/// <summary>
/// Creates a new instance of <see cref="PooledIntegerSet"/>.
/// </summary>
/// <param name="pool">A <see cref="DynamicArrayPool{Int32}"/> instance from which the memory
/// for this set should be allocated.</param>
/// <param name="capacity">The initial capacity to allocate for this set.</param>
public PooledIntegerSet(DynamicArrayPool <int> pool, int capacity = 0)
{
m_pool = pool;
m_token = pool.allocate((capacity > 0) ? DataStructureUtil.nextPowerOf2(capacity - 1) : 4);
m_pool.getSpan(m_token).Fill(EMPTY_SLOT);
m_count = 0;
}
/// <summary>
/// Releases any memory being used by the set back to its array pool. Once this method
/// is called the set can no longer be used.
/// </summary>
/// <remarks>
/// This method has no effect when called on the default value of <see cref="PooledIntegerSet"/>.
/// </remarks>
public void free()
{
if (m_pool != null)
{
m_pool.free(m_token);
m_token = default;
}
}
/// <summary>
/// Returns a span that can be used to access an array allocated with the
/// <see cref="allocate(Int32)"/> method.
/// </summary>
///
/// <param name="token">A <see cref="DynamicArrayPoolToken{T}"/> that was obtained from
/// a call to <see cref="allocate(Int32)"/>. If this is the default value of
/// <see cref="DynamicArrayPoolToken{T}"/>, an empty span is returned.</param>
/// <returns>A <see cref="Span{T}"/> that provides access to the allocated memory.</returns>
///
/// <remarks>
/// The returned span is guaranteed to refer to the memory associated with the token
/// <paramref name="token"/> as long as the <see cref="allocate(Int32)"/>,
/// <see cref="resize(DynamicArrayPoolToken{T}, Int32)"/> and <see cref="append(DynamicArrayPoolToken{T}, T)"/>
/// methods are not called on this <see cref="DynamicArrayPool{T}"/> instance. These methods may move
/// the data associated with the token to new location in memory, and this method must then be called
/// again to get the span for the new backing memory.
/// </remarks>
/// <remarks>
/// If the token was obtained from a different <see cref="DynamicArrayPoolToken{T}"/>
/// instance, or if the memory backed by the token was released by calling <see cref="free"/>
/// or <see cref="clear"/>, the returned span may refer to the memory of some other allocated
/// array in the pool or an exception may be thrown.
/// </remarks>
public Span <T> getSpan(DynamicArrayPoolToken <T> token)
{
int id = token.m_id;
if (id == 0)
{
return(Span <T> .Empty);
}
ref Segment segment = ref m_segments[id - 1];
