Rename Labels to Attributes. (#171)

11 files changed, 393 insertions, 390 deletions

diff --git a/core/src/main/java/com/google/instrumentation/trace/LabelValue.java b/core/src/main/java/com/google/instrumentation/trace/AttributeValue.java
index 31e37a31..f5d47c75 100644
--- a/core/src/main/java/com/google/instrumentation/trace/LabelValue.java
+++ b/core/src/main/java/com/google/instrumentation/trace/AttributeValue.java
@@ -19,38 +19,39 @@ import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 
 /**
- * A class that represents all the possible values for a label in {@link Labels}.. A label can have
- * 3 types of values: {@link String}, {@link Boolean} or {@link Long}.
+ * A class that represents all the possible values for an attribute in {@link Attributes}. A
+ * attribute can have 3 types of values: {@code String}, {@code Boolean} or {@code Long}.
  */
 @Immutable
-public final class LabelValue {
+public final class AttributeValue {
   private final String stringValue;
   private final Boolean booleanValue;
   private final Long longValue;
 
-  static LabelValue stringLabelValue(String stringValue) {
-    return new LabelValue(stringValue, null, null);
+  static AttributeValue stringAttributeValue(String stringValue) {
+    return new AttributeValue(stringValue, null, null);
   }
 
-  static LabelValue booleanLabelValue(boolean booleanValue) {
-    return new LabelValue(null, booleanValue, null);
+  static AttributeValue booleanAttributeValue(boolean booleanValue) {
+    return new AttributeValue(null, booleanValue, null);
   }
 
-  static LabelValue longLabelValue(long longValue) {
-    return new LabelValue(null, null, longValue);
+  static AttributeValue longAttributeValue(long longValue) {
+    return new AttributeValue(null, null, longValue);
   }
 
-  private LabelValue(String stringValue, Boolean booleanValue, Long longValue) {
+  private AttributeValue(
+      @Nullable String stringValue, @Nullable Boolean booleanValue, @Nullable Long longValue) {
     this.stringValue = stringValue;
     this.booleanValue = booleanValue;
     this.longValue = longValue;
   }
 
   /**
-   * Returns the {@link String} value if this is a string {@code LabelValue}, otherwise {@code
+   * Returns the {@code String} value if this is a string {@code AttributeValue}, otherwise {@code
    * null}.
    *
-   * @return the {@link String} value if this is a string {@code LabelValue}, otherwise {@code
+   * @return the {@code String} value if this is a string {@code AttributeValue}, otherwise {@code
    *     null}.
    */
   @Nullable
@@ -59,10 +60,10 @@ public final class LabelValue {
   }
 
   /**
-   * Returns the {@link Boolean} value if this is a boolean {@code LabelValue}, otherwise {@code
+   * Returns the {@code Boolean} value if this is a boolean {@code AttributeValue}, otherwise {@code
    * null}.
    *
-   * @return the {@link Boolean} value if this is a boolean {@code LabelValue}, otherwise {@code
+   * @return the {@code Boolean} value if this is a boolean {@code AttributeValue}, otherwise {@code
    *     null}.
    */
   @Nullable
@@ -71,9 +72,11 @@ public final class LabelValue {
   }
 
   /**
-   * Returns the {@link Long} value if this is a long {@code LabelValue}, otherwise {@code null}.
+   * Returns the {@code Long} value if this is a long {@code AttributeValue}, otherwise {@code
+   * null}.
    *
-   * @return the {@link Long} value if this is a long {@code LabelValue}, otherwise {@code null}.
+   * @return the {@code Long} value if this is a long {@code AttributeValue}, otherwise {@code
+   *     null}.
    */
   @Nullable
   public Long getLongValue() {
@@ -86,11 +89,11 @@ public final class LabelValue {
       return true;
     }
 
-    if (!(obj instanceof LabelValue)) {
+    if (!(obj instanceof AttributeValue)) {
       return false;
     }
 
-    LabelValue that = (LabelValue) obj;
+    AttributeValue that = (AttributeValue) obj;
     return Objects.equal(stringValue, that.stringValue)
         && Objects.equal(booleanValue, that.booleanValue)
         && Objects.equal(longValue, that.longValue);
@@ -120,6 +123,6 @@ public final class LabelValue {
           .toString();
     }
     // This should never happen
-    throw new RuntimeException("Not a supported label value");
+    throw new RuntimeException("Not a supported attribute value");
   }
 }
diff --git a/core/src/main/java/com/google/instrumentation/trace/Attributes.java b/core/src/main/java/com/google/instrumentation/trace/Attributes.java
new file mode 100644
index 00000000..4c385f20
--- /dev/null
+++ b/core/src/main/java/com/google/instrumentation/trace/Attributes.java
@@ -0,0 +1,137 @@
+/*
+ * Copyright 2016, Google Inc.
+ * 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 com.google.instrumentation.trace;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import com.google.common.base.MoreObjects;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * A class that represents a set of Attributes. Each Attribute is a key-value pair, where the key is
+ * a string and the value is a {@link AttributeValue}, which can be one of String/Long/Boolean.
+ */
+@Immutable
+public final class Attributes {
+  // This object is an immutable Map.
+  private final Map<String, AttributeValue> attributes;
+
+  private Attributes(Map<String, AttributeValue> attributes) {
+    // Make attributes an immutable map.
+    this.attributes = Collections.unmodifiableMap(new HashMap<String, AttributeValue>(attributes));
+  }
+
+  /**
+   * Returns a new {@link Builder} for this class.
+   *
+   * @return a new {@code Builder} for this class.
+   */
+  public static Builder builder() {
+    return new Builder();
+  }
+
+  /**
+   * Returns the {@link AttributeValue} associated with the key, or {@code null} if it does not
+   * exist.
+   *
+   * @param key The attribute key to lookup.
+   * @return The {@code AttributeValue} associated with the key, or {@code null} if it does not
+   *     exist.
+   * @throws NullPointerException if key is {@code null}.
+   */
+  @Nullable
+  public AttributeValue getAttributeValue(String key) {
+    return attributes.get(checkNotNull(key, "key"));
+  }
+
+  /**
+   * Returns The full set of attributes as an immutable {@link Map}.
+   *
+   * @return The full set of attributes as an immutable {@code Map}.
+   */
+  public Map<String, AttributeValue> getAll() {
+    // It is safe to return the attributes directly because it is an immutable Map.
+    return attributes;
+  }
+
+  @Override
+  public String toString() {
+    MoreObjects.ToStringHelper toStringHelper = MoreObjects.toStringHelper(this);
+    for (Map.Entry<String, AttributeValue> entry : attributes.entrySet()) {
+      toStringHelper.add(entry.getKey(), entry.getValue());
+    }
+    return toStringHelper.toString();
+  }
+
+  /** Builder class for {@link Attributes}. */
+  public static final class Builder {
+    private final Map<String, AttributeValue> attributes = new HashMap<String, AttributeValue>();
+
+    private Builder() {}
+
+    /**
+     * Puts an attribute with a string value. Replaces any existing attribute with the key.
+     *
+     * @param key Key to associate with the value.
+     * @param stringValue The new value.
+     * @return this.
+     * @throws NullPointerException if {@code key} or {@code stringValue} are {@code null}.
+     */
+    public Builder putStringAttribute(String key, String stringValue) {
+      attributes.put(
+          checkNotNull(key, "key"),
+          AttributeValue.stringAttributeValue(checkNotNull(stringValue, "stringValue")));
+      return this;
+    }
+
+    /**
+     * Puts an attribute with a boolean value. Replaces any existing attribute with the key.
+     *
+     * @param key Key to associate with the value.
+     * @param booleanValue The new value.
+     * @return this.
+     * @throws NullPointerException if {@code key} is {@code null}.
+     */
+    public Builder putBooleanAttribute(String key, boolean booleanValue) {
+      attributes.put(checkNotNull(key, "key"), AttributeValue.booleanAttributeValue(booleanValue));
+      return this;
+    }
+
+    /**
+     * Puts an attribute with a long value. Replaces any existing attribute with the key.
+     *
+     * @param key Key to associate with the value.
+     * @param longValue The new value.
+     * @return this.
+     * @throws NullPointerException if {@code key} is {@code null}.
+     */
+    public Builder putLongAttribute(String key, long longValue) {
+      attributes.put(checkNotNull(key, "key"), AttributeValue.longAttributeValue(longValue));
+      return this;
+    }
+
+    /**
+     * Builds and returns a {@code Attributes} with the desired values.
+     *
+     * @return a {@code Attributes} with the desired values.
+     */
+    public Attributes build() {
+      return new Attributes(attributes);
+    }
+  }
+}
diff --git a/core/src/main/java/com/google/instrumentation/trace/BlankSpan.java b/core/src/main/java/com/google/instrumentation/trace/BlankSpan.java
index 35dfc3f3..af2c8f8e 100644
--- a/core/src/main/java/com/google/instrumentation/trace/BlankSpan.java
+++ b/core/src/main/java/com/google/instrumentation/trace/BlankSpan.java
@@ -30,17 +30,17 @@ public final class BlankSpan extends Span {
     super(SpanContext.INVALID, null);
   }
 
-  /** No-op implementation of the {@link Span#addLabels(Labels)} method. */
+  /** No-op implementation of the {@link Span#addAttributes(Attributes)} method. */
   @Override
-  public void addLabels(Labels labels) {}
+  public void addAttributes(Attributes attributes) {}
 
   /** No-op implementation of the {@link Span#addAnnotation(String)} method. */
   @Override
   public void addAnnotation(String description) {}
 
-  /** No-op implementation of the {@link Span#addAnnotation(String, Labels)} method. */
+  /** No-op implementation of the {@link Span#addAnnotation(String, Attributes)} method. */
   @Override
-  public void addAnnotation(String description, Labels labels) {}
+  public void addAnnotation(String description, Attributes attributes) {}
 
   /** No-op implementation of the {@link Span#addNetworkEvent(NetworkEvent)} method. */
   @Override
diff --git a/core/src/main/java/com/google/instrumentation/trace/Labels.java b/core/src/main/java/com/google/instrumentation/trace/Labels.java
deleted file mode 100644
index 4589960d..00000000
--- a/core/src/main/java/com/google/instrumentation/trace/Labels.java
+++ /dev/null
@@ -1,137 +0,0 @@
-/*
- * Copyright 2016, Google Inc.
- * 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 com.google.instrumentation.trace;
-
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import com.google.common.base.MoreObjects;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.Map;
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.Immutable;
-
-/**
- * A class that represents a set of Labels. Each Label is a key-value pair, where the key is a
- * string and the value is a {@link LabelValue}, which can be one of String/Long/Boolean.
- *
- * @see LabelValue
- */
-@Immutable
-public final class Labels {
-  // This object is an immutable Map.
-  private final Map<String, LabelValue> labels;
-
-  private Labels(Map<String, LabelValue> labels) {
-    // Make labels an immutable map.
-    this.labels = Collections.unmodifiableMap(new HashMap<String, LabelValue>(labels));
-  }
-
-  /**
-   * Returns a new {@link Builder} for this class.
-   *
-   * @return a new {@code Builder} for this class.
-   */
-  public static Builder builder() {
-    return new Builder();
-  }
-
-  /**
-   * Returns the {@link LabelValue} associated with the key, or {@code null} if it does not exist.
-   *
-   * @param key The label key to lookup.
-   * @return The {@code LabelValue} associated with the key, or {@code null} if it does not exist.
-   * @throws NullPointerException if key is {@code null}.
-   */
-  @Nullable
-  public LabelValue getLabelValue(String key) {
-    return labels.get(checkNotNull(key, "key"));
-  }
-
-  /**
-   * Returns The full set of labels as an immutable {@link Map}.
-   *
-   * @return The full set of labels as an immutable {@code Map}.
-   */
-  public Map<String, LabelValue> getAll() {
-    // It is safe to return the labels directly because it is an immutable Map.
-    return labels;
-  }
-
-  @Override
-  public String toString() {
-    MoreObjects.ToStringHelper toStringHelper = MoreObjects.toStringHelper(this);
-    for (Map.Entry<String, LabelValue> entry : labels.entrySet()) {
-      toStringHelper.add(entry.getKey(), entry.getValue());
-    }
-    return toStringHelper.toString();
-  }
-
-  /** Builder class for {@link Labels}. */
-  public static final class Builder {
-    private final Map<String, LabelValue> labels = new HashMap<String, LabelValue>();
-
-    private Builder() {}
-
-    /**
-     * Puts a label with a string value. Replaces any existing label with the key.
-     *
-     * @param key Key to associate with the value.
-     * @param stringValue The new value.
-     * @return this.
-     * @throws NullPointerException if {@code key} or {@code stringValue} are {@code null}.
-     */
-    public Builder putStringLabel(String key, String stringValue) {
-      labels.put(
-          checkNotNull(key, "key"),
-          LabelValue.stringLabelValue(checkNotNull(stringValue, "stringValue")));
-      return this;
-    }
-
-    /**
-     * Puts a label with a boolean value. Replaces any existing label with the key.
-     *
-     * @param key Key to associate with the value.
-     * @param booleanValue The new value.
-     * @return this.
-     * @throws NullPointerException if {@code key} is {@code null}.
-     */
-    public Builder putBooleanLabel(String key, boolean booleanValue) {
-      labels.put(checkNotNull(key, "key"), LabelValue.booleanLabelValue(booleanValue));
-      return this;
-    }
-
-    /**
-     * Puts a label with a long value. Replaces any existing label with the key.
-     *
-     * @param key Key to associate with the value.
-     * @param longValue The new value.
-     * @return this.
-     * @throws NullPointerException if {@code key} is {@code null}.
-     */
-    public Builder putLongLabel(String key, long longValue) {
-      labels.put(checkNotNull(key, "key"), LabelValue.longLabelValue(longValue));
-      return this;
-    }
-
-    /**
-     * Builds and returns a {@code Labels} with the desired values.
-     *
-     * @return a {@code Labels} with the desired values.
-     */
-    public Labels build() {
-      return new Labels(labels);
-    }
-  }
-}
diff --git a/core/src/main/java/com/google/instrumentation/trace/Span.java b/core/src/main/java/com/google/instrumentation/trace/Span.java
index 28ddd732..864df8fc 100644
--- a/core/src/main/java/com/google/instrumentation/trace/Span.java
+++ b/core/src/main/java/com/google/instrumentation/trace/Span.java
@@ -71,11 +71,11 @@ public abstract class Span {
   }
 
   /**
-   * Adds a set of labels to the {@code Span}.
+   * Adds a set of attributes to the {@code Span}.
    *
-   * @param labels The labels that will be added and associated with the {@code Span}.
+   * @param attributes The attributes that will be added and associated with the {@code Span}.
    */
-  public abstract void addLabels(Labels labels);
+  public abstract void addAttributes(Attributes attributes);
 
   /**
    * Adds an annotation to the {@code Span}.
@@ -88,10 +88,10 @@ public abstract class Span {
    * Adds an annotation to the {@code Span}.
    *
    * @param description The description of the annotation time event.
-   * @param labels The labels that will be added; these are associated with this annotation, not the
-   *     {@code Span} as for {@link #addLabels}.
+   * @param attributes The attributes that will be added; these are associated with this annotation,
+   *     not the {@code Span} as for {@link #addAttributes}.
    */
-  public abstract void addAnnotation(String description, Labels labels);
+  public abstract void addAnnotation(String description, Attributes attributes);
 
   /**
    * Adds a NetworkEvent to the {@code Span}.
diff --git a/core/src/test/java/com/google/instrumentation/trace/AttributeValueTest.java b/core/src/test/java/com/google/instrumentation/trace/AttributeValueTest.java
new file mode 100644
index 00000000..337aa36e
--- /dev/null
+++ b/core/src/test/java/com/google/instrumentation/trace/AttributeValueTest.java
@@ -0,0 +1,76 @@
+/*
+ * Copyright 2017, Google Inc.
+ * 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 com.google.instrumentation.trace;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.google.common.testing.EqualsTester;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Unit tests for {@link AttributeValue}. */
+@RunWith(JUnit4.class)
+public class AttributeValueTest {
+  @Test
+  public void stringAttributeValue() {
+    AttributeValue attribute = AttributeValue.stringAttributeValue("MyStringAttributeValue");
+    assertThat(attribute.getStringValue()).isEqualTo("MyStringAttributeValue");
+    assertThat(attribute.getBooleanValue()).isNull();
+    assertThat(attribute.getLongValue()).isNull();
+  }
+
+  @Test
+  public void booleanAttributeValue() {
+    AttributeValue attribute = AttributeValue.booleanAttributeValue(true);
+    assertThat(attribute.getStringValue()).isNull();
+    assertThat(attribute.getBooleanValue()).isTrue();
+    assertThat(attribute.getLongValue()).isNull();
+  }
+
+  @Test
+  public void longAttributeValue() {
+    AttributeValue attribute = AttributeValue.longAttributeValue(123456L);
+    assertThat(attribute.getStringValue()).isNull();
+    assertThat(attribute.getBooleanValue()).isNull();
+    assertThat(attribute.getLongValue()).isEqualTo(123456L);
+  }
+
+  @Test
+  public void attributeValue_EqualsAndHashCode() {
+    EqualsTester tester = new EqualsTester();
+    tester.addEqualityGroup(
+        AttributeValue.stringAttributeValue("MyStringAttributeValue"),
+        AttributeValue.stringAttributeValue("MyStringAttributeValue"));
+    tester.addEqualityGroup(AttributeValue.stringAttributeValue("MyStringAttributeDiffValue"));
+    tester.addEqualityGroup(AttributeValue.booleanAttributeValue(true), AttributeValue.booleanAttributeValue(true));
+    tester.addEqualityGroup(AttributeValue.booleanAttributeValue(false));
+    tester.addEqualityGroup(AttributeValue.longAttributeValue(123456L), AttributeValue.longAttributeValue(123456L));
+    tester.addEqualityGroup(AttributeValue.longAttributeValue(1234567L));
+    tester.testEquals();
+  }
+
+  @Test
+  public void attributeValue_ToString() {
+    AttributeValue attribute = AttributeValue.stringAttributeValue("MyStringAttributeValue");
+    assertThat(attribute.toString()).contains("string");
+    assertThat(attribute.toString()).contains("MyStringAttributeValue");
+    attribute = AttributeValue.booleanAttributeValue(true);
+    assertThat(attribute.toString()).contains("boolean");
+    assertThat(attribute.toString()).contains("true");
+    attribute = AttributeValue.longAttributeValue(123456L);
+    assertThat(attribute.toString()).contains("long");
+    assertThat(attribute.toString()).contains("123456");
+  }
+}
diff --git a/core/src/test/java/com/google/instrumentation/trace/AttributesTest.java b/core/src/test/java/com/google/instrumentation/trace/AttributesTest.java
new file mode 100644
index 00000000..95dc5c73
--- /dev/null
+++ b/core/src/test/java/com/google/instrumentation/trace/AttributesTest.java
@@ -0,0 +1,143 @@
+/*
+ * Copyright 2017, Google Inc.
+ * 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 com.google.instrumentation.trace;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Unit tests for {@link Attributes}. */
+@RunWith(JUnit4.class)
+public class AttributesTest {
+  @Test
+  public void putStringAttribute() {
+    Attributes attributes =
+        Attributes.builder().putStringAttribute("MyStringAttributeKey", "MyStringAttributeValue").build();
+    assertThat(attributes.getAll().size()).isEqualTo(1);
+    assertThat(attributes.getAll().containsKey("MyStringAttributeKey")).isTrue();
+    assertThat(attributes.getAttributeValue("MyStringAttributeKey"))
+        .isEqualTo(AttributeValue.stringAttributeValue("MyStringAttributeValue"));
+  }
+
+  @Test(expected = NullPointerException.class)
+  public void putStringAttribute_NullKey() {
+    Attributes.builder().putStringAttribute(null, "MyStringAttributeValue").build();
+  }
+
+  @Test(expected = NullPointerException.class)
+  public void putStringAttribute_NullValue() {
+    Attributes.builder().putStringAttribute("MyStringAttributeKey", null).build();
+  }
+
+  @Test
+  public void putBooleanAttribute() {
+    Attributes attributes = Attributes.builder().putBooleanAttribute("MyBooleanAttributeKey", true).build();
+    assertThat(attributes.getAll().size()).isEqualTo(1);
+    assertThat(attributes.getAll().containsKey("MyBooleanAttributeKey")).isTrue();
+    assertThat(attributes.getAttributeValue("MyBooleanAttributeKey"))
+        .isEqualTo(AttributeValue.booleanAttributeValue(true));
+  }
+
+  @Test(expected = NullPointerException.class)
+  public void putBooleanAttribute_NullKey() {
+    Attributes.builder().putBooleanAttribute(null, true).build();
+  }
+
+  @Test
+  public void putLongAttribute() {
+    Attributes attributes = Attributes.builder().putLongAttribute("MyLongAttributeKey", 123L).build();
+    assertThat(attributes.getAll().size()).isEqualTo(1);
+    assertThat(attributes.getAll().containsKey("MyLongAttributeKey")).isTrue();
+    assertThat(attributes.getAttributeValue("MyLongAttributeKey")).isEqualTo(AttributeValue.longAttributeValue(123L));
+  }
+
+  @Test(expected = NullPointerException.class)
+  public void putLongAttribute_NullKey() {
+    Attributes.builder().putLongAttribute(null, 123L).build();
+  }
+
+  @Test(expected = NullPointerException.class)
+  public void getAttributeValue_NullKey() {
+    Attributes.builder()
+        .putStringAttribute("MyStringAttributeKey", "MyStringAttributeValue")
+        .build()
+        .getAttributeValue(null);
+  }
+
+  @Test
+  public void putMultipleAttributes() {
+    Attributes attributes =
+        Attributes.builder()
+            .putStringAttribute("MyStringAttributeKey", "MyStringAttributeValue")
+            .putBooleanAttribute("MyBooleanAttributeKey", true)
+            .putLongAttribute("MyLongAttributeKey", 123L)
+            .build();
+    assertThat(attributes.getAll().size()).isEqualTo(3);
+    assertThat(attributes.getAll().containsKey("MyStringAttributeKey")).isTrue();
+    assertThat(attributes.getAttributeValue("MyStringAttributeKey"))
+        .isEqualTo(AttributeValue.stringAttributeValue("MyStringAttributeValue"));
+    assertThat(attributes.getAll().containsKey("MyBooleanAttributeKey")).isTrue();
+    assertThat(attributes.getAttributeValue("MyBooleanAttributeKey"))
+        .isEqualTo(AttributeValue.booleanAttributeValue(true));
+    assertThat(attributes.getAll().containsKey("MyLongAttributeKey")).isTrue();
+    assertThat(attributes.getAttributeValue("MyLongAttributeKey")).isEqualTo(AttributeValue.longAttributeValue(123L));
+  }
+
+  @Test
+  public void putMultipleAttribute_SameKey() {
+    Attributes attributes =
+        Attributes.builder()
+            .putStringAttribute("MyAttributeKey", "MyStringAttributeValue")
+            .putLongAttribute("MyAttributeKey", 123L)
+            .build();
+    assertThat(attributes.getAll().size()).isEqualTo(1);
+    assertThat(attributes.getAll().containsKey("MyAttributeKey")).isTrue();
+    assertThat(attributes.getAttributeValue("MyAttributeKey")).isEqualTo(AttributeValue.longAttributeValue(123L));
+  }
+
+  @Test
+  public void putMultipleAttributes_SameType() {
+    Attributes attributes =
+        Attributes.builder()
+            .putLongAttribute("MyLongAttributeKey1", 1L)
+            .putLongAttribute("MyLongAttributeKey12", 12L)
+            .putLongAttribute("MyLongAttributeKey123", 123L)
+            .build();
+    assertThat(attributes.getAll().size()).isEqualTo(3);
+    assertThat(attributes.getAll().containsKey("MyLongAttributeKey1")).isTrue();
+    assertThat(attributes.getAttributeValue("MyLongAttributeKey1")).isEqualTo(AttributeValue.longAttributeValue(1L));
+    assertThat(attributes.getAll().containsKey("MyLongAttributeKey12")).isTrue();
+    assertThat(attributes.getAttributeValue("MyLongAttributeKey12")).isEqualTo(AttributeValue.longAttributeValue(12L));
+    assertThat(attributes.getAll().containsKey("MyLongAttributeKey123")).isTrue();
+    assertThat(attributes.getAttributeValue("MyLongAttributeKey123"))
+        .isEqualTo(AttributeValue.longAttributeValue(123L));
+  }
+
+  @Test
+  public void attributes_ToString() {
+    Attributes attributes =
+        Attributes.builder().putStringAttribute("MyStringAttributeKey", "MyStringAttributeValue").build();
+    assertThat(attributes.toString()).contains("MyStringAttributeKey");
+    assertThat(attributes.toString())
+        .contains(AttributeValue.stringAttributeValue("MyStringAttributeValue").toString());
+    attributes = Attributes.builder().putBooleanAttribute("MyBooleanAttributeKey", true).build();
+    assertThat(attributes.toString()).contains("MyBooleanAttributeKey");
+    assertThat(attributes.toString()).contains(AttributeValue.booleanAttributeValue(true).toString());
+    attributes = Attributes.builder().putLongAttribute("MyLongAttributeKey", 123L).build();
+    assertThat(attributes.toString()).contains("MyLongAttributeKey");
+    assertThat(attributes.toString()).contains(AttributeValue.longAttributeValue(123L).toString());
+  }
+}
diff --git a/core/src/test/java/com/google/instrumentation/trace/BlankSpanTest.java b/core/src/test/java/com/google/instrumentation/trace/BlankSpanTest.java
index e16b2a39..19e8fea1 100644
--- a/core/src/test/java/com/google/instrumentation/trace/BlankSpanTest.java
+++ b/core/src/test/java/com/google/instrumentation/trace/BlankSpanTest.java
@@ -31,11 +31,11 @@ public class BlankSpanTest {
   @Test
   public void doNotCrash() {
     // Tests only that all the methods are not crashing/throwing errors.
-    BlankSpan.INSTANCE.addLabels(
-        Labels.builder().putStringLabel("MyLabelKey", "MyLabelValue").build());
+    BlankSpan.INSTANCE.addAttributes(
+        Attributes.builder().putStringAttribute("MyAttributeKey", "MyAttributeValue").build());
     BlankSpan.INSTANCE.addAnnotation("MyAnnotation");
     BlankSpan.INSTANCE.addAnnotation(
-        "MyAnnotation", Labels.builder().putStringLabel("MyLabelKey", "MyLabelValue").build());
+        "MyAnnotation", Attributes.builder().putStringAttribute("MyAttributeKey", "MyAttributeValue").build());
     BlankSpan.INSTANCE.addNetworkEvent(NetworkEvent.builder(NetworkEvent.Type.SENT, 1L).build());
     BlankSpan.INSTANCE.addChildLink(BlankSpan.INSTANCE);
     BlankSpan.INSTANCE.end(EndSpanOptions.DEFAULT);
diff --git a/core/src/test/java/com/google/instrumentation/trace/LabelValueTest.java b/core/src/test/java/com/google/instrumentation/trace/LabelValueTest.java
deleted file mode 100644
index b929d8c5..00000000
--- a/core/src/test/java/com/google/instrumentation/trace/LabelValueTest.java
+++ /dev/null
@@ -1,76 +0,0 @@
-/*
- * Copyright 2017, Google Inc.
- * 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 com.google.instrumentation.trace;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import com.google.common.testing.EqualsTester;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-/** Unit tests for {@link LabelValue}. */
-@RunWith(JUnit4.class)
-public class LabelValueTest {
-  @Test
-  public void stringLabelValue() {
-    LabelValue label = LabelValue.stringLabelValue("MyStringLabelValue");
-    assertThat(label.getStringValue()).isEqualTo("MyStringLabelValue");
-    assertThat(label.getBooleanValue()).isNull();
-    assertThat(label.getLongValue()).isNull();
-  }
-
-  @Test
-  public void booleanLabelValue() {
-    LabelValue label = LabelValue.booleanLabelValue(true);
-    assertThat(label.getStringValue()).isNull();
-    assertThat(label.getBooleanValue()).isTrue();
-    assertThat(label.getLongValue()).isNull();
-  }
-
-  @Test
-  public void longLabelValue() {
-    LabelValue label = LabelValue.longLabelValue(123456L);
-    assertThat(label.getStringValue()).isNull();
-    assertThat(label.getBooleanValue()).isNull();
-    assertThat(label.getLongValue()).isEqualTo(123456L);
-  }
-
-  @Test
-  public void labelValue_EqualsAndHashCode() {
-    EqualsTester tester = new EqualsTester();
-    tester.addEqualityGroup(
-        LabelValue.stringLabelValue("MyStringLabelValue"),
-        LabelValue.stringLabelValue("MyStringLabelValue"));
-    tester.addEqualityGroup(LabelValue.stringLabelValue("MyStringLabelDiffValue"));
-    tester.addEqualityGroup(LabelValue.booleanLabelValue(true), LabelValue.booleanLabelValue(true));
-    tester.addEqualityGroup(LabelValue.booleanLabelValue(false));
-    tester.addEqualityGroup(LabelValue.longLabelValue(123456L), LabelValue.longLabelValue(123456L));
-    tester.addEqualityGroup(LabelValue.longLabelValue(1234567L));
-    tester.testEquals();
-  }
-
-  @Test
-  public void labelValue_ToString() {
-    LabelValue label = LabelValue.stringLabelValue("MyStringLabelValue");
-    assertThat(label.toString()).contains("string");
-    assertThat(label.toString()).contains("MyStringLabelValue");
-    label = LabelValue.booleanLabelValue(true);
-    assertThat(label.toString()).contains("boolean");
-    assertThat(label.toString()).contains("true");
-    label = LabelValue.longLabelValue(123456L);
-    assertThat(label.toString()).contains("long");
-    assertThat(label.toString()).contains("123456");
-  }
-}
diff --git a/core/src/test/java/com/google/instrumentation/trace/LabelsTest.java b/core/src/test/java/com/google/instrumentation/trace/LabelsTest.java
deleted file mode 100644
index dc5bd6b7..00000000
--- a/core/src/test/java/com/google/instrumentation/trace/LabelsTest.java
+++ /dev/null
@@ -1,143 +0,0 @@
-/*
- * Copyright 2017, Google Inc.
- * 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 com.google.instrumentation.trace;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-/** Unit tests for {@link Labels}. */
-@RunWith(JUnit4.class)
-public class LabelsTest {
-  @Test
-  public void putStringLabel() {
-    Labels labels =
-        Labels.builder().putStringLabel("MyStringLabelKey", "MyStringLabelValue").build();
-    assertThat(labels.getAll().size()).isEqualTo(1);
-    assertThat(labels.getAll().containsKey("MyStringLabelKey")).isTrue();
-    assertThat(labels.getLabelValue("MyStringLabelKey"))
-        .isEqualTo(LabelValue.stringLabelValue("MyStringLabelValue"));
-  }
-
-  @Test(expected = NullPointerException.class)
-  public void putStringLabel_NullKey() {
-    Labels.builder().putStringLabel(null, "MyStringLabelValue").build();
-  }
-
-  @Test(expected = NullPointerException.class)
-  public void putStringLabel_NullValue() {
-    Labels.builder().putStringLabel("MyStringLabelKey", null).build();
-  }
-
-  @Test
-  public void putBooleanLabel() {
-    Labels labels = Labels.builder().putBooleanLabel("MyBooleanLabelKey", true).build();
-    assertThat(labels.getAll().size()).isEqualTo(1);
-    assertThat(labels.getAll().containsKey("MyBooleanLabelKey")).isTrue();
-    assertThat(labels.getLabelValue("MyBooleanLabelKey"))
-        .isEqualTo(LabelValue.booleanLabelValue(true));
-  }
-
-  @Test(expected = NullPointerException.class)
-  public void putBooleanLabel_NullKey() {
-    Labels.builder().putBooleanLabel(null, true).build();
-  }
-
-  @Test
-  public void putLongLabel() {
-    Labels labels = Labels.builder().putLongLabel("MyLongLabelKey", 123L).build();
-    assertThat(labels.getAll().size()).isEqualTo(1);
-    assertThat(labels.getAll().containsKey("MyLongLabelKey")).isTrue();
-    assertThat(labels.getLabelValue("MyLongLabelKey")).isEqualTo(LabelValue.longLabelValue(123L));
-  }
-
-  @Test(expected = NullPointerException.class)
-  public void putLongLabel_NullKey() {
-    Labels.builder().putLongLabel(null, 123L).build();
-  }
-
-  @Test(expected = NullPointerException.class)
-  public void getLabelValue_NullKey() {
-    Labels.builder()
-        .putStringLabel("MyStringLabelKey", "MyStringLabelValue")
-        .build()
-        .getLabelValue(null);
-  }
-
-  @Test
-  public void putMultipleLabels() {
-    Labels labels =
-        Labels.builder()
-            .putStringLabel("MyStringLabelKey", "MyStringLabelValue")
-            .putBooleanLabel("MyBooleanLabelKey", true)
-            .putLongLabel("MyLongLabelKey", 123L)
-            .build();
-    assertThat(labels.getAll().size()).isEqualTo(3);
-    assertThat(labels.getAll().containsKey("MyStringLabelKey")).isTrue();
-    assertThat(labels.getLabelValue("MyStringLabelKey"))
-        .isEqualTo(LabelValue.stringLabelValue("MyStringLabelValue"));
-    assertThat(labels.getAll().containsKey("MyBooleanLabelKey")).isTrue();
-    assertThat(labels.getLabelValue("MyBooleanLabelKey"))
-        .isEqualTo(LabelValue.booleanLabelValue(true));
-    assertThat(labels.getAll().containsKey("MyLongLabelKey")).isTrue();
-    assertThat(labels.getLabelValue("MyLongLabelKey")).isEqualTo(LabelValue.longLabelValue(123L));
-  }
-
-  @Test
-  public void putMultipleLabel_SameKey() {
-    Labels labels =
-        Labels.builder()
-            .putStringLabel("MyLabelKey", "MyStringLabelValue")
-            .putLongLabel("MyLabelKey", 123L)
-            .build();
-    assertThat(labels.getAll().size()).isEqualTo(1);
-    assertThat(labels.getAll().containsKey("MyLabelKey")).isTrue();
-    assertThat(labels.getLabelValue("MyLabelKey")).isEqualTo(LabelValue.longLabelValue(123L));
-  }
-
-  @Test
-  public void putMultipleLabels_SameType() {
-    Labels labels =
-        Labels.builder()
-            .putLongLabel("MyLongLabelKey1", 1L)
-            .putLongLabel("MyLongLabelKey12", 12L)
-            .putLongLabel("MyLongLabelKey123", 123L)
-            .build();
-    assertThat(labels.getAll().size()).isEqualTo(3);
-    assertThat(labels.getAll().containsKey("MyLongLabelKey1")).isTrue();
-    assertThat(labels.getLabelValue("MyLongLabelKey1")).isEqualTo(LabelValue.longLabelValue(1L));
-    assertThat(labels.getAll().containsKey("MyLongLabelKey12")).isTrue();
-    assertThat(labels.getLabelValue("MyLongLabelKey12")).isEqualTo(LabelValue.longLabelValue(12L));
-    assertThat(labels.getAll().containsKey("MyLongLabelKey123")).isTrue();
-    assertThat(labels.getLabelValue("MyLongLabelKey123"))
-        .isEqualTo(LabelValue.longLabelValue(123L));
-  }
-
-  @Test
-  public void labels_ToString() {
-    Labels labels =
-        Labels.builder().putStringLabel("MyStringLabelKey", "MyStringLabelValue").build();
-    assertThat(labels.toString()).contains("MyStringLabelKey");
-    assertThat(labels.toString())
-        .contains(LabelValue.stringLabelValue("MyStringLabelValue").toString());
-    labels = Labels.builder().putBooleanLabel("MyBooleanLabelKey", true).build();
-    assertThat(labels.toString()).contains("MyBooleanLabelKey");
-    assertThat(labels.toString()).contains(LabelValue.booleanLabelValue(true).toString());
-    labels = Labels.builder().putLongLabel("MyLongLabelKey", 123L).build();
-    assertThat(labels.toString()).contains("MyLongLabelKey");
-    assertThat(labels.toString()).contains(LabelValue.longLabelValue(123L).toString());
-  }
-}
diff --git a/core/src/test/java/com/google/instrumentation/trace/SpanTest.java b/core/src/test/java/com/google/instrumentation/trace/SpanTest.java
index fcbf9aac..7dfbcfe6 100644
--- a/core/src/test/java/com/google/instrumentation/trace/SpanTest.java
+++ b/core/src/test/java/com/google/instrumentation/trace/SpanTest.java
@@ -91,13 +91,13 @@ public class SpanTest {
     }
 
     @Override
-    public void addLabels(Labels labels) {}
+    public void addAttributes(Attributes attributes) {}
 
     @Override
     public void addAnnotation(String description) {}
 
     @Override
-    public void addAnnotation(String description, Labels labels) {}
+    public void addAnnotation(String description, Attributes attributes) {}
 
     @Override
     public void addNetworkEvent(NetworkEvent networkEvent) {}