tracetypes/org.eclipse.tracecompass.incubator.ftrace.core/src/org/eclipse/tracecompass/incubator/internal/ftrace/core/trace/FtraceTrace.java

/*******************************************************************************
 * Copyright (c) 2018 Ecole Polytechnique de Montreal
 *
 * 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
 *******************************************************************************/

package org.eclipse.tracecompass.incubator.internal.ftrace.core.trace;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Arrays;

import org.eclipse.core.resources.IProject;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.tracecompass.incubator.internal.ftrace.core.Activator;
import org.eclipse.tracecompass.incubator.internal.ftrace.core.event.GenericFtraceField;
import org.eclipse.tracecompass.tmf.core.io.BufferedRandomAccessFile;
import org.eclipse.tracecompass.tmf.core.trace.TmfTraceUtils;
import org.eclipse.tracecompass.tmf.core.trace.TraceValidationStatus;

/**
 * Ftrace trace.
 *
 * @author Guillaume Champagne
 * @author Alexis-Maurer Fortin
 * @author Hugo Genesse
 * @author Pierre-Yves Lajoie
 * @author Eva Terriault
 */
public class FtraceTrace extends GenericFtrace {

    private static final int MAX_LINES = 100;
    private static final int MAX_CONFIDENCE = 100;

    @Override
    public IStatus validate(IProject project, String path) {
        File file = new File(path);
        if (!file.exists()) {
            return new Status(IStatus.ERROR, Activator.PLUGIN_ID, "File not found: " + path); //$NON-NLS-1$
        }
        if (!file.isFile()) {
            return new Status(IStatus.ERROR, Activator.PLUGIN_ID, "Not a file. It's a directory: " + path); //$NON-NLS-1$
        }
        int confidence = 0;
        try {
            if (!TmfTraceUtils.isText(file)) {
                int magicLength = TRACE_CMD_DAT_MAGIC.length;
                if (file.length() > magicLength) {
                    try (FileInputStream fis = new FileInputStream(file)) {
                        byte[] start = new byte[magicLength];
                        int read = fis.read(start);
                        if (read == magicLength && Arrays.equals(TRACE_CMD_DAT_MAGIC, start)) {
                            // TODO: offer to do this programatically
                            return new Status(IStatus.ERROR, Activator.PLUGIN_ID, "This file looks like a binary trace-cmd, try running 'trace-cmd report -R' on it."); //$NON-NLS-1$
                        }
                    }
                }
                return new TraceValidationStatus(confidence, Activator.PLUGIN_ID);
            }
        } catch (IOException e) {
            Activator.getInstance().logError("Error validating file: " + path, e); //$NON-NLS-1$
            return new Status(IStatus.ERROR, Activator.PLUGIN_ID, "IOException validating file: " + path, e); //$NON-NLS-1$
        }
        try (BufferedRandomAccessFile rafile = new BufferedRandomAccessFile(path, "r")) { //$NON-NLS-1$
            int lineCount = 0;
            int matches = 0;
            String line = rafile.readLine();
            while ((line != null) && (lineCount++ < MAX_LINES)) {
                try {
                    GenericFtraceField field = GenericFtraceField.parseLine(line);
                    if (field != null) {
                        matches++;
                    }
                } catch (RuntimeException e) {
                    confidence = Integer.MIN_VALUE;
                }

                confidence = MAX_CONFIDENCE * matches / lineCount;
                line = rafile.readLine();
            }
            if (matches == 0) {
                return new Status(IStatus.ERROR, Activator.PLUGIN_ID, "Most assuredly NOT an fTrace text trace"); //$NON-NLS-1$
            }
        } catch (IOException e) {
            Activator.getInstance().logError("Error validating file: " + path, e); //$NON-NLS-1$
            return new Status(IStatus.ERROR, Activator.PLUGIN_ID, "IOException validating file: " + path, e); //$NON-NLS-1$
        }
        return new TraceValidationStatus(confidence, Activator.PLUGIN_ID);
    }
}