Examples » Core » Metrics

Using the metrics system.

Registering metrics and profiling in Cubos can be done through the metric macros defined in core/metrics.hpp and the core::Metrics class. In order to enable these features, compile with -DENABLE_PROFILING.

#include <cubos/core/metrics.hpp>

using cubos::core::Metrics;

The following example demonstrates a simple usage of the core::Metrics class, simulating a random function that takes X milliseconds to finish, where X is randomly generated, and also registering metrics values.

This is the main loop:

    const int numFrames = 10;
    for (int i = 0; i < numFrames; ++i)
    {
        // simulate frame by calling a function that does work..
        simulateFrame(randomMs(0, 500));

        // register some metrics, this could be FPS, entities count, ....
        CUBOS_METRIC("i", i);
    }

Which calls these utility functions:

static void simulateFrame(int ms)
{
    CUBOS_PROFILE();
    std::this_thread::sleep_for(std::chrono::milliseconds(ms));
}

static int randomMs(int min, int max)
{
    int range = (min - max) + 1;
    return rand() % range + min;
}

We can now get the existing metrics and their values:

    std::string name;
    std::size_t seenCount = 0;
    while (Metrics::readName(name, seenCount))
    {
        CUBOS_DEBUG("Found new metric: {}", name);
        double value;
        std::size_t offset = 0;
        while (Metrics::readValue(name, value, offset))
        {
            CUBOS_DEBUG("{} : {}", name, value);
        }
    }

Output:

[11:34:13.824] [main.cpp:51 main] debug: Found new metric: "profiling:/home/cubos/core/samples/metrics/main.cpp:simulateFrame:27"
[11:34:13.824] [main.cpp:56 main] debug: "profiling:/home/cubos/core/samples/metrics/main.cpp:simulateFrame:27" : 103.0721
[11:34:13.824] [main.cpp:56 main] debug: "profiling:/home/cubos/core/samples/metrics/main.cpp:simulateFrame:27" : 469.1480
[11:34:13.825] [main.cpp:56 main] debug: "profiling:/home/cubos/core/samples/metrics/main.cpp:simulateFrame:27" : 379.0656
[11:34:13.825] [main.cpp:56 main] debug: "profiling:/home/cubos/core/samples/metrics/main.cpp:simulateFrame:27" : 388.1754
[11:34:13.825] [main.cpp:56 main] debug: "profiling:/home/cubos/core/samples/metrics/main.cpp:simulateFrame:27" : 37.1140
[11:34:13.825] [main.cpp:56 main] debug: "profiling:/home/cubos/core/samples/metrics/main.cpp:simulateFrame:27" : 14.0966
[11:34:13.825] [main.cpp:56 main] debug: "profiling:/home/cubos/core/samples/metrics/main.cpp:simulateFrame:27" : 8.1281
[11:34:13.825] [main.cpp:56 main] debug: "profiling:/home/cubos/core/samples/metrics/main.cpp:simulateFrame:27" : 464.1636
[11:34:13.826] [main.cpp:56 main] debug: "profiling:/home/cubos/core/samples/metrics/main.cpp:simulateFrame:27" : 313.1553
[11:34:13.826] [main.cpp:56 main] debug: "profiling:/home/cubos/core/samples/metrics/main.cpp:simulateFrame:27" : 57.0801
[11:34:13.826] [main.cpp:51 main] debug: Found new metric: "i"
[11:34:13.826] [main.cpp:56 main] debug: "i" : 0.0000
[11:34:13.827] [main.cpp:56 main] debug: "i" : 1.0000
[11:34:13.827] [main.cpp:56 main] debug: "i" : 2.0000
[11:34:13.827] [main.cpp:56 main] debug: "i" : 3.0000
[11:34:13.827] [main.cpp:56 main] debug: "i" : 4.0000
[11:34:13.827] [main.cpp:56 main] debug: "i" : 5.0000
[11:34:13.828] [main.cpp:56 main] debug: "i" : 6.0000
[11:34:13.828] [main.cpp:56 main] debug: "i" : 7.0000
[11:34:13.828] [main.cpp:56 main] debug: "i" : 8.0000
[11:34:13.828] [main.cpp:56 main] debug: "i" : 9.0000