Move stats and tags packages to opencensus-api to prepare for release. (#723)

1 files changed, 33 insertions, 0 deletions

diff --git a/api/src/main/java/io/opencensus/tags/package-info.java b/api/src/main/java/io/opencensus/tags/package-info.java
new file mode 100644
index 00000000..2a332f6d
--- /dev/null
+++ b/api/src/main/java/io/opencensus/tags/package-info.java
@@ -0,0 +1,33 @@
+/*
+ * Copyright 2017, OpenCensus 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.
+ */
+
+/**
+ * API for associating tags with scoped operations.
+ *
+ * <p>This package manages a set of tags in the {@code io.grpc.Context}. The tags can be used to
+ * label anything that is associated with a specific operation. For example, the {@code
+ * io.opencensus.stats} package labels all stats with the current tags.
+ *
+ * <p>{@link io.opencensus.tags.Tag Tags} are key-value pairs. The {@link io.opencensus.tags.TagKey
+ * keys} are wrapped {@code String}s, but the values can have multiple types, such as {@code
+ * String}, {@code long}, and {@code boolean}. They are stored as a map in a {@link
+ * io.opencensus.tags.TagContext}.
+ *
+ * <p>Note that tags are independent of the tracing data that is propagated in the {@code
+ * io.grpc.Context}, such as trace ID.
+ */
+// TODO(sebright): Add code examples after the API is updated to use a TagContext factory.
+package io.opencensus.tags;