1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400
|
// Copyright (c) 2009-2010 Sun Microsystems, Inc.
//
// MySQL Connector/NET is licensed under the terms of the GPLv2
// <http://www.gnu.org/licenses/old-licenses/gpl-2.0.html>, like most
// MySQL Connectors. There are special exceptions to the terms and
// conditions of the GPLv2 as it is applied to this software, see the
// FLOSS License Exception
// <http://www.mysql.com/about/legal/licensing/foss-exception.html>.
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published
// by the Free Software Foundation; version 2 of the License.
//
// This program 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
// for more details.
//
// You should have received a copy of the GNU General Public License along
// with this program; if not, write to the Free Software Foundation, Inc.,
// 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Diagnostics;
using System.Collections;
using MySql.Data.MySqlClient.Properties;
namespace MySql.Data.Common
{
internal class QueryNormalizer
{
private static List<string> keywords = new List<string>();
private List<Token> tokens = new List<Token>();
private int pos;
private string fullSql;
private string queryType;
static QueryNormalizer()
{
StringReader sr = new StringReader(Resources.keywords);
string keyword = sr.ReadLine();
while (keyword != null)
{
keywords.Add(keyword);
keyword = sr.ReadLine();
}
}
public string QueryType
{
get { return queryType; }
}
public string Normalize(string sql)
{
tokens.Clear();
StringBuilder newSql = new StringBuilder();
fullSql = sql;
TokenizeSql(sql);
DetermineStatementType(tokens);
ProcessMathSymbols(tokens);
CollapseValueLists(tokens);
CollapseInLists(tokens);
CollapseWhitespace(tokens);
foreach (Token t in tokens)
if (t.Output)
newSql.Append(t.Text);
return newSql.ToString();
}
private void DetermineStatementType(List<Token> tok)
{
foreach (Token t in tok)
{
if (t.Type == TokenType.Keyword)
{
queryType = t.Text.ToUpperInvariant();
//string s = t.Text.ToLowerInvariant();
//if (s == "select")
// queryType = "SELECT";
//else if (s == "update" || s == "insert")
// queryType = "UPSERT";
//else
// queryType = "OTHER";
break;
}
}
}
/// <summary>
/// Mark - or + signs that are unary ops as no output
/// </summary>
/// <param name="tok"></param>
private void ProcessMathSymbols(List<Token> tok)
{
Token lastToken = null;
foreach (Token t in tok)
{
if (t.Type == TokenType.Symbol &&
(t.Text == "-" || t.Text == "+"))
{
if (lastToken != null &&
lastToken.Type != TokenType.Number &&
lastToken.Type != TokenType.Identifier &&
(lastToken.Type != TokenType.Symbol || lastToken.Text != ")"))
t.Output = false;
}
if (t.IsRealToken)
lastToken = t;
}
}
private void CollapseWhitespace(List<Token> tok)
{
Token lastToken = null;
foreach (Token t in tok)
{
if (t.Output &&
t.Type == TokenType.Whitespace &&
lastToken != null &&
lastToken.Type == TokenType.Whitespace)
{
t.Output = false;
}
if (t.Output)
lastToken = t;
}
}
private void CollapseValueLists(List<Token> tok)
{
int pos = -1;
while (++pos < tok.Count)
{
Token t = tok[pos];
if (t.Type != TokenType.Keyword) continue;
if (!t.Text.StartsWith("VALUE")) continue;
CollapseValueList(tok, ref pos);
}
}
private void CollapseValueList(List<Token> tok, ref int pos)
{
List<int> parenIndices = new List<int>();
// this while loop will find all closing parens in this value list
while (true)
{
// find the close ')'
while (++pos < tok.Count)
{
if (tok[pos].Type == TokenType.Symbol && tok[pos].Text == ")")
break;
if (pos == tok.Count-1)
break;
}
parenIndices.Add(pos);
// now find the next "real" token
while (++pos < tok.Count)
if (tok[pos].IsRealToken) break;
if (pos == tok.Count) break;
if (tok[pos].Text != ",")
{
pos--;
break;
}
}
// if we only have 1 value then we don't collapse
if (parenIndices.Count < 2) return;
int index = parenIndices[0];
tok[++index] = new Token(TokenType.Whitespace, " ");
tok[++index] = new Token(TokenType.Comment, "/* , ... */");
index++;
// now mark all the other tokens as no output
while (index <= parenIndices[parenIndices.Count - 1])
tok[index++].Output = false;
}
private void CollapseInLists(List<Token> tok)
{
int pos = -1;
while (++pos < tok.Count)
{
Token t = tok[pos];
if (t.Type != TokenType.Keyword) continue;
if (!(t.Text == "IN")) continue;
CollapseInList(tok, ref pos);
}
}
private Token GetNextRealToken(List<Token> tok, ref int pos)
{
while (++pos < tok.Count)
{
if (tok[pos].IsRealToken) return tok[pos];
}
return null;
}
private void CollapseInList(List<Token> tok, ref int pos)
{
Token t = GetNextRealToken(tok, ref pos);
// Debug.Assert(t.Text == "(");
if (t == null)
return;
// if the first token is a keyword then we likely have a
// SELECT .. IN (SELECT ...)
t = GetNextRealToken(tok, ref pos);
if (t == null || t.Type == TokenType.Keyword) return;
int start = pos;
// first find all the tokens that make up the in list
while (++pos < tok.Count)
{
t = tok[pos];
if (t.Type == TokenType.CommandComment) return;
if (!t.IsRealToken) continue;
if (t.Text == "(") return;
if (t.Text == ")") break;
}
int stop = pos;
for (int i = stop; i > start; i--)
tok.RemoveAt(i);
tok.Insert(++start, new Token(TokenType.Whitespace, " "));
tok.Insert(++start, new Token(TokenType.Comment, "/* , ... */"));
tok.Insert(++start, new Token(TokenType.Whitespace, " "));
tok.Insert(++start, new Token(TokenType.Symbol, ")"));
}
private void TokenizeSql(string sql)
{
pos = 0;
while (pos < sql.Length)
{
char c = sql[pos];
if (LetterStartsComment(c) && ConsumeComment())
continue;
if (Char.IsWhiteSpace(c))
ConsumeWhitespace();
else if (c == '\'' || c == '\"' || c == '`')
ConsumeQuotedToken(c);
else if (!IsSpecialCharacter(c))
ConsumeUnquotedToken();
else
ConsumeSymbol();
}
}
private bool LetterStartsComment(char c)
{
return c == '#' || c == '/' || c == '-';
}
private bool IsSpecialCharacter(char c)
{
if (Char.IsLetterOrDigit(c) ||
c == '$' || c == '_' || c == '.') return false;
return true;
}
private bool ConsumeComment()
{
char c = fullSql[pos];
// make sure the comment starts correctly
if (c == '/' && ((pos + 1) >= fullSql.Length || fullSql[pos + 1] != '*')) return false;
if (c == '-' && ((pos + 2) >= fullSql.Length || fullSql[pos + 1] != '-' || fullSql[pos + 2] != ' ')) return false;
string endingPattern = "\n";
if (c == '/')
endingPattern = "*/";
int startingIndex = pos;
int index = fullSql.IndexOf(endingPattern, pos);
if (index == -1)
index = fullSql.Length - 1;
else
index += endingPattern.Length;
string comment = fullSql.Substring(pos, index - pos);
if (comment.StartsWith("/*!"))
tokens.Add(new Token(TokenType.CommandComment, comment));
pos = index;
return true;
}
private void ConsumeSymbol()
{
char c = fullSql[pos++];
tokens.Add(new Token(TokenType.Symbol, c.ToString()));
}
private void ConsumeQuotedToken(char c)
{
bool escaped = false;
int start = pos;
pos++;
while (pos < fullSql.Length)
{
char x = fullSql[pos];
if (x == c && !escaped) break;
if (escaped)
escaped = false;
else if (x == '\\')
escaped = true;
pos++;
}
pos++;
if (c == '\'')
tokens.Add(new Token(TokenType.String, "?"));
else
tokens.Add(new Token(TokenType.Identifier, fullSql.Substring(start, pos - start)));
}
private void ConsumeUnquotedToken()
{
int startPos = pos;
while (pos < fullSql.Length && !IsSpecialCharacter(fullSql[pos]))
pos++;
string word = fullSql.Substring(startPos, pos - startPos);
double v;
if (Double.TryParse(word, out v))
tokens.Add(new Token(TokenType.Number, "?"));
else
{
Token t = new Token(TokenType.Identifier, word);
if (IsKeyword(word))
{
t.Type = TokenType.Keyword;
t.Text = t.Text.ToUpperInvariant();
}
tokens.Add(t);
}
}
private void ConsumeWhitespace()
{
tokens.Add(new Token(TokenType.Whitespace, " "));
while (pos < fullSql.Length && Char.IsWhiteSpace(fullSql[pos]))
pos++;
}
private bool IsKeyword(string word)
{
return keywords.Contains(word.ToUpperInvariant());
}
}
internal class Token
{
public TokenType Type;
public string Text;
public bool Output;
public Token(TokenType type, string text)
{
Type = type;
Text = text;
Output = true;
}
public bool IsRealToken
{
get
{
return Type != TokenType.Comment &&
Type != TokenType.CommandComment &&
Type != TokenType.Whitespace &&
Output; }
}
}
internal enum TokenType
{
Keyword,
String,
Number,
Symbol,
Identifier,
Comment,
CommandComment,
Whitespace
}
}
|