/*

 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; 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.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package gc.g1.plab.lib;

import java.util.EnumMap;

import java.util.HashMap;

import java.util.Map;

import java.util.Optional;

import java.util.Scanner;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

/**

 * LogParser class parses VM output to get PLAB and ConsumptionStats values.

 *

 * Typical GC log with PLAB statistics (options - -Xlog:gc=debug,gc+plab=debug) looks like:

 *

 * [0.330s][debug][gc,plab  ] GC(0) Young PLAB allocation: allocated: 1825632B, wasted: 29424B, unused: 2320B, used: 1793888B, undo waste: 0B,

 * [0.330s][debug][gc,plab  ] GC(0) Young other allocation: region end waste: 0B, regions filled: 2, direct allocated: 271520B, failure used: 0B, failure wasted: 0B

 * [0.330s][debug][gc,plab  ] GC(0) Young sizing: calculated: 358776B, actual: 358776B

 * [0.330s][debug][gc,plab  ] GC(0) Old PLAB allocation: allocated: 427248B, wasted: 592B, unused: 368584B, used: 58072B, undo waste: 0B,

 * [0.330s][debug][gc,plab  ] GC(0) Old other allocation: region end waste: 0B, regions filled: 1, direct allocated: 41704B, failure used: 0B, failure wasted: 0B

 * [0.330s][debug][gc,plab  ] GC(0) Old sizing: calculated: 11608B, actual: 11608B

 */

final public class LogParser {

    // Name for GC ID field in report.

    public final static String GC_ID = "gc_id";

    /**

     * Type of parsed log element.

     */

    public static enum ReportType {

        SURVIVOR_STATS,

        OLD_STATS

    }

    private final String log;

    // GC ID

    private static final Pattern GC_ID_PATTERN = Pattern.compile("\\[gc,plab\\s*\\] GC\\((\\d+)\\)");

    // Pattern for extraction pair <name>: <numeric value>

    private static final Pattern PAIRS_PATTERN = Pattern.compile("\\w* \\w+:\\s+\\d+");

    /**

     *

     * @param log - VM Output

     */

    public LogParser(String log) {

        if (log == null) {

            throw new IllegalArgumentException("Parameter log should not be null.");

        }

        this.log = log;

    }

    /**

     */

    public String getLog() {

        return log;

    }

    /**

     *

     */

    }

        Scanner lineScanner = new Scanner(log);

        Optional<Long> gc_id;

        while (lineScanner.hasNextLine()) {

            String line = lineScanner.nextLine();

            gc_id = getGcId(line);

                Matcher matcher = PAIRS_PATTERN.matcher(line);

                if (matcher.find()) {

                    ReportType reportType;

                    if (!allocationStatistics.containsKey(gc_id.get())) {

                    }

                        reportType = ReportType.SURVIVOR_STATS;

                    } else {

                        reportType = ReportType.OLD_STATS;

                    }

                    oneReportItem = allocationStatistics.get(gc_id.get());

                    if (!oneReportItem.containsKey(reportType)) {

                    }

                    // Extract all pairs from log.

                    Map<String, Long> plabStats = oneReportItem.get(reportType);

                    do {

                        String pair = matcher.group();

                        String[] nameValue = pair.replaceAll(": ", ":").split(":");

                        plabStats.put(nameValue[0].trim(), Long.parseLong(nameValue[1]));

                    } while (matcher.find());

                }

            }

        }

        return allocationStatistics;

    }

    private Optional<Long> getGcId(String line) {

        Matcher number = GC_ID_PATTERN.matcher(line);

        if (number.find()) {

            return Optional.of(Long.parseLong(number.group(1)));

        }

        return Optional.empty();

    }

}