improve sql parser performance

src/main/java/com/alibaba/druid/sql/dialect/mysql/parser/MySqlLexer.java

@@ -209,13 +209,24 @@ public class MySqlLexer extends Lexer {
         {
             boolean hasSpecial = false;
             int startIndex = pos + 1;
-            int endIndex = text.indexOf('\'', startIndex);
+            int endIndex = -1; //text.indexOf('\'', startIndex);
+            for (int i = startIndex; i < text.length(); ++i) {
+                final char ch = text.charAt(i);
+                if (ch == '\\') {
+                    hasSpecial = true;
+                }
+                if (ch == '\'') {
+                    endIndex = i;
+                    break;
+                }
+            }
+            
             if (endIndex == -1) {
                 throw new ParserException("unclosed str");
             }
 
             String stringVal = subString(startIndex, endIndex - startIndex);
-            hasSpecial = stringVal.indexOf('\\') != -1;
+//            hasSpecial = stringVal.indexOf('\\') != -1;
 
             if (!hasSpecial) {
                 this.stringVal = stringVal;

src/main/java/com/alibaba/druid/sql/parser/Lexer.java

@@ -79,7 +79,7 @@ public class Lexer {
         return text.charAt(index);
     }
     
-    public String addSymbol() {
+    public final String addSymbol() {
         return subString(mark, bufPos);
     }
 

src/main/java/com/alibaba/druid/sql/visitor/SchemaStatVisitor.java

@@ -137,9 +137,30 @@ public class SchemaStatVisitor extends SQLASTVisitorAdapter {
     }
 
     private String handleName(String ident) {
-        ident = ident.replaceAll("\"", "");
-        ident = ident.replaceAll("`", "");
-        ident = ident.replaceAll(" ", "");
+        boolean flag0 = false;
+        boolean flag1 = false;
+        boolean flag2 = false;
+        for (int i = 0; i < ident.length(); ++i) {
+            final char ch = ident.charAt(i);
+            if (ch == '\"') {
+                flag0 = true;
+            } else if (ch == '`') {
+                flag1 = true;
+            } else if (ch == ' ') {
+                flag2 = true;
+            }
+        }
+        if (flag0) {
+            ident = ident.replaceAll("\"", "");
+        }
+        
+        if (flag1) {
+            ident = ident.replaceAll("`", "");
+        }
+        
+        if (flag2) {
+            ident = ident.replaceAll(" ", "");
+        }
 
         ident = aliasWrap(ident);
 

src/main/java/com/alibaba/druid/stat/TableStat.java

@@ -20,6 +20,8 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
+import com.alibaba.druid.util.StringUtils;
+
 public class TableStat {
 
     int selectCount      = 0;
@@ -170,7 +172,7 @@ public class TableStat {
         }
 
         public int hashCode() {
-            return this.name.toLowerCase().hashCode();
+            return StringUtils.lowerHashCode(name);
         }
 
         public boolean equals(Object o) {
@@ -401,8 +403,8 @@ public class TableStat {
         }
 
         public int hashCode() {
-            int tableHashCode = table != null ? table.toLowerCase().hashCode() : 0;
-            int nameHashCode = name != null ? name.toLowerCase().hashCode() : 0;
+            int tableHashCode = table != null ? StringUtils.lowerHashCode(table) : 0;
+            int nameHashCode = name != null ? StringUtils.lowerHashCode(name) : 0;
 
             return tableHashCode + nameHashCode;
         }

src/main/java/com/alibaba/druid/util/StringUtils.java

@@ -91,4 +91,18 @@ public class StringUtils {
 
         return false;
     }
+    
+    public static int lowerHashCode(String text) {
+//        return text.toLowerCase().hashCode();
+        int h = 0;
+        for (int i = 0; i < text.length(); ++i) {
+            char ch = text.charAt(i);
+            if (ch >= 'A' && ch <= 'Z') {
+                ch = (char) (ch + 32);
+            }
+
+            h = 31 * h + ch;
+        }
+        return h;
+    }
 }

src/test/java/com/alibaba/druid/benckmark/sql/MySqlPerfMain_select.java

@@ -20,9 +20,8 @@ import java.util.List;
 
 import com.alibaba.druid.sql.ast.SQLStatement;
 import com.alibaba.druid.sql.dialect.mysql.parser.MySqlStatementParser;
-import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlOutputVisitor;
+import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlASTVisitorAdapter;
 import com.alibaba.druid.sql.test.TestUtils;
-import com.alibaba.druid.util.IOUtils;
 
 public class MySqlPerfMain_select {
 
@@ -30,9 +29,9 @@ public class MySqlPerfMain_select {
         System.out.println(System.getProperty("java.vm.name") + " " + System.getProperty("java.runtime.version"));
         List<String> arguments = ManagementFactory.getRuntimeMXBean().getInputArguments();
         System.out.println(arguments);
-        
+
         String sql = "SELECT ID, NAME, AGE FROM USER WHERE ID = ?";
-        
+
         for (int i = 0; i < 10; ++i) {
             perfMySql(sql);
         }
@@ -57,15 +56,18 @@ public class MySqlPerfMain_select {
         return millis;
     }
 
-    static String execMySql(String sql) {
-        StringBuilder out = new StringBuilder();
-        MySqlOutputVisitor visitor = new MySqlOutputVisitor(out);
+    static void execMySql(String sql) {
+
         MySqlStatementParser parser = new MySqlStatementParser(sql);
         List<SQLStatement> statementList = parser.parseStatementList();
-        // for (SQLStatement statement : statementList) {
-        // statement.accept(visitor);
-        // visitor.println();
-        // }
-        return out.toString();
+
+        // StringBuilder out = new StringBuilder();
+        // MySqlOutputVisitor visitor = new MySqlOutputVisitor(out);
+//        MySqlASTVisitorAdapter visitor = new MySqlASTVisitorAdapter();
+//
+//        for (SQLStatement statement : statementList) {
+//            statement.accept(visitor);
+//        }
+        // out.toString();
     }
 }