feat(metrics): add composable metric views support

docs/apidiffs/current_vs_latest/opentelemetry-sdk-metrics.txt

@@ -1,2 +1,5 @@
 Comparing source compatibility of opentelemetry-sdk-metrics-1.69.0-SNAPSHOT.jar against opentelemetry-sdk-metrics-1.68.0.jar
-No changes.
+***  MODIFIED CLASS: PUBLIC ABSTRACT io.opentelemetry.sdk.metrics.View  (not serializable)
+	===  CLASS FILE FORMAT VERSION: 52.0 <- 52.0
+	+++  NEW METHOD: PUBLIC(+) FINAL(+) boolean equals(java.lang.Object)
+	+++  NEW METHOD: PUBLIC(+) FINAL(+) int hashCode()

sdk-extensions/declarative-config/src/main/java/io/opentelemetry/sdk/autoconfigure/declarativeconfig/MeterProviderFactory.java

@@ -16,6 +16,7 @@
 import io.opentelemetry.sdk.autoconfigure.declarativeconfig.model.internal.ExperimentalMeterConfigModel;
 import io.opentelemetry.sdk.autoconfigure.declarativeconfig.model.internal.ExperimentalMeterConfiguratorModel;
 import io.opentelemetry.sdk.autoconfigure.declarativeconfig.model.internal.ExperimentalMeterMatcherAndConfigModel;
+import io.opentelemetry.sdk.autoconfigure.declarativeconfig.model.internal.ExperimentalViewMatchingModeModel;
 import io.opentelemetry.sdk.autoconfigure.declarativeconfig.model.internal.MeterProviderModelAccessor;
 import io.opentelemetry.sdk.common.internal.ScopeConfigurator;
 import io.opentelemetry.sdk.common.internal.ScopeConfiguratorBuilder;
@@ -24,6 +25,7 @@
 import io.opentelemetry.sdk.metrics.export.CardinalityLimitSelector;
 import io.opentelemetry.sdk.metrics.internal.MeterConfig;
 import io.opentelemetry.sdk.metrics.internal.SdkMeterProviderUtil;
+import io.opentelemetry.sdk.metrics.internal.view.ViewMatchingMode;
 import java.util.List;
 
 final class MeterProviderFactory implements Factory<MeterProviderModel, SdkMeterProviderBuilder> {
@@ -95,6 +97,16 @@ public SdkMeterProviderBuilder create(
       SdkMeterProviderUtil.setMeterConfigurator(builder, configuratorBuilder.build());
     }
 
+    ExperimentalViewMatchingModeModel viewMatchingModeModel =
+        MeterProviderModelAccessor.getViewMatchingMode(model);
+    if (viewMatchingModeModel != null) {
+      ViewMatchingMode viewMatchingMode =
+          viewMatchingModeModel == ExperimentalViewMatchingModeModel.COMPOSABLE
+              ? ViewMatchingMode.COMPOSABLE
+              : ViewMatchingMode.INDEPENDENT;
+      SdkMeterProviderUtil.setViewMatchingMode(builder, viewMatchingMode);
+    }
+
     ExemplarFilterModel exemplarFilterModel = model.getExemplarFilter();
     if (exemplarFilterModel != null) {
       builder.setExemplarFilter(

sdk-extensions/declarative-config/src/test/java/io/opentelemetry/sdk/autoconfigure/declarativeconfig/MeterProviderFactoryTest.java

@@ -6,6 +6,7 @@
 package io.opentelemetry.sdk.autoconfigure.declarativeconfig;
 
 import static io.opentelemetry.sdk.metrics.internal.SdkMeterProviderUtil.setMeterConfigurator;
+import static io.opentelemetry.sdk.metrics.internal.SdkMeterProviderUtil.setViewMatchingMode;
 import static io.opentelemetry.sdk.testing.assertj.OpenTelemetryAssertions.assertThat;
 
 import io.opentelemetry.common.ComponentLoader;
@@ -23,6 +24,7 @@
 import io.opentelemetry.sdk.autoconfigure.declarativeconfig.model.internal.ExperimentalMeterConfigModel;
 import io.opentelemetry.sdk.autoconfigure.declarativeconfig.model.internal.ExperimentalMeterConfiguratorModel;
 import io.opentelemetry.sdk.autoconfigure.declarativeconfig.model.internal.ExperimentalMeterMatcherAndConfigModel;
+import io.opentelemetry.sdk.autoconfigure.declarativeconfig.model.internal.ExperimentalViewMatchingModeModel;
 import io.opentelemetry.sdk.autoconfigure.declarativeconfig.model.internal.MeterProviderModelAccessor;
 import io.opentelemetry.sdk.common.internal.ScopeConfigurator;
 import io.opentelemetry.sdk.common.internal.ScopeConfiguratorBuilder;
@@ -32,6 +34,7 @@
 import io.opentelemetry.sdk.metrics.View;
 import io.opentelemetry.sdk.metrics.export.PeriodicMetricReader;
 import io.opentelemetry.sdk.metrics.internal.MeterConfig;
+import io.opentelemetry.sdk.metrics.internal.view.ViewMatchingMode;
 import java.io.Closeable;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -73,6 +76,11 @@ private static Stream<Arguments> createArguments() {
     return Stream.of(
         Arguments.argumentSet(
             "defaults", new MeterProviderModel(), SdkMeterProvider.builder().build()),
+        Arguments.argumentSet(
+            "with view matching mode composable",
+            MeterProviderModelAccessor.setViewMatchingMode(
+                new MeterProviderModel(), ExperimentalViewMatchingModeModel.COMPOSABLE),
+            setViewMatchingMode(SdkMeterProvider.builder(), ViewMatchingMode.COMPOSABLE).build()),
         Arguments.argumentSet(
             "with reader view and meter configurator",
             MeterProviderModelAccessor.setMeterConfigurator(

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/SdkMeter.java

@@ -305,7 +305,7 @@ WriteableMetricStorage registerSynchronousMetricStorage(InstrumentDescriptor ins
         if (Aggregation.drop() == registeredView.getView().getAggregation()) {
           continue;
         }
-        registeredStorages.add(
+        SynchronousMetricStorage storage =
             registry.register(
                 SynchronousMetricStorage.create(
                     reader,
@@ -314,7 +314,10 @@ WriteableMetricStorage registerSynchronousMetricStorage(InstrumentDescriptor ins
                     instrument,
                     meterProviderSharedState.getExemplarFilter(),
                     meterEnabled,
-                    getContextScopedAttributesFilter())));
+                    getContextScopedAttributesFilter()));
+        if (!registeredStorages.contains(storage)) {
+          registeredStorages.add(storage);
+        }
       }
     }
 
@@ -339,15 +342,18 @@ SdkObservableMeasurement registerObservableMeasurement(
         if (Aggregation.drop() == registeredView.getView().getAggregation()) {
           continue;
         }
-        registeredStorages.add(
+        AsynchronousMetricStorage<?> storage =
             registry.register(
                 AsynchronousMetricStorage.create(
                     reader,
                     registeredView,
                     meterProviderSharedState.getClock(),
                     instrumentDescriptor,
                     meterProviderSharedState.getExemplarFilter(),
-                    meterEnabled)));
+                    meterEnabled));
+        if (!registeredStorages.contains(storage)) {
+          registeredStorages.add(storage);
+        }
       }
     }
 

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/SdkMeterProvider.java

@@ -27,6 +27,7 @@
 import io.opentelemetry.sdk.metrics.internal.export.RegisteredReader;
 import io.opentelemetry.sdk.metrics.internal.state.MeterProviderSharedState;
 import io.opentelemetry.sdk.metrics.internal.view.RegisteredView;
+import io.opentelemetry.sdk.metrics.internal.view.ViewMatchingMode;
 import io.opentelemetry.sdk.metrics.internal.view.ViewRegistry;
 import io.opentelemetry.sdk.resources.Resource;
 import io.opentelemetry.sdk.resources.internal.SdkResourceProvider;
@@ -55,6 +56,7 @@ public final class SdkMeterProvider implements MeterProvider, Closeable {
   static final String DEFAULT_METER_NAME = "unknown";
 
   private final List<RegisteredView> registeredViews;
+  private final ViewMatchingMode viewMatchingMode;
   private final List<RegisteredReader> registeredReaders;
   private final List<MetricProducer> metricProducers;
   private final MeterProviderSharedState sharedState;
@@ -78,15 +80,18 @@ public static SdkMeterProviderBuilder builder() {
       ExemplarFilterInternal exemplarFilter,
       ScopeConfigurator<MeterConfig> meterConfigurator,
       @Nullable
-          BiPredicate<InstrumentationScopeInfo, AttributeKey<?>> contextScopedAttributesFilter) {
+          BiPredicate<InstrumentationScopeInfo, AttributeKey<?>> contextScopedAttributesFilter,
+      ViewMatchingMode viewMatchingMode) {
     this.resourceProvider = resourceProvider;
     this.registeredViews = registeredViews;
+    this.viewMatchingMode = viewMatchingMode;
     this.registeredReaders =
         metricReaders.entrySet().stream()
             .map(entry ->
                 RegisteredReader.create(
                     entry.getKey(),
-                    ViewRegistry.create(entry.getKey(), entry.getValue(), registeredViews)))
+                    ViewRegistry.create(
+                        entry.getKey(), entry.getValue(), registeredViews, viewMatchingMode)))
             .collect(toList());
     this.metricProducers = metricProducers;
     this.sharedState =
@@ -210,6 +215,8 @@ public String toString() {
         + metricProducers
         + ", views="
         + registeredViews
+        + ", viewMatchingMode="
+        + viewMatchingMode
         + ", meterConfigurator="
         + meterConfigurator
         + "}";

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/SdkMeterProviderBuilder.java

@@ -19,6 +19,7 @@
 import io.opentelemetry.sdk.metrics.internal.exemplar.ExemplarFilterInternal;
 import io.opentelemetry.sdk.metrics.internal.view.AttributesFilters;
 import io.opentelemetry.sdk.metrics.internal.view.RegisteredView;
+import io.opentelemetry.sdk.metrics.internal.view.ViewMatchingMode;
 import io.opentelemetry.sdk.resources.Resource;
 import io.opentelemetry.sdk.resources.internal.SdkResourceProvider;
 import java.util.ArrayList;
@@ -52,6 +53,7 @@ public final class SdkMeterProviderBuilder {
       new IdentityHashMap<>();
   private final List<MetricProducer> metricProducers = new ArrayList<>();
   private final List<RegisteredView> registeredViews = new ArrayList<>();
+  private ViewMatchingMode viewMatchingMode = ViewMatchingMode.INDEPENDENT;
   private ExemplarFilterInternal exemplarFilter = DEFAULT_EXEMPLAR_FILTER;
   private ScopeConfiguratorBuilder<MeterConfig> meterConfiguratorBuilder =
       MeterConfig.configuratorBuilder();
@@ -171,7 +173,10 @@ public SdkMeterProviderBuilder registerView(InstrumentSelector selector, View vi
             view,
             AttributesFilters.byKeyName(view.getAttributeFilter()),
             view.getCardinalityLimit(),
-            SourceInfo.fromCurrentStack()));
+            SourceInfo.fromCurrentStack(),
+            view.getExplicitAggregation(),
+            view.getExplicitAttributeFilter(),
+            view.getExplicitCardinalityLimit()));
     return this;
   }
 
@@ -263,6 +268,17 @@ SdkMeterProviderBuilder setContextScopedAttributesFilter(
     return this;
   }
 
+  /**
+   * Set the view matching mode.
+   *
+   * <p>This method is experimental so not public. You may reflectively call it using {@link
+   * SdkMeterProviderUtil#setViewMatchingMode(SdkMeterProviderBuilder, ViewMatchingMode)}.
+   */
+  SdkMeterProviderBuilder setViewMatchingMode(ViewMatchingMode viewMatchingMode) {
+    this.viewMatchingMode = Objects.requireNonNull(viewMatchingMode, "viewMatchingMode");
+    return this;
+  }
+
   /** Returns an {@link SdkMeterProvider} built with the configuration of this builder. */
   public SdkMeterProvider build() {
     SdkResourceProvider effectiveSdkResourceProvider =
@@ -275,6 +291,7 @@ public SdkMeterProvider build() {
         effectiveSdkResourceProvider,
         exemplarFilter,
         meterConfiguratorBuilder.build(),
-        contextScopedAttributesFilter);
+        contextScopedAttributesFilter,
+        viewMatchingMode);
   }
 }

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/View.java

@@ -6,6 +6,7 @@
 package io.opentelemetry.sdk.metrics;
 
 import com.google.auto.value.AutoValue;
+import java.util.Objects;
 import java.util.StringJoiner;
 import java.util.function.Predicate;
 import javax.annotation.Nullable;
@@ -33,8 +34,19 @@ static View create(
       @Nullable String description,
       Aggregation aggregation,
       Predicate<String> attributeFilter,
-      int cardinalityLimit) {
-    return new AutoValue_View(name, description, aggregation, attributeFilter, cardinalityLimit);
+      int cardinalityLimit,
+      @Nullable Aggregation explicitAggregation,
+      @Nullable Predicate<String> explicitAttributeFilter,
+      @Nullable Integer explicitCardinalityLimit) {
+    return new AutoValue_View(
+        name,
+        description,
+        aggregation,
+        attributeFilter,
+        cardinalityLimit,
+        explicitAggregation,
+        explicitAttributeFilter,
+        explicitCardinalityLimit);
   }
 
   View() {}
@@ -71,6 +83,15 @@ static View create(
    */
   public abstract int getCardinalityLimit();
 
+  @Nullable
+  abstract Aggregation getExplicitAggregation();
+
+  @Nullable
+  abstract Predicate<String> getExplicitAttributeFilter();
+
+  @Nullable
+  abstract Integer getExplicitCardinalityLimit();
+
   @Override
   public final String toString() {
     StringJoiner joiner = new StringJoiner(", ", "View{", "}");
@@ -85,4 +106,36 @@ public final String toString() {
     joiner.add("cardinalityLimit=" + getCardinalityLimit());
     return joiner.toString();
   }
+
+  @Override
+  public final boolean equals(@Nullable Object o) {
+    if (o == this) {
+      return true;
+    }
+    if (o instanceof View) {
+      View that = (View) o;
+      return Objects.equals(this.getName(), that.getName())
+          && Objects.equals(this.getDescription(), that.getDescription())
+          && this.getAggregation().equals(that.getAggregation())
+          && this.getAttributeFilter().equals(that.getAttributeFilter())
+          && this.getCardinalityLimit() == that.getCardinalityLimit();
+    }
+    return false;
+  }
+
+  @Override
+  public final int hashCode() {
+    int hash = 1;
+    hash *= 1000003;
+    hash ^= (getName() == null) ? 0 : getName().hashCode();
+    hash *= 1000003;
+    hash ^= (getDescription() == null) ? 0 : getDescription().hashCode();
+    hash *= 1000003;
+    hash ^= getAggregation().hashCode();
+    hash *= 1000003;
+    hash ^= getAttributeFilter().hashCode();
+    hash *= 1000003;
+    hash ^= getCardinalityLimit();
+    return hash;
+  }
 }

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/ViewBuilder.java

@@ -25,9 +25,9 @@ public final class ViewBuilder {
 
   @Nullable private String name;
   @Nullable private String description;
-  private Aggregation aggregation = Aggregation.defaultAggregation();
-  private Predicate<String> attributeFilter = StringPredicates.ALL;
-  private int cardinalityLimit = MetricStorage.DEFAULT_MAX_CARDINALITY;
+  @Nullable private Aggregation explicitAggregation;
+  @Nullable private Predicate<String> explicitAttributeFilter;
+  @Nullable private Integer explicitCardinalityLimit;
 
   ViewBuilder() {}
 
@@ -58,12 +58,13 @@ public ViewBuilder setDescription(String description) {
    * @param aggregation aggregation to use.
    */
   public ViewBuilder setAggregation(Aggregation aggregation) {
+    Objects.requireNonNull(aggregation, "aggregation");
     if (!(aggregation instanceof AggregatorFactory)) {
       throw new IllegalArgumentException(
           "Custom Aggregation implementations are currently not supported. "
               + "Use one of the standard implementations returned by the static factories in the Aggregation class.");
     }
-    this.aggregation = aggregation;
+    this.explicitAggregation = aggregation;
     return this;
   }
 
@@ -104,7 +105,7 @@ public ViewBuilder setAttributeFilter(Set<String> keysToRetain) {
    */
   public ViewBuilder setAttributeFilter(Predicate<String> keyFilter) {
     Objects.requireNonNull(keyFilter, "keyFilter");
-    this.attributeFilter = keyFilter;
+    this.explicitAttributeFilter = keyFilter;
     return this;
   }
 
@@ -121,12 +122,28 @@ public ViewBuilder setCardinalityLimit(int cardinalityLimit) {
     if (cardinalityLimit <= 0) {
       throw new IllegalArgumentException("cardinalityLimit must be > 0");
     }
-    this.cardinalityLimit = cardinalityLimit;
+    this.explicitCardinalityLimit = cardinalityLimit;
     return this;
   }
 
   /** Returns a {@link View} with the configuration of this builder. */
   public View build() {
-    return View.create(name, description, aggregation, attributeFilter, cardinalityLimit);
+    Aggregation aggregation =
+        explicitAggregation != null ? explicitAggregation : Aggregation.defaultAggregation();
+    Predicate<String> attributeFilter =
+        explicitAttributeFilter != null ? explicitAttributeFilter : StringPredicates.ALL;
+    int cardinalityLimit =
+        explicitCardinalityLimit != null
+            ? explicitCardinalityLimit
+            : MetricStorage.DEFAULT_MAX_CARDINALITY;
+    return View.create(
+        name,
+        description,
+        aggregation,
+        attributeFilter,
+        cardinalityLimit,
+        explicitAggregation,
+        explicitAttributeFilter,
+        explicitCardinalityLimit);
   }
 }

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/internal/SdkMeterProviderUtil.java

@@ -10,6 +10,7 @@
 import io.opentelemetry.sdk.common.internal.ScopeConfigurator;
 import io.opentelemetry.sdk.metrics.SdkMeterProvider;
 import io.opentelemetry.sdk.metrics.SdkMeterProviderBuilder;
+import io.opentelemetry.sdk.metrics.internal.view.ViewMatchingMode;
 import io.opentelemetry.sdk.resources.internal.SdkResourceProvider;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
@@ -133,4 +134,20 @@ public static SdkMeterProviderBuilder setContextScopedAttributesFilter(
     }
     return sdkMeterProviderBuilder;
   }
+
+  /** Reflectively set the {@link ViewMatchingMode} on the {@link SdkMeterProviderBuilder}. */
+  public static SdkMeterProviderBuilder setViewMatchingMode(
+      SdkMeterProviderBuilder sdkMeterProviderBuilder, ViewMatchingMode viewMatchingMode) {
+    try {
+      Method method =
+          SdkMeterProviderBuilder.class.getDeclaredMethod(
+              "setViewMatchingMode", ViewMatchingMode.class);
+      method.setAccessible(true);
+      method.invoke(sdkMeterProviderBuilder, viewMatchingMode);
+    } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) {
+      throw new IllegalStateException(
+          "Error calling setViewMatchingMode on SdkMeterProviderBuilder", e);
+    }
+    return sdkMeterProviderBuilder;
+  }
 }