Modify loading mechanism of authority rules: only pick first

- Comment/javadoc refinement

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

sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/block/authority/AuthorityRule.java

@@ -21,14 +21,15 @@ import com.alibaba.csp.sentinel.node.DefaultNode;
 import com.alibaba.csp.sentinel.slots.block.AbstractRule;
 import com.alibaba.csp.sentinel.slots.block.RuleConstant;
 
-/***
- *
+/**
  * @author youji.zj
  */
 public class AuthorityRule extends AbstractRule {
 
-    /*** 0代表白名单；1代表黑名单 ***/
-    private int strategy;
+    /**
+     * Mode: 0 for whitelist; 1 for blacklist.
+     */
+    private int strategy = RuleConstant.AUTHORITY_WHITE;
 
     public int getStrategy() {
         return strategy;
@@ -60,12 +61,12 @@ public class AuthorityRule extends AbstractRule {
     public boolean passCheck(Context context, DefaultNode node, int count, Object... args) {
         String requester = context.getOrigin();
 
-        // 来源或者限流的应用为null直接通过
-        if (StringUtil.isEmpty(requester) || this.getLimitApp() == null) {
+        // Empty origin or empty limitApp will pass.
+        if (StringUtil.isEmpty(requester) || StringUtil.isEmpty(this.getLimitApp())) {
             return true;
         }
 
-        // 白名单、黑名单列表为逗号分隔的应用列表, indexOf还不行，需要精确匹配
+        // Do exact match with origin name.
         int pos = this.getLimitApp().indexOf(requester);
         boolean contain = pos > -1;
 
@@ -99,6 +100,6 @@ public class AuthorityRule extends AbstractRule {
             "resource=" + getResource() +
             ", limitApp=" + getLimitApp() +
             ", strategy=" + strategy +
-            "} " + super.toString();
+            "} ";
     }
 }

sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/block/authority/AuthorityRuleManager.java

@@ -31,9 +31,12 @@ import com.alibaba.csp.sentinel.slotchain.ResourceWrapper;
 import com.alibaba.csp.sentinel.slots.block.BlockException;
 import com.alibaba.csp.sentinel.slots.block.flow.FlowRule;
 
-/***
+/**
+ * Manager for authority rules.
+ *
  * @author youji.zj
  * @author jialiang.linjl
+ * @author Eric Zhao
  */
 public class AuthorityRuleManager {
 
@@ -60,7 +63,9 @@ public class AuthorityRuleManager {
     }
 
     /**
-     * @param rules
+     * Load the authority rules to memory.
+     *
+     * @param rules list of authority rules
      */
     public static void loadRules(List<AuthorityRule> rules) {
         currentProperty.updateValue(rules);
@@ -114,7 +119,7 @@ public class AuthorityRuleManager {
             if (rules != null) {
                 authorityRules.putAll(rules);
             }
-            RecordLog.info("receive authority config: " + authorityRules);
+            RecordLog.info("[AuthorityRuleManager] Authority rules received: " + authorityRules);
         }
 
         private Map<String, List<AuthorityRule>> loadAuthorityConf(List<AuthorityRule> list) {
@@ -129,12 +134,15 @@ public class AuthorityRuleManager {
 
                 String identity = rule.getResource();
                 List<AuthorityRule> ruleM = newRuleMap.get(identity);
+                // putIfAbsent
                 if (ruleM == null) {
                     ruleM = new ArrayList<AuthorityRule>();
+                    ruleM.add(rule);
                     newRuleMap.put(identity, ruleM);
+                } else {
+                    // One resource should only have at most one authority rule, so just ignore redundant rules.
+                    RecordLog.warn("[AuthorityRuleManager] Ignoring redundant rule: " + rule.toString());
                 }
-                ruleM.add(rule);
-
             }
 
             return newRuleMap;
@@ -148,9 +156,8 @@ public class AuthorityRuleManager {
             if (rules != null) {
                 authorityRules.putAll(rules);
             }
-            RecordLog.info("load authority config: " + authorityRules);
+            RecordLog.info("[AuthorityRuleManager] Load authority rules: " + authorityRules);
         }
-
     }
 
 }