dev.vality.woody.api.trace.TraceData Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of woody-api Show documentation
There is a newer version: 2.0.8
package dev.vality.woody.api.trace;

import dev.vality.woody.api.trace.context.TraceContext;

public class TraceData {
    private final ClientSpan clientSpan;
    private final ServiceSpan serviceSpan;

    public TraceData() {
        this.clientSpan = new ClientSpan();
        this.serviceSpan = new ServiceSpan();
    }

    public TraceData(TraceData oldTraceData) {
        this(oldTraceData, false);
    }

    public TraceData(TraceData oldTraceData, boolean copyCustomServiceMetadata) {
        this.clientSpan = copyCustomServiceMetadata
                ? new ClientSpan(oldTraceData.clientSpan, oldTraceData.serviceSpan.customMetadata) :
                oldTraceData.clientSpan.cloneObject();
        this.serviceSpan = oldTraceData.serviceSpan.cloneObject();
    }

    public ClientSpan getClientSpan() {
        return clientSpan;
    }

    public ServiceSpan getServiceSpan() {
        return serviceSpan;
    }

    /**
     * Checks if {@link ServiceSpan} is filled to determine root:
     * - request initialized by server: span must be filled by server with data referred from client:
     *      has filled server span, it's not root by default -> false
     * - request initialized by client, produced by any server request handling event:
     *      has filled server span, it's not root -> false
     * - request initialized by client, not produced by any server request handling event:
     *      server span not filled, it's root -> true
     *
     * @return true - if root call is running; false - otherwise
     */
    public boolean isRoot() {
        return !serviceSpan.isFilled();
    }

    /**
     * Checks combination of client and server spans to determine current state:
     * Consider this states scheme (S - server span, C - client span; 1 - if it's set,
     *      0 - if not set, determined by checking traceId existence in corresponding span):
     * 
     * S | C
     * -----
     * 0 | 0
     * 0 | 1
     * 1 | 0
     * 1 | 1
     * 

     * 0,0 and 0,1 combinations don't have server span and context in the state can't be server by default
     *      (no server span is set) - it's client state -> true
     * 1,0 means that server span is created and no client span exists - it's server state -> false
     * 1,1 means that both spans exist and child client call is active now because for any client request client span
     *      is cleared after call completion, so after child call state returns to (1,0)
     *      case - (1,1) is child client state -> true
     * 
     * This allows to eliminate the necessity for call processing code to be explicitly configured with expected
     *      call state. This can be figured out directly from the context in runtime.
     * The only exclusion is {@link TraceContext} itself. It uses already filled trace id field for server state
     *      initialization
     *
     * @return true - if call is running as root client or child client call for server request handling;
     *      false - if call is running in server request handing
     */
    public boolean isClient() {
        return !serviceSpan.isFilled() || clientSpan.isFilled();
    }

    public ContextSpan getActiveSpan() {
        return isClient() ? clientSpan : serviceSpan;
    }

    public ContextSpan getSpan(boolean isClient) {
        return isClient ? clientSpan : serviceSpan;
    }

    public void reset() {
        clientSpan.reset();
        serviceSpan.reset();
    }

    public TraceData cloneObject() {
        return new TraceData(this);
    }
}