| /******************************************************************************* |
| * Copyright (c) 2011, 2014 Ericsson, Ecole Polytechnique de Montreal and others |
| * |
| * All rights reserved. This program and the accompanying materials are made |
| * available under the terms of the Eclipse Public License 2.0 which |
| * accompanies this distribution, and is available at |
| * https://www.eclipse.org/legal/epl-2.0/ |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| * Contributors: Matthew Khouzam - Initial API and implementation |
| * Contributors: Simon Marchi - Initial API and implementation |
| *******************************************************************************/ |
| |
| package org.eclipse.tracecompass.ctf.core.event; |
| |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| /** |
| * Clock description used in CTF traces. |
| * |
| * From the TSDL perspective, they describe the clock topology of the system, as well as to detail |
| * each clock parameter. In absence of clock description, it is assumed that all fields named |
| * timestamp use the same clock source, which increments once per nanosecond. |
| * <p> |
| * Describing a clock and how it is used by streams is threefold: |
| * <ol> |
| * <li>the clock and clock topology should be described in a clock description block</li> |
| * <li>a reference to this clock should be added within an integer type. (timestamp)</li> |
| * <li>stream declarations can reference the clock they use as a timestamp source</li></ol> |
| * In for trace compass's perspective, clock attributes are added when the trace is parsed. The ones |
| * used at this moment are: |
| * <ul><li>offsets</li><li>names</li><li>frequencies</li></ul> |
| * |
| * Most traces only have one clock source. As all events have timestamps offsetted by the same clock. |
| * It is however possible especially with mixed traces (hardware and software) to have different |
| * clock sources for a given event. |
| * <p> |
| * An individual event should only have one timestamp and therefore only one clock source though. |
| */ |
| public class CTFClock { |
| |
| private static final long ONE_BILLION_L = 1000000000L; |
| private static final double ONE_BILLION_D = 1000000000.0; |
| |
| private static final String NAME = "name"; //$NON-NLS-1$ |
| private static final String FREQ = "freq"; //$NON-NLS-1$ |
| private static final String OFFSET = "offset"; //$NON-NLS-1$ |
| |
| private long fClockOffset = 0; |
| private double fClockScale = 1.0; |
| private double fClockAntiScale = 1.0; |
| |
| /** |
| * Field properties. |
| */ |
| private final Map<String, Object> fProperties = new HashMap<>(); |
| /** |
| * Field name. |
| */ |
| private String fName; |
| private boolean fIsScaled = false; |
| |
| /** |
| * Default constructor |
| */ |
| public CTFClock() { |
| // The attributes are added later using addAttribute |
| } |
| |
| /** |
| * Method addAttribute. |
| * |
| * @param key |
| * String |
| * @param value |
| * Object |
| */ |
| public void addAttribute(String key, Object value) { |
| fProperties.put(key, value); |
| if (key.equals(NAME)) { |
| fName = (String) value; |
| } |
| if (key.equals(FREQ)) { |
| /* |
| * Long is converted to a double. the double is then dividing |
| * another double that double is saved. this is precise as long as |
| * the long is under 53 bits long. this is ok as long as we don't |
| * have a system with a frequency of > 1 600 000 000 GHz with |
| * 200 ppm precision |
| */ |
| fIsScaled = !((Long) getProperty(FREQ)).equals(ONE_BILLION_L); |
| fClockScale = ONE_BILLION_D / ((Long) getProperty(FREQ)).doubleValue(); |
| fClockAntiScale = 1.0 / fClockScale; |
| |
| } |
| if (key.equals(OFFSET)) { |
| fClockOffset = (Long) getProperty(OFFSET); |
| } |
| } |
| |
| /** |
| * Method getName. |
| * |
| * @return String |
| */ |
| public String getName() { |
| return fName; |
| } |
| |
| /** |
| * Method getProperty. |
| * |
| * @param key |
| * String |
| * @return Object |
| */ |
| public Object getProperty(String key) { |
| return fProperties.get(key); |
| } |
| |
| /** |
| * @return the clockOffset |
| */ |
| public long getClockOffset() { |
| return fClockOffset; |
| } |
| |
| /** |
| * @return the clockScale |
| */ |
| public double getClockScale() { |
| return fClockScale; |
| } |
| |
| /** |
| * @return the clockAntiScale |
| */ |
| public double getClockAntiScale() { |
| return fClockAntiScale; |
| } |
| |
| /** |
| * @return is the clock in ns or cycles? |
| */ |
| public boolean isClockScaled() { |
| return fIsScaled; |
| } |
| |
| } |