Implement OpenTelemetry meter instrument builders

dd-java-agent/agent-otel/otel-shim/src/main/java/datadog/opentelemetry/shim/metrics/OtelDoubleCounter.java

@@ -0,0 +1,75 @@
+package datadog.opentelemetry.shim.metrics;
+
+import static datadog.opentelemetry.shim.metrics.OtelInstrumentBuilder.ofDoubles;
+import static datadog.opentelemetry.shim.metrics.OtelInstrumentType.COUNTER;
+import static datadog.opentelemetry.shim.metrics.OtelMeter.NOOP_INSTRUMENT_NAME;
+import static datadog.opentelemetry.shim.metrics.OtelMeter.NOOP_METER;
+
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.metrics.DoubleCounter;
+import io.opentelemetry.api.metrics.DoubleCounterBuilder;
+import io.opentelemetry.api.metrics.ObservableDoubleCounter;
+import io.opentelemetry.api.metrics.ObservableDoubleMeasurement;
+import io.opentelemetry.context.Context;
+import java.util.function.Consumer;
+import javax.annotation.ParametersAreNonnullByDefault;
+
+@ParametersAreNonnullByDefault
+final class OtelDoubleCounter implements DoubleCounter {
+
+  @Override
+  public void add(double value) {
+    // FIXME: implement recording
+  }
+
+  @Override
+  public void add(double value, Attributes attributes) {
+    // FIXME: implement recording
+  }
+
+  @Override
+  public void add(double value, Attributes attributes, Context context) {
+    // FIXME: implement recording
+  }
+
+  static final class Builder implements DoubleCounterBuilder {
+    private final OtelInstrumentBuilder instrumentBuilder;
+
+    Builder(OtelInstrumentBuilder builder) {
+      this.instrumentBuilder = ofDoubles(builder, COUNTER);
+    }
+
+    @Override
+    public DoubleCounterBuilder setDescription(String description) {
+      instrumentBuilder.setDescription(description);
+      return this;
+    }
+
+    @Override
+    public DoubleCounterBuilder setUnit(String unit) {
+      instrumentBuilder.setUnit(unit);
+      return this;
+    }
+
+    @Override
+    public DoubleCounter build() {
+      return new OtelDoubleCounter();
+    }
+
+    @Override
+    public ObservableDoubleCounter buildWithCallback(
+        Consumer<ObservableDoubleMeasurement> callback) {
+      // FIXME: implement callback
+      return NOOP_METER
+          .counterBuilder(NOOP_INSTRUMENT_NAME)
+          .ofDoubles()
+          .buildWithCallback(callback);
+    }
+
+    @Override
+    public ObservableDoubleMeasurement buildObserver() {
+      // FIXME: implement observer
+      return NOOP_METER.counterBuilder(NOOP_INSTRUMENT_NAME).ofDoubles().buildObserver();
+    }
+  }
+}

dd-java-agent/agent-otel/otel-shim/src/main/java/datadog/opentelemetry/shim/metrics/OtelDoubleGauge.java

@@ -0,0 +1,77 @@
+package datadog.opentelemetry.shim.metrics;
+
+import static datadog.opentelemetry.shim.metrics.OtelInstrumentBuilder.ofDoubles;
+import static datadog.opentelemetry.shim.metrics.OtelInstrumentType.GAUGE;
+import static datadog.opentelemetry.shim.metrics.OtelMeter.NOOP_INSTRUMENT_NAME;
+import static datadog.opentelemetry.shim.metrics.OtelMeter.NOOP_METER;
+
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.metrics.DoubleGauge;
+import io.opentelemetry.api.metrics.DoubleGaugeBuilder;
+import io.opentelemetry.api.metrics.LongGaugeBuilder;
+import io.opentelemetry.api.metrics.ObservableDoubleGauge;
+import io.opentelemetry.api.metrics.ObservableDoubleMeasurement;
+import io.opentelemetry.context.Context;
+import java.util.function.Consumer;
+import javax.annotation.ParametersAreNonnullByDefault;
+
+@ParametersAreNonnullByDefault
+final class OtelDoubleGauge implements DoubleGauge {
+
+  @Override
+  public void set(double value) {
+    // FIXME: implement recording
+  }
+
+  @Override
+  public void set(double value, Attributes attributes) {
+    // FIXME: implement recording
+  }
+
+  @Override
+  public void set(double value, Attributes attributes, Context context) {
+    // FIXME: implement recording
+  }
+
+  static final class Builder implements DoubleGaugeBuilder {
+    private final OtelInstrumentBuilder instrumentBuilder;
+
+    Builder(OtelMeter meter, String instrumentName) {
+      this.instrumentBuilder = ofDoubles(meter, instrumentName, GAUGE);
+    }
+
+    @Override
+    public DoubleGaugeBuilder setDescription(String description) {
+      instrumentBuilder.setDescription(description);
+      return this;
+    }
+
+    @Override
+    public DoubleGaugeBuilder setUnit(String unit) {
+      instrumentBuilder.setUnit(unit);
+      return this;
+    }
+
+    @Override
+    public LongGaugeBuilder ofLongs() {
+      return new OtelLongGauge.Builder(instrumentBuilder);
+    }
+
+    @Override
+    public DoubleGauge build() {
+      return new OtelDoubleGauge();
+    }
+
+    @Override
+    public ObservableDoubleGauge buildWithCallback(Consumer<ObservableDoubleMeasurement> callback) {
+      // FIXME: implement callback
+      return NOOP_METER.gaugeBuilder(NOOP_INSTRUMENT_NAME).buildWithCallback(callback);
+    }
+
+    @Override
+    public ObservableDoubleMeasurement buildObserver() {
+      // FIXME: implement observer
+      return NOOP_METER.gaugeBuilder(NOOP_INSTRUMENT_NAME).buildObserver();
+    }
+  }
+}

dd-java-agent/agent-otel/otel-shim/src/main/java/datadog/opentelemetry/shim/metrics/OtelDoubleHistogram.java

@@ -0,0 +1,67 @@
+package datadog.opentelemetry.shim.metrics;
+
+import static datadog.opentelemetry.shim.metrics.OtelInstrumentBuilder.ofDoubles;
+import static datadog.opentelemetry.shim.metrics.OtelInstrumentType.HISTOGRAM;
+
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.metrics.DoubleHistogram;
+import io.opentelemetry.api.metrics.DoubleHistogramBuilder;
+import io.opentelemetry.api.metrics.LongHistogramBuilder;
+import io.opentelemetry.context.Context;
+import java.util.List;
+import javax.annotation.ParametersAreNonnullByDefault;
+
+@ParametersAreNonnullByDefault
+final class OtelDoubleHistogram implements DoubleHistogram {
+
+  @Override
+  public void record(double value) {
+    // FIXME: implement recording
+  }
+
+  @Override
+  public void record(double value, Attributes attributes) {
+    // FIXME: implement recording
+  }
+
+  @Override
+  public void record(double value, Attributes attributes, Context context) {
+    // FIXME: implement recording
+  }
+
+  static final class Builder implements DoubleHistogramBuilder {
+    private final OtelInstrumentBuilder instrumentBuilder;
+
+    Builder(OtelMeter meter, String instrumentName) {
+      this.instrumentBuilder = ofDoubles(meter, instrumentName, HISTOGRAM);
+    }
+
+    @Override
+    public DoubleHistogramBuilder setDescription(String description) {
+      instrumentBuilder.setDescription(description);
+      return this;
+    }
+
+    @Override
+    public DoubleHistogramBuilder setUnit(String unit) {
+      instrumentBuilder.setUnit(unit);
+      return this;
+    }
+
+    @Override
+    public DoubleHistogramBuilder setExplicitBucketBoundariesAdvice(List<Double> bucketBoundaries) {
+      // FIXME: implement boundary advice
+      return this;
+    }
+
+    @Override
+    public LongHistogramBuilder ofLongs() {
+      return new OtelLongHistogram.Builder(instrumentBuilder);
+    }
+
+    @Override
+    public DoubleHistogram build() {
+      return new OtelDoubleHistogram();
+    }
+  }
+}

dd-java-agent/agent-otel/otel-shim/src/main/java/datadog/opentelemetry/shim/metrics/OtelDoubleUpDownCounter.java

@@ -0,0 +1,75 @@
+package datadog.opentelemetry.shim.metrics;
+
+import static datadog.opentelemetry.shim.metrics.OtelInstrumentBuilder.ofDoubles;
+import static datadog.opentelemetry.shim.metrics.OtelInstrumentType.UP_DOWN_COUNTER;
+import static datadog.opentelemetry.shim.metrics.OtelMeter.NOOP_INSTRUMENT_NAME;
+import static datadog.opentelemetry.shim.metrics.OtelMeter.NOOP_METER;
+
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.metrics.DoubleUpDownCounter;
+import io.opentelemetry.api.metrics.DoubleUpDownCounterBuilder;
+import io.opentelemetry.api.metrics.ObservableDoubleMeasurement;
+import io.opentelemetry.api.metrics.ObservableDoubleUpDownCounter;
+import io.opentelemetry.context.Context;
+import java.util.function.Consumer;
+import javax.annotation.ParametersAreNonnullByDefault;
+
+@ParametersAreNonnullByDefault
+final class OtelDoubleUpDownCounter implements DoubleUpDownCounter {
+
+  @Override
+  public void add(double value) {
+    // FIXME: implement recording
+  }
+
+  @Override
+  public void add(double value, Attributes attributes) {
+    // FIXME: implement recording
+  }
+
+  @Override
+  public void add(double value, Attributes attributes, Context context) {
+    // FIXME: implement recording
+  }
+
+  static final class Builder implements DoubleUpDownCounterBuilder {
+    private final OtelInstrumentBuilder instrumentBuilder;
+
+    Builder(OtelInstrumentBuilder builder) {
+      this.instrumentBuilder = ofDoubles(builder, UP_DOWN_COUNTER);
+    }
+
+    @Override
+    public DoubleUpDownCounterBuilder setDescription(String description) {
+      instrumentBuilder.setDescription(description);
+      return this;
+    }
+
+    @Override
+    public DoubleUpDownCounterBuilder setUnit(String unit) {
+      instrumentBuilder.setUnit(unit);
+      return this;
+    }
+
+    @Override
+    public DoubleUpDownCounter build() {
+      return new OtelDoubleUpDownCounter();
+    }
+
+    @Override
+    public ObservableDoubleUpDownCounter buildWithCallback(
+        Consumer<ObservableDoubleMeasurement> callback) {
+      // FIXME: implement callback
+      return NOOP_METER
+          .upDownCounterBuilder(NOOP_INSTRUMENT_NAME)
+          .ofDoubles()
+          .buildWithCallback(callback);
+    }
+
+    @Override
+    public ObservableDoubleMeasurement buildObserver() {
+      // FIXME: implement observer
+      return NOOP_METER.upDownCounterBuilder(NOOP_INSTRUMENT_NAME).ofDoubles().buildObserver();
+    }
+  }
+}

dd-java-agent/agent-otel/otel-shim/src/main/java/datadog/opentelemetry/shim/metrics/OtelInstrumentBuilder.java

@@ -0,0 +1,83 @@
+package datadog.opentelemetry.shim.metrics;
+
+import javax.annotation.Nullable;
+
+final class OtelInstrumentBuilder {
+
+  private final OtelMeter meter;
+  private final String instrumentName;
+  private final OtelInstrumentType instrumentType;
+  private final boolean longValues;
+
+  @Nullable private String description;
+  @Nullable private String unit;
+
+  /**
+   * Starts building an instrument of long values with the given name and type.
+   *
+   * @param meter the owning mete
+   * @param instrumentName the name of the instrument
+   * @param instrumentType the type of the instrument
+   * @return new instrument builder
+   */
+  static OtelInstrumentBuilder ofLongs(
+      OtelMeter meter, String instrumentName, OtelInstrumentType instrumentType) {
+    return new OtelInstrumentBuilder(meter, instrumentName, instrumentType, true);
+  }
+
+  /**
+   * Starts building an instrument of long values based on another builder.
+   *
+   * @param builder the builder to copy details from
+   * @param instrumentType the type of the instrument
+   * @return new instrument builder
+   */
+  static OtelInstrumentBuilder ofLongs(
+      OtelInstrumentBuilder builder, OtelInstrumentType instrumentType) {
+    return new OtelInstrumentBuilder(builder.meter, builder.instrumentName, instrumentType, true);
+  }
+
+  /**
+   * Starts building an instrument of double values with the given name and type.
+   *
+   * @param meter the owning mete
+   * @param instrumentName the name of the instrument
+   * @param instrumentType the type of the instrument
+   * @return new instrument builder
+   */
+  static OtelInstrumentBuilder ofDoubles(
+      OtelMeter meter, String instrumentName, OtelInstrumentType instrumentType) {
+    return new OtelInstrumentBuilder(meter, instrumentName, instrumentType, false);
+  }
+
+  /**
+   * Starts building an instrument of double values based on another builder.
+   *
+   * @param builder the builder to copy details from
+   * @param instrumentType the type of the instrument
+   * @return new instrument builder
+   */
+  static OtelInstrumentBuilder ofDoubles(
+      OtelInstrumentBuilder builder, OtelInstrumentType instrumentType) {
+    return new OtelInstrumentBuilder(builder.meter, builder.instrumentName, instrumentType, false);
+  }
+
+  private OtelInstrumentBuilder(
+      OtelMeter meter,
+      String instrumentName,
+      OtelInstrumentType instrumentType,
+      boolean longValues) {
+    this.meter = meter;
+    this.instrumentName = instrumentName;
+    this.instrumentType = instrumentType;
+    this.longValues = longValues;
+  }
+
+  void setDescription(String description) {
+    this.description = description;
+  }
+
+  void setUnit(String unit) {
+    this.unit = unit;
+  }
+}

dd-java-agent/agent-otel/otel-shim/src/main/java/datadog/opentelemetry/shim/metrics/OtelInstrumentType.java

@@ -0,0 +1,8 @@
+package datadog.opentelemetry.shim.metrics;
+
+enum OtelInstrumentType {
+  COUNTER,
+  UP_DOWN_COUNTER,
+  HISTOGRAM,
+  GAUGE
+}