From 4a8f32142919c1f87ed1d4a3f2872d45b1542dae Mon Sep 17 00:00:00 2001
From: Carlos O'Ryan <coryan@google.com>
Date: Mon, 9 May 2022 09:16:52 -0700
Subject: [PATCH] cleanup(storage): refactor `HeadersMap` definition (#8924)

---
 .../storage/google_cloud_cpp_storage.bzl      |  1 +
 .../storage/google_cloud_cpp_storage.cmake    |  1 +
 google/cloud/storage/headers_map.h            | 35 +++++++++++++++++++
 .../internal/grpc_object_read_source.cc       |  2 --
 google/cloud/storage/object_read_stream.h     |  5 +--
 google/cloud/storage/object_write_stream.h    |  5 +--
 6 files changed, 39 insertions(+), 10 deletions(-)
 create mode 100644 google/cloud/storage/headers_map.h

diff --git a/google/cloud/storage/google_cloud_cpp_storage.bzl b/google/cloud/storage/google_cloud_cpp_storage.bzl
index 8e7aa0cbbd680..44ca76aa32158 100644
--- a/google/cloud/storage/google_cloud_cpp_storage.bzl
+++ b/google/cloud/storage/google_cloud_cpp_storage.bzl
@@ -25,6 +25,7 @@ google_cloud_cpp_storage_hdrs = [
     "download_options.h",
     "hash_mismatch_error.h",
     "hashing_options.h",
+    "headers_map.h",
     "hmac_key_metadata.h",
     "iam_policy.h",
     "idempotency_policy.h",
diff --git a/google/cloud/storage/google_cloud_cpp_storage.cmake b/google/cloud/storage/google_cloud_cpp_storage.cmake
index 637ec3155d1f1..b07d6fde6cb8b 100644
--- a/google/cloud/storage/google_cloud_cpp_storage.cmake
+++ b/google/cloud/storage/google_cloud_cpp_storage.cmake
@@ -35,6 +35,7 @@ add_library(
     hash_mismatch_error.h
     hashing_options.cc
     hashing_options.h
+    headers_map.h
     hmac_key_metadata.cc
     hmac_key_metadata.h
     iam_policy.cc
diff --git a/google/cloud/storage/headers_map.h b/google/cloud/storage/headers_map.h
new file mode 100644
index 0000000000000..6cc830e758669
--- /dev/null
+++ b/google/cloud/storage/headers_map.h
@@ -0,0 +1,35 @@
+// Copyright 2022 Google LLC
+//
+// 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
+//
+//     https://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.
+
+#ifndef GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_STORAGE_HEADERS_MAP_H
+#define GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_STORAGE_HEADERS_MAP_H
+
+#include "google/cloud/storage/version.h"
+#include <map>
+#include <string>
+
+namespace google {
+namespace cloud {
+namespace storage {
+GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_BEGIN
+
+/// Represents the headers returned in a streaming upload or download operation.
+using HeadersMap = std::multimap<std::string, std::string>;
+
+GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_END
+}  // namespace storage
+}  // namespace cloud
+}  // namespace google
+
+#endif  // GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_STORAGE_HEADERS_MAP_H
diff --git a/google/cloud/storage/internal/grpc_object_read_source.cc b/google/cloud/storage/internal/grpc_object_read_source.cc
index 58a43b43d1341..15b01d95f1716 100644
--- a/google/cloud/storage/internal/grpc_object_read_source.cc
+++ b/google/cloud/storage/internal/grpc_object_read_source.cc
@@ -24,8 +24,6 @@ namespace storage {
 GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_BEGIN
 namespace internal {
 
-using HeadersMap = std::multimap<std::string, std::string>;
-
 GrpcObjectReadSource::GrpcObjectReadSource(std::unique_ptr<StreamingRpc> stream)
     : stream_(std::move(stream)) {}
 
diff --git a/google/cloud/storage/object_read_stream.h b/google/cloud/storage/object_read_stream.h
index 4d3a4bbb11041..bee1ad98e2218 100644
--- a/google/cloud/storage/object_read_stream.h
+++ b/google/cloud/storage/object_read_stream.h
@@ -15,10 +15,10 @@
 #ifndef GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_STORAGE_OBJECT_READ_STREAM_H
 #define GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_STORAGE_OBJECT_READ_STREAM_H
 
+#include "google/cloud/storage/headers_map.h"
 #include "google/cloud/storage/internal/object_read_streambuf.h"
 #include "google/cloud/storage/version.h"
 #include <istream>
-#include <map>
 #include <memory>
 #include <string>
 
@@ -27,9 +27,6 @@ namespace cloud {
 namespace storage {
 GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_BEGIN
 
-/// Represents the headers returned in a streaming upload or download operation.
-using HeadersMap = std::multimap<std::string, std::string>;
-
 /**
  * Defines a `std::basic_istream<char>` to read from a GCS Object.
  */
diff --git a/google/cloud/storage/object_write_stream.h b/google/cloud/storage/object_write_stream.h
index 2c6923510ca39..45aac88d0f95a 100644
--- a/google/cloud/storage/object_write_stream.h
+++ b/google/cloud/storage/object_write_stream.h
@@ -15,9 +15,9 @@
 #ifndef GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_STORAGE_OBJECT_WRITE_STREAM_H
 #define GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_STORAGE_OBJECT_WRITE_STREAM_H
 
+#include "google/cloud/storage/headers_map.h"
 #include "google/cloud/storage/internal/object_write_streambuf.h"
 #include "google/cloud/storage/version.h"
-#include <map>
 #include <memory>
 #include <ostream>
 #include <string>
@@ -27,9 +27,6 @@ namespace cloud {
 namespace storage {
 GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_BEGIN
 
-/// Represents the headers returned in a streaming upload or download operation.
-using HeadersMap = std::multimap<std::string, std::string>;
-
 /**
  * Defines a `std::basic_ostream<char>` to write to a GCS object.
  *