de.hpi.isg.profiledb.instrumentation.StopWatch Maven / Gradle / Ivy

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package de.hpi.isg.profiledb.instrumentation;


import de.hpi.isg.profiledb.store.model.Experiment;
import de.hpi.isg.profiledb.store.model.Measurement;
import de.hpi.isg.profiledb.store.model.TimeMeasurement;

import java.util.Collection;
import java.util.LinkedHashMap;
import java.util.Map;

/**
 * Utility to create {@link TimeMeasurement}s for an {@link Experiment}.
 */
public class StopWatch {

    private final Map rounds = new LinkedHashMap<>();

    private final Experiment experiment;

    /**
     * Creates a new instance for the given {@link Experiment}.
     *
     * @param experiment that should be instrumented
     */
    public StopWatch(Experiment experiment) {
        this.experiment = experiment;
        for (Measurement measurement : this.experiment.getMeasurements()) {
            if (measurement instanceof TimeMeasurement) {
                this.rounds.put(measurement.getId(), (TimeMeasurement) measurement);
            }
        }
    }

    /**
     * Retrieves a {@link TimeMeasurement} by its ID from {@link #rounds}. If it does not exist, it will be
     * created and also registered with the {@link #experiment}.
     *
     * @param id         the ID of the {@link TimeMeasurement}
     * @param furtherIds IDs of further nested {@link TimeMeasurement}s
     * @return the {@link TimeMeasurement}
     */
    public TimeMeasurement getOrCreateRound(String id, String... furtherIds) {
        TimeMeasurement round = this.rounds.get(id);
        if (round == null) {
            round = new TimeMeasurement(id);
            this.rounds.put(round.getId(), round);
            this.experiment.addMeasurement(round);
        }
        for (String furtherId : furtherIds) {
            round = round.getOrCreateRound(furtherId);
        }
        return round;
    }

    /**
     * Starts a {@link TimeMeasurement}. Any required parent {@link TimeMeasurement} will be started if necessary.
     *
     * @param id         ID of the root {@link TimeMeasurement}
     * @param furtherIds IDs of further nested {@link TimeMeasurement}s
     * @return the (potentially new) {@link TimeMeasurement}
     */
    public TimeMeasurement start(String id, String... furtherIds) {
        return this.getOrCreateRound(id).start(furtherIds);
    }

    /**
     * Stops a {@link TimeMeasurement} (if it exists).
     *
     * @param id         ID of the root {@link TimeMeasurement}
     * @param furtherIds IDs of further nested {@link TimeMeasurement}s
     */
    public void stop(String id, String... furtherIds) {
        final TimeMeasurement rootRound = this.rounds.get(id);
        if (rootRound != null) {
            rootRound.stop(furtherIds);
        }
    }

    /**
     * Formats the {@link TimeMeasurement}s to something easily readable.
     *
     * @return the "pretty" {@link String}
     */
    public String toPrettyString() {
        return this.toPrettyString("  ", "* ");
    }

    /**
     * Formats the {@link TimeMeasurement}s to something easily readable.
     *
     * @param indent indent to be used when formatting sub-{@link TimeMeasurement}s
     * @param bullet bullet point character
     * @return the "pretty" {@link String}
     */
    public String toPrettyString(String indent, String bullet) {
        StringBuilder sb = new StringBuilder(1000);
        int firstColumnWidth = this.determineFirstColumnWidth(this.rounds.values(), indent.length(), 0, bullet.length());
        this.rounds.values().forEach(round -> this.append(round, indent, 0, bullet, firstColumnWidth, sb));
        // Trim trailing newline.
        if (sb.length() > 0 && sb.charAt(sb.length() - 1) == '\n') {
            sb.setLength(sb.length() - 1);
        }
        return sb.toString();
    }

    private int determineFirstColumnWidth(Collection rounds, int indentWidth, int numIndents, int bulletWidth) {
        return rounds.stream()
                .map(round -> this.determineFirstColumnWidth(round, indentWidth, numIndents, bulletWidth))
                .reduce(0, Math::max);
    }

    private int determineFirstColumnWidth(TimeMeasurement round, int indentWidth, int numIndents, int bulletWidth) {
        return Math.max(
                round.getId().length() + (numIndents * indentWidth) + bulletWidth,
                this.determineFirstColumnWidth(round.getRounds(), indentWidth, numIndents + 1, bulletWidth)
        );
    }

    private void append(TimeMeasurement round, String indent, int numIndents, String bullet, int firstColumnWidth, StringBuilder sb) {
        int originalLength = sb.length();
        for (int i = 0; i < numIndents; i++) {
            sb.append(indent);
        }
        sb.append(bullet).append(round.getId());
        while (sb.length() < originalLength + firstColumnWidth) sb.append(" ");
        sb.append(" - ").append(TimeMeasurement.formatDuration(round.getMillis())).append('\n');
        round.getRounds().forEach(subround -> this.append(subround, indent, numIndents + 1, bullet, firstColumnWidth, sb));
    }

    /**
     * Stops all {@link TimeMeasurement}s known to this instance.
     */
    public void stopAll() {
        this.rounds.values().forEach(TimeMeasurement::stop);
    }

    /**
     * Get the {@link Experiment} managed by this instance.
     *
     * @return the {@link Experiment}
     */
    public Experiment getExperiment() {
        return this.experiment;
    }
}