Prototype of removing bare span attribute keys

api/src/main/java/io/opentelemetry/common/BooleanValuedKey.java

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2020, OpenTelemetry Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.opentelemetry.common;
+
+public interface BooleanValuedKey {
+  String key();
+}

api/src/main/java/io/opentelemetry/common/DoubleValuedKey.java

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2020, OpenTelemetry Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.opentelemetry.common;
+
+public interface DoubleValuedKey {
+  String key();
+}

api/src/main/java/io/opentelemetry/common/LongValuedKey.java

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2020, OpenTelemetry Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.opentelemetry.common;
+
+public interface LongValuedKey {
+  String key();
+}

api/src/main/java/io/opentelemetry/common/StringValuedKey.java

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2020, OpenTelemetry Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.opentelemetry.common;
+
+public interface StringValuedKey {
+  String key();
+}

api/src/main/java/io/opentelemetry/trace/DefaultSpan.java

@@ -17,6 +17,10 @@
 package io.opentelemetry.trace;
 
 import io.opentelemetry.common.AttributeValue;
+import io.opentelemetry.common.BooleanValuedKey;
+import io.opentelemetry.common.DoubleValuedKey;
+import io.opentelemetry.common.LongValuedKey;
+import io.opentelemetry.common.StringValuedKey;
 import io.opentelemetry.internal.Utils;
 import java.util.Map;
 import java.util.Random;
@@ -73,29 +77,29 @@ static DefaultSpan createRandom() {
   }
 
   @Override
-  public void setAttribute(String key, String value) {
+  public void setAttribute(String key, AttributeValue value) {
     Utils.checkNotNull(key, "key");
+    Utils.checkNotNull(value, "value");
   }
 
   @Override
-  public void setAttribute(String key, long value) {
+  public void setAttribute(StringValuedKey key, String value) {
     Utils.checkNotNull(key, "key");
   }
 
   @Override
-  public void setAttribute(String key, double value) {
+  public void setAttribute(DoubleValuedKey key, double value) {
     Utils.checkNotNull(key, "key");
   }
 
   @Override
-  public void setAttribute(String key, boolean value) {
+  public void setAttribute(BooleanValuedKey key, boolean value) {
     Utils.checkNotNull(key, "key");
   }
 
   @Override
-  public void setAttribute(String key, AttributeValue value) {
+  public void setAttribute(LongValuedKey key, long value) {
     Utils.checkNotNull(key, "key");
-    Utils.checkNotNull(value, "value");
   }
 
   @Override

api/src/main/java/io/opentelemetry/trace/DefaultTracer.java

@@ -17,6 +17,10 @@
 package io.opentelemetry.trace;
 
 import io.opentelemetry.common.AttributeValue;
+import io.opentelemetry.common.BooleanValuedKey;
+import io.opentelemetry.common.DoubleValuedKey;
+import io.opentelemetry.common.LongValuedKey;
+import io.opentelemetry.common.StringValuedKey;
 import io.opentelemetry.context.Scope;
 import io.opentelemetry.internal.Utils;
 import java.util.Map;
@@ -116,33 +120,33 @@ public NoopSpanBuilder addLink(Link link) {
     }
 
     @Override
-    public NoopSpanBuilder setAttribute(String key, String value) {
+    public NoopSpanBuilder setAttribute(String key, AttributeValue value) {
       Utils.checkNotNull(key, "key");
+      Utils.checkNotNull(value, "value");
       return this;
     }
 
     @Override
-    public NoopSpanBuilder setAttribute(String key, long value) {
+    public NoopSpanBuilder setAttribute(StringValuedKey key, String value) {
       Utils.checkNotNull(key, "key");
       return this;
     }
 
     @Override
-    public NoopSpanBuilder setAttribute(String key, double value) {
+    public NoopSpanBuilder setAttribute(DoubleValuedKey key, double value) {
       Utils.checkNotNull(key, "key");
       return this;
     }
 
     @Override
-    public NoopSpanBuilder setAttribute(String key, boolean value) {
+    public NoopSpanBuilder setAttribute(BooleanValuedKey key, boolean value) {
       Utils.checkNotNull(key, "key");
       return this;
     }
 
     @Override
-    public NoopSpanBuilder setAttribute(String key, AttributeValue value) {
+    public NoopSpanBuilder setAttribute(LongValuedKey key, long value) {
       Utils.checkNotNull(key, "key");
-      Utils.checkNotNull(value, "value");
       return this;
     }
 

api/src/main/java/io/opentelemetry/trace/Span.java

@@ -17,6 +17,10 @@
 package io.opentelemetry.trace;
 
 import io.opentelemetry.common.AttributeValue;
+import io.opentelemetry.common.BooleanValuedKey;
+import io.opentelemetry.common.DoubleValuedKey;
+import io.opentelemetry.common.LongValuedKey;
+import io.opentelemetry.common.StringValuedKey;
 import java.util.Map;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.ThreadSafe;
@@ -84,24 +88,24 @@ enum Kind {
    * Sets an attribute to the {@code Span}. If the {@code Span} previously contained a mapping for
    * the key, the old value is replaced by the specified value.
    *
-   * <p>If a null or empty String {@code value} is passed in, the attribute will be silently
-   * dropped. Note: this behavior could change in the future.
-   *
    * @param key the key for this attribute.
    * @param value the value for this attribute.
    * @since 0.1.0
    */
-  void setAttribute(String key, @Nullable String value);
+  void setAttribute(String key, AttributeValue value);
 
   /**
    * Sets an attribute to the {@code Span}. If the {@code Span} previously contained a mapping for
    * the key, the old value is replaced by the specified value.
    *
+   * <p>If a null or empty String {@code value} is passed in, the attribute will be silently
+   * dropped. Note: this behavior could change in the future.
+   *
    * @param key the key for this attribute.
    * @param value the value for this attribute.
    * @since 0.1.0
    */
-  void setAttribute(String key, long value);
+  void setAttribute(StringValuedKey key, @Nullable String value);
 
   /**
    * Sets an attribute to the {@code Span}. If the {@code Span} previously contained a mapping for
@@ -111,7 +115,7 @@ enum Kind {
    * @param value the value for this attribute.
    * @since 0.1.0
    */
-  void setAttribute(String key, double value);
+  void setAttribute(DoubleValuedKey key, double value);
 
   /**
    * Sets an attribute to the {@code Span}. If the {@code Span} previously contained a mapping for
@@ -121,7 +125,7 @@ enum Kind {
    * @param value the value for this attribute.
    * @since 0.1.0
    */
-  void setAttribute(String key, boolean value);
+  void setAttribute(BooleanValuedKey key, boolean value);
 
   /**
    * Sets an attribute to the {@code Span}. If the {@code Span} previously contained a mapping for
@@ -131,7 +135,7 @@ enum Kind {
    * @param value the value for this attribute.
    * @since 0.1.0
    */
-  void setAttribute(String key, AttributeValue value);
+  void setAttribute(LongValuedKey key, long value);
 
   /**
    * Adds an event to the {@code Span}.
@@ -263,7 +267,7 @@ enum Kind {
 
   /**
    * Returns {@code true} if this {@code Span} records tracing events (e.g. {@link
-   * #addEvent(String)}, {@link #setAttribute(String, long)}).
+   * #addEvent(String)}, {@link #setAttribute(LongValuedKey, long)}).
    *
    * @return {@code true} if this {@code Span} records tracing events.
    * @since 0.1.0
@@ -459,28 +463,29 @@ interface Builder {
      * Sets an attribute to the newly created {@code Span}. If {@code Span.Builder} previously
      * contained a mapping for the key, the old value is replaced by the specified value.
      *
-     * <p>If a null or empty String {@code value} is passed in, the attribute will be silently
-     * dropped. Note: this behavior could change in the future.
-     *
      * @param key the key for this attribute.
      * @param value the value for this attribute.
      * @return this.
      * @throws NullPointerException if {@code key} is {@code null}.
+     * @throws NullPointerException if {@code value} is {@code null}.
      * @since 0.3.0
      */
-    Builder setAttribute(String key, @Nullable String value);
+    Builder setAttribute(String key, AttributeValue value);
 
     /**
      * Sets an attribute to the newly created {@code Span}. If {@code Span.Builder} previously
      * contained a mapping for the key, the old value is replaced by the specified value.
      *
+     * <p>If a null or empty String {@code value} is passed in, the attribute will be silently
+     * dropped. Note: this behavior could change in the future.
+     *
      * @param key the key for this attribute.
      * @param value the value for this attribute.
      * @return this.
      * @throws NullPointerException if {@code key} is {@code null}.
      * @since 0.3.0
      */
-    Builder setAttribute(String key, long value);
+    Builder setAttribute(StringValuedKey key, @Nullable String value);
 
     /**
      * Sets an attribute to the newly created {@code Span}. If {@code Span.Builder} previously
@@ -492,7 +497,7 @@ interface Builder {
      * @throws NullPointerException if {@code key} is {@code null}.
      * @since 0.3.0
      */
-    Builder setAttribute(String key, double value);
+    Builder setAttribute(DoubleValuedKey key, double value);
 
     /**
      * Sets an attribute to the newly created {@code Span}. If {@code Span.Builder} previously
@@ -504,7 +509,7 @@ interface Builder {
      * @throws NullPointerException if {@code key} is {@code null}.
      * @since 0.3.0
      */
-    Builder setAttribute(String key, boolean value);
+    Builder setAttribute(BooleanValuedKey key, boolean value);
 
     /**
      * Sets an attribute to the newly created {@code Span}. If {@code Span.Builder} previously
@@ -514,10 +519,9 @@ interface Builder {
      * @param value the value for this attribute.
      * @return this.
      * @throws NullPointerException if {@code key} is {@code null}.
-     * @throws NullPointerException if {@code value} is {@code null}.
      * @since 0.3.0
      */
-    Builder setAttribute(String key, AttributeValue value);
+    Builder setAttribute(LongValuedKey key, long value);
 
     /**
      * Sets the {@link Span.Kind} for the newly created {@code Span}. If not called, the

api/src/main/java/io/opentelemetry/trace/attributes/BooleanAttributeSetter.java

@@ -16,20 +16,21 @@
 
 package io.opentelemetry.trace.attributes;
 
+import io.opentelemetry.common.BooleanValuedKey;
 import io.opentelemetry.trace.Span;
 import javax.annotation.concurrent.Immutable;
 
 /** Defines the behavior for a span attribute with boolean values. */
 @Immutable
-public final class BooleanAttributeSetter {
+public final class BooleanAttributeSetter implements BooleanValuedKey {
 
   /**
    * Returns a new attribute setter.
    *
    * @param attributeKey the attribute name
    * @return the setter object
    */
-  public static BooleanAttributeSetter create(String attributeKey) {
+  public static BooleanAttributeSetter booleanKey(String attributeKey) {
     return new BooleanAttributeSetter(attributeKey);
   }
 
@@ -47,6 +48,7 @@ private BooleanAttributeSetter(String attributeKey) {
    *
    * @return the attribute map key
    */
+  @Override
   public String key() {
     return attributeKey;
   }
@@ -58,6 +60,6 @@ public String key() {
    * @param value the value for this attribute
    */
   public void set(Span span, boolean value) {
-    span.setAttribute(key(), value);
+    span.setAttribute(booleanKey(attributeKey), value);
   }
 }