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/*
 * Copyright (c) 2006, PostgreSQL Global Development Group
 * See the LICENSE file in the project root for more information.
 */

package org.postgresql.core;

import org.postgresql.jdbc.EscapeSyntaxCallMode;
import org.postgresql.jdbc.EscapedFunctions2;
import org.postgresql.util.GT;
import org.postgresql.util.PSQLException;
import org.postgresql.util.PSQLState;

import org.checkerframework.checker.nullness.qual.Nullable;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 * Basic query parser infrastructure.
 * Note: This class should not be considered as pgjdbc public API.
 *
 * @author Michael Paesold ([email protected])
 * @author Christopher Deckers ([email protected])
 */
public class Parser {
  private static final int[] NO_BINDS = new int[0];

  /**
   * Parses JDBC query into PostgreSQL's native format. Several queries might be given if separated
   * by semicolon.
   *
   * @param query                     jdbc query to parse
   * @param standardConformingStrings whether to allow backslashes to be used as escape characters
   *                                  in single quote literals
   * @param withParameters            whether to replace ?, ? with $1, $2, etc
   * @param splitStatements           whether to split statements by semicolon
   * @param isBatchedReWriteConfigured whether re-write optimization is enabled
   * @param quoteReturningIdentifiers whether to quote identifiers returned using returning clause
   * @param returningColumnNames      for simple insert, update, delete add returning with given column names
   * @return list of native queries
   * @throws SQLException if unable to add returning clause (invalid column names)
   */
  public static List parseJdbcSql(String query, boolean standardConformingStrings,
      boolean withParameters, boolean splitStatements,
      boolean isBatchedReWriteConfigured,
      boolean quoteReturningIdentifiers,
      String... returningColumnNames) throws SQLException {
    if (!withParameters && !splitStatements
        && returningColumnNames != null && returningColumnNames.length == 0) {
      return Collections.singletonList(new NativeQuery(query,
        SqlCommand.createStatementTypeInfo(SqlCommandType.BLANK)));
    }

    int fragmentStart = 0;
    int inParen = 0;

    char[] aChars = query.toCharArray();

    StringBuilder nativeSql = new StringBuilder(query.length() + 10);
    List bindPositions = null; // initialized on demand
    List nativeQueries = null;
    boolean isCurrentReWriteCompatible = false;
    boolean isValuesFound = false;
    int valuesBraceOpenPosition = -1;
    int valuesBraceClosePosition = -1;
    boolean valuesBraceCloseFound = false;
    boolean isInsertPresent = false;
    boolean isReturningPresent = false;
    boolean isReturningPresentPrev = false;
    SqlCommandType currentCommandType = SqlCommandType.BLANK;
    SqlCommandType prevCommandType = SqlCommandType.BLANK;
    int numberOfStatements = 0;

    boolean whitespaceOnly = true;
    int keyWordCount = 0;
    int keywordStart = -1;
    int keywordEnd = -1;
    for (int i = 0; i < aChars.length; ++i) {
      char aChar = aChars[i];
      boolean isKeyWordChar = false;
      // ';' is ignored as it splits the queries
      whitespaceOnly &= aChar == ';' || Character.isWhitespace(aChar);
      keywordEnd = i; // parseSingleQuotes, parseDoubleQuotes, etc move index so we keep old value
      switch (aChar) {
        case '\'': // single-quotes
          i = Parser.parseSingleQuotes(aChars, i, standardConformingStrings);
          break;

        case '"': // double-quotes
          i = Parser.parseDoubleQuotes(aChars, i);
          break;

        case '-': // possibly -- style comment
          i = Parser.parseLineComment(aChars, i);
          break;

        case '/': // possibly /* */ style comment
          i = Parser.parseBlockComment(aChars, i);
          break;

        case '$': // possibly dollar quote start
          i = Parser.parseDollarQuotes(aChars, i);
          break;

        // case '(' moved below to parse "values(" properly

        case ')':
          inParen--;
          if (inParen == 0 && isValuesFound && !valuesBraceCloseFound) {
            // If original statement is multi-values like VALUES (...), (...), ... then
            // search for the latest closing paren
            valuesBraceClosePosition = nativeSql.length() + i - fragmentStart;
          }
          break;

        case '?':
          nativeSql.append(aChars, fragmentStart, i - fragmentStart);
          if (i + 1 < aChars.length && aChars[i + 1] == '?') /* replace ?? with ? */ {
            nativeSql.append('?');
            i++; // make sure the coming ? is not treated as a bind
          } else {
            if (!withParameters) {
              nativeSql.append('?');
            } else {
              if (bindPositions == null) {
                bindPositions = new ArrayList();
              }
              bindPositions.add(nativeSql.length());
              int bindIndex = bindPositions.size();
              nativeSql.append(NativeQuery.bindName(bindIndex));
            }
          }
          fragmentStart = i + 1;
          break;

        case ';':
          if (inParen == 0) {
            if (!whitespaceOnly) {
              numberOfStatements++;
              nativeSql.append(aChars, fragmentStart, i - fragmentStart);
              whitespaceOnly = true;
            }
            fragmentStart = i + 1;
            if (nativeSql.length() > 0) {
              if (addReturning(nativeSql, currentCommandType, returningColumnNames, isReturningPresent, quoteReturningIdentifiers)) {
                isReturningPresent = true;
              }

              if (splitStatements) {
                if (nativeQueries == null) {
                  nativeQueries = new ArrayList();
                }

                if (!isValuesFound || !isCurrentReWriteCompatible || valuesBraceClosePosition == -1
                    || (bindPositions != null
                    && valuesBraceClosePosition < bindPositions.get(bindPositions.size() - 1))) {
                  valuesBraceOpenPosition = -1;
                  valuesBraceClosePosition = -1;
                }

                nativeQueries.add(new NativeQuery(nativeSql.toString(),
                    toIntArray(bindPositions), false,
                    SqlCommand.createStatementTypeInfo(
                        currentCommandType, isBatchedReWriteConfigured, valuesBraceOpenPosition,
                        valuesBraceClosePosition,
                        isReturningPresent, nativeQueries.size())));
              }
            }
            prevCommandType = currentCommandType;
            isReturningPresentPrev = isReturningPresent;
            currentCommandType = SqlCommandType.BLANK;
            isReturningPresent = false;
            if (splitStatements) {
              // Prepare for next query
              if (bindPositions != null) {
                bindPositions.clear();
              }
              nativeSql.setLength(0);
              isValuesFound = false;
              isCurrentReWriteCompatible = false;
              valuesBraceOpenPosition = -1;
              valuesBraceClosePosition = -1;
              valuesBraceCloseFound = false;
            }
          }
          break;

        default:
          if (keywordStart >= 0) {
            // When we are inside a keyword, we need to detect keyword end boundary
            // Note that isKeyWordChar is initialized to false before the switch, so
            // all other characters would result in isKeyWordChar=false
            isKeyWordChar = isIdentifierContChar(aChar);
            break;
          }
          // Not in keyword, so just detect next keyword start
          isKeyWordChar = isIdentifierStartChar(aChar);
          if (isKeyWordChar) {
            keywordStart = i;
            if (valuesBraceOpenPosition != -1 && inParen == 0) {
              // When the statement already has multi-values, stop looking for more of them
              // Since values(?,?),(?,?),... should not contain keywords in the middle
              valuesBraceCloseFound = true;
            }
          }
          break;
      }
      if (keywordStart >= 0 && (i == aChars.length - 1 || !isKeyWordChar)) {
        int wordLength = (isKeyWordChar ? i + 1 : keywordEnd) - keywordStart;
        if (currentCommandType == SqlCommandType.BLANK) {
          if (wordLength == 6 && parseCreateKeyword(aChars, keywordStart)) {
            currentCommandType = SqlCommandType.CREATE;
          } else if (wordLength == 5 && parseAlterKeyword(aChars, keywordStart)) {
            currentCommandType = SqlCommandType.ALTER;
          } else if (wordLength == 6 && parseUpdateKeyword(aChars, keywordStart)) {
            currentCommandType = SqlCommandType.UPDATE;
          } else if (wordLength == 6 && parseDeleteKeyword(aChars, keywordStart)) {
            currentCommandType = SqlCommandType.DELETE;
          } else if (wordLength == 4 && parseMoveKeyword(aChars, keywordStart)) {
            currentCommandType = SqlCommandType.MOVE;
          } else if (wordLength == 6 && parseSelectKeyword(aChars, keywordStart)) {
            currentCommandType = SqlCommandType.SELECT;
          } else if (wordLength == 4 && parseWithKeyword(aChars, keywordStart)) {
            currentCommandType = SqlCommandType.WITH;
          } else if (wordLength == 6 && parseInsertKeyword(aChars, keywordStart)) {
            if (!isInsertPresent && (nativeQueries == null || nativeQueries.isEmpty())) {
              // Only allow rewrite for insert command starting with the insert keyword.
              // Else, too many risks of wrong interpretation.
              isCurrentReWriteCompatible = keyWordCount == 0;
              isInsertPresent = true;
              currentCommandType = SqlCommandType.INSERT;
            } else {
              isCurrentReWriteCompatible = false;
            }
          }
        } else if (currentCommandType == SqlCommandType.WITH
            && inParen == 0) {
          SqlCommandType command = parseWithCommandType(aChars, i, keywordStart, wordLength);
          if (command != null) {
            currentCommandType = command;
          }
        }
        if (inParen != 0 || aChar == ')') {
          // RETURNING and VALUES cannot be present in braces
        } else if (wordLength == 9 && parseReturningKeyword(aChars, keywordStart)) {
          isReturningPresent = true;
        } else if (wordLength == 6 && parseValuesKeyword(aChars, keywordStart)) {
          isValuesFound = true;
        }
        keywordStart = -1;
        keyWordCount++;
      }
      if (aChar == '(') {
        inParen++;
        if (inParen == 1 && isValuesFound && valuesBraceOpenPosition == -1) {
          valuesBraceOpenPosition = nativeSql.length() + i - fragmentStart;
        }
      }
    }

    if (!isValuesFound || !isCurrentReWriteCompatible || valuesBraceClosePosition == -1
        || (bindPositions != null
        && valuesBraceClosePosition < bindPositions.get(bindPositions.size() - 1))) {
      valuesBraceOpenPosition = -1;
      valuesBraceClosePosition = -1;
    }

    if (fragmentStart < aChars.length && !whitespaceOnly) {
      nativeSql.append(aChars, fragmentStart, aChars.length - fragmentStart);
    } else {
      if (numberOfStatements > 1) {
        isReturningPresent = false;
        currentCommandType = SqlCommandType.BLANK;
      } else if (numberOfStatements == 1) {
        isReturningPresent = isReturningPresentPrev;
        currentCommandType = prevCommandType;
      }
    }

    if (nativeSql.length() == 0) {
      return nativeQueries != null ? nativeQueries : Collections.emptyList();
    }

    if (addReturning(nativeSql, currentCommandType, returningColumnNames, isReturningPresent, quoteReturningIdentifiers)) {
      isReturningPresent = true;
    }

    NativeQuery lastQuery = new NativeQuery(nativeSql.toString(),
        toIntArray(bindPositions), !splitStatements,
        SqlCommand.createStatementTypeInfo(currentCommandType,
            isBatchedReWriteConfigured, valuesBraceOpenPosition, valuesBraceClosePosition,
            isReturningPresent, (nativeQueries == null ? 0 : nativeQueries.size())));

    if (nativeQueries == null) {
      return Collections.singletonList(lastQuery);
    }

    if (!whitespaceOnly) {
      nativeQueries.add(lastQuery);
    }
    return nativeQueries;
  }

  private static @Nullable SqlCommandType parseWithCommandType(char[] aChars, int i, int keywordStart,
      int wordLength) {
    // This parses `with x as (...) ...`
    // Corner case is `with select as (insert ..) select * from select
    SqlCommandType command;
    if (wordLength == 6 && parseUpdateKeyword(aChars, keywordStart)) {
      command = SqlCommandType.UPDATE;
    } else if (wordLength == 6 && parseDeleteKeyword(aChars, keywordStart)) {
      command = SqlCommandType.DELETE;
    } else if (wordLength == 6 && parseInsertKeyword(aChars, keywordStart)) {
      command = SqlCommandType.INSERT;
    } else if (wordLength == 6 && parseSelectKeyword(aChars, keywordStart)) {
      command = SqlCommandType.SELECT;
    } else {
      return null;
    }
    // update/delete/insert/select keyword detected
    // Check if `AS` follows
    int nextInd = i;
    // The loop should skip whitespace and comments
    for (; nextInd < aChars.length; nextInd++) {
      char nextChar = aChars[nextInd];
      if (nextChar == '-') {
        nextInd = Parser.parseLineComment(aChars, nextInd);
      } else if (nextChar == '/') {
        nextInd = Parser.parseBlockComment(aChars, nextInd);
      } else if (Character.isWhitespace(nextChar)) {
        // Skip whitespace
        continue;
      } else {
        break;
      }
    }
    if (nextInd + 2 >= aChars.length
        || (!parseAsKeyword(aChars, nextInd)
        || isIdentifierContChar(aChars[nextInd + 2]))) {
      return command;
    }
    return null;
  }

  private static boolean addReturning(StringBuilder nativeSql, SqlCommandType currentCommandType,
      String[] returningColumnNames, boolean isReturningPresent, boolean quoteReturningIdentifiers) throws SQLException {
    if (isReturningPresent || returningColumnNames.length == 0) {
      return false;
    }
    if (currentCommandType != SqlCommandType.INSERT
        && currentCommandType != SqlCommandType.UPDATE
        && currentCommandType != SqlCommandType.DELETE
        && currentCommandType != SqlCommandType.WITH) {
      return false;
    }

    nativeSql.append("\nRETURNING ");
    if (returningColumnNames.length == 1 && returningColumnNames[0].charAt(0) == '*') {
      nativeSql.append('*');
      return true;
    }
    for (int col = 0; col < returningColumnNames.length; col++) {
      String columnName = returningColumnNames[col];
      if (col > 0) {
        nativeSql.append(", ");
      }
      /*
      If the client quotes identifiers then doing so again would create an error
       */
      if (quoteReturningIdentifiers) {
        Utils.escapeIdentifier(nativeSql, columnName);
      } else {
        nativeSql.append( columnName );
      }
    }
    return true;
  }

  /**
   * Converts {@code List} to {@code int[]}. Empty and {@code null} lists are converted to
   * empty array.
   *
   * @param list input list
   * @return output array
   */
  private static int[] toIntArray(@Nullable List list) {
    if (list == null || list.isEmpty()) {
      return NO_BINDS;
    }
    int[] res = new int[list.size()];
    for (int i = 0; i < list.size(); i++) {
      res[i] = list.get(i); // must not be null
    }
    return res;
  }

  /**
   * 

Find the end of the single-quoted string starting at the given offset.

* *

Note: for {@code 'single '' quote in string'}, this method currently returns the offset of * first {@code '} character after the initial one. The caller must call the method a second time * for the second part of the quoted string.

* * @param query query * @param offset start offset * @param standardConformingStrings standard conforming strings * @return position of the end of the single-quoted string */ public static int parseSingleQuotes(final char[] query, int offset, boolean standardConformingStrings) { // check for escape string syntax (E'') if (standardConformingStrings && offset >= 2 && (query[offset - 1] == 'e' || query[offset - 1] == 'E') && charTerminatesIdentifier(query[offset - 2])) { standardConformingStrings = false; } if (standardConformingStrings) { // do NOT treat backslashes as escape characters while (++offset < query.length) { switch (query[offset]) { case '\'': return offset; default: break; } } } else { // treat backslashes as escape characters while (++offset < query.length) { switch (query[offset]) { case '\\': ++offset; break; case '\'': return offset; default: break; } } } return query.length; } /** *

Find the end of the double-quoted string starting at the given offset.

* *

Note: for {@code "double "" quote in string"}, this method currently * returns the offset of first {@code "} character after the initial one. The caller must * call the method a second time for the second part of the quoted string.

* * @param query query * @param offset start offset * @return position of the end of the double-quoted string */ public static int parseDoubleQuotes(final char[] query, int offset) { while (++offset < query.length && query[offset] != '"') { // do nothing } return offset; } /** * Test if the dollar character ({@code $}) at the given offset starts a dollar-quoted string and * return the offset of the ending dollar character. * * @param query query * @param offset start offset * @return offset of the ending dollar character */ public static int parseDollarQuotes(final char[] query, int offset) { if (offset + 1 < query.length && (offset == 0 || !isIdentifierContChar(query[offset - 1]))) { int endIdx = -1; if (query[offset + 1] == '$') { endIdx = offset + 1; } else if (isDollarQuoteStartChar(query[offset + 1])) { for (int d = offset + 2; d < query.length; ++d) { if (query[d] == '$') { endIdx = d; break; } else if (!isDollarQuoteContChar(query[d])) { break; } } } if (endIdx > 0) { // found; note: tag includes start and end $ character int tagIdx = offset; int tagLen = endIdx - offset + 1; offset = endIdx; // loop continues at endIdx + 1 for (++offset; offset < query.length; ++offset) { if (query[offset] == '$' && subArraysEqual(query, tagIdx, offset, tagLen)) { offset += tagLen - 1; break; } } } } return offset; } /** * Test if the {@code -} character at {@code offset} starts a {@code --} style line comment, * and return the position of the first {@code \r} or {@code \n} character. * * @param query query * @param offset start offset * @return position of the first {@code \r} or {@code \n} character */ public static int parseLineComment(final char[] query, int offset) { if (offset + 1 < query.length && query[offset + 1] == '-') { while (offset + 1 < query.length) { offset++; if (query[offset] == '\r' || query[offset] == '\n') { break; } } } return offset; } /** * Test if the {@code /} character at {@code offset} starts a block comment, and return the * position of the last {@code /} character. * * @param query query * @param offset start offset * @return position of the last {@code /} character */ public static int parseBlockComment(final char[] query, int offset) { if (offset + 1 < query.length && query[offset + 1] == '*') { // /* /* */ */ nest, according to SQL spec int level = 1; for (offset += 2; offset < query.length; ++offset) { switch (query[offset - 1]) { case '*': if (query[offset] == '/') { --level; ++offset; // don't parse / in */* twice } break; case '/': if (query[offset] == '*') { ++level; ++offset; // don't parse * in /*/ twice } break; default: break; } if (level == 0) { --offset; // reset position to last '/' char break; } } } return offset; } /** * Parse string to check presence of DELETE keyword regardless of case. The initial character is * assumed to have been matched. * * @param query char[] of the query statement * @param offset position of query to start checking * @return boolean indicates presence of word */ public static boolean parseDeleteKeyword(final char[] query, int offset) { if (query.length < (offset + 6)) { return false; } return (query[offset] | 32) == 'd' && (query[offset + 1] | 32) == 'e' && (query[offset + 2] | 32) == 'l' && (query[offset + 3] | 32) == 'e' && (query[offset + 4] | 32) == 't' && (query[offset + 5] | 32) == 'e'; } /** * Parse string to check presence of INSERT keyword regardless of case. * * @param query char[] of the query statement * @param offset position of query to start checking * @return boolean indicates presence of word */ public static boolean parseInsertKeyword(final char[] query, int offset) { if (query.length < (offset + 7)) { return false; } return (query[offset] | 32) == 'i' && (query[offset + 1] | 32) == 'n' && (query[offset + 2] | 32) == 's' && (query[offset + 3] | 32) == 'e' && (query[offset + 4] | 32) == 'r' && (query[offset + 5] | 32) == 't'; } /** * Parse string to check presence of MOVE keyword regardless of case. * * @param query char[] of the query statement * @param offset position of query to start checking * @return boolean indicates presence of word */ public static boolean parseMoveKeyword(final char[] query, int offset) { if (query.length < (offset + 4)) { return false; } return (query[offset] | 32) == 'm' && (query[offset + 1] | 32) == 'o' && (query[offset + 2] | 32) == 'v' && (query[offset + 3] | 32) == 'e'; } /** * Parse string to check presence of RETURNING keyword regardless of case. * * @param query char[] of the query statement * @param offset position of query to start checking * @return boolean indicates presence of word */ public static boolean parseReturningKeyword(final char[] query, int offset) { if (query.length < (offset + 9)) { return false; } return (query[offset] | 32) == 'r' && (query[offset + 1] | 32) == 'e' && (query[offset + 2] | 32) == 't' && (query[offset + 3] | 32) == 'u' && (query[offset + 4] | 32) == 'r' && (query[offset + 5] | 32) == 'n' && (query[offset + 6] | 32) == 'i' && (query[offset + 7] | 32) == 'n' && (query[offset + 8] | 32) == 'g'; } /** * Parse string to check presence of SELECT keyword regardless of case. * * @param query char[] of the query statement * @param offset position of query to start checking * @return boolean indicates presence of word */ public static boolean parseSelectKeyword(final char[] query, int offset) { if (query.length < (offset + 6)) { return false; } return (query[offset] | 32) == 's' && (query[offset + 1] | 32) == 'e' && (query[offset + 2] | 32) == 'l' && (query[offset + 3] | 32) == 'e' && (query[offset + 4] | 32) == 'c' && (query[offset + 5] | 32) == 't'; } /** * Parse string to check presence of CREATE keyword regardless of case. * * @param query char[] of the query statement * @param offset position of query to start checking * @return boolean indicates presence of word */ public static boolean parseAlterKeyword(final char[] query, int offset) { if (query.length < (offset + 5)) { return false; } return (query[offset] | 32) == 'a' && (query[offset + 1] | 32) == 'l' && (query[offset + 2] | 32) == 't' && (query[offset + 3] | 32) == 'e' && (query[offset + 4] | 32) == 'r'; } /** * Parse string to check presence of CREATE keyword regardless of case. * * @param query char[] of the query statement * @param offset position of query to start checking * @return boolean indicates presence of word */ public static boolean parseCreateKeyword(final char[] query, int offset) { if (query.length < (offset + 6)) { return false; } return (query[offset] | 32) == 'c' && (query[offset + 1] | 32) == 'r' && (query[offset + 2] | 32) == 'e' && (query[offset + 3] | 32) == 'a' && (query[offset + 4] | 32) == 't' && (query[offset + 5] | 32) == 'e'; } /** * Parse string to check presence of UPDATE keyword regardless of case. * * @param query char[] of the query statement * @param offset position of query to start checking * @return boolean indicates presence of word */ public static boolean parseUpdateKeyword(final char[] query, int offset) { if (query.length < (offset + 6)) { return false; } return (query[offset] | 32) == 'u' && (query[offset + 1] | 32) == 'p' && (query[offset + 2] | 32) == 'd' && (query[offset + 3] | 32) == 'a' && (query[offset + 4] | 32) == 't' && (query[offset + 5] | 32) == 'e'; } /** * Parse string to check presence of VALUES keyword regardless of case. * * @param query char[] of the query statement * @param offset position of query to start checking * @return boolean indicates presence of word */ public static boolean parseValuesKeyword(final char[] query, int offset) { if (query.length < (offset + 6)) { return false; } return (query[offset] | 32) == 'v' && (query[offset + 1] | 32) == 'a' && (query[offset + 2] | 32) == 'l' && (query[offset + 3] | 32) == 'u' && (query[offset + 4] | 32) == 'e' && (query[offset + 5] | 32) == 's'; } /** * Faster version of {@link Long#parseLong(String)} when parsing a substring is required * * @param s string to parse * @param beginIndex begin index * @param endIndex end index * @return long value */ public static long parseLong(String s, int beginIndex, int endIndex) { // Fallback to default implementation in case the string is long if (endIndex - beginIndex > 16) { return Long.parseLong(s.substring(beginIndex, endIndex)); } long res = digitAt(s, beginIndex); for (beginIndex++; beginIndex < endIndex; beginIndex++) { res = res * 10 + digitAt(s, beginIndex); } return res; } /** * Parse string to check presence of WITH keyword regardless of case. * * @param query char[] of the query statement * @param offset position of query to start checking * @return boolean indicates presence of word */ public static boolean parseWithKeyword(final char[] query, int offset) { if (query.length < (offset + 4)) { return false; } return (query[offset] | 32) == 'w' && (query[offset + 1] | 32) == 'i' && (query[offset + 2] | 32) == 't' && (query[offset + 3] | 32) == 'h'; } /** * Parse string to check presence of AS keyword regardless of case. * * @param query char[] of the query statement * @param offset position of query to start checking * @return boolean indicates presence of word */ public static boolean parseAsKeyword(final char[] query, int offset) { if (query.length < (offset + 2)) { return false; } return (query[offset] | 32) == 'a' && (query[offset + 1] | 32) == 's'; } /** * Returns true if a given string {@code s} has digit at position {@code pos}. * @param s input string * @param pos position (0-based) * @return true if input string s has digit at position pos */ public static boolean isDigitAt(String s, int pos) { return pos > 0 && pos < s.length() && Character.isDigit(s.charAt(pos)); } /** * Converts digit at position {@code pos} in string {@code s} to integer or throws. * @param s input string * @param pos position (0-based) * @return integer value of a digit at position pos * @throws NumberFormatException if character at position pos is not an integer */ public static int digitAt(String s, int pos) { int c = s.charAt(pos) - '0'; if (c < 0 || c > 9) { throw new NumberFormatException("Input string: \"" + s + "\", position: " + pos); } return c; } /** * Identifies characters which the backend scanner considers to be whitespace. * *

* https://github.com/postgres/postgres/blob/17bb62501787c56e0518e61db13a523d47afd724/src/backend/parser/scan.l#L194-L198 *

* * @param c character * @return true if the character is a whitespace character as defined in the backend's parser */ public static boolean isSpace(char c) { return c == ' ' || c == '\t' || c == '\n' || c == '\r' || c == '\f'; } /** * Identifies white space characters which the backend uses to determine if a * {@code String} value needs to be quoted in array representation. * *

* https://github.com/postgres/postgres/blob/f2c587067a8eb9cf1c8f009262381a6576ba3dd0/src/backend/utils/adt/arrayfuncs.c#L421-L438 *

* * @param c * Character to examine. * @return Indication if the character is a whitespace which back end will * escape. */ public static boolean isArrayWhiteSpace(char c) { return c == ' ' || c == '\t' || c == '\n' || c == '\r' || c == '\f' || c == 0x0B; } /** * @param c character * @return true if the given character is a valid character for an operator in the backend's * parser */ public static boolean isOperatorChar(char c) { /* * Extracted from operators defined by {self} and {op_chars} * in pgsql/src/backend/parser/scan.l. */ return ",()[].;:+-*/%^<>=~!@#&|`?".indexOf(c) != -1; } /** * Checks if a character is valid as the start of an identifier. * PostgreSQL 9.4 allows column names like _, ‿, ⁀, ⁔, ︳, ︴, ﹍, ﹎, ﹏, _, so * it is assumed isJavaIdentifierPart is good enough for PostgreSQL. * * @param c the character to check * @return true if valid as first character of an identifier; false if not * @see Identifiers and Key Words */ public static boolean isIdentifierStartChar(char c) { /* * PostgreSQL's implmementation is located in * pgsql/src/backend/parser/scan.l: * ident_start [A-Za-z\200-\377_] * ident_cont [A-Za-z\200-\377_0-9\$] * however is is not clear how that interacts with unicode, so we just use Java's implementation. */ return Character.isJavaIdentifierStart(c); } /** * Checks if a character is valid as the second or later character of an identifier. * * @param c the character to check * @return true if valid as second or later character of an identifier; false if not */ public static boolean isIdentifierContChar(char c) { return Character.isJavaIdentifierPart(c); } /** * @param c character * @return true if the character terminates an identifier */ public static boolean charTerminatesIdentifier(char c) { return c == '"' || isSpace(c) || isOperatorChar(c); } /** * Checks if a character is valid as the start of a dollar quoting tag. * * @param c the character to check * @return true if valid as first character of a dollar quoting tag; false if not */ public static boolean isDollarQuoteStartChar(char c) { /* * The allowed dollar quote start and continuation characters * must stay in sync with what the backend defines in * pgsql/src/backend/parser/scan.l * * The quoted string starts with $foo$ where "foo" is an optional string * in the form of an identifier, except that it may not contain "$", * and extends to the first occurrence of an identical string. * There is *no* processing of the quoted text. */ return c != '$' && isIdentifierStartChar(c); } /** * Checks if a character is valid as the second or later character of a dollar quoting tag. * * @param c the character to check * @return true if valid as second or later character of a dollar quoting tag; false if not */ public static boolean isDollarQuoteContChar(char c) { return c != '$' && isIdentifierContChar(c); } /** * Compares two sub-arrays of the given character array for equalness. If the length is zero, the * result is true if and only if the offsets are within the bounds of the array. * * @param arr a char array * @param offA first sub-array start offset * @param offB second sub-array start offset * @param len length of the sub arrays to compare * @return true if the sub-arrays are equal; false if not */ private static boolean subArraysEqual(final char[] arr, final int offA, final int offB, final int len) { if (offA < 0 || offB < 0 || offA >= arr.length || offB >= arr.length || offA + len > arr.length || offB + len > arr.length) { return false; } for (int i = 0; i < len; ++i) { if (arr[offA + i] != arr[offB + i]) { return false; } } return true; } /** * Converts JDBC-specific callable statement escapes {@code { [? =] call [(?, * [?,..])] }} into the PostgreSQL format which is {@code select (?, [?, ...]) as * result} or {@code select * from (?, [?, ...]) as result} (7.3) * * @param jdbcSql sql text with JDBC escapes * @param stdStrings if backslash in single quotes should be regular character or escape one * @param serverVersion server version * @param protocolVersion protocol version * @param escapeSyntaxCallMode mode specifying whether JDBC escape call syntax is transformed into a CALL/SELECT statement * @return SQL in appropriate for given server format * @throws SQLException if given SQL is malformed */ public static JdbcCallParseInfo modifyJdbcCall(String jdbcSql, boolean stdStrings, int serverVersion, int protocolVersion, EscapeSyntaxCallMode escapeSyntaxCallMode) throws SQLException { // Mini-parser for JDBC function-call syntax (only) // TODO: Merge with escape processing (and parameter parsing?) so we only parse each query once. // RE: frequently used statements are cached (see {@link org.postgresql.jdbc.PgConnection#borrowQuery}), so this "merge" is not that important. String sql = jdbcSql; boolean isFunction = false; boolean outParamBeforeFunc = false; int len = jdbcSql.length(); int state = 1; boolean inQuotes = false; boolean inEscape = false; int startIndex = -1; int endIndex = -1; boolean syntaxError = false; int i = 0; while (i < len && !syntaxError) { char ch = jdbcSql.charAt(i); switch (state) { case 1: // Looking for { at start of query if (ch == '{') { ++i; ++state; } else if (Character.isWhitespace(ch)) { ++i; } else { // Not function-call syntax. Skip the rest of the string. i = len; } break; case 2: // After {, looking for ? or =, skipping whitespace if (ch == '?') { outParamBeforeFunc = isFunction = true; // { ? = call ... } -- function with one out parameter ++i; ++state; } else if (ch == 'c' || ch == 'C') { // { call ... } -- proc with no out parameters state += 3; // Don't increase 'i' } else if (Character.isWhitespace(ch)) { ++i; } else { // "{ foo ...", doesn't make sense, complain. syntaxError = true; } break; case 3: // Looking for = after ?, skipping whitespace if (ch == '=') { ++i; ++state; } else if (Character.isWhitespace(ch)) { ++i; } else { syntaxError = true; } break; case 4: // Looking for 'call' after '? =' skipping whitespace if (ch == 'c' || ch == 'C') { ++state; // Don't increase 'i'. } else if (Character.isWhitespace(ch)) { ++i; } else { syntaxError = true; } break; case 5: // Should be at 'call ' either at start of string or after ?= if ((ch == 'c' || ch == 'C') && i + 4 <= len && jdbcSql.substring(i, i + 4) .equalsIgnoreCase("call")) { isFunction = true; i += 4; ++state; } else if (Character.isWhitespace(ch)) { ++i; } else { syntaxError = true; } break; case 6: // Looking for whitespace char after 'call' if (Character.isWhitespace(ch)) { // Ok, we found the start of the real call. ++i; ++state; startIndex = i; } else { syntaxError = true; } break; case 7: // In "body" of the query (after "{ [? =] call ") if (ch == '\'') { inQuotes = !inQuotes; ++i; } else if (inQuotes && ch == '\\' && !stdStrings) { // Backslash in string constant, skip next character. i += 2; } else if (!inQuotes && ch == '{') { inEscape = !inEscape; ++i; } else if (!inQuotes && ch == '}') { if (!inEscape) { // Should be end of string. endIndex = i; ++i; ++state; } else { inEscape = false; } } else if (!inQuotes && ch == ';') { syntaxError = true; } else { // Everything else is ok. ++i; } break; case 8: // At trailing end of query, eating whitespace if (Character.isWhitespace(ch)) { ++i; } else { syntaxError = true; } break; default: throw new IllegalStateException("somehow got into bad state " + state); } } // We can only legally end in a couple of states here. if (i == len && !syntaxError) { if (state == 1) { // Not an escaped syntax. // Detect PostgreSQL native CALL. // (OUT parameter registration, needed for stored procedures with INOUT arguments, will fail without this) i = 0; while (i < len && Character.isWhitespace(jdbcSql.charAt(i))) { i++; // skip any preceding whitespace } if (i < len - 5) { // 5 == length of "call" + 1 whitespace //Check for CALL followed by whitespace char ch = jdbcSql.charAt(i); if ((ch == 'c' || ch == 'C') && jdbcSql.substring(i, i + 4).equalsIgnoreCase("call") && Character.isWhitespace(jdbcSql.charAt(i + 4))) { isFunction = true; } } return new JdbcCallParseInfo(sql, isFunction); } if (state != 8) { syntaxError = true; // Ran out of query while still parsing } } if (syntaxError) { throw new PSQLException( GT.tr("Malformed function or procedure escape syntax at offset {0}.", i), PSQLState.STATEMENT_NOT_ALLOWED_IN_FUNCTION_CALL); } String prefix; String suffix; if (escapeSyntaxCallMode == EscapeSyntaxCallMode.SELECT || serverVersion < 110000 || (outParamBeforeFunc && escapeSyntaxCallMode == EscapeSyntaxCallMode.CALL_IF_NO_RETURN)) { prefix = "select * from "; suffix = " as result"; } else { prefix = "call "; suffix = ""; } String s = jdbcSql.substring(startIndex, endIndex); int prefixLength = prefix.length(); StringBuilder sb = new StringBuilder(prefixLength + jdbcSql.length() + suffix.length() + 10); sb.append(prefix); sb.append(s); int opening = s.indexOf('(') + 1; if (opening == 0) { // here the function call has no parameters declaration eg : "{ ? = call pack_getValue}" sb.append(outParamBeforeFunc ? "(?)" : "()"); } else if (outParamBeforeFunc) { // move the single out parameter into the function call // so that it can be treated like all other parameters boolean needComma = false; // the following loop will check if the function call has parameters // eg "{ ? = call pack_getValue(?) }" vs "{ ? = call pack_getValue() } for (int j = opening + prefixLength; j < sb.length(); j++) { char c = sb.charAt(j); if (c == ')') { break; } if (!Character.isWhitespace(c)) { needComma = true; break; } } // insert the return parameter as the first parameter of the function call if (needComma) { sb.insert(opening + prefixLength, "?,"); } else { sb.insert(opening + prefixLength, "?"); } } if (!suffix.isEmpty()) { sql = sb.append(suffix).toString(); } else { sql = sb.toString(); } return new JdbcCallParseInfo(sql, isFunction); } /** *

Filter the SQL string of Java SQL Escape clauses.

* *

Currently implemented Escape clauses are those mentioned in 11.3 in the specification. * Basically we look through the sql string for {d xxx}, {t xxx}, {ts xxx}, {oj xxx} or {fn xxx} * in non-string sql code. When we find them, we just strip the escape part leaving only the xxx * part. So, something like "select * from x where d={d '2001-10-09'}" would return "select * from * x where d= '2001-10-09'".

* * @param sql the original query text * @param replaceProcessingEnabled whether replace_processing_enabled is on * @param standardConformingStrings whether standard_conforming_strings is on * @return PostgreSQL-compatible SQL * @throws SQLException if given SQL is wrong */ public static String replaceProcessing(String sql, boolean replaceProcessingEnabled, boolean standardConformingStrings) throws SQLException { if (replaceProcessingEnabled) { // Since escape codes can only appear in SQL CODE, we keep track // of if we enter a string or not. int len = sql.length(); char[] chars = sql.toCharArray(); StringBuilder newsql = new StringBuilder(len); int i = 0; while (i < len) { i = parseSql(chars, i, newsql, false, standardConformingStrings); // We need to loop here in case we encounter invalid // SQL, consider: SELECT a FROM t WHERE (1 > 0)) ORDER BY a // We can't ending replacing after the extra closing paren // because that changes a syntax error to a valid query // that isn't what the user specified. if (i < len) { newsql.append(chars[i]); i++; } } return newsql.toString(); } else { return sql; } } /** * parse the given sql from index i, appending it to the given buffer until we hit an unmatched * right parentheses or end of string. When the stopOnComma flag is set we also stop processing * when a comma is found in sql text that isn't inside nested parenthesis. * * @param sql the original query text * @param i starting position for replacing * @param newsql where to write the replaced output * @param stopOnComma should we stop after hitting the first comma in sql text? * @param stdStrings whether standard_conforming_strings is on * @return the position we stopped processing at * @throws SQLException if given SQL is wrong */ private static int parseSql(char[] sql, int i, StringBuilder newsql, boolean stopOnComma, boolean stdStrings) throws SQLException { SqlParseState state = SqlParseState.IN_SQLCODE; int len = sql.length; int nestedParenthesis = 0; boolean endOfNested = false; // because of the ++i loop i--; while (!endOfNested && ++i < len) { char c = sql[i]; state_switch: switch (state) { case IN_SQLCODE: if (c == '$') { int i0 = i; i = parseDollarQuotes(sql, i); checkParsePosition(i, len, i0, sql, "Unterminated dollar quote started at position {0} in SQL {1}. Expected terminating $$"); newsql.append(sql, i0, i - i0 + 1); break; } else if (c == '\'') { // start of a string? int i0 = i; i = parseSingleQuotes(sql, i, stdStrings); checkParsePosition(i, len, i0, sql, "Unterminated string literal started at position {0} in SQL {1}. Expected ' char"); newsql.append(sql, i0, i - i0 + 1); break; } else if (c == '"') { // start of a identifier? int i0 = i; i = parseDoubleQuotes(sql, i); checkParsePosition(i, len, i0, sql, "Unterminated identifier started at position {0} in SQL {1}. Expected \" char"); newsql.append(sql, i0, i - i0 + 1); break; } else if (c == '/') { int i0 = i; i = parseBlockComment(sql, i); checkParsePosition(i, len, i0, sql, "Unterminated block comment started at position {0} in SQL {1}. Expected */ sequence"); newsql.append(sql, i0, i - i0 + 1); break; } else if (c == '-') { int i0 = i; i = parseLineComment(sql, i); newsql.append(sql, i0, i - i0 + 1); break; } else if (c == '(') { // begin nested sql nestedParenthesis++; } else if (c == ')') { // end of nested sql nestedParenthesis--; if (nestedParenthesis < 0) { endOfNested = true; break; } } else if (stopOnComma && c == ',' && nestedParenthesis == 0) { endOfNested = true; break; } else if (c == '{') { // start of an escape code? if (i + 1 < len) { SqlParseState[] availableStates = SqlParseState.VALUES; // skip first state, it's not a escape code state for (int j = 1; j < availableStates.length; j++) { SqlParseState availableState = availableStates[j]; int matchedPosition = availableState.getMatchedPosition(sql, i + 1); if (matchedPosition == 0) { continue; } i += matchedPosition; if (availableState.replacementKeyword != null) { newsql.append(availableState.replacementKeyword); } state = availableState; break state_switch; } } } newsql.append(c); break; case ESC_FUNCTION: // extract function name i = escapeFunction(sql, i, newsql, stdStrings); state = SqlParseState.IN_SQLCODE; // end of escaped function (or query) break; case ESC_DATE: case ESC_TIME: case ESC_TIMESTAMP: case ESC_OUTERJOIN: case ESC_ESCAPECHAR: if (c == '}') { state = SqlParseState.IN_SQLCODE; // end of escape code. } else { newsql.append(c); } break; } // end switch } return i; } private static int findOpenBrace(char[] sql, int i) { int posArgs = i; while (posArgs < sql.length && sql[posArgs] != '(') { posArgs++; } return posArgs; } private static void checkParsePosition(int i, int len, int i0, char[] sql, String message) throws PSQLException { if (i < len) { return; } throw new PSQLException( GT.tr(message, i0, new String(sql)), PSQLState.SYNTAX_ERROR); } private static int escapeFunction(char[] sql, int i, StringBuilder newsql, boolean stdStrings) throws SQLException { String functionName; int argPos = findOpenBrace(sql, i); if (argPos < sql.length) { functionName = new String(sql, i, argPos - i).trim(); // extract arguments i = argPos + 1;// we start the scan after the first ( i = escapeFunctionArguments(newsql, functionName, sql, i, stdStrings); } // go to the end of the function copying anything found i++; while (i < sql.length && sql[i] != '}') { newsql.append(sql[i++]); } return i; } /** * Generate sql for escaped functions. * * @param newsql destination StringBuilder * @param functionName the escaped function name * @param sql input SQL text (containing arguments of a function call with possible JDBC escapes) * @param i position in the input SQL * @param stdStrings whether standard_conforming_strings is on * @return the right PostgreSQL sql * @throws SQLException if something goes wrong */ private static int escapeFunctionArguments(StringBuilder newsql, String functionName, char[] sql, int i, boolean stdStrings) throws SQLException { // Maximum arity of functions in EscapedFunctions is 3 List parsedArgs = new ArrayList(3); while (true) { StringBuilder arg = new StringBuilder(); int lastPos = i; i = parseSql(sql, i, arg, true, stdStrings); if (i != lastPos) { parsedArgs.add(arg); } if (i >= sql.length // should not happen || sql[i] != ',') { break; } i++; } Method method = EscapedFunctions2.getFunction(functionName); if (method == null) { newsql.append(functionName); EscapedFunctions2.appendCall(newsql, "(", ",", ")", parsedArgs); return i; } try { method.invoke(null, newsql, parsedArgs); } catch (InvocationTargetException e) { Throwable targetException = e.getTargetException(); if (targetException instanceof SQLException) { throw (SQLException) targetException; } else { String message = targetException == null ? "no message" : targetException.getMessage(); throw new PSQLException(message, PSQLState.SYSTEM_ERROR); } } catch (IllegalAccessException e) { throw new PSQLException(e.getMessage(), PSQLState.SYSTEM_ERROR); } return i; } private static final char[] QUOTE_OR_ALPHABETIC_MARKER = {'\"', '0'}; private static final char[] QUOTE_OR_ALPHABETIC_MARKER_OR_PARENTHESIS = {'\"', '0', '('}; private static final char[] SINGLE_QUOTE = {'\''}; // Static variables for parsing SQL when replaceProcessing is true. private enum SqlParseState { IN_SQLCODE, ESC_DATE("d", SINGLE_QUOTE, "DATE "), ESC_TIME("t", SINGLE_QUOTE, "TIME "), ESC_TIMESTAMP("ts", SINGLE_QUOTE, "TIMESTAMP "), ESC_FUNCTION("fn", QUOTE_OR_ALPHABETIC_MARKER, null), ESC_OUTERJOIN("oj", QUOTE_OR_ALPHABETIC_MARKER_OR_PARENTHESIS, null), ESC_ESCAPECHAR("escape", SINGLE_QUOTE, "ESCAPE "); private static final SqlParseState[] VALUES = values(); private final char[] escapeKeyword; private final char[] allowedValues; private final @Nullable String replacementKeyword; SqlParseState() { this("", new char[0], null); } SqlParseState(String escapeKeyword, char[] allowedValues, @Nullable String replacementKeyword) { this.escapeKeyword = escapeKeyword.toCharArray(); this.allowedValues = allowedValues; this.replacementKeyword = replacementKeyword; } private boolean startMatches(char[] sql, int pos) { // check for the keyword for (char c : escapeKeyword) { if (pos >= sql.length) { return false; } char curr = sql[pos++]; if (curr != c && curr != Character.toUpperCase(c)) { return false; } } return pos < sql.length; } private int getMatchedPosition(char[] sql, int pos) { // check for the keyword if (!startMatches(sql, pos)) { return 0; } int newPos = pos + escapeKeyword.length; // check for the beginning of the value char curr = sql[newPos]; // ignore any in-between whitespace while (curr == ' ') { newPos++; if (newPos >= sql.length) { return 0; } curr = sql[newPos]; } for (char c : allowedValues) { if (curr == c || (c == '0' && Character.isLetter(curr))) { return newPos - pos; } } return 0; } } }




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