com.facebook.buck.debug.TraceEvent.java Source code

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Here is the source code for com.facebook.buck.debug.TraceEvent.java

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/*
 * Copyright 2012-present Facebook, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License. You may obtain
 * a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */

package com.facebook.buck.debug;

import com.google.common.base.Preconditions;
import com.google.common.base.Strings;

/**
 * Single event for a trace.
 */
class TraceEvent {

    private final long id;
    private final String comment;
    private final String type;
    private final long eventTime;
    private final long startTime;

    TraceEvent(long id, String comment, String type, long startTime) {
        this.id = id;
        this.comment = comment;
        this.type = type;
        this.eventTime = System.currentTimeMillis();
        this.startTime = startTime;
    }

    public long getId() {
        return id;
    }

    public String getComment() {
        return comment;
    }

    public String getType() {
        return type;
    }

    public long getEventTime() {
        return eventTime;
    }

    /**
     * Returns a formatted string for the event.
     *
     * @param traceStartTime the start time of the trace to generate relative times
     * @param prevTime the completion time of the previous event or -1
     * @param indent extra indent for the message if there was no previous event.
     * @return the formatted tracer string
     */
    String toTraceString(long traceStartTime, long prevTime, String indent) {
        // TODO(user): move to ThreadTrace to split formatting from representation
        StringBuilder sb = new StringBuilder();

        if (prevTime == -1) {
            sb.append("-----");
        } else {
            sb.append(longToPaddedString(this.eventTime - prevTime));
        }

        sb.append(" ");
        sb.append(formatTime(this.eventTime - traceStartTime));
        if (this instanceof TraceStart) {
            sb.append(" Start         ");
        } else if (this instanceof TraceStop) {
            sb.append(" Done ");
            long delta = eventTime - startTime;
            sb.append(longToPaddedString(delta));
            sb.append(" ms ");
        } else {
            sb.append(" Comment      ");
        }

        sb.append(indent);
        sb.append(this.toString());
        return sb.toString();
    }

    /**
     * @return A string describing the tracer event.
     */
    @Override
    public String toString() {
        if (this.type == null) {
            return comment;
        } else {
            return String.format("[%s] %s", type, comment);
        }
    }

    /**
     * Converts {@code value} to a string and pads it with up to 4 spaces for improved alignment.
     * @param value A nonnegative value.
     * @return A padded string.
     */
    static String longToPaddedString(long value) {
        Preconditions.checkArgument(value >= 0, "value must be positive");
        return Strings.padStart(String.valueOf(value), 5, '0');
    }

    /**
     * Return the sec.ms part of time (if time = "20:06:11.566", "11.566")
     *
     * @param time The time in milliseconds.
     * @return A formatted string as "sec.ms".
     */
    static String formatTime(long time) {
        String sec = String.valueOf(Math.max(0, (time / 1000) % 60));
        String ms = String.valueOf(Math.max(time % 1000, 0));
        return Strings.padStart(sec, 2, '0') + '.' + Strings.padStart(ms, 3, '0');
    }

}