Class ValueSetIndexProxy<E>
- java.lang.Object
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- com.exonum.binding.proxy.AbstractNativeProxy
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- com.exonum.binding.storage.indices.ValueSetIndexProxy<E>
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- Type Parameters:
E
- the type of elements in this set
- All Implemented Interfaces:
Iterable<ValueSetIndexProxy.Entry<E>>
public final class ValueSetIndexProxy<E> extends AbstractNativeProxy implements Iterable<ValueSetIndexProxy.Entry<E>>
A value set is an index that contains no duplicate elements (values). This implementation does not permit null elements.The elements are stored in the underlying database as values, whereas their cryptographic hashes are used as keys, making this set implementation more suitable for storing large elements. If your application has small elements and does not need to perform set operations by hashes of the elements, consider using a
KeySetIndexProxy
.The "destructive" methods of the set, i.e., the ones that change its contents, are specified to throw
UnsupportedOperationException
if the set has been created with a read-only database view.All method arguments are non-null by default.
This class is not thread-safe and and its instances shall not be shared between threads.
When the view goes out of scope, this set is destroyed. Subsequent use of the closed set is prohibited and will result in
IllegalStateException
.- See Also:
KeySetIndexProxy
,View
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Nested Class Summary
Nested Classes Modifier and Type Class Description static class
ValueSetIndexProxy.Entry<E>
An entry of a value set index: a hash-value pair.
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Field Summary
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Fields inherited from class com.exonum.binding.proxy.AbstractNativeProxy
nativeHandle
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Method Summary
Modifier and Type Method Description void
add(E e)
Adds a new element to the set.void
clear()
Removes all of the elements from this set.boolean
contains(E e)
Returns true if this set contains the specified element.boolean
containsByHash(HashCode elementHash)
Returns true if this set contains an element with the specified hash.String
getName()
Returns the name of this index.Iterator<HashCode>
hashes()
Creates an iterator over the hashes of the elements in this set.Iterator<ValueSetIndexProxy.Entry<E>>
iterator()
Returns an iterator over the entries of this set.static <E> ValueSetIndexProxy<E>
newInGroupUnsafe(String groupName, byte[] indexId, View view, Serializer<E> serializer)
Creates a new value set in a collection group with the given name.static <E> ValueSetIndexProxy<E>
newInstance(String name, View view, Serializer<E> serializer)
Creates a new value set.static <E extends com.google.protobuf.MessageLite>
ValueSetIndexProxy<E>newInstance(String name, View view, Class<E> valueType)
Creates a new value set storing protobuf messages.void
remove(E e)
Removes the element from this set.void
removeByHash(HashCode elementHash)
Removes an element from this set by its hash.String
toString()
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Methods inherited from class com.exonum.binding.proxy.AbstractNativeProxy
getNativeHandle, isValidHandle
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Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
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Methods inherited from interface java.lang.Iterable
forEach, spliterator
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Method Detail
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newInstance
public static <E extends com.google.protobuf.MessageLite> ValueSetIndexProxy<E> newInstance(String name, View view, Class<E> valueType)
Creates a new value set storing protobuf messages.- Type Parameters:
E
- the type of values in this set; must be a protobuf message that has a public static#parseFrom(byte[])
method- Parameters:
name
- a unique alphanumeric non-empty identifier of this set in the underlying storage: [a-zA-Z0-9_]view
- a database view. Must be valid. If a view is read-only, "destructive" operations are not permitted.valueType
- the class of values-protobuf messages- Throws:
IllegalStateException
- if the view is not validIllegalArgumentException
- if the name is empty
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newInstance
public static <E> ValueSetIndexProxy<E> newInstance(String name, View view, Serializer<E> serializer)
Creates a new value set.- Type Parameters:
E
- the type of values in this set- Parameters:
name
- a unique alphanumeric non-empty identifier of this set in the underlying storage: [a-zA-Z0-9_]view
- a database view. Must be valid. If a view is read-only, "destructive" operations are not permitted.serializer
- a serializer of values- Throws:
IllegalStateException
- if the view is not validIllegalArgumentException
- if the name is empty- See Also:
StandardSerializers
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newInGroupUnsafe
public static <E> ValueSetIndexProxy<E> newInGroupUnsafe(String groupName, byte[] indexId, View view, Serializer<E> serializer)
Creates a new value set in a collection group with the given name.See a caveat on index identifiers.
- Type Parameters:
E
- the type of values in this set- Parameters:
groupName
- a name of the collection groupindexId
- an identifier of this collection in the group, see the caveatsview
- a database viewserializer
- a serializer of set values- Returns:
- a new value set
- Throws:
IllegalStateException
- if the view is not validIllegalArgumentException
- if the name or index id is empty- See Also:
StandardSerializers
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add
public void add(E e)
Adds a new element to the set. The method has no effect if the set already contains such element.- Parameters:
e
- an element to add- Throws:
IllegalStateException
- if this set is not validUnsupportedOperationException
- if this set is read-only
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clear
public void clear()
Removes all of the elements from this set. The set will be empty after this method returns.- Throws:
IllegalStateException
- if this set is not validUnsupportedOperationException
- if this set is read-only
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contains
public boolean contains(E e)
Returns true if this set contains the specified element.- Throws:
IllegalStateException
- if this set is not valid- See Also:
containsByHash(HashCode)
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containsByHash
public boolean containsByHash(HashCode elementHash)
Returns true if this set contains an element with the specified hash.- Parameters:
elementHash
- a hash of an element- Throws:
IllegalStateException
- if this set is not valid
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hashes
public Iterator<HashCode> hashes()
Creates an iterator over the hashes of the elements in this set. The hashes are ordered lexicographically.Any destructive operation on the same
Fork
this set uses (but not necessarily on this set) will invalidate the iterator.- Returns:
- an iterator over the hashes of the elements in this set
- Throws:
IllegalStateException
- if this set is not valid
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iterator
public Iterator<ValueSetIndexProxy.Entry<E>> iterator()
Returns an iterator over the entries of this set. An entry is a hash-value pair. The entries are ordered by keys lexicographically.Any destructive operation on the same
Fork
this set uses (but not necessarily on this set) will invalidate the iterator.- Specified by:
iterator
in interfaceIterable<E>
- Returns:
- an iterator over the entries of this set
- Throws:
IllegalStateException
- if this set is not valid
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remove
public void remove(E e)
Removes the element from this set. If it's not in the set, does nothing.- Parameters:
e
- an element to remove.- Throws:
IllegalStateException
- if this set is not validUnsupportedOperationException
- if this set is read-only
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removeByHash
public void removeByHash(HashCode elementHash)
Removes an element from this set by its hash. If there is no such element in the set, does nothing.- Parameters:
elementHash
- the hash of an element to remove.- Throws:
IllegalStateException
- if this set is not validUnsupportedOperationException
- if this set is read-only
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getName
public final String getName()
Returns the name of this index.
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