+
−/*
+
− * SPDX-License-Identifier: MPL-2.0
+
− *
+
− * This Source Code Form is subject to the terms of the Mozilla Public
+
− * License, v. 2.0.  If a copy of the MPL was not distributed with this
+
− * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
− *
+
− * Copyright 2024 MonetDB Foundation;
+
− * Copyright August 2008 - 2023 MonetDB B.V.;
+
− * Copyright 1997 - July 2008 CWI.
+
− */
+
−
+
−package org.monetdb.mcl.parser;
+
−
+
−
+
−/**
+
− * The HeaderLineParser is a generic MCLParser that extracts values from
+
− * a metadata header in the MCL protocol either as string or integer values.
+
− *
+
− * @author Fabian Groffen
+
− */
+
−public final class HeaderLineParser extends MCLParser {
+
−	/* types of meta data supported by MCL protocol */
+
−	public final static int NAME   = 1;	// name of column
+
−	public final static int LENGTH = 2;
+
−	public final static int TABLE  = 3;	// may include the schema name
+
−	public final static int TYPE   = 4;
+
−	public final static int TYPESIZES = 5;	// precision and scale
+
−
+
−	 /** The int values found while parsing.  Public, you may touch it. */
+
−	public final int intValues[];
+
−
+
−	/**
+
−	 * Constructs a HeaderLineParser which expects columncount columns.
+
−	 *
+
−	 * @param columncount the number of columns in the to be parsed string
+
−	 */
+
−	public HeaderLineParser(final int columncount) {
+
−		super(columncount);
+
−		intValues = new int[columncount];
+
−	}
+
−
+
−	/**
+
−	 * Parses the given String source as header line.  If source cannot
+
−	 * be parsed, an MCLParseException is thrown.  The columncount argument
+
−	 * given during construction is used for allocation of the backing array.
+
−	 *
+
−	 * @param source a String which should be parsed
+
−	 * @return the type of the parsed header line
+
−	 * @throws MCLParseException if an error occurs during parsing
+
−	 */
+
−	@Override
+
−	public int parse(final String source) throws MCLParseException {
+
−		final char[] chrLine = source.toCharArray();
+
−		int len = chrLine.length;
+
−		int pos = 0;
+
−		boolean foundChar = false;
+
−		boolean nameFound = false;
+
−		int i;
+
−
+
−		// find header name searching from the end of the line
+
−		for (i = len - 1; i >= 0; i--) {
+
−			switch (chrLine[i]) {
+
−				case ' ':
+
−				case '\n':
+
−				case '\t':
+
−				case '\r':
+
−					if (!foundChar) {
+
−						len = i - 1;
+
−					} else {
+
−						pos = i + 1;
+
−					}
+
−					break;
+
−				case '#':
+
−					// found!
+
−					nameFound = true;
+
−					if (pos == 0)
+
−						pos = i + 1;
+
−					i = 0;	// force the loop to terminate
+
−					break;
+
−				default:
+
−					foundChar = true;
+
−					pos = 0;
+
−					break;
+
−			}
+
−		}
+
−		if (!nameFound)
+
−			throw new MCLParseException("invalid header, no header name found", pos);
+
−
+
−		// depending on the name of the header, we continue
+
−		int type = 0;
+
−		i = pos;
+
−		switch (len - pos) {
+
−			case 4:
+
−				// source.regionMatches(pos + 1, "name", 0, 4)
+
−				if (chrLine[i] == 'n' && chrLine[++i] == 'a' && chrLine[++i] == 'm' && chrLine[++i] == 'e') {
+
−					getValues(chrLine, 2, pos - 3);
+
−					type = NAME;
+
−				} else
+
−				// source.regionMatches(pos + 1, "type", 0, 4)
+
−				if (chrLine[i] == 't' && chrLine[++i] == 'y' && chrLine[++i] == 'p' && chrLine[++i] == 'e') {
+
−					getValues(chrLine, 2, pos - 3);
+
−					type = TYPE;
+
−				}
+
−				break;
+
−			case 6:
+
−				// source.regionMatches(pos + 1, "length", 0, 6)
+
−				if (chrLine[ i ] == 'l' && chrLine[++i] == 'e' && chrLine[++i] == 'n' && chrLine[++i] == 'g'
+
−				 && chrLine[++i] == 't' && chrLine[++i] == 'h') {
+
−					getIntValues(chrLine, 2, pos - 3);
+
−					type = LENGTH;
+
−				}
+
−				break;
+
−			case 9:
+
−				// System.out.println("In HeaderLineParser.parse() case 9: source line = " + source);
+
−				// source.regionMatches(pos + 1, "typesizes", 0, 9)
+
−				if (chrLine[ i ] == 't' && chrLine[++i] == 'y' && chrLine[++i] == 'p' && chrLine[++i] == 'e'
+
−				 && chrLine[++i] == 's' && chrLine[++i] == 'i' && chrLine[++i] == 'z' && chrLine[++i] == 'e' && chrLine[++i] == 's') {
+
−					getValues(chrLine, 2, pos - 3);	/* these contain precision and scale values (separated by a space), so read them as strings */
+
−					type = TYPESIZES;
+
−				}
+
−				break;
+
−			case 10:
+
−				// source.regionMatches(pos + 1, "table_name", 0, 10)
+
−				if (chrLine[ i ] == 't' && chrLine[++i] == 'a' && chrLine[++i] == 'b' && chrLine[++i] == 'l' && chrLine[++i] == 'e'
+
−				 && chrLine[++i] == '_' && chrLine[++i] == 'n' && chrLine[++i] == 'a' && chrLine[++i] == 'm' && chrLine[++i] == 'e') {
+
−					getValues(chrLine, 2, pos - 3);
+
−					type = TABLE;
+
−				}
+
−				break;
+
−			default:
+
−				throw new MCLParseException("unknown header: " + (new String(chrLine, pos, len - pos)));
+
−		}
+
−
+
−		// adjust colno
+
−		colnr = 0;
+
−
+
−		return type;
+
−	}
+
−
+
−	/**
+
−	 * Fills an array of Strings containing the values between
+
−	 * ',\t' separators.
+
−	 *
+
−	 * As of Oct2014-SP1 release MAPI adds double quotes around names when
+
−	 * the name contains a comma or a tab or a space or a # or " or \ escape character.
+
−	 * See issue: https://github.com/MonetDB/MonetDB/issues/3616
+
−	 * If the parsed name string part has a " as first and last character,
+
−	 * we remove those added double quotes here.
+
−	 *
+
−	 * @param chrLine a character array holding the input data
+
−	 * @param start where the relevant data starts
+
−	 * @param stop where the relevant data stops
+
−	 */
+
−	private final void getValues(final char[] chrLine, int start, final int stop) {
+
−		int elem = 0;
+
−		boolean inString = false, escaped = false;
+
−
+
−		for (int i = start; i < stop; i++) {
+
−			switch(chrLine[i]) {
+
−				case '\\':
+
−					escaped = !escaped;
+
−					break;
+
−				case '"':
+
−					/**
+
−					 * If all strings are wrapped between two quotes, a \" can
+
−					 * never exist outside a string. Thus if we believe that we
+
−					 * are not within a string, we can safely assume we're about
+
−					 * to enter a string if we find a quote.
+
−					 * If we are in a string we should stop being in a string if
+
−					 * we find a quote which is not prefixed by a \, for that
+
−					 * would be an escaped quote. However, a nasty situation can
+
−					 * occur where the string is like "test \\" as obvious, a
+
−					 * test for a \ in front of a " doesn't hold here for all
+
−					 * cases. Because "test \\\"" can exist as well, we need to
+
−					 * know if a quote is prefixed by an escaping slash or not.
+
−					 */
+
−					if (!inString) {
+
−						inString = true;
+
−					} else if (!escaped) {
+
−						inString = false;
+
−					}
+
−					// reset escaped flag
+
−					escaped = false;
+
−					break;
+
−				case ',':
+
−					if (!inString && chrLine[i + 1] == '\t') {
+
−						// we found the field separator
+
−						if (chrLine[start] == '"')
+
−							start++;  // skip leading double quote
+
−						if (elem < values.length) {
+
−							// TODO: also deal with escape characters as done in TupleLineParser.parse()
+
−							values[elem++] = new String(chrLine, start, i - (chrLine[i - 1] == '"' ? 1 : 0) - start);
+
−						}
+
−						i++;
+
−						start = i + 1;	// reset start for the next name, skipping the field separator (a comma and tab)
+
−					}
+
−					// reset escaped flag
+
−					escaped = false;
+
−					break;
+
−				default:
+
−					escaped = false;
+
−					break;
+
−			}
+
−		}
+
−		// add the left over part (last column)
+
−		if (chrLine[start] == '"')
+
−			start++;  // skip leading double quote
+
−		if (elem < values.length)
+
−			values[elem] = new String(chrLine, start, stop - (chrLine[stop - 1] == '"' ? 1 : 0) - start);
+
−	}
+
−
+
−	/**
+
−	 * Fills an array of ints containing the values between
+
−	 * ',\t' separators.
+
−	 *
+
−	 * Feb2017 note - This integer parser doesn't have to parse negative
+
−	 * numbers, because it is only used to parse column lengths
+
−	 * which are always greater than 0.
+
−	 *
+
−	 * @param chrLine a character array holding the input data
+
−	 * @param start where the relevant data starts
+
−	 * @param stop where the relevant data stops
+
−	 * @throws MCLParseException if an error occurs during parsing
+
−	 */
+
−	private final void getIntValues(final char[] chrLine, final int start, final int stop) throws MCLParseException {
+
−		int elem = 0;
+
−		int tmp = 0;
+
−
+
−		for (int i = start; i < stop; i++) {
+
−			if (chrLine[i] == ',' && chrLine[i + 1] == '\t') {
+
−				if (elem < intValues.length) {
+
−					intValues[elem++] = tmp;
+
−				}
+
−				tmp = 0;
+
−				i++;
+
−			} else {
+
−				// note: don't use Character.isDigit() here, because
+
−				// we only want ISO-LATIN-1 digits
+
−				if (chrLine[i] >= '0' && chrLine[i] <= '9') {
+
−					tmp *= 10;
+
−					tmp += (int)chrLine[i] - (int)'0';
+
−				} else {
+
−					throw new MCLParseException("expected a digit in " + new String(chrLine) + " at " + i);
+
−				}
+
−			}
+
−		}
+
−		// add the left over part (last column)
+
−		if (elem < intValues.length)
+
−			intValues[elem] = tmp;
+
−	}
+
−}