Struct NativeHashMap<TKey, TValue>

Unordered associative array, a collection of keys and values.

Namespace: Unity.Collections
Syntax
public struct NativeHashMap<TKey, TValue> : IDisposable where TKey : struct, IEquatable<TKey> where TValue : struct
Type Parameters
Name Description
TKey

The type of the keys in the container.
TValue

The type of the values in the container.

Constructors

NativeHashMap(Int32, Allocator)

Constructs a new container with the specified initial capacity and type of memory allocation.

Declaration
public NativeHashMap(int capacity, Allocator allocator)
Parameters
Type Name Description
Int32 capacity

The initial capacity of the container. If the list grows larger than its capacity, the internal array is copied to a new, larger array.
Allocator allocator

A member of the Unity.Collections.Allocator enumeration.

Properties

Capacity

The number of items that can fit in the container.

Declaration
public int Capacity { get; set; }
Property Value
Type Description
Int32

The number of items that the container can hold before it resizes its internal storage.
Remarks

Capacity specifies the number of items the container can currently hold. You can change Capacity to fit more or fewer items. Changing Capacity creates a new array of the specified size, copies the old array to the new one, and then deallocates the original array memory.

IsCreated

Reports whether memory for the container is allocated.

Declaration
public bool IsCreated { get; }
Property Value
Type Description
Boolean

True if this container object's internal storage has been allocated.
Remarks

Note that the container storage is not created if you use the default constructor. You must specify at least an allocation type to construct a usable container.

Item[TKey]

Retrieve a value by key.

Declaration
public TValue this[TKey key] { get; set; }
Parameters
Type Name Description
TKey key
Property Value
Type Description
TValue

Length

The current number of items in the container.

Declaration
public int Length { get; }
Property Value
Type Description
Int32

The item count.

Methods

Add(TKey, TValue)

Add an element with the specified key and value into the container. If the key already exist an ArgumentException will be thrown.

Declaration
public void Add(TKey key, TValue value)
Parameters
Type Name Description
TKey key

The key of the element to add.
TValue value

The value of the element to add.

AsParallelWriter()

Returns parallel writer instance.

Declaration
public NativeHashMap<TKey, TValue>.ParallelWriter AsParallelWriter()
Returns
Type Description
NativeHashMap.ParallelWriter<>

Clear()

Clears the container.

Declaration
public void Clear()
Remarks

Containers capacity remains unchanged.

ContainsKey(TKey)

Determines whether an key is in the container.

Declaration
public bool ContainsKey(TKey key)
Parameters
Type Name Description
TKey key

The key to locate in the container.
Returns
Type Description
Boolean

Returns true if the container contains the key.

Dispose()

Disposes of this container and deallocates its memory immediately.

Declaration
public void Dispose()

Dispose(JobHandle)

Safely disposes of this container and deallocates its memory when the jobs that use it have completed.

Declaration
public JobHandle Dispose(JobHandle inputDeps)
Parameters
Type Name Description
JobHandle inputDeps
Returns
Type Description
JobHandle

A new job handle containing the prior handles as well as the handle for the job that deletes the container.
Remarks

You can call this function dispose of the container immediately after scheduling the job. Pass the JobHandle returned by the Job.Schedule method using the jobHandle parameter so the job scheduler can dispose the container after all jobs using it have run.

GetKeyArray(Allocator)

Retrive array of key from the container.

Declaration
public NativeArray<TKey> GetKeyArray(Allocator allocator)
Parameters
Type Name Description
Allocator allocator

A member of the Unity.Collections.Allocator enumeration.
Returns
Type Description
NativeArray<TKey>

Key array.

GetKeyValueArrays(Allocator)

Retrieve key/value arrays.

Declaration
public NativeKeyValueArrays<TKey, TValue> GetKeyValueArrays(Allocator allocator)
Parameters
Type Name Description
Allocator allocator

A member of the Unity.Collections.Allocator enumeration.
Returns
Type Description
NativeKeyValueArrays<TKey, TValue>

Key/value arrays.

GetValueArray(Allocator)

Retreive array of values from the container.

Declaration
public NativeArray<TValue> GetValueArray(Allocator allocator)
Parameters
Type Name Description
Allocator allocator

A member of the Unity.Collections.Allocator enumeration.
Returns
Type Description
NativeArray<TValue>

Value array.

Remove(TKey)

Removes the element with the specified key from the container.

Declaration
public bool Remove(TKey key)
Parameters
Type Name Description
TKey key

The key of the element to remove.
Returns
Type Description
Boolean

Returns true if the key was removed from the container, otherwise returns false indicating key wasn't in the container.

TryAdd(TKey, TValue)

Try adding an element with the specified key and value into the container. If the key already exist, the value won't be updated.

Declaration
public bool TryAdd(TKey key, TValue value)
Parameters
Type Name Description
TKey key

The key of the element to add.
TValue value

The value of the element to add.
Returns
Type Description
Boolean

Returns true if value is added into the container, otherwise returns false.

TryGetValue(TKey, out TValue)

Gets the value associated with the specified key.

Declaration
public bool TryGetValue(TKey key, out TValue item)
Parameters
Type Name Description
TKey key

The key of the value to get.
TValue item

If key is found item parameter will contain value
Returns
Type Description
Boolean

Returns true if key is found, otherwise returns false.

Extension Methods