fix dangdangdotcom#215

yihaijun · Mar 18, 2016 · 85d110b · 85d110b
1 parent 405003a
commit 85d110b
Showing 1 changed file with 77 additions and 56 deletions.
diff --git a/...luster/src/main/java/com/alibaba/dubbo/rpc/cluster/loadbalance/RoundRobinLoadBalance.java b/...luster/src/main/java/com/alibaba/dubbo/rpc/cluster/loadbalance/RoundRobinLoadBalance.java
@@ -13,70 +13,91 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package com.alibaba.dubbo.rpc.cluster.loadbalance;
-
-import java.util.ArrayList;
+package com.alibaba.dubbo.rpc.cluster.loadbalance;
+
+import java.util.LinkedHashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 
 import com.alibaba.dubbo.common.URL;
 import com.alibaba.dubbo.common.utils.AtomicPositiveInteger;
 import com.alibaba.dubbo.rpc.Invocation;
 import com.alibaba.dubbo.rpc.Invoker;
-
-/**
- * Round robin load balance.
- *
- * @author qian.lei
- * @author william.liangf
- */
+
+/**
+ * Round robin load balance.
+ *
+ * @author qian.lei
+ * @author william.liangf
+ */
 public class RoundRobinLoadBalance extends AbstractLoadBalance {
-
-    public static final String NAME = "roundrobin"; 
-
-    private final ConcurrentMap<String, AtomicPositiveInteger> sequences = new ConcurrentHashMap<String, AtomicPositiveInteger>();
 
-    private final ConcurrentMap<String, AtomicPositiveInteger> weightSequences = new ConcurrentHashMap<String, AtomicPositiveInteger>();
-
-    protected <T> Invoker<T> doSelect(List<Invoker<T>> invokers, URL url, Invocation invocation) {
-        String key = invokers.get(0).getUrl().getServiceKey() + "." + invocation.getMethodName();
-        int length = invokers.size(); // 总个数
-        int maxWeight = 0; // 最大权重
-        int minWeight = Integer.MAX_VALUE; // 最小权重
-        for (int i = 0; i < length; i++) {
-            int weight = getWeight(invokers.get(i), invocation);
-            maxWeight = Math.max(maxWeight, weight); // 累计最大权重
-            minWeight = Math.min(minWeight, weight); // 累计最小权重
-        }
-        if (maxWeight > 0 && minWeight < maxWeight) { // 权重不一样
-            AtomicPositiveInteger weightSequence = weightSequences.get(key);
-            if (weightSequence == null) {
-                weightSequences.putIfAbsent(key, new AtomicPositiveInteger());
-                weightSequence = weightSequences.get(key);
-            }
-            int currentWeight = weightSequence.getAndIncrement() % maxWeight;
-            List<Invoker<T>> weightInvokers = new ArrayList<Invoker<T>>();
-            for (Invoker<T> invoker : invokers) { // 筛选权重大于当前权重基数的Invoker
-                if (getWeight(invoker, invocation) > currentWeight) {
-                    weightInvokers.add(invoker);
-                }
-            }
-            int weightLength = weightInvokers.size();
-            if (weightLength == 1) {
-                return weightInvokers.get(0);
-            } else if (weightLength > 1) {
-                invokers = weightInvokers;
-                length = invokers.size();
-            }
-        }
-        AtomicPositiveInteger sequence = sequences.get(key);
-        if (sequence == null) {
-            sequences.putIfAbsent(key, new AtomicPositiveInteger());
-            sequence = sequences.get(key);
-        }
-        // 取模轮循
-        return invokers.get(sequence.getAndIncrement() % length);
-    }
-
+    public static final String NAME = "roundrobin";
+
+    private final ConcurrentMap<String, AtomicPositiveInteger> sequences = new ConcurrentHashMap<String, AtomicPositiveInteger>();
+
+	private static final class IntegerWrapper {
+		public IntegerWrapper(int value) {
+			this.value = value;
+		}
+
+		private int value;
+
+		public int getValue() {
+			return value;
+		}
+
+		public void setValue(int value) {
+			this.value = value;
+		}
+
+		public void decrement() {
+			this.value--;
+		}
+	}
+
+	protected <T> Invoker<T> doSelect(List<Invoker<T>> invokers, URL url, Invocation invocation) {
+		String key = invokers.get(0).getUrl().getServiceKey() + "." + invocation.getMethodName();
+		int length = invokers.size(); // 总个数
+		int maxWeight = 0; // 最大权重
+		int minWeight = Integer.MAX_VALUE; // 最小权重
+		final LinkedHashMap<Invoker<T>, IntegerWrapper> invokerToWeightMap = new LinkedHashMap<Invoker<T>, IntegerWrapper>();
+		int weightSum = 0;
+		for (int i = 0; i < length; i++) {
+			int weight = getWeight(invokers.get(i), invocation);
+			maxWeight = Math.max(maxWeight, weight); // 累计最大权重
+			minWeight = Math.min(minWeight, weight); // 累计最小权重
+			if (weight > 0) {
+				invokerToWeightMap.put(invokers.get(i), new IntegerWrapper(weight));
+				weightSum += weight;
+			}
+		}
+		AtomicPositiveInteger sequence = sequences.get(key);
+		if (sequence == null) {
+			sequences.putIfAbsent(key, new AtomicPositiveInteger());
+			sequence = sequences.get(key);
+		}
+        int currentSequence = sequence.getAndIncrement();
+		if (maxWeight > 0 && minWeight < maxWeight) { // 权重不一样
+			int mod = currentSequence % weightSum;
+			for (int i = 0; i < maxWeight; i++) {
+				for (Map.Entry<Invoker<T>, IntegerWrapper> each : invokerToWeightMap.entrySet()) {
+					final Invoker<T> k = each.getKey();
+					final IntegerWrapper v = each.getValue();
+					if (mod == 0 && v.getValue() > 0) {
+						return k;
+					}
+					if (v.getValue() > 0) {
+						v.decrement();
+						mod--;
+					}
+				}
+			}
+		}
+		// 取模轮循
+		return invokers.get(currentSequence % length);
+	}
+
 }