| /* |
| * Copyright (C) 2019 The Android Open Source Project |
| * |
| * 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 android.database.sqlite; |
| |
| import android.annotation.NonNull; |
| import android.annotation.Nullable; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.Locale; |
| import java.util.function.Consumer; |
| |
| /** |
| * SQL Tokenizer specialized to extract tokens from SQL (snippets). |
| * <p> |
| * Based on sqlite3GetToken() in tokenzie.c in SQLite. |
| * <p> |
| * Source for v3.8.6 (which android uses): http://www.sqlite.org/src/artifact/ae45399d6252b4d7 |
| * (Latest source as of now: http://www.sqlite.org/src/artifact/78c8085bc7af1922) |
| * <p> |
| * Also draft spec: http://www.sqlite.org/draft/tokenreq.html |
| * |
| * @hide |
| */ |
| public class SQLiteTokenizer { |
| private static boolean isAlpha(char ch) { |
| return ('a' <= ch && ch <= 'z') || ('A' <= ch && ch <= 'Z') || (ch == '_'); |
| } |
| |
| private static boolean isNum(char ch) { |
| return ('0' <= ch && ch <= '9'); |
| } |
| |
| private static boolean isAlNum(char ch) { |
| return isAlpha(ch) || isNum(ch); |
| } |
| |
| private static boolean isAnyOf(char ch, String set) { |
| return set.indexOf(ch) >= 0; |
| } |
| |
| private static IllegalArgumentException genException(String message, String sql) { |
| throw new IllegalArgumentException(message + " in '" + sql + "'"); |
| } |
| |
| private static char peek(String s, int index) { |
| return index < s.length() ? s.charAt(index) : '\0'; |
| } |
| |
| public static final int OPTION_NONE = 0; |
| |
| /** |
| * Require that SQL contains only tokens; any comments or values will result |
| * in an exception. |
| */ |
| public static final int OPTION_TOKEN_ONLY = 1 << 0; |
| |
| /** |
| * Tokenize the given SQL, returning the list of each encountered token. |
| * |
| * @throws IllegalArgumentException if invalid SQL is encountered. |
| */ |
| public static List<String> tokenize(@Nullable String sql, int options) { |
| final ArrayList<String> res = new ArrayList<>(); |
| tokenize(sql, options, res::add); |
| return res; |
| } |
| |
| /** |
| * Tokenize the given SQL, sending each encountered token to the given |
| * {@link Consumer}. |
| * |
| * @throws IllegalArgumentException if invalid SQL is encountered. |
| */ |
| public static void tokenize(@Nullable String sql, int options, Consumer<String> checker) { |
| if (sql == null) { |
| return; |
| } |
| int pos = 0; |
| final int len = sql.length(); |
| while (pos < len) { |
| final char ch = peek(sql, pos); |
| |
| // Regular token. |
| if (isAlpha(ch)) { |
| final int start = pos; |
| pos++; |
| while (isAlNum(peek(sql, pos))) { |
| pos++; |
| } |
| final int end = pos; |
| |
| final String token = sql.substring(start, end); |
| checker.accept(token); |
| |
| continue; |
| } |
| |
| // Handle quoted tokens |
| if (isAnyOf(ch, "'\"`")) { |
| final int quoteStart = pos; |
| pos++; |
| |
| for (;;) { |
| pos = sql.indexOf(ch, pos); |
| if (pos < 0) { |
| throw genException("Unterminated quote", sql); |
| } |
| if (peek(sql, pos + 1) != ch) { |
| break; |
| } |
| // Quoted quote char -- e.g. "abc""def" is a single string. |
| pos += 2; |
| } |
| final int quoteEnd = pos; |
| pos++; |
| |
| if (ch != '\'') { |
| // Extract the token |
| final String tokenUnquoted = sql.substring(quoteStart + 1, quoteEnd); |
| |
| final String token; |
| |
| // Unquote if needed. i.e. "aa""bb" -> aa"bb |
| if (tokenUnquoted.indexOf(ch) >= 0) { |
| token = tokenUnquoted.replaceAll( |
| String.valueOf(ch) + ch, String.valueOf(ch)); |
| } else { |
| token = tokenUnquoted; |
| } |
| checker.accept(token); |
| } else { |
| if ((options &= OPTION_TOKEN_ONLY) != 0) { |
| throw genException("Non-token detected", sql); |
| } |
| } |
| continue; |
| } |
| // Handle tokens enclosed in [...] |
| if (ch == '[') { |
| final int quoteStart = pos; |
| pos++; |
| |
| pos = sql.indexOf(']', pos); |
| if (pos < 0) { |
| throw genException("Unterminated quote", sql); |
| } |
| final int quoteEnd = pos; |
| pos++; |
| |
| final String token = sql.substring(quoteStart + 1, quoteEnd); |
| |
| checker.accept(token); |
| continue; |
| } |
| if ((options &= OPTION_TOKEN_ONLY) != 0) { |
| throw genException("Non-token detected", sql); |
| } |
| |
| // Detect comments. |
| if (ch == '-' && peek(sql, pos + 1) == '-') { |
| pos += 2; |
| pos = sql.indexOf('\n', pos); |
| if (pos < 0) { |
| // We disallow strings ending in an inline comment. |
| throw genException("Unterminated comment", sql); |
| } |
| pos++; |
| |
| continue; |
| } |
| if (ch == '/' && peek(sql, pos + 1) == '*') { |
| pos += 2; |
| pos = sql.indexOf("*/", pos); |
| if (pos < 0) { |
| throw genException("Unterminated comment", sql); |
| } |
| pos += 2; |
| |
| continue; |
| } |
| |
| // Semicolon is never allowed. |
| if (ch == ';') { |
| throw genException("Semicolon is not allowed", sql); |
| } |
| |
| // For this purpose, we can simply ignore other characters. |
| // (Note it doesn't handle the X'' literal properly and reports this X as a token, |
| // but that should be fine...) |
| pos++; |
| } |
| } |
| |
| /** |
| * Test if given token is a |
| * <a href="https://www.sqlite.org/lang_keywords.html">SQLite reserved |
| * keyword</a>. |
| */ |
| public static boolean isKeyword(@NonNull String token) { |
| switch (token.toUpperCase(Locale.US)) { |
| case "ABORT": case "ACTION": case "ADD": case "AFTER": |
| case "ALL": case "ALTER": case "ANALYZE": case "AND": |
| case "AS": case "ASC": case "ATTACH": case "AUTOINCREMENT": |
| case "BEFORE": case "BEGIN": case "BETWEEN": case "BINARY": |
| case "BY": case "CASCADE": case "CASE": case "CAST": |
| case "CHECK": case "COLLATE": case "COLUMN": case "COMMIT": |
| case "CONFLICT": case "CONSTRAINT": case "CREATE": case "CROSS": |
| case "CURRENT": case "CURRENT_DATE": case "CURRENT_TIME": case "CURRENT_TIMESTAMP": |
| case "DATABASE": case "DEFAULT": case "DEFERRABLE": case "DEFERRED": |
| case "DELETE": case "DESC": case "DETACH": case "DISTINCT": |
| case "DO": case "DROP": case "EACH": case "ELSE": |
| case "END": case "ESCAPE": case "EXCEPT": case "EXCLUDE": |
| case "EXCLUSIVE": case "EXISTS": case "EXPLAIN": case "FAIL": |
| case "FILTER": case "FOLLOWING": case "FOR": case "FOREIGN": |
| case "FROM": case "FULL": case "GLOB": case "GROUP": |
| case "GROUPS": case "HAVING": case "IF": case "IGNORE": |
| case "IMMEDIATE": case "IN": case "INDEX": case "INDEXED": |
| case "INITIALLY": case "INNER": case "INSERT": case "INSTEAD": |
| case "INTERSECT": case "INTO": case "IS": case "ISNULL": |
| case "JOIN": case "KEY": case "LEFT": case "LIKE": |
| case "LIMIT": case "MATCH": case "NATURAL": case "NO": |
| case "NOCASE": case "NOT": case "NOTHING": case "NOTNULL": |
| case "NULL": case "OF": case "OFFSET": case "ON": |
| case "OR": case "ORDER": case "OTHERS": case "OUTER": |
| case "OVER": case "PARTITION": case "PLAN": case "PRAGMA": |
| case "PRECEDING": case "PRIMARY": case "QUERY": case "RAISE": |
| case "RANGE": case "RECURSIVE": case "REFERENCES": case "REGEXP": |
| case "REINDEX": case "RELEASE": case "RENAME": case "REPLACE": |
| case "RESTRICT": case "RIGHT": case "ROLLBACK": case "ROW": |
| case "ROWS": case "RTRIM": case "SAVEPOINT": case "SELECT": |
| case "SET": case "TABLE": case "TEMP": case "TEMPORARY": |
| case "THEN": case "TIES": case "TO": case "TRANSACTION": |
| case "TRIGGER": case "UNBOUNDED": case "UNION": case "UNIQUE": |
| case "UPDATE": case "USING": case "VACUUM": case "VALUES": |
| case "VIEW": case "VIRTUAL": case "WHEN": case "WHERE": |
| case "WINDOW": case "WITH": case "WITHOUT": |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| /** |
| * Test if given token is a |
| * <a href="https://www.sqlite.org/lang_corefunc.html">SQLite reserved |
| * function</a>. |
| */ |
| public static boolean isFunction(@NonNull String token) { |
| switch (token.toLowerCase(Locale.US)) { |
| case "abs": case "avg": case "char": case "coalesce": |
| case "count": case "glob": case "group_concat": case "hex": |
| case "ifnull": case "instr": case "length": case "like": |
| case "likelihood": case "likely": case "lower": case "ltrim": |
| case "max": case "min": case "nullif": case "random": |
| case "randomblob": case "replace": case "round": case "rtrim": |
| case "substr": case "sum": case "total": case "trim": |
| case "typeof": case "unicode": case "unlikely": case "upper": |
| case "zeroblob": |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| /** |
| * Test if given token is a |
| * <a href="https://www.sqlite.org/datatype3.html">SQLite reserved type</a>. |
| */ |
| public static boolean isType(@NonNull String token) { |
| switch (token.toUpperCase(Locale.US)) { |
| case "INT": case "INTEGER": case "TINYINT": case "SMALLINT": |
| case "MEDIUMINT": case "BIGINT": case "INT2": case "INT8": |
| case "CHARACTER": case "VARCHAR": case "NCHAR": case "NVARCHAR": |
| case "TEXT": case "CLOB": case "BLOB": case "REAL": |
| case "DOUBLE": case "FLOAT": case "NUMERIC": case "DECIMAL": |
| case "BOOLEAN": case "DATE": case "DATETIME": |
| return true; |
| default: |
| return false; |
| } |
| } |
| } |