找到了sql关键字8位索引，BKDRHash 24~31

Author: ishotoli

src/main/java/io/mycat/MatchMethodGenerator.java

@@ -3,8 +3,11 @@
 import com.alibaba.druid.sql.parser.Token;
 
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
 
 /**
  * Created by Administrator on 2017/2/13 0013.
@@ -14,21 +17,19 @@ public class MatchMethodGenerator {
     static Map<String, Token> map = new HashMap<String, Token>();
 
     static {
+
         map.put("ALL", Token.ALL);
         map.put("ALTER", Token.ALTER);
         map.put("AND", Token.AND);
         map.put("ANY", Token.ANY);
         map.put("AS", Token.AS);
-
         map.put("ENABLE", Token.ENABLE);
         map.put("DISABLE", Token.DISABLE);
-
         map.put("ASC", Token.ASC);
         map.put("BETWEEN", Token.BETWEEN);
         map.put("BY", Token.BY);
         map.put("CASE", Token.CASE);
         map.put("CAST", Token.CAST);
-
         map.put("CHECK", Token.CHECK);
         map.put("CONSTRAINT", Token.CONSTRAINT);
         map.put("CREATE", Token.CREATE);
@@ -38,62 +39,52 @@ public class MatchMethodGenerator {
         map.put("TABLESPACE", Token.TABLESPACE);
         map.put("PROCEDURE", Token.PROCEDURE);
         map.put("FUNCTION", Token.FUNCTION);
-
         map.put("DELETE", Token.DELETE);
         map.put("DESC", Token.DESC);
         map.put("DISTINCT", Token.DISTINCT);
         map.put("DROP", Token.DROP);
         map.put("ELSE", Token.ELSE);
         map.put("EXPLAIN", Token.EXPLAIN);
         map.put("EXCEPT", Token.EXCEPT);
-
         map.put("END", Token.END);
         map.put("ESCAPE", Token.ESCAPE);
         map.put("EXISTS", Token.EXISTS);
         map.put("FOR", Token.FOR);
         map.put("FOREIGN", Token.FOREIGN);
-
         map.put("FROM", Token.FROM);
         map.put("FULL", Token.FULL);
         map.put("GROUP", Token.GROUP);
         map.put("HAVING", Token.HAVING);
         map.put("IN", Token.IN);
-
         map.put("INDEX", Token.INDEX);
         map.put("INNER", Token.INNER);
         map.put("INSERT", Token.INSERT);
         map.put("INTERSECT", Token.INTERSECT);
         map.put("INTERVAL", Token.INTERVAL);
-
         map.put("INTO", Token.INTO);
         map.put("IS", Token.IS);
         map.put("JOIN", Token.JOIN);
         map.put("KEY", Token.KEY);
         map.put("LEFT", Token.LEFT);
-
         map.put("LIKE", Token.LIKE);
         map.put("LOCK", Token.LOCK);
         map.put("MINUS", Token.MINUS);
         map.put("NOT", Token.NOT);
-
         map.put("NULL", Token.NULL);
         map.put("ON", Token.ON);
         map.put("OR", Token.OR);
         map.put("ORDER", Token.ORDER);
         map.put("OUTER", Token.OUTER);
-
         map.put("PRIMARY", Token.PRIMARY);
         map.put("REFERENCES", Token.REFERENCES);
         map.put("RIGHT", Token.RIGHT);
         map.put("SCHEMA", Token.SCHEMA);
         map.put("SELECT", Token.SELECT);
-
         map.put("SET", Token.SET);
         map.put("SOME", Token.SOME);
         map.put("TABLE", Token.TABLE);
         map.put("THEN", Token.THEN);
         map.put("TRUNCATE", Token.TRUNCATE);
-
         map.put("UNION", Token.UNION);
         map.put("UNIQUE", Token.UNIQUE);
         map.put("UPDATE", Token.UPDATE);
@@ -102,23 +93,18 @@ public class MatchMethodGenerator {
         map.put("SEQUENCE", Token.SEQUENCE);
         map.put("TRIGGER", Token.TRIGGER);
         map.put("USER", Token.USER);
-
         map.put("WHEN", Token.WHEN);
         map.put("WHERE", Token.WHERE);
         map.put("XOR", Token.XOR);
-
         map.put("OVER", Token.OVER);
         map.put("TO", Token.TO);
         map.put("USE", Token.USE);
-
         map.put("REPLACE", Token.REPLACE);
-
         map.put("COMMENT", Token.COMMENT);
         map.put("COMPUTE", Token.COMPUTE);
         map.put("WITH", Token.WITH);
         map.put("GRANT", Token.GRANT);
         map.put("REVOKE", Token.REVOKE);
-
         // MySql procedure: add by zz
         map.put("WHILE", Token.WHILE);
         map.put("DO", Token.DO);
@@ -137,9 +123,57 @@ public class MatchMethodGenerator {
     }
 
     public static void main(String[] args) {
-        isXXXTokenGenerator();
-        skipXXXTokenGenerator();
+        //isXXXTokenGenerator();
+        //skipXXXTokenGenerator();
+        IntStream.range(24, 31).forEach(x -> {
+            Map<Long, List<Token>> map = Stream.of(Token.values())
+                    .filter((t) -> t.name() != null)
+                    .collect(Collectors.groupingBy((t) -> {
+                                String name = t.name();
+                                char size = (char)name.length();
+                                int b = 378551;
+                                int a = 63689;
+                                int seed = 13131;
+                                long hash = 0;
+                                int low = 0;
+                                int high = 0;
+                                for(int i=0; i<size; i++) {
+                                    char c = name.charAt(i);
+                                    //BKDRHash
+                                    low = low * seed + c;
+                                    //RS Hash
+                                    high = high * a + c;
+                                    a *= b;
+                                };
+                                hash = (long)(high & 0x7FFFFFFF) << 32 | (long)(low & 0x7FFFFFFF);
+                                return (hash & (0xff << x));
+//                            return t.name().chars().sum();
+                            }
+                    ));
+            /*long count = map.entrySet().stream()
+                    .filter((k) -> k.getValue().size() > 2)
+                    .count();
+                    if (count == 0) {
+                System.out.println("result = "+x);
+            }
+                    */
+            System.out.println("result = "+x+" >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>");
+            map.entrySet().stream()
+                    //.filter((k) -> k.getValue().size() > 1)
+                    .forEach((e) -> System.out.format("%d : %s %n", e.getKey(), e.getValue().toString()));
 
+
+        });
+        //当左移位数为
+//        result = 24
+//        result = 25
+//        result = 26
+//        result = 27
+//        result = 28
+//        result = 29
+//        result = 30
+//        result = 31
+                //.forEach((e) -> System.out.format("%d : %s %n", e.getKey(), e.getValue().toString()));
     }
 
     /**