/*
* Copyright (c) 2013, OpenCloudDB/MyCAT and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software;Designed and Developed mainly by many Chinese
* opensource volunteers. you can redistribute it and/or modify it under the
* terms of the GNU General Public License version 2 only, as published by the
* Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Any questions about this component can be directed to it's project Web address
* https://code.google.com/p/opencloudb/.
*
*/
package org.opencloudb.server.parser;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.opencloudb.parser.util.ParseUtil;
/**
* @author mycat
*/
public final class ServerParseShow {
public static final int OTHER = -1;
public static final int DATABASES = 1;
public static final int DATASOURCES = 2;
public static final int MYCAT_STATUS = 3;
public static final int MYCAT_CLUSTER = 4;
public static final int TABLES = 5;
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 'M':
case 'm':
return mycatCheck(stmt, i);
case 'D':
case 'd':
return dataCheck(stmt, i);
case 'T':
case 't':
return tableCheck(stmt, i);
default:
return OTHER;
}
}
return OTHER;
}
// SHOW MYCAT_
static int mycatCheck(String stmt, int offset) {
if (stmt.length() > offset + "ycat_?".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 == 'Y' || c1 == 'y') && (c2 == 'C' || c2 == 'c')
&& (c3 == 'A' || c3 == 'a') && (c4 == 'T' || c4 == 't')
&& (c5 == '_')) {
switch (stmt.charAt(++offset)) {
case 'S':
case 's':
return showMyCatStatus(stmt, offset);
case 'C':
case 'c':
return showMyCatCluster(stmt, offset);
default:
return OTHER;
}
}
}
return OTHER;
}
// SHOW MyCat_STATUS
static int showMyCatStatus(String stmt, int offset) {
if (stmt.length() > offset + "tatus".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 == 't' || c1 == 'T')
&& (c2 == 'a' || c2 == 'A')
&& (c3 == 't' || c3 == 'T')
&& (c4 == 'u' || c4 == 'U')
&& (c5 == 's' || c5 == 'S')
&& (stmt.length() == ++offset || ParseUtil.isEOF(stmt
.charAt(offset)))) {
return MYCAT_STATUS;
}
}
return OTHER;
}
// SHOW MyCat_CLUSTER
static int showMyCatCluster(String stmt, int offset) {
if (stmt.length() > offset + "luster".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);
if ((c1 == 'L' || c1 == 'l')
&& (c2 == 'U' || c2 == 'u')
&& (c3 == 'S' || c3 == 's')
&& (c4 == 'T' || c4 == 't')
&& (c5 == 'E' || c5 == 'e')
&& (c6 == 'R' || c6 == 'r')
&& (stmt.length() == ++offset || ParseUtil.isEOF(stmt
.charAt(offset)))) {
return MYCAT_CLUSTER;
}
}
return OTHER;
}
// SHOW DATA
static int dataCheck(String stmt, int offset) {
if (stmt.length() > offset + "ata?".length()) {
char c1 = stmt.charAt(++offset);
char c2 = stmt.charAt(++offset);
char c3 = stmt.charAt(++offset);
if ((c1 == 'A' || c1 == 'a') && (c2 == 'T' || c2 == 't')
&& (c3 == 'A' || c3 == 'a')) {
switch (stmt.charAt(++offset)) {
case 'B':
case 'b':
return showDatabases(stmt, offset);
case 'S':
case 's':
return showDataSources(stmt, offset);
default:
return OTHER;
}
}
}
return OTHER;
}
// SHOW TABLE
static int tableCheck(String stmt, int offset) {
// strict match
String pat1 = "^\\s*(SHOW)\\s+(TABLES)\\s*";
String pat2 = "^\\s*(SHOW)\\s+(TABLES)\\s+(LIKE\\s+'(.*)')\\s*";
String pat3 = "^\\s*(SHOW)\\s+(TABLES)\\s+(FROM)\\s+([a-zA-Z_0-9]+)\\s*";
String pat4 = "^\\s*(SHOW)\\s+(TABLES)\\s+(FROM)\\s+([a-zA-Z_0-9]+)\\s+(LIKE\\s+'(.*)')\\s*";
boolean flag = isShowTableMatched(stmt, pat1);
if (flag) {
return TABLES;
}
flag = isShowTableMatched(stmt, pat2);
if (flag) {
return TABLES;
}
flag = isShowTableMatched(stmt, pat3);
if (flag) {
return TABLES;
}
flag = isShowTableMatched(stmt, pat4);
if (flag) {
return TABLES;
}
return OTHER;
}
private static boolean isShowTableMatched(String stmt, String pat1) {
Pattern pattern = Pattern.compile(pat1, Pattern.CASE_INSENSITIVE);
Matcher ma = pattern.matcher(stmt);
boolean flag = ma.matches();
return flag;
}
// SHOW DATABASES
static int showDatabases(String stmt, int offset) {
if (stmt.length() > offset + "ases".length()) {
char c1 = stmt.charAt(++offset);
char c2 = stmt.charAt(++offset);
char c3 = stmt.charAt(++offset);
char c4 = stmt.charAt(++offset);
if ((c1 == 'A' || c1 == 'a')
&& (c2 == 'S' || c2 == 's')
&& (c3 == 'E' || c3 == 'e')
&& (c4 == 'S' || c4 == 's')
&& (stmt.length() == ++offset || ParseUtil.isEOF(stmt
.charAt(offset)))) {
return DATABASES;
}
}
return OTHER;
}
// SHOW DATASOURCES
static int showDataSources(String stmt, int offset) {
if (stmt.length() > offset + "ources".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);
if ((c1 == 'O' || c1 == 'o')
&& (c2 == 'U' || c2 == 'u')
&& (c3 == 'R' || c3 == 'r')
&& (c4 == 'C' || c4 == 'c')
&& (c5 == 'E' || c5 == 'e')
&& (c6 == 'S' || c6 == 's')
&& (stmt.length() == ++offset || ParseUtil.isEOF(stmt
.charAt(offset)))) {
return DATASOURCES;
}
}
return OTHER;
}
}