tests for new monitoring utils

src/main/java/com/onthegomap/flatmap/monitoring/PrometheusStats.java

@@ -9,8 +9,10 @@ import io.prometheus.client.GaugeMetricFamily;
 import io.prometheus.client.Histogram;
 import io.prometheus.client.exporter.BasicAuthHttpConnectionFactory;
 import io.prometheus.client.exporter.PushGateway;
+import io.prometheus.client.exporter.common.TextFormat;
 import io.prometheus.client.hotspot.DefaultExports;
 import java.io.IOException;
+import java.io.StringWriter;
 import java.lang.management.ManagementFactory;
 import java.lang.management.OperatingSystemMXBean;
 import java.net.URL;
@@ -37,24 +39,26 @@ public class PrometheusStats implements Stats {
 
   private final CollectorRegistry registry = new CollectorRegistry();
   private final Timers timers = new Timers();
-  private static final String NAMESPACE = "flatmap";
   private static final String BASE = "flatmap_";
-  private final PushGateway pg;
-  private final ScheduledExecutorService executor;
+  private PushGateway pg;
+  private ScheduledExecutorService executor;
   private final String job;
   private final Map<String, Path> filesToMonitor = Collections.synchronizedMap(new LinkedHashMap<>());
   private final Map<String, MemoryEstimator.HasEstimate> heapObjectsToMonitor = Collections
     .synchronizedMap(new LinkedHashMap<>());
 
-  public PrometheusStats(String destination, String job, Duration interval) {
+  public PrometheusStats(String job) {
     this.job = job;
-    try {
-      DefaultExports.register(registry);
-      new ThreadDetailsExports().register(registry);
-      new InProgressTasks().register(registry);
-      new FileSizeCollector().register(registry);
-      new HeapObjectSizeCollector().register(registry);
+    DefaultExports.register(registry);
+    new ThreadDetailsExports().register(registry);
+    new InProgressTasks().register(registry);
+    new FileSizeCollector().register(registry);
+    new HeapObjectSizeCollector().register(registry);
+  }
 
+  public PrometheusStats(String destination, String job, Duration interval) {
+    this(job);
+    try {
       URL url = new URL(destination);
       pg = new PushGateway(url);
       if (url.getUserInfo() != null) {
@@ -134,6 +138,15 @@ public class PrometheusStats implements Stats {
     emittedFeatures.labels(Integer.toString(z), layer).inc(number);
   }
 
+  public String getMetricsAsString() {
+    try (StringWriter writer = new StringWriter()) {
+      TextFormat.write004(writer, registry.metricFamilySamples());
+      return writer.toString();
+    } catch (IOException e) {
+      throw new IllegalStateException(e);
+    }
+  }
+
   private final Histogram tilesWrittenBytes = Histogram
     .build(BASE + "mbtiles_tile_written_bytes", "Written tile sizes by zoom level")
     .buckets(1_000, 10_000, 100_000, 500_000)

src/test/java/com/onthegomap/flatmap/monitoring/CounterTest.java

@@ -0,0 +1,57 @@
+package com.onthegomap.flatmap.monitoring;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class CounterTest {
+
+  @Test
+  public void testSingleThreadedCounter() {
+    var counter = Counter.newSingleThreadCounter();
+    assertEquals(0, counter.get());
+
+    counter.inc();
+    assertEquals(1, counter.get());
+    counter.incBy(2);
+    assertEquals(3, counter.get());
+    counter.incBy(-1);
+    assertEquals(2, counter.get());
+  }
+
+  @Test
+  public void testMultiThreadedCounter() throws InterruptedException {
+    var counter = Counter.newMultiThreadCounter();
+    Thread t1 = new Thread(() -> {
+      counter.incBy(1);
+      counter.incBy(1);
+    });
+    t1.start();
+    Thread t2 = new Thread(() -> {
+      counter.incBy(1);
+    });
+    t2.start();
+    t1.join();
+    t2.join();
+    assertEquals(3, counter.get());
+  }
+
+  @Test
+  public void testMultiThreadedSubCounter() throws InterruptedException {
+    var counter = Counter.newMultiThreadCounter();
+    Thread t1 = new Thread(() -> {
+      var subCounter = counter.counterForThread();
+      subCounter.incBy(1);
+      subCounter.incBy(1);
+    });
+    t1.start();
+    Thread t2 = new Thread(() -> {
+      var subCounter = counter.counterForThread();
+      subCounter.incBy(1);
+    });
+    t2.start();
+    t1.join();
+    t2.join();
+    assertEquals(3, counter.get());
+  }
+}

src/test/java/com/onthegomap/flatmap/monitoring/PrometheusStatsTest.java

@@ -0,0 +1,154 @@
+package com.onthegomap.flatmap.monitoring;
+
+import static io.prometheus.client.Collector.NANOSECONDS_PER_SECOND;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.fail;
+import static org.junit.jupiter.api.DynamicTest.dynamicTest;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Map;
+import java.util.regex.Pattern;
+import java.util.stream.Stream;
+import org.junit.jupiter.api.DynamicTest;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.TestFactory;
+import org.junit.jupiter.api.io.TempDir;
+
+public class PrometheusStatsTest {
+
+  @TestFactory
+  public Stream<DynamicTest> testInitialStat() {
+    PrometheusStats stats = new PrometheusStats("job");
+    String metrics = stats.getMetricsAsString();
+    return testContains(metrics,
+      "^jvm_thread_cpu_time_seconds_total\\{",
+      "^jvm_thread_user_time_seconds_total\\{",
+      "^jvm_system_load_avg ",
+      "^jvm_available_processors [0-9\\.]+$"
+    );
+  }
+
+  @Test
+  public void testTimer() {
+    PrometheusStats stats = new PrometheusStats("job");
+    stats.time("task1", () -> {
+      assertContainsStat("^flatmap_task1_running 1", stats);
+      assertContainsStat("^flatmap_task1_elapsed_time_seconds [0-9\\.]+$", stats);
+      assertContainsStat("^flatmap_task1_cpu_time_seconds [0-9\\.]+$", stats);
+    });
+    assertContainsStat("^flatmap_task1_running 0", stats);
+    assertContainsStat("^flatmap_task1_elapsed_time_seconds [0-9\\.]+$", stats);
+    assertContainsStat("^flatmap_task1_cpu_time_seconds [0-9\\.]+$", stats);
+
+    assertFalse(stats.timers().all().get("task1").running());
+  }
+
+  @Test
+  public void testGauge() {
+    PrometheusStats stats = new PrometheusStats("job");
+    stats.gauge("gauge1", 1);
+    stats.gauge("gauge2", () -> 2);
+    assertContainsStat("^flatmap_gauge1 1", stats);
+    assertContainsStat("^flatmap_gauge2 2", stats);
+  }
+
+  @Test
+  public void testProcessedElement() {
+    PrometheusStats stats = new PrometheusStats("job");
+    stats.processedElement("type1", "layer1");
+    stats.processedElement("type1", "layer1");
+    stats.processedElement("type1", "layer2");
+    assertContainsStat("^flatmap_renderer_elements_processed_total\\{.*layer1.* 2", stats);
+    assertContainsStat("^flatmap_renderer_elements_processed_total\\{.*layer2.* 1", stats);
+  }
+
+  @Test
+  public void testDataError() {
+    PrometheusStats stats = new PrometheusStats("job");
+    stats.dataError("err1");
+    stats.dataError("err1");
+    stats.dataError("err2");
+    assertContainsStat("^flatmap_bad_input_data_total\\{.*err1.* 2", stats);
+    assertContainsStat("^flatmap_bad_input_data_total\\{.*err2.* 1", stats);
+  }
+
+  @Test
+  public void testEmittedFeatures() {
+    PrometheusStats stats = new PrometheusStats("job");
+    stats.emittedFeatures(0, "layer1", 2);
+    stats.emittedFeatures(0, "layer1", 2);
+    stats.emittedFeatures(0, "layer2", 1);
+    assertContainsStat("^flatmap_renderer_features_emitted_total\\{.*layer1.* 4", stats);
+    assertContainsStat("^flatmap_renderer_features_emitted_total\\{.*layer2.* 1", stats);
+  }
+
+  @Test
+  public void testWroteTile() {
+    PrometheusStats stats = new PrometheusStats("job");
+    stats.wroteTile(0, 10);
+    stats.wroteTile(0, 10_000);
+    assertContainsStat("^flatmap_mbtiles_tile_written_bytes_bucket\\{.*le=\"1000\\..* 1", stats);
+    assertContainsStat("^flatmap_mbtiles_tile_written_bytes_bucket\\{.*le=\"10000\\..* 2", stats);
+  }
+
+  @Test
+  public void testMonitorFile(@TempDir Path path) throws IOException {
+    PrometheusStats stats = new PrometheusStats("job");
+    stats.monitorFile("test", path);
+    assertContainsStat("^flatmap_file_test_size_bytes 0", stats);
+
+    Files.writeString(path.resolve("data"), "abc");
+    assertContainsStat("^flatmap_file_test_size_bytes [0-9]", stats);
+  }
+
+  @Test
+  public void testMonitorInMemoryObject() {
+    PrometheusStats stats = new PrometheusStats("job");
+    stats.monitorInMemoryObject("test", () -> 10);
+    assertContainsStat("^flatmap_heap_object_test_size_bytes 10", stats);
+  }
+
+  private static Counter.Readable counterAt(int num) {
+    var result = Counter.newSingleThreadCounter();
+    result.incBy(num);
+    return result;
+  }
+
+  @Test
+  public void testCounter() {
+    PrometheusStats stats = new PrometheusStats("job");
+    stats.counter("counter1", () -> 1);
+    stats.counter("counter2", "label", () -> Map.of(
+      "value1", counterAt(1),
+      "value2", counterAt(2)
+    ));
+    stats.longCounter("long").incBy(100);
+    stats.nanoCounter("nanos").incBy((long) (NANOSECONDS_PER_SECOND / 2));
+    assertContainsStat("^flatmap_counter1_total 1", stats);
+    assertContainsStat("^flatmap_counter2_total\\{.*label=\"value1\".* 1", stats);
+    assertContainsStat("^flatmap_counter2_total\\{.*label=\"value2\".* 2", stats);
+    assertContainsStat("^flatmap_long_total 100", stats);
+    assertContainsStat("^flatmap_nanos_total 0.5", stats);
+  }
+
+  private static Stream<DynamicTest> testContains(String stats, String... regexes) {
+    return Stream.of(regexes).map(re -> dynamicTest(re, () -> assertContainsStat(re, stats)));
+  }
+
+  private static void assertContainsStat(String regex, PrometheusStats stats) {
+    assertContainsStat(regex, stats.getMetricsAsString());
+  }
+
+  private static void assertContainsStat(String regex, String stats) {
+    Pattern pattern = Pattern.compile(regex);
+    for (String line : stats.split("\n")) {
+      if (!line.startsWith("#") && pattern.matcher(line).find()) {
+        return;
+      }
+    }
+    System.err.println(stats);
+    fail("could not find " + regex);
+  }
+}

src/test/java/com/onthegomap/flatmap/monitoring/TimerTest.java

@@ -0,0 +1,26 @@
+package com.onthegomap.flatmap.monitoring;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.Test;
+
+public class TimerTest {
+
+  @Test
+  public void testTimer() {
+    Timer timer = new Timer().start();
+    ProcessTime elapsed1 = timer.elapsed();
+    ProcessTime elapsed2 = timer.stop().elapsed();
+    ProcessTime elapsed3 = timer.elapsed();
+
+    assertEquals(elapsed2.wall(), elapsed3.wall());
+    assertLessThan(elapsed1.wall(), elapsed2.wall());
+    assertFalse(elapsed3.cpu().isEmpty(), "no CPU time");
+  }
+
+  private <T extends Comparable<T>> void assertLessThan(T a, T b) {
+    assertTrue(a.compareTo(b) < 0, a + " is not less than " + b);
+  }
+}

src/test/java/com/onthegomap/flatmap/monitoring/TimersTest.java

@@ -0,0 +1,29 @@
+package com.onthegomap.flatmap.monitoring;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.Test;
+
+public class TimersTest {
+
+  @Test
+  public void testTimers() {
+    Timers timers = new Timers();
+    assertTrue(timers.all().isEmpty());
+    timers.printSummary();
+
+    timers.time("task1", () -> {
+      assertTrue(timers.all().get("task1").running());
+    });
+
+    assertFalse(timers.all().get("task1").running());
+
+    var finish = timers.startTimer("task2");
+    assertTrue(timers.all().get("task2").running());
+    finish.stop();
+    assertFalse(timers.all().get("task2").running());
+
+    timers.printSummary();
+  }
+}