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Fili web service library provides core capabilities for RESTful aggregation navigation, query planning and metadata

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// Copyright 2016 Yahoo Inc.
// Licensed under the terms of the Apache license. Please see LICENSE.md file distributed with this work for terms.
package com.yahoo.bard.webservice.logging;

import com.fasterxml.jackson.annotation.JsonAnyGetter;

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

/**
 * Represents the information that is written in a single log line per http request.
 * Information is progressively appended to this context according to the handling path of the request.
 * Finally, the LogBlock is exported as JSON string and written to the appropriate output via the logging framework.
 */
public class LogBlock {

    public final String uuid;
    private final Map body;

    /**
     * Given a universally unique identifier as string construct a logging context.
     *
     * @param uuid  A string identifier that is meant to be unique across the logfile.
     */
    public LogBlock(String uuid) {
        this.uuid = uuid;
        this.body = new LinkedHashMap<>();
    }

    /**
     * Append a part of logging information defined in this LogBlock.
     *
     * @param phase  A {@link LogInfo} object including the information to be logged.
     */
    public void add(LogInfo phase) {
        body.put(phase.getName(), phase);
    }

    /**
     * Return a part of logging information in this LogBlock.
     *
     * @param name  Name of a {@link LogInfo} object to be returned
     *
     * @return a part of logging information in this LogBlock
     */
    public LogInfo get(String name) {
        return body.get(name);
    }

    /**
     * Create a new LogBlock with the same body but updated uuid.
     *
     * @param uuid  New uuid.
     * @return New LogBlock with updated uuid.
     */
    public LogBlock withUuid(String uuid) {
        LogBlock newLogBlock = new LogBlock(uuid);
        body.entrySet().forEach(entry -> newLogBlock.body.put(entry.getKey(), entry.getValue()));
        return newLogBlock;
    }

    /**
     * Add an entry of given class in this LogBlock that holds no information.
     * It is meant to be used only to define the order of {@link LogInfo} parts inside a LogBlock.
     *
     * @param phaseClass  A string to identify the class that will hold the logs passed as arguments.
     */
    protected void add(Class phaseClass) {
        body.put(phaseClass.getSimpleName(), null);
    }

    /**
     * JSON serialization-focused getter that will "un wrap" the map, making it's entries appear to be those of the
     * parent class.
     *
     * @return  The map to unwrap
     */
    @JsonAnyGetter
    public Map any() {
        return body;
    }
}