美文网首页Sentinel
Sentinel资源节点树构成

Sentinel资源节点树构成

作者: 晴天哥_王志 | 来源:发表于2021-06-13 21:40 被阅读0次

    系列

    相同资源名场景分析

    Entry entry = null;

try {
    entry = SphU.entry("abc");
    entry = SphU.entry("abc");
} catch (BlockException e1) {

} finally {
    if (entry != null) {
        entry.exit();
    }
}

    创建Context

    public class ContextUtil {

    protected static Context trueEnter(String name, String origin) {
        Context context = contextHolder.get();
        if (context == null) {
            Map<String, DefaultNode> localCacheNameMap = contextNameNodeMap;
            DefaultNode node = localCacheNameMap.get(name);
            if (node == null) {
                if (localCacheNameMap.size() > Constants.MAX_CONTEXT_NAME_SIZE) {
                    setNullContext();
                    return NULL_CONTEXT;
                } else {
                    LOCK.lock();
                    try {
                        node = contextNameNodeMap.get(name);
                        if (node == null) {
                            if (contextNameNodeMap.size() > Constants.MAX_CONTEXT_NAME_SIZE) {
                                setNullContext();
                                return NULL_CONTEXT;
                            } else {
                                node = new EntranceNode(new StringResourceWrapper(name, EntryType.IN), null);
                                // Add entrance node.
                                Constants.ROOT.addChild(node);

                                Map<String, DefaultNode> newMap = new HashMap<>(contextNameNodeMap.size() + 1);
                                newMap.putAll(contextNameNodeMap);
                                newMap.put(name, node);
                                contextNameNodeMap = newMap;
                            }
                        }
                    } finally {
                        LOCK.unlock();
                    }
                }
            }
            // 这里的node设置的是Context的EntranceNode
            context = new Context(node, name);
            context.setOrigin(origin);
            contextHolder.set(context);
        }

        return context;
    }
}
    • 首先在ThreadLocal获取，获取不到就创建，不然就返回
    • 然后再Map中根据ContextName找一个Node
    • 没有找到Node就加锁的方式，创建一个EntranceNode，然后放入Map中
    • 创建Context，设置node，name，origin，再放入ThreadLocal中

    第一次创建Entry

    Entry e = new CtEntry(resourceWrapper, chain, context);

class CtEntry extends Entry {
    protected Entry parent = null;
    protected Entry child = null;

    protected ProcessorSlot<Object> chain;
    protected Context context;
    protected LinkedList<BiConsumer<Context, Entry>> exitHandlers;

    CtEntry(ResourceWrapper resourceWrapper, ProcessorSlot<Object> chain, Context context) {
        super(resourceWrapper);
        this.chain = chain;
        this.context = context;

        setUpEntryFor(context);
    }

    private void setUpEntryFor(Context context) {
        // The entry should not be associated to NullContext.
        if (context instanceof NullContext) {
            return;
        }
        // 首次返回为null
        this.parent = context.getCurEntry();
        if (parent != null) {
            ((CtEntry) parent).child = this;
        }
        // 设置Context的curEntry为当前的CtEntry
        context.setCurEntry(this);
    }
}

    第一次执行NodeSelectorSlot

    @Spi(isSingleton = false, order = Constants.ORDER_NODE_SELECTOR_SLOT)
public class NodeSelectorSlot extends AbstractLinkedProcessorSlot<Object> {

    private volatile Map<String, DefaultNode> map = new HashMap<String, DefaultNode>(10);

    @Override
    public void entry(Context context, ResourceWrapper resourceWrapper, Object obj, int count, boolean prioritized, Object... args)
        throws Throwable {

        DefaultNode node = map.get(context.getName());
        if (node == null) {
            synchronized (this) {
                node = map.get(context.getName());
                if (node == null) {
                    node = new DefaultNode(resourceWrapper, null);
                    HashMap<String, DefaultNode> cacheMap = new HashMap<String, DefaultNode>(map.size());
                    cacheMap.putAll(map);
                    cacheMap.put(context.getName(), node);
                    map = cacheMap;
                    // 构建调用树，添加entranceNode的子节点
                    ((DefaultNode) context.getLastNode()).addChild(node);
                }

            }
        }
        // 设置Context的当前节点
        context.setCurNode(node);
        fireEntry(context, resourceWrapper, node, count, prioritized, args);
    }
}

public class Context {
    private final String name;
    private DefaultNode entranceNode;
    private Entry curEntry;
    private String origin = "";
    private final boolean async;

    public Node getLastNode() {
        if (curEntry != null && curEntry.getLastNode() != null) {
            return curEntry.getLastNode();
        } else {
            return entranceNode;
        }
    }

    public Context setCurNode(Node node) {
        this.curEntry.setCurNode(node);
        return this;
    }
}

    第二次创建Entry

    Entry e = new CtEntry(resourceWrapper, chain, context);

class CtEntry extends Entry {
    protected Entry parent = null;
    protected Entry child = null;

    protected ProcessorSlot<Object> chain;
    protected Context context;
    protected LinkedList<BiConsumer<Context, Entry>> exitHandlers;

    CtEntry(ResourceWrapper resourceWrapper, ProcessorSlot<Object> chain, Context context) {
        super(resourceWrapper);
        this.chain = chain;
        this.context = context;

        setUpEntryFor(context);
    }

    private void setUpEntryFor(Context context) {
        // The entry should not be associated to NullContext.
        if (context instanceof NullContext) {
            return;
        }
        // 首次返回为null
        this.parent = context.getCurEntry();
        if (parent != null) {
            ((CtEntry) parent).child = this;
        }
        // 设置Context的curEntry为当前的CtEntry
        context.setCurEntry(this);
    }
}

    第二次执行NodeSelectorSlot

    @Spi(isSingleton = false, order = Constants.ORDER_NODE_SELECTOR_SLOT)
public class NodeSelectorSlot extends AbstractLinkedProcessorSlot<Object> {

    private volatile Map<String, DefaultNode> map = new HashMap<String, DefaultNode>(10);

    @Override
    public void entry(Context context, ResourceWrapper resourceWrapper, Object obj, int count, boolean prioritized, Object... args)
        throws Throwable {

        DefaultNode node = map.get(context.getName());
        if (node == null) {
            synchronized (this) {
                node = map.get(context.getName());
                if (node == null) {
                    node = new DefaultNode(resourceWrapper, null);
                    HashMap<String, DefaultNode> cacheMap = new HashMap<String, DefaultNode>(map.size());
                    cacheMap.putAll(map);
                    cacheMap.put(context.getName(), node);
                    map = cacheMap;
                    // 构建调用树，添加entranceNode的子节点
                    ((DefaultNode) context.getLastNode()).addChild(node);
                }

            }
        }
        // 设置Context的当前节点
        context.setCurNode(node);
        fireEntry(context, resourceWrapper, node, count, prioritized, args);
    }
}

public class Context {
    private final String name;
    private DefaultNode entranceNode;
    private Entry curEntry;
    private String origin = "";

    private final boolean async;
    public Node getLastNode() {
        if (curEntry != null && curEntry.getLastNode() != null) {
            return curEntry.getLastNode();
        } else {
            return entranceNode;
        }
    }

    public Context setCurNode(Node node) {
        this.curEntry.setCurNode(node);
        return this;
    }
}

    不同资源名场景分析

    Entry entry = null;

try {
    entry = SphU.entry("abc");
    entry = SphU.entry("abcd");
} catch (BlockException e1) {

} finally {
    if (entry != null) {
        entry.exit();
    }
}

    第一次创建Entry

    Entry e = new CtEntry(resourceWrapper, chain, context);

class CtEntry extends Entry {
    protected Entry parent = null;
    protected Entry child = null;

    protected ProcessorSlot<Object> chain;
    protected Context context;
    protected LinkedList<BiConsumer<Context, Entry>> exitHandlers;

    CtEntry(ResourceWrapper resourceWrapper, ProcessorSlot<Object> chain, Context context) {
        super(resourceWrapper);
        this.chain = chain;
        this.context = context;

        setUpEntryFor(context);
    }

    private void setUpEntryFor(Context context) {
        // The entry should not be associated to NullContext.
        if (context instanceof NullContext) {
            return;
        }
        // 首次返回为null
        this.parent = context.getCurEntry();
        if (parent != null) {
            ((CtEntry) parent).child = this;
        }
        // 设置Context的curEntry为当前的CtEntry
        context.setCurEntry(this);
    }
}

    第一次执行NodeSelectorSlot

    @Spi(isSingleton = false, order = Constants.ORDER_NODE_SELECTOR_SLOT)
public class NodeSelectorSlot extends AbstractLinkedProcessorSlot<Object> {

    private volatile Map<String, DefaultNode> map = new HashMap<String, DefaultNode>(10);

    @Override
    public void entry(Context context, ResourceWrapper resourceWrapper, Object obj, int count, boolean prioritized, Object... args)
        throws Throwable {

        DefaultNode node = map.get(context.getName());
        if (node == null) {
            synchronized (this) {
                node = map.get(context.getName());
                if (node == null) {
                    node = new DefaultNode(resourceWrapper, null);
                    HashMap<String, DefaultNode> cacheMap = new HashMap<String, DefaultNode>(map.size());
                    cacheMap.putAll(map);
                    cacheMap.put(context.getName(), node);
                    map = cacheMap;
                    // 构建调用树，添加entranceNode的子节点
                    ((DefaultNode) context.getLastNode()).addChild(node);
                }

            }
        }
        // 设置Context的当前节点
        context.setCurNode(node);
        fireEntry(context, resourceWrapper, node, count, prioritized, args);
    }
}

public class Context {
    private final String name;
    private DefaultNode entranceNode;
    private Entry curEntry;
    private String origin = "";

    private final boolean async;
    public Node getLastNode() {
        if (curEntry != null && curEntry.getLastNode() != null) {
            return curEntry.getLastNode();
        } else {
            return entranceNode;
        }
    }

    public Context setCurNode(Node node) {
        this.curEntry.setCurNode(node);
        return this;
    }
}

    第二次创建Entry

    Entry e = new CtEntry(resourceWrapper, chain, context);

class CtEntry extends Entry {
    protected Entry parent = null;
    protected Entry child = null;

    protected ProcessorSlot<Object> chain;
    protected Context context;
    protected LinkedList<BiConsumer<Context, Entry>> exitHandlers;

    CtEntry(ResourceWrapper resourceWrapper, ProcessorSlot<Object> chain, Context context) {
        super(resourceWrapper);
        this.chain = chain;
        this.context = context;

        setUpEntryFor(context);
    }

    private void setUpEntryFor(Context context) {
        // The entry should not be associated to NullContext.
        if (context instanceof NullContext) {
            return;
        }
        // 首次返回为null
        this.parent = context.getCurEntry();
        if (parent != null) {
            ((CtEntry) parent).child = this;
        }
        // 设置Context的curEntry为当前的CtEntry
        context.setCurEntry(this);
    }
}

    第二次执行NodeSelectorSlot

    @Spi(isSingleton = false, order = Constants.ORDER_NODE_SELECTOR_SLOT)
public class NodeSelectorSlot extends AbstractLinkedProcessorSlot<Object> {

    private volatile Map<String, DefaultNode> map = new HashMap<String, DefaultNode>(10);

    @Override
    public void entry(Context context, ResourceWrapper resourceWrapper, Object obj, int count, boolean prioritized, Object... args)
        throws Throwable {

        DefaultNode node = map.get(context.getName());
        if (node == null) {
            synchronized (this) {
                node = map.get(context.getName());
                if (node == null) {
                    node = new DefaultNode(resourceWrapper, null);
                    HashMap<String, DefaultNode> cacheMap = new HashMap<String, DefaultNode>(map.size());
                    cacheMap.putAll(map);
                    cacheMap.put(context.getName(), node);
                    map = cacheMap;
                    // 构建调用树，第一次添加entranceNode的子节点
                    // 第二次添加到当前节点的父节点当中
                    ((DefaultNode) context.getLastNode()).addChild(node);
                }

            }
        }
        // 设置Context的当前节点
        context.setCurNode(node);
        fireEntry(context, resourceWrapper, node, count, prioritized, args);
    }
}

public class Context {
    private final String name;
    private DefaultNode entranceNode;
    private Entry curEntry;
    private String origin = "";

    private final boolean async;
    public Node getLastNode() {
        if (curEntry != null && curEntry.getLastNode() != null) {
            return curEntry.getLastNode();
        } else {
            return entranceNode;
        }
    }

    public Context setCurNode(Node node) {
        this.curEntry.setCurNode(node);
        return this;
    }
}

class CtEntry extends Entry {

    protected Entry parent = null;
    protected Entry child = null;

    @Override
    public Node getLastNode() {
        return parent == null ? null : parent.getCurNode();
    }
}

    • 因为资源名不同所以对应的职责链条，因此NodeSelectorSlot会重新创建DefaultNode。


    相关文章

      网友评论

        本文标题：Sentinel资源节点树构成

        本文链接：https://www.haomeiwen.com/subject/txugeltx.html

        延伸阅读

        深度阅读

        • 您也可以注册成为美文阅读网的作者，发表您的原创作品、分享您的心情！

        栏目导航

        热点阅读

        Sentinel

        关于我们|服务条款|联系我们|Sentinel资源节点树构成|投稿指南|网站地图|RSS订阅|排版工具|手机版

        提供经典美文摘抄,优美散文欣赏,现代诗歌精选,短篇小说,心情随笔,表白情书范文,故事会在线阅读欣赏

        Copyright © 2014-2023 Haomeiwen.com All Rights Reserved. 好美文阅读网 版权所有

        备案信息：桂公网安备 45052102000051号 · 桂ICP备13007215号-3

        本站所收录作品、热点评论等信息部分来源互联网，目的只是为了系统归纳学习和传递资讯

        所有作品版权归原创作者所有，与本站立场无关，如不慎侵犯了你的权益，请联系我们告知，我们将做删除处理！