content: /*
   * Copyright 1999-2012 Alibaba Group.
   *  
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *  
   *      http://www.apache.org/licenses/LICENSE-2.0
   *  
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package com.alibaba.cobar.manager.parser;
  
  import com.alibaba.cobar.parser.util.ParseUtil;
  
  /**
   * @author xianmao.hexm 2012-4-16
   */
  public class ManagerParseClear {
  
      public static final int OTHER = -1;
      public static final int SLOW_SCHEMA = 1;
      public static final int SLOW_DATANODE = 2;
  
      public static int parse(String stmt, int offset) {
          int i = offset;
          for (; i < stmt.length(); i++) {
              switch (stmt.charAt(i)) {
              case ' ':
                  continue;
              case '/':
              case '#':
                  i = ParseUtil.comment(stmt, i);
                  continue;
              case '@':
                  return clear2Check(stmt, i);
              default:
                  return OTHER;
              }
          }
          return OTHER;
      }
  
      // CLEAR @@SLOW
      static int clear2Check(String stmt, int offset) {
          if (stmt.length() > ++offset && stmt.charAt(offset) == '@') {
              if (stmt.length() > offset + "SLOW ".length()) {
                  char c1 = stmt.charAt(++offset);
                  char c2 = stmt.charAt(++offset);
                  char c3 = stmt.charAt(++offset);
                  char c4 = stmt.charAt(++offset);
                  char c5 = stmt.charAt(++offset);
                  if ((c1 == 'S' || c1 == 's') && (c2 == 'L' || c2 == 'l') && (c3 == 'O' || c3 == 'o')
                          && (c4 == 'W' || c4 == 'w') && (c5 == ' ')) {
                      while (stmt.length() > ++offset) {
                          switch (stmt.charAt(offset)) {
                          case ' ':
                              continue;
                          case 'W':
                          case 'w':
                              return clear2WhereCheck(stmt, offset);
                          default:
                              return OTHER;
                          }
                      }
                  }
              }
          }
          return OTHER;
      }
  
      // CLEAR @@SLOW WHERE
      static int clear2WhereCheck(String stmt, int offset) {
          if (stmt.length() > offset + "HERE ".length()) {
              char c1 = stmt.charAt(++offset);
              char c2 = stmt.charAt(++offset);
              char c3 = stmt.charAt(++offset);
              char c4 = stmt.charAt(++offset);
              char c5 = stmt.charAt(++offset);
              if ((c1 == 'H' || c1 == 'h') && (c2 == 'E' || c2 == 'e') && (c3 == 'R' || c3 == 'r')
                      && (c4 == 'E' || c4 == 'e') && (c5 == ' ')) {
                  while (stmt.length() > ++offset) {
                      switch (stmt.charAt(offset)) {
                      case ' ':
                          continue;
                      case 'D':
                      case 'd':
                          return clear2DCheck(stmt, offset);
                      case 'S':
                      case 's':
                          return clear2SCheck(stmt, offset);
                      default:
                          return OTHER;
                      }
                  }
              }
          }
          return OTHER;
      }
  
      // CLEAR @@SLOW WHERE DATANODE = XXXXXX
      static int clear2DCheck(String stmt, int offset) {
          if (stmt.length() > offset + "ATANODE".length()) {
              char c1 = stmt.charAt(++offset);
              char c2 = stmt.charAt(++offset);
              char c3 = stmt.charAt(++offset);
              char c4 = stmt.charAt(++offset);
              char c5 = stmt.charAt(++offset);
              char c6 = stmt.charAt(++offset);
              char c7 = stmt.charAt(++offset);
              if ((c1 == 'A' || c1 == 'a') && (c2 == 'T' || c2 == 't') && (c3 == 'A' || c3 == 'a')
                      && (c4 == 'N' || c4 == 'n') && (c5 == 'O' || c5 == 'o') && (c6 == 'D' || c6 == 'd')
                      && (c7 == 'E' || c7 == 'e')) {
                  while (stmt.length() > ++offset) {
                      switch (stmt.charAt(offset)) {
                      case ' ':
                          continue;
                      case '=':
                          while (stmt.length() > ++offset) {
                              switch (stmt.charAt(offset)) {
                              case ' ':
                                  continue;
                              default:
                                  return (offset << 8) | SLOW_DATANODE;
                              }
                          }
                          return OTHER;
                      default:
                          return OTHER;
                      }
                  }
              }
          }
          return OTHER;
      }
  
      // CLEAR @@SLOW WHERE SCHEMA = XXXXXX
      static int clear2SCheck(String stmt, int offset) {
          if (stmt.length() > offset + "CHEMA".length()) {
              char c1 = stmt.charAt(++offset);
              char c2 = stmt.charAt(++offset);
              char c3 = stmt.charAt(++offset);
              char c4 = stmt.charAt(++offset);
              char c5 = stmt.charAt(++offset);
              if ((c1 == 'C' || c1 == 'c') && (c2 == 'H' || c2 == 'h') && (c3 == 'E' || c3 == 'e')
                      && (c4 == 'M' || c4 == 'm') && (c5 == 'A' || c5 == 'a')) {
                  while (stmt.length() > ++offset) {
                      switch (stmt.charAt(offset)) {
                      case ' ':
                          continue;
                      case '=':
                          while (stmt.length() > ++offset) {
                              switch (stmt.charAt(offset)) {
                              case ' ':
                                  continue;
                              default:
                                  return (offset << 8) | SLOW_SCHEMA;
                              }
                          }
                          return OTHER;
                      default:
                          return OTHER;
                      }
                  }
              }
          }
          return OTHER;
      }
  
  }
  