SessionInfoStore.java

/*******************************************************************************
 * Copyright (c) 2009, 2025 Mountainminds GmbH & Co. KG and Contributors
 * This program and the accompanying materials are made available under
 * the terms of the Eclipse Public License 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *    Marc R. Hoffmann - initial API and implementation
 *
 *******************************************************************************/
package org.jacoco.core.data;

import static java.lang.Math.max;
import static java.lang.Math.min;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 * Container to collect and merge session {@link SessionInfo} objects. An
 * instance of this class is not thread safe.
 */
public class SessionInfoStore implements ISessionInfoVisitor {

    private final List<SessionInfo> infos = new ArrayList<SessionInfo>();

    /**
     * Tests whether the store is empty.
     *
     * @return <code>true</code> if the store is empty
     */
    public boolean isEmpty() {
        return infos.isEmpty();
    }

    /**
     * Returns all {@link SessionInfo} objects currently contained in the store.
     * The info objects are ordered by its natural ordering (i.e. by the dump
     * time stamp).
     *
     * @return list of stored {@link SessionInfo} objects
     */
    public List<SessionInfo> getInfos() {
        final List<SessionInfo> copy = new ArrayList<SessionInfo>(infos);
        Collections.sort(copy);
        return copy;
    }

    /**
     * Returns a new session info with the given id that contains a merged
     * version from all contained version. The start timestamp is the minimum of
     * all contained sessions, the dump timestamp the maximum of all contained
     * sessions. If no session is currently contained both timestamps are set to
     * <code>0</code>.
     *
     * @param id
     *            identifier for the merged session info
     * @return new {@link SessionInfo} object
     *
     */
    public SessionInfo getMerged(final String id) {
        if (infos.isEmpty()) {
            return new SessionInfo(id, 0, 0);
        }
        long start = Long.MAX_VALUE;
        long dump = Long.MIN_VALUE;
        for (final SessionInfo i : infos) {
            start = min(start, i.getStartTimeStamp());
            dump = max(dump, i.getDumpTimeStamp());
        }
        return new SessionInfo(id, start, dump);
    }

    /**
     * Writes all contained {@link SessionInfo} objects into the given visitor.
     * The info objects are emitted in chronological order by dump timestamp.
     *
     * @param visitor
     *            visitor to emit {@link SessionInfo} objects to
     */
    public void accept(final ISessionInfoVisitor visitor) {
        for (final SessionInfo i : getInfos()) {
            visitor.visitSessionInfo(i);
        }
    }

    // === ISessionInfoVisitor ===

    public void visitSessionInfo(final SessionInfo info) {
        infos.add(info);
    }

}