2d9e0f53a5
Motivation: The old DefaultAttributeMap impl did more synchronization then needed and also did not expose a efficient way to check if an attribute exists with a specific key. Modifications: * Rewrite DefaultAttributeMap to not use IdentityHashMap and synchronization on the map directly. The new impl uses a combination of AtomicReferenceArray and synchronization per chain (linked-list). Also access the first Attribute per bucket can be done without any synchronization at all and just uses atomic operations. This should fit for most use-cases pretty weel. * Add hasAttr(...) implementation Result: It's now possible to check for the existence of a attribute without create one. Synchronization is per linked-list and the first entry can even be added via atomic operation.
35 lines
1.2 KiB
Java
35 lines
1.2 KiB
Java
/*
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* Copyright 2012 The Netty Project
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*
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* The Netty Project licenses this file to you under the Apache License,
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* version 2.0 (the "License"); you may not use this file except in compliance
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* with the License. You may obtain a copy of the License at:
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*/
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package io.netty.util;
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/**
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* Holds {@link Attribute}s which can be accessed via {@link AttributeKey}.
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*
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* Implementations must be Thread-safe.
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*/
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public interface AttributeMap {
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/**
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* Get the {@link Attribute} for the given {@link AttributeKey}. This method will never return null, but may return
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* an {@link Attribute} which does not have a value set yet.
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*/
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<T> Attribute<T> attr(AttributeKey<T> key);
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/**
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* Returns {@code} true if and only if the given {@link Attribute} exists in this {@link AttributeMap}.
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*/
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<T> boolean hasAttr(AttributeKey<T> key);
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}
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