Add sort for flow rules when loading rules

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/block/flow/FlowRuleManager.java

@@ -16,6 +16,8 @@
 package com.alibaba.csp.sentinel.slots.block.flow;
 
 import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
@@ -144,6 +146,15 @@ public class FlowRuleManager {
             ruleM.add(rule);
 
         }
+
+        if (!newRuleMap.isEmpty()) {
+            Comparator<FlowRule> comparator = new FlowRuleComparator();
+            // Sort the rules.
+            for (List<FlowRule> rules : newRuleMap.values()) {
+                Collections.sort(rules, comparator);
+            }
+        }
+
         return newRuleMap;
     }
 

sentinel-core/src/test/java/com/alibaba/csp/sentinel/slots/block/flow/FlowRuleComparatorTest.java

@@ -0,0 +1,45 @@
+package com.alibaba.csp.sentinel.slots.block.flow;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+import com.alibaba.csp.sentinel.slots.block.RuleConstant;
+
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+/**
+ * @author Eric Zhao
+ */
+public class FlowRuleComparatorTest {
+
+    @Test
+    public void testFlowRuleComparator() {
+        FlowRule ruleA = new FlowRule("abc")
+            .setCount(10);
+        ruleA.setLimitApp(RuleConstant.LIMIT_APP_DEFAULT);
+        FlowRule ruleB = new FlowRule("abc");
+        ruleB.setLimitApp("originA");
+        FlowRule ruleC = new FlowRule("abc");
+        ruleC.setLimitApp("originB");
+        FlowRule ruleD = new FlowRule("abc");
+        ruleD.setLimitApp(RuleConstant.LIMIT_APP_OTHER);
+        FlowRule ruleE = new FlowRule("abc")
+            .setCount(20);
+        ruleE.setLimitApp(RuleConstant.LIMIT_APP_DEFAULT);
+
+        List<FlowRule> list = Arrays.asList(ruleA, ruleB, ruleC, ruleD, ruleE);
+        FlowRuleComparator comparator = new FlowRuleComparator();
+        Collections.sort(list, comparator);
+        List<FlowRule> expected = Arrays.asList(ruleB, ruleC, ruleD, ruleA, ruleE);
+        assertOrderEqual(expected.size(), expected, list);
+    }
+
+    private void assertOrderEqual(int size, List<FlowRule> expected, List<FlowRule> actual) {
+        for (int i = 0; i < size; i++) {
+            assertEquals(expected.get(i), actual.get(i));
+        }
+    }
+}