K, E> keyMapper, Throwables.ByteFunction<? extends V, E2> valueMapper, BinaryOperator<V> mergeFunction) toMap
(Throwables.ByteFunction<? extends K, E> keyMapper, Throwables.ByteFunction<? extends V, E2> valueMapper, BinaryOperator<V> mergeFunction, Supplier<? extends M> mapFactory) toMap
(Throwables.ByteFunction<? extends K, E> keyMapper, Throwables.ByteFunction<? extends V, E2> valueMapper, Supplier<? extends M> mapFactory) <SS extends BaseStream>
SStransform
(Function<? super ByteStream, ? extends SS> transfer) static ByteStream
zip
(byte[] a, byte[] b, byte[] c, byte valueForNoneA, byte valueForNoneB, byte valueForNoneC, ByteTernaryOperator zipFunction) Zip together the "a", "b" and "c" iterators until all of them runs out of values.static ByteStream
zip
(byte[] a, byte[] b, byte[] c, ByteTernaryOperator zipFunction) Zip together the "a", "b" and "c" arrays until one of them runs out of values.static ByteStream
zip
(byte[] a, byte[] b, byte valueForNoneA, byte valueForNoneB, ByteBinaryOperator zipFunction) Zip together the "a" and "b" iterators until all of them runs out of values.static ByteStream
zip
(byte[] a, byte[] b, ByteBinaryOperator zipFunction) Zip together the "a" and "b" arrays until one of them runs out of values.static ByteStream
zip
(ByteIterator a, ByteIterator b, byte valueForNoneA, byte valueForNoneB, ByteBinaryOperator zipFunction) Zip together the "a" and "b" iterators until all of them runs out of values.static ByteStream
zip
(ByteIterator a, ByteIterator b, ByteIterator c, byte valueForNoneA, byte valueForNoneB, byte valueForNoneC, ByteTernaryOperator zipFunction) Zip together the "a", "b" and "c" iterators until all of them runs out of values.static ByteStream
zip
(ByteIterator a, ByteIterator b, ByteIterator c, ByteTernaryOperator zipFunction) Zip together the "a", "b" and "c" iterators until one of them runs out of values.static ByteStream
zip
(ByteIterator a, ByteIterator b, ByteBinaryOperator zipFunction) Zip together the "a" and "b" iterators until one of them runs out of values.static ByteStream
zip
(ByteStream a, ByteStream b, byte valueForNoneA, byte valueForNoneB, ByteBinaryOperator zipFunction) Zip together the "a" and "b" iterators until all of them runs out of values.static ByteStream
zip
(ByteStream a, ByteStream b, ByteBinaryOperator zipFunction) Zip together the "a" and "b" streams until one of them runs out of values.static ByteStream
zip
(ByteStream a, ByteStream b, ByteStream c, byte valueForNoneA, byte valueForNoneB, byte valueForNoneC, ByteTernaryOperator zipFunction) Zip together the "a", "b" and "c" iterators until all of them runs out of values.static ByteStream
zip
(ByteStream a, ByteStream b, ByteStream c, ByteTernaryOperator zipFunction) Zip together the "a", "b" and "c" streams until one of them runs out of values.static ByteStream
zip
(Collection<? extends ByteStream> c, byte[] valuesForNone, ByteNFunction<Byte> zipFunction) Zip together the iterators until all of them runs out of values.static ByteStream
zip
(Collection<? extends ByteStream> c, ByteNFunction<Byte> zipFunction) Zip together the iterators until one of them runs out of values.abstract ByteStream
zipWith
(ByteStream b, byte valueForNoneA, byte valueForNoneB, ByteBinaryOperator zipFunction) abstract ByteStream
zipWith
(ByteStream b, ByteBinaryOperator zipFunction) abstract ByteStream
zipWith
(ByteStream b, ByteStream c, byte valueForNoneA, byte valueForNoneB, byte valueForNoneC, ByteTernaryOperator zipFunction) abstract ByteStream
zipWith
(ByteStream b, ByteStream c, ByteTernaryOperator zipFunction) Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods inherited from interface com.landawn.abacus.util.stream.BaseStream
acceptIfNotEmpty, append, append, appendIfEmpty, applyIfNotEmpty, count, cycled, cycled, difference, distinct, dropWhile, dropWhile, filter, filter, first, indexed, intersection, join, last, limit, onClose, onEach, onlyOne, percentiles, prepend, prepend, reversed, reverseSorted, rotated, shuffled, skip, skip, sliding, slidingToList, sorted, split, split, splitAt, splitAt, splitToList, splitToList, step, symmetricDifference, takeWhile, toCollection, toList, toLongMultiset, toLongMultiset, toMultiset, toMultiset, toSet
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Method Details
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rateLimited
- Parameters:
rateLimiter
-- Returns:
- See Also:
-
delay
- Parameters:
delay
-- Returns:
-
skipUntil
- Parameters:
predicate
-- Returns:
- See Also:
-
map
- Parameters:
mapper
-- Returns:
-
mapToInt
- Parameters:
mapper
-- Returns:
-
mapToObj
@ParallelSupported @IntermediateOp public abstract <T> Stream<T> mapToObj(ByteFunction<? extends T> mapper) - Type Parameters:
T
-- Parameters:
mapper
-- Returns:
-
flatMap
@ParallelSupported @IntermediateOp public abstract ByteStream flatMap(ByteFunction<? extends ByteStream> mapper) - Parameters:
mapper
-- Returns:
-
flatmap
- Parameters:
mapper
-- Returns:
-
flatMapToInt
@ParallelSupported @IntermediateOp public abstract IntStream flatMapToInt(ByteFunction<? extends IntStream> mapper) - Parameters:
mapper
-- Returns:
-
flatMapToObj
@ParallelSupported @IntermediateOp public abstract <T> Stream<T> flatMapToObj(ByteFunction<? extends Stream<? extends T>> mapper) - Type Parameters:
T
-- Parameters:
mapper
-- Returns:
-
flatmapToObj
@ParallelSupported @IntermediateOp public abstract <T> Stream<T> flatmapToObj(ByteFunction<? extends Collection<? extends T>> mapper) - Type Parameters:
T
-- Parameters:
mapper
-- Returns:
-
flattMapToObj
@ParallelSupported @IntermediateOp public abstract <T> Stream<T> flattMapToObj(ByteFunction<T[]> mapper) - Type Parameters:
T
-- Parameters:
mapper
-- Returns:
-
mapPartial
@Beta @ParallelSupported @IntermediateOp public abstract ByteStream mapPartial(ByteFunction<u.OptionalByte> mapper) Note: copied from StreamEx: https://github.com/amaembo/streamex- Parameters:
mapper
-- Returns:
-
rangeMap
@SequentialOnly @IntermediateOp public abstract ByteStream rangeMap(ByteBiPredicate sameRange, ByteBinaryOperator mapper) Note: copied from StreamEx: https://github.com/amaembo/streamex
Returns a stream consisting of results of applying the given function to the ranges created from the source elements. This is a quasi-intermediate partial reduction operation.- Parameters:
sameRange
- a non-interfering, stateless predicate to apply to the leftmost and next elements which returns true for elements which belong to the same range.mapper
- a non-interfering, stateless function to apply to the range borders and produce the resulting element. If value was not merged to the interval, then mapper will receive the same value twice, otherwise it will receive the leftmost and the rightmost values which were merged to the range.- Returns:
- See Also:
-
rangeMapToObj
@SequentialOnly @IntermediateOp public abstract <T> Stream<T> rangeMapToObj(ByteBiPredicate sameRange, ByteBiFunction<? extends T> mapper) Note: copied from StreamEx: https://github.com/amaembo/streamex
Returns a stream consisting of results of applying the given function to the ranges created from the source elements. This is a quasi-intermediate partial reduction operation.- Type Parameters:
T
-- Parameters:
sameRange
- a non-interfering, stateless predicate to apply to the leftmost and next elements which returns true for elements which belong to the same range.mapper
- a non-interfering, stateless function to apply to the range borders and produce the resulting element. If value was not merged to the interval, then mapper will receive the same value twice, otherwise it will receive the leftmost and the rightmost values which were merged to the range.- Returns:
- See Also:
-
collapse
@SequentialOnly @IntermediateOp public abstract Stream<ByteList> collapse(ByteBiPredicate collapsible) Merge series of adjacent elements which satisfy the given predicate using the merger function and return a new stream.
This method only runs sequentially, even in parallel stream.- Parameters:
collapsible
-- Returns:
-
collapse
@SequentialOnly @IntermediateOp public abstract ByteStream collapse(ByteBiPredicate collapsible, ByteBinaryOperator mergeFunction) Merge series of adjacent elements which satisfy the given predicate using the merger function and return a new stream.
This method only runs sequentially, even in parallel stream.- Parameters:
collapsible
-mergeFunction
-- Returns:
-
collapse
@SequentialOnly @IntermediateOp public abstract ByteStream collapse(ByteTriPredicate collapsible, ByteBinaryOperator mergeFunction) - Parameters:
collapsible
- test the current element with the first element and previous element in the series. The first parameter is the first element of this series, the second parameter is the previous element and the third parameter is the current element.mergeFunction
-- Returns:
-
scan
Returns aStream
produced by iterative application of a accumulation function to an initial elementinit
and next element of the current stream. Produces aStream
consisting ofinit
,acc(init, value1)
,acc(acc(init, value1), value2)
, etc.This is an intermediate operation.
Example:
accumulator: (a, b) -> a + b stream: [1, 2, 3, 4, 5] result: [1, 3, 6, 10, 15]
This method only runs sequentially, even in parallel stream.- Parameters:
accumulator
- the accumulation function- Returns:
-
scan
@SequentialOnly @IntermediateOp public abstract ByteStream scan(byte init, ByteBinaryOperator accumulator) Returns aStream
produced by iterative application of a accumulation function to an initial elementinit
and next element of the current stream. Produces aStream
consisting ofinit
,acc(init, value1)
,acc(acc(init, value1), value2)
, etc.This is an intermediate operation.
Example:
init:10 accumulator: (a, b) -> a + b stream: [1, 2, 3, 4, 5] result: [11, 13, 16, 20, 25]
This method only runs sequentially, even in parallel stream.- Parameters:
init
- the initial value. it's only used once byaccumulator
to calculate the fist element in the returned stream. It will be ignored if this stream is empty and won't be the first element of the returned stream.accumulator
- the accumulation function- Returns:
-
scan
@SequentialOnly @IntermediateOp public abstract ByteStream scan(byte init, ByteBinaryOperator accumulator, boolean initIncluded) - Parameters:
init
-accumulator
-initIncluded
-- Returns:
-
prepend
- Parameters:
a
-- Returns:
-
append
- Parameters:
a
-- Returns:
-
appendIfEmpty
- Parameters:
a
-- Returns:
-
toByteList
- Returns:
-
toMap
@ParallelSupported @TerminalOp public abstract <K,V, Map<K,E extends Exception, E2 extends Exception> V> toMap(Throwables.ByteFunction<? extends K, E> keyMapper, Throwables.ByteFunction<? extends V, throws E, E2E2> valueMapper) - Type Parameters:
K
-V
-E
-E2
-- Parameters:
keyMapper
-valueMapper
-- Returns:
- Throws:
E
E2
- See Also:
-
toMap
@ParallelSupported @TerminalOp public abstract <K,V, M toMapM extends Map<K, V>, E extends Exception, E2 extends Exception> (Throwables.ByteFunction<? extends K, E> keyMapper, Throwables.ByteFunction<? extends V, throws E, E2E2> valueMapper, Supplier<? extends M> mapFactory) - Type Parameters:
K
-V
-M
-E
-E2
-- Parameters:
keyMapper
-valueMapper
-mapFactory
-- Returns:
- Throws:
E
E2
- See Also:
-
toMap
@ParallelSupported @TerminalOp public abstract <K,V, Map<K,E extends Exception, E2 extends Exception> V> toMap(Throwables.ByteFunction<? extends K, E> keyMapper, Throwables.ByteFunction<? extends V, throws E, E2E2> valueMapper, BinaryOperator<V> mergeFunction) - Type Parameters:
K
-V
-E
-E2
-- Parameters:
keyMapper
-valueMapper
-mergeFunction
-- Returns:
- Throws:
E
E2
- See Also:
-
toMap
@ParallelSupported @TerminalOp public abstract <K,V, M toMapM extends Map<K, V>, E extends Exception, E2 extends Exception> (Throwables.ByteFunction<? extends K, E> keyMapper, Throwables.ByteFunction<? extends V, throws E, E2E2> valueMapper, BinaryOperator<V> mergeFunction, Supplier<? extends M> mapFactory) - Type Parameters:
K
-V
-M
-E
-E2
-- Parameters:
keyMapper
-valueMapper
-mergeFunction
-mapFactory
-- Returns:
- Throws:
E
E2
- See Also:
-
groupTo
@ParallelSupported @TerminalOp public abstract <K,D, Map<K,E extends Exception> D> groupTo(Throwables.ByteFunction<? extends K, E> keyMapper, Collector<? super Byte, throws E?, D> downstream) - Type Parameters:
K
-D
-E
-- Parameters:
keyMapper
-downstream
-- Returns:
- Throws:
E
- See Also:
-
groupTo
@ParallelSupported @TerminalOp public abstract <K,D, M groupToM extends Map<K, D>, E extends Exception> (Throwables.ByteFunction<? extends K, E> keyMapper, Collector<? super Byte, throws E?, D> downstream, Supplier<? extends M> mapFactory) - Type Parameters:
K
-D
-M
-E
-- Parameters:
keyMapper
-downstream
-mapFactory
-- Returns:
- Throws:
E
- See Also:
-
reduce
- Parameters:
identity
-op
-- Returns:
-
reduce
- Parameters:
op
-- Returns:
-
collect
@ParallelSupported @TerminalOp public abstract <R> R collect(Supplier<R> supplier, ObjByteConsumer<? super R> accumulator, BiConsumer<R, R> combiner) - Type Parameters:
R
-- Parameters:
supplier
-accumulator
-combiner
-- Returns:
- See Also:
-
collect
@ParallelSupported @TerminalOp public abstract <R> R collect(Supplier<R> supplier, ObjByteConsumer<? super R> accumulator) Only call this method when the returned typeR
is one types:Collection/Map/StringBuilder/Multiset/LongMultiset/Multimap/BooleanList/IntList/.../DoubleList
. Otherwise, please callcollect(Supplier, ObjByteConsumer, BiConsumer)
.- Type Parameters:
R
-- Parameters:
supplier
-accumulator
-- Returns:
- See Also:
-
forEach
@ParallelSupported @TerminalOp public abstract <E extends Exception> void forEach(Throwables.ByteConsumer<E> action) throws E - Type Parameters:
E
-- Parameters:
action
-- Throws:
E
-
forEachIndexed
@ParallelSupported @TerminalOp public abstract <E extends Exception> void forEachIndexed(Throwables.IndexedByteConsumer<E> action) throws E - Type Parameters:
E
-- Parameters:
action
-- Throws:
E
-
anyMatch
@ParallelSupported @TerminalOp public abstract <E extends Exception> boolean anyMatch(Throwables.BytePredicate<E> predicate) throws E - Type Parameters:
E
-- Parameters:
predicate
-- Returns:
- Throws:
E
-
allMatch
@ParallelSupported @TerminalOp public abstract <E extends Exception> boolean allMatch(Throwables.BytePredicate<E> predicate) throws E - Type Parameters:
E
-- Parameters:
predicate
-- Returns:
- Throws:
E
-
noneMatch
@ParallelSupported @TerminalOp public abstract <E extends Exception> boolean noneMatch(Throwables.BytePredicate<E> predicate) throws E - Type Parameters:
E
-- Parameters:
predicate
-- Returns:
- Throws:
E
-
findFirst
@ParallelSupported @TerminalOp public abstract <E extends Exception> u.OptionalByte findFirst(Throwables.BytePredicate<E> predicate) throws E - Type Parameters:
E
-- Parameters:
predicate
-- Returns:
- Throws:
E
-
findFirstOrAny
@ParallelSupported @TerminalOp public abstract <E extends Exception> u.OptionalByte findFirstOrAny(Throwables.BytePredicate<E> predicateForFirst) throws E Returns the first element matched bypredicateForFirst
if found or the first element if this stream is not empty Otherwise an emptyOptionalByte
will be returned.- Type Parameters:
E
-- Parameters:
predicateForFirst
-- Returns:
- Throws:
E
-
findFirstOrLast
@ParallelSupported @TerminalOp public abstract <E extends Exception> u.OptionalByte findFirstOrLast(Throwables.BytePredicate<E> predicateForFirst) throws E Returns the first element matched bypredicateForFirst
if found or the last element if this stream is not empty Otherwise an emptyOptionalByte
will be returned.- Type Parameters:
E
-- Parameters:
predicateForFirst
-- Returns:
- Throws:
E
-
findLast
@ParallelSupported @TerminalOp public abstract <E extends Exception> u.OptionalByte findLast(Throwables.BytePredicate<E> predicate) throws E Consider using:stream.reversed().findFirst(predicate)
for better performance if possible.- Type Parameters:
E
-- Parameters:
predicate
-- Returns:
- Throws:
E
-
findAny
@ParallelSupported @TerminalOp public abstract <E extends Exception> u.OptionalByte findAny(Throwables.BytePredicate<E> predicate) throws E - Type Parameters:
E
-- Parameters:
predicate
-- Returns:
- Throws:
E
-
min
- Returns:
-
max
- Returns:
-
kthLargest
- Parameters:
k
-- Returns:
- OptionalByte.empty() if there is no element or count less than k, otherwise the kth largest element.
-
sum
- Returns:
- int
-
average
- Returns:
-
summarize
- Returns:
-
summarizeAndPercentiles
@SequentialOnly @TerminalOp public abstract Pair<ByteSummaryStatistics,u.Optional<Map<Percentage, summarizeAndPercentiles()Byte>>> - Returns:
-
mergeWith
@SequentialOnly @IntermediateOp public abstract ByteStream mergeWith(ByteStream b, ByteBiFunction<MergeResult> nextSelector) - Parameters:
b
-nextSelector
- first parameter is selected ifNth.FIRST
is returned, otherwise the second parameter is selected.- Returns:
-
zipWith
@ParallelSupported @IntermediateOp public abstract ByteStream zipWith(ByteStream b, ByteBinaryOperator zipFunction) - Parameters:
b
-zipFunction
-- Returns:
-
zipWith
@ParallelSupported @IntermediateOp public abstract ByteStream zipWith(ByteStream b, ByteStream c, ByteTernaryOperator zipFunction) - Parameters:
b
-c
-zipFunction
-- Returns:
-
zipWith
@ParallelSupported @IntermediateOp public abstract ByteStream zipWith(ByteStream b, byte valueForNoneA, byte valueForNoneB, ByteBinaryOperator zipFunction) - Parameters:
b
-valueForNoneA
-valueForNoneB
-zipFunction
-- Returns:
-
zipWith
@ParallelSupported @IntermediateOp public abstract ByteStream zipWith(ByteStream b, ByteStream c, byte valueForNoneA, byte valueForNoneB, byte valueForNoneC, ByteTernaryOperator zipFunction) - Parameters:
b
-c
-valueForNoneA
-valueForNoneB
-valueForNoneC
-zipFunction
-- Returns:
-
asIntStream
- Returns:
-
boxed
- Returns:
-
iterator
Remember to close this Stream after the iteration is done, if needed.- Returns:
-
empty
- Returns:
-
ofNullable
- Parameters:
e
-- Returns:
-
of
- Parameters:
a
-- Returns:
-
of
- Parameters:
a
-startIndex
-endIndex
-- Returns:
-
of
- Parameters:
a
-- Returns:
-
of
- Parameters:
a
-startIndex
-endIndex
-- Returns:
-
of
- Parameters:
c
-- Returns:
-
of
- Parameters:
iterator
-- Returns:
-
of
- Parameters:
buf
-- Returns:
-
of
- Parameters:
file
-- Returns:
-
of
- Parameters:
is
-- Returns:
-
of
- Parameters:
is
-closeReaderAferExecution
-- Returns:
-
defer
Lazy evaluation.
This is equal to:Stream.just(supplier).flatMapToByte(it -> it.get())
.- Parameters:
supplier
-- Returns:
-
flatten
- Parameters:
a
-- Returns:
-
flatten
- Parameters:
a
-vertically
-- Returns:
-
flatten
- Parameters:
a
-valueForNone
-vertically
-- Returns:
-
flatten
- Parameters:
a
-- Returns:
-
range
- Parameters:
startInclusive
-endExclusive
-- Returns:
-
range
- Parameters:
startInclusive
-endExclusive
-by
-- Returns:
-
rangeClosed
- Parameters:
startInclusive
-endInclusive
-- Returns:
-
rangeClosed
- Parameters:
startInclusive
-endInclusive
-by
-- Returns:
-
repeat
- Parameters:
element
-n
-- Returns:
-
random
- Returns:
-
iterate
- Parameters:
hasNext
-next
-- Returns:
-
iterate
- Parameters:
init
-hasNext
-f
-- Returns:
-
iterate
- Parameters:
init
-hasNext
- test if has next by hasNext.test(init) for first time and hasNext.test(f.apply(previous)) for remaining.f
-- Returns:
-
iterate
- Parameters:
init
-f
-- Returns:
-
generate
- Parameters:
s
-- Returns:
-
concat
- Parameters:
a
-- Returns:
-
concat
- Parameters:
a
-- Returns:
-
concat
- Parameters:
a
-- Returns:
-
concat
- Parameters:
c
-- Returns:
-
concat
- Parameters:
c
-- Returns:
-
concatIterators
- Parameters:
c
-- Returns:
-
zip
Zip together the "a" and "b" arrays until one of them runs out of values. Each pair of values is combined into a single value using the supplied zipFunction function.- Parameters:
a
-b
-zipFunction
-- Returns:
-
zip
Zip together the "a", "b" and "c" arrays until one of them runs out of values. Each triple of values is combined into a single value using the supplied zipFunction function.- Parameters:
a
-b
-c
-zipFunction
-- Returns:
-
zip
Zip together the "a" and "b" iterators until one of them runs out of values. Each pair of values is combined into a single value using the supplied zipFunction function.- Parameters:
a
-b
-zipFunction
-- Returns:
-
zip
public static ByteStream zip(ByteIterator a, ByteIterator b, ByteIterator c, ByteTernaryOperator zipFunction) Zip together the "a", "b" and "c" iterators until one of them runs out of values. Each triple of values is combined into a single value using the supplied zipFunction function.- Parameters:
a
-b
-c
-zipFunction
-- Returns:
-
zip
Zip together the "a" and "b" streams until one of them runs out of values. Each pair of values is combined into a single value using the supplied zipFunction function.- Parameters:
a
-b
-zipFunction
-- Returns:
-
zip
public static ByteStream zip(ByteStream a, ByteStream b, ByteStream c, ByteTernaryOperator zipFunction) Zip together the "a", "b" and "c" streams until one of them runs out of values. Each triple of values is combined into a single value using the supplied zipFunction function.- Parameters:
a
-b
-c
-zipFunction
-- Returns:
-
zip
Zip together the iterators until one of them runs out of values. Each array of values is combined into a single value using the supplied zipFunction function.- Parameters:
c
-zipFunction
-- Returns:
-
zip
public static ByteStream zip(byte[] a, byte[] b, byte valueForNoneA, byte valueForNoneB, ByteBinaryOperator zipFunction) Zip together the "a" and "b" iterators until all of them runs out of values. Each pair of values is combined into a single value using the supplied zipFunction function.- Parameters:
a
-b
-valueForNoneA
- value to fill if "a" runs out of values first.valueForNoneB
- value to fill if "b" runs out of values first.zipFunction
-- Returns:
-
zip
public static ByteStream zip(byte[] a, byte[] b, byte[] c, byte valueForNoneA, byte valueForNoneB, byte valueForNoneC, ByteTernaryOperator zipFunction) Zip together the "a", "b" and "c" iterators until all of them runs out of values. Each triple of values is combined into a single value using the supplied zipFunction function.- Parameters:
a
-b
-c
-valueForNoneA
- value to fill if "a" runs out of values.valueForNoneB
- value to fill if "b" runs out of values.valueForNoneC
- value to fill if "c" runs out of values.zipFunction
-- Returns:
-
zip
public static ByteStream zip(ByteIterator a, ByteIterator b, byte valueForNoneA, byte valueForNoneB, ByteBinaryOperator zipFunction) Zip together the "a" and "b" iterators until all of them runs out of values. Each pair of values is combined into a single value using the supplied zipFunction function.- Parameters:
a
-b
-valueForNoneA
- value to fill if "a" runs out of values first.valueForNoneB
- value to fill if "b" runs out of values first.zipFunction
-- Returns:
-
zip
public static ByteStream zip(ByteIterator a, ByteIterator b, ByteIterator c, byte valueForNoneA, byte valueForNoneB, byte valueForNoneC, ByteTernaryOperator zipFunction) Zip together the "a", "b" and "c" iterators until all of them runs out of values. Each triple of values is combined into a single value using the supplied zipFunction function.- Parameters:
a
-b
-c
-valueForNoneA
- value to fill if "a" runs out of values.valueForNoneB
- value to fill if "b" runs out of values.valueForNoneC
- value to fill if "c" runs out of values.zipFunction
-- Returns:
-
zip
public static ByteStream zip(ByteStream a, ByteStream b, byte valueForNoneA, byte valueForNoneB, ByteBinaryOperator zipFunction) Zip together the "a" and "b" iterators until all of them runs out of values. Each pair of values is combined into a single value using the supplied zipFunction function.- Parameters:
a
-b
-valueForNoneA
- value to fill if "a" runs out of values first.valueForNoneB
- value to fill if "b" runs out of values first.zipFunction
-- Returns:
-
zip
public static ByteStream zip(ByteStream a, ByteStream b, ByteStream c, byte valueForNoneA, byte valueForNoneB, byte valueForNoneC, ByteTernaryOperator zipFunction) Zip together the "a", "b" and "c" iterators until all of them runs out of values. Each triple of values is combined into a single value using the supplied zipFunction function.- Parameters:
a
-b
-c
-valueForNoneA
- value to fill if "a" runs out of values.valueForNoneB
- value to fill if "b" runs out of values.valueForNoneC
- value to fill if "c" runs out of values.zipFunction
-- Returns:
-
zip
public static ByteStream zip(Collection<? extends ByteStream> c, byte[] valuesForNone, ByteNFunction<Byte> zipFunction) Zip together the iterators until all of them runs out of values. Each array of values is combined into a single value using the supplied zipFunction function.- Parameters:
c
-valuesForNone
- value to fill for any iterator runs out of values.zipFunction
-- Returns:
-
merge
- Parameters:
a
-b
-nextSelector
- first parameter is selected ifNth.FIRST
is returned, otherwise the second parameter is selected.- Returns:
-
merge
public static ByteStream merge(byte[] a, byte[] b, byte[] c, ByteBiFunction<MergeResult> nextSelector) - Parameters:
a
-b
-c
-nextSelector
- first parameter is selected ifNth.FIRST
is returned, otherwise the second parameter is selected.- Returns:
-
merge
public static ByteStream merge(ByteIterator a, ByteIterator b, ByteBiFunction<MergeResult> nextSelector) - Parameters:
a
-b
-nextSelector
- first parameter is selected ifNth.FIRST
is returned, otherwise the second parameter is selected.- Returns:
-
merge
public static ByteStream merge(ByteIterator a, ByteIterator b, ByteIterator c, ByteBiFunction<MergeResult> nextSelector) - Parameters:
a
-b
-c
-nextSelector
- first parameter is selected ifNth.FIRST
is returned, otherwise the second parameter is selected.- Returns:
-
merge
public static ByteStream merge(ByteStream a, ByteStream b, ByteBiFunction<MergeResult> nextSelector) - Parameters:
a
-b
-nextSelector
- first parameter is selected ifNth.FIRST
is returned, otherwise the second parameter is selected.- Returns:
-
merge
public static ByteStream merge(ByteStream a, ByteStream b, ByteStream c, ByteBiFunction<MergeResult> nextSelector) - Parameters:
a
-b
-c
-nextSelector
- first parameter is selected ifNth.FIRST
is returned, otherwise the second parameter is selected.- Returns:
-
merge
public static ByteStream merge(Collection<? extends ByteStream> c, ByteBiFunction<MergeResult> nextSelector) - Parameters:
c
-nextSelector
- first parameter is selected ifNth.FIRST
is returned, otherwise the second parameter is selected.- Returns:
-
parallelMerge
public static ByteStream parallelMerge(Collection<? extends ByteStream> c, ByteBiFunction<MergeResult> nextSelector) All the elements from each inputCollection/Iterator/Stream
will be merged into two queues by multiple threads. Then these two new queues will be merged into oneIterator/Stream
by one thread. So it's not totally lazy evaluation and may cause out of memory error if there are too many elements merged into the new queues. Consider usingmerge
, which is totally lazy evaluation.- Parameters:
c
-nextSelector
- first parameter is selected ifNth.FIRST
is returned, otherwise the second parameter is selected.- Returns:
-
parallelMerge
public static ByteStream parallelMerge(Collection<? extends ByteStream> c, ByteBiFunction<MergeResult> nextSelector, int maxThreadNum) All the elements from each inputCollection/Iterator/Stream
will be merged into two queues by multiple threads. Then these two new queues will be merged into oneIterator/Stream
by one thread. So it's not totally lazy evaluation and may cause out of memory error if there are too many elements merged into the new queues. Consider usingmerge
, which is totally lazy evaluation.- Parameters:
c
-nextSelector
- first parameter is selected ifNth.FIRST
is returned, otherwise the second parameter is selected.maxThreadNum
-- Returns:
-
elementAt
- Specified by:
elementAt
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Parameters:
position
-- Returns:
-
rateLimited
- Specified by:
rateLimited
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Parameters:
permitsPerSecond
-- Returns:
- See Also:
-
peek
- Specified by:
peek
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Parameters:
action
-- Returns:
-
sliding
- Specified by:
sliding
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Parameters:
windowSize
-- Returns:
- See Also:
-
slidingToList
- Specified by:
slidingToList
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Parameters:
windowSize
-- Returns:
- See Also:
-
shuffled
Description copied from interface:BaseStream
This method only runs sequentially, even in parallel stream and all elements will be loaded to memory.- Specified by:
shuffled
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Returns:
-
throwIfEmpty
- Specified by:
throwIfEmpty
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Returns:
-
throwIfEmpty
@SequentialOnly @IntermediateOp public ByteStream throwIfEmpty(Supplier<? extends RuntimeException> exceptionSupplier) - Specified by:
throwIfEmpty
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Parameters:
exceptionSupplier
-- Returns:
-
toImmutableList
- Specified by:
toImmutableList
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Returns:
-
toImmutableSet
- Specified by:
toImmutableSet
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Returns:
-
join
- Specified by:
join
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Parameters:
delimiter
-- Returns:
-
println
public void println()- Specified by:
println
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>>
-
transform
- Specified by:
transform
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Type Parameters:
SS
-- Parameters:
transfer
-- Returns:
-
__
@Deprecated public <SS extends BaseStream> SS __(Function<? super ByteStream, ? extends SS> transfer) Deprecated.replaced byBaseStream.transform(Function)
- Specified by:
__
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Type Parameters:
SS
-- Parameters:
transfer
-- Returns:
-
isParallel
public boolean isParallel()- Specified by:
isParallel
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Returns:
-
sequential
- Specified by:
sequential
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Returns:
-
parallel
Description copied from interface:BaseStream
Consider usingsps(Function)
if only next operation need to be parallelized. For example:stream.parallel().map(f).filter(p)...; // Replace above line of code with "sps" if only "f" need to be parallelized. And "p" is fast enough to be executed in sequential Stream. stream.sps(s -> s.map(f)).filter(p)...; // Or switch the stream back sequential stream if don't use "sps". stream.parallel().map(f).sequential().filter(p)...;
In most scenarios, there could be only one operation need be parallelized in the stream. Sosps(Function)
is recommended in most of scenarios.- Specified by:
parallel
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Returns:
- See Also:
-
parallel
Description copied from interface:BaseStream
Consider usingsps(int, Function)
if only next operation need to be parallelized. For example:stream.parallel(maxThreadNum).map(f).filter(p)...; // Replace above line of code with "sps" if only "f" need to be parallelized. And "p" is fast enough to be executed in sequential Stream. stream.sps(maxThreadNum, s -> s.map(f)).filter(p)...; // Or switch the stream back sequential stream if don't use "sps". stream.parallel(maxThreadNum).map(f).sequential().filter(p)...;
In most scenarios, there could be only one operation need be parallelized in the stream. Sosps(int, Function)
is recommended in most of scenarios.- Specified by:
parallel
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Parameters:
maxThreadNum
-- Returns:
- See Also:
-
parallel
- Specified by:
parallel
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Parameters:
splitor
-- Returns:
- See Also:
-
parallel
Description copied from interface:BaseStream
Returns an equivalent stream that is parallel. May return itself if the stream was already parallel with the samemaxThreadNum
andsplitor
as the specified ones.
When to use parallel Streams?- First of all, do NOT and should NOT use parallel Streams if you don't have any problem with sequential Streams, because using parallel Streams has extra cost.
- Consider using parallel Streams only when N(the number of elements) * Q(cost per element of F, the per-element function (usually a lambda)) is big enough(e.g. IO involved. Network: DB/web service request..., Reading/Writing file...).
- It's easy to test out the differences of performance by sequential Streams and parallel Streams with Profiler:
Profiler.run(1, 1, 3, "sequential", () -> Stream.of(list).operation(F)...).printResult(); Profiler.run(1, 1, 3, "parallel", () -> Stream.of(list).parallel().operation(F)...).printResult();
public void test_perf() { final String[] strs = new String[10_000]; N.fill(strs, Strings.uuid()); final int m = 10; final Function<String, Long> mapper = str -> { long result = 0; for (int i = 0; i < m; i++) { result += N.sum(str.toCharArray()) + 1; } return result; }; final MutableLong sum = MutableLong.of(0); for (int i = 0, len = strs.length; i < len; i++) { sum.add(mapper.apply(strs[i])); } final int threadNum = 1, loopNum = 100, roundNum = 3; Profiler.run(threadNum, loopNum, roundNum, "For Loop", () -> { long result = 0; for (int i = 0, len = strs.length; i < len; i++) { result += mapper.apply(strs[i]); } assertEquals(sum.longValue(), result); }).printResult(); Profiler.run(threadNum, loopNum, roundNum, "JDK Sequential", () -> assertEquals(sum.longValue(), java.util.stream.Stream.of(strs).map(mapper).mapToLong(e -> e).sum())).printResult(); Profiler.run(threadNum, loopNum, roundNum, "JDK Parallel", () -> assertEquals(sum.longValue(), java.util.stream.Stream.of(strs).parallel().map(mapper).mapToLong(e -> e).sum())).printResult(); Profiler.run(threadNum, loopNum, roundNum, "Abcus Sequential", () -> assertEquals(sum.longValue(), Stream.of(strs).map(mapper).mapToLong(e -> e).sum())) .printResult(); Profiler.run(threadNum, loopNum, roundNum, "Abcus Parallel", () -> assertEquals(sum.longValue(), Stream.of(strs).parallel().map(mapper).mapToLong(e -> e).sum())).printResult(); Profiler.run(threadNum, loopNum, roundNum, "Abcus Parallel by chunck", () -> assertEquals(sum.longValue(), Stream.of(strs).splitToList(100).parallel().map(it -> N.sumLong(it, e -> mapper.apply(e))).mapToLong(e -> e).sum())).printResult(); }
mapper
) is calculated by: value of 'For loop' / N(10_000).m = 1 m = 10 m = 50 m = 100 m = 500 m = 1000 Q 0.00002 0.0002 0.001 0.002 0.01 0.02 For Loop 0.23 2.3 11 22 110 219 JDK Sequential 0.28 2.3 11 22 114 212 JDK Parallel 0.22 1.3 6 12 66 122 Abcus Sequential 0.3 2 11 22 112 212 Abcus Parallel 11 11 11 16 77 128 - Again, do NOT and should NOT use parallel Streams if you don't have any performance problem with sequential Streams, because using parallel Streams has extra cost.
- Again, consider using parallel Streams only when N(the number of elements) * Q(cost per element of F, the per-element function (usually a lambda)) is big enough.
- The implementation of parallel Streams in Abacus is more than 10 times, slower than parallel Streams in JDK when Q is tiny(here is less than 0.0002 milliseconds by the test):
- The implementation of parallel Streams in JDK 8 still can beat the sequential/for loop when Q is tiny(Here is 0.00002 milliseconds by the test). That's amazing, considering the extra cost brought by parallel computation. It's well done.
- The implementation of parallel Streams in Abacus is pretty simple and straight forward. The extra cost(starting threads/synchronization/queue...) brought by parallel Streams in Abacus is too bigger to tiny Q(Here is less than 0.001 milliseconds by the test). But it starts to be faster than sequential Streams when Q is big enough(Here is 0.001 milliseconds by the test) and starts to catch the parallel Streams in JDK when Q is bigger(Here is 0.01 milliseconds by the test).
- Consider using the parallel Streams in Abacus when Q is big enough, specially when IO involved in F. Because one IO operation(e.g. DB/web service request..., Reading/Writing file...) usually takes 1 to 1000 milliseconds, or even longer. By the parallel Streams APIs in Abacus, it's very simple to specify max thread numbers. Sometimes, it's much faster to execute IO/Network requests with a bit more threads. It's fair to say that the parallel Streams in Abacus is high efficient, may same as or faster than the parallel Streams in JDK when Q is big enough, except F is heavy cpu-used operation. Most of the times, the Q is big enough to consider using parallel Stream is because IO/Network is involved in F.
- JDK 7 is supported by the Streams in Abacus. It's perfect to work with retrolambda on Android
- All primitive types are supported by Stream APIs in Abacus except boolean
A bit more about Lambdas/Stream APIs, you may heard that Lambdas/Stream APIs is 5 time slower than imperative programming. It's true when Q and F is VERY, VERY tiny, likef = (int a, int b) -> a + b;
. But if we look into the samples in the article and think about it: it just takes less than 1 milliseconds to get the max value in 100k numbers. There is potential performance issue only if the "get the max value in 100K numbers" call many, many times in your API or single request. Otherwise, the difference between 0.1 milliseconds to 0.5 milliseconds can be totally ignored. Usually we meet performance issue only if Q and F is big enough. However, the performance of Lambdas/Streams APIs is closed to for loop when Q and F is big enough. No matter in which scenario, We don't need and should not concern the performance of Lambdas/Stream APIs.
Although it's is parallel Streams, it doesn't means all the methods are executed in parallel. Because the sequential way is as fast, or even faster than the parallel way for some methods, or is pretty difficult, if not possible, to implement the method by parallel approach. Here are the methods which are executed sequentially even in parallel Streams.
splitXXX/splitAt/splitBy/slidingXXX/collapse, distinct, reverse, rotate, shuffle, indexed, cached, top, kthLargest, count, toArray, toList, toList, toSet, toMultiset, toLongMultiset, intersection(Collection c), difference(Collection c), symmetricDifference(Collection c), forEach(identity, accumulator, predicate), findFirstOrLast, findFirstAndLast- Specified by:
parallel
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Parameters:
maxThreadNum
-splitor
-- Returns:
- See Also:
-
BaseStream.parallel(Executor)
BaseStream.parallel(int, Executor)
BaseStream.parallel(int, Splitor, Executor)
BaseStream.sps(Function)
BaseStream.sps(int, Function)
MergeResult
Profiler.run(int, int, int, com.landawn.abacus.util.Throwables.Runnable)
- Understanding Parallel Stream Performance in Java SE 8
- When to use parallel Streams
-
parallel
Description copied from interface:BaseStream
// Replace above line of code with "sps" if only "f" need to be parallelized. And "p" is fast enough to be executed in sequential Stream. stream.sps(SP.create(maxThreadNum, executor), s -> s.map(f)).filter(p)...; // Or switch the stream back sequential stream if don't use "sps". stream.parallel(maxThreadNum, executor).map(f).sequential().filter(p)...;- Specified by:
parallel
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Parameters:
maxThreadNum
-executor
-- Returns:
- See Also:
-
parallel
Description copied from interface:BaseStream
stream.parallel(executor).map(f).filter(p)...; // Replace above line of code with "sps" if only "f" need to be parallelized. And "p" is fast enough to be executed in sequential Stream. stream.sps(SP.create(executor), s -> s.map(f)).filter(p)...; // Or switch the stream back sequential stream if don't use "sps". stream.parallel(executor).map(f).sequential().filter(p)...;
- Specified by:
parallel
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Parameters:
executor
-- Returns:
- See Also:
-
parallel
Description copied from interface:BaseStream
stream.parallel(maxThreadNum, splitor, executor).map(f).filter(p)...; // Replace above line of code with "sps" if only "f" need to be parallelized. And "p" is fast enough to be executed in sequential Stream. stream.sps(SP.create(maxThreadNum, splitor, executor), s -> s.map(f)).filter(p)...; // Or switch the stream back sequential stream if don't use "sps". stream.parallel(maxThreadNum, splitor, executor).map(f).sequential().filter(p)...;
- Specified by:
parallel
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Parameters:
maxThreadNum
-splitor
-executor
-- Returns:
- See Also:
-
parallel
Description copied from interface:BaseStream
stream.parallel(parallelSettings).map(f).filter(p)...; // Replace above line of code with "sps" if only "f" need to be parallelized. And "p" is fast enough to be executed in sequential Stream. stream.sps(SP.create(parallelSettings), s -> s.map(f)).filter(p)...; // Or switch the stream back sequential stream if don't use "sps". stream.parallel(parallelSettings).map(f).sequential().filter(p)...;
- Specified by:
parallel
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Parameters:
ps
-- Returns:
- See Also:
-
sps
Description copied from interface:BaseStream
Temporarily switch the stream to parallel stream for operationops
and then switch back to sequence stream.
stream().parallel().ops(map/filter/...).sequence()
- Specified by:
sps
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Type Parameters:
SS
-- Parameters:
ops
-- Returns:
-
sps
public <SS extends BaseStream> SS sps(int maxThreadNum, Function<? super ByteStream, ? extends SS> ops) Description copied from interface:BaseStream
Temporarily switch the stream to parallel stream for operationops
and then switch back to sequence stream.
stream().parallel(maxThreadNum).ops(map/filter/...).sequence()
- Specified by:
sps
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Type Parameters:
SS
-- Parameters:
maxThreadNum
-ops
-- Returns:
-
psp
Description copied from interface:BaseStream
Temporarily switch the stream to sequence stream for operationops
and then switch back to parallel stream with samemaxThreadNum/splitor/asyncExecutor
.
stream().sequence().ops(map/filter/...).parallel(sameMaxThreadNum, sameSplitor, sameAsyncExecutor)
- Specified by:
psp
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Type Parameters:
SS
-- Parameters:
ops
-- Returns:
-
toArray
public byte[] toArray()- Specified by:
toArray
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Returns:
-
close
public void close()Description copied from interface:BaseStream
It will be called by terminal operations in final.- Specified by:
close
in interfaceAutoCloseable
- Specified by:
close
in interfaceBaseStream<T,
A, P, C, PL, OT, IT, ITER extends Iterator<T>, S extends com.landawn.abacus.util.stream.StreamBase<T, A, P, C, PL, OT, IT, ITER, S>> - Specified by:
close
in interfaceCloseable
-
BaseStream.transform(Function)