Releasing the former Stadia file transfer tools

The tools allow efficient and fast synchronization of large directory
trees from a Windows workstation to a Linux target machine.

cdc_rsync* support efficient copy of files by using content-defined
chunking (CDC) to identify chunks within files that can be reused.

asset_stream_manager + cdc_fuse_fs support efficient streaming of a
local directory to a remote virtual file system based on FUSE. It also
employs CDC to identify and reuse unchanged data chunks.

common/url.cc

@@ -0,0 +1,59 @@
+// 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
+//
+//      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.
+
+#include "common/url.h"
+
+#include <ctype.h>
+
+#include <regex>
+
+#include "absl/strings/str_format.h"
+
+namespace cdc_ft {
+
+absl::StatusOr<Url> Url::Parse(const std::string& url_string) {
+  std::string url_copy = url_string;
+  std::for_each(url_copy.begin(), url_copy.end(),
+                [](char& c) { c = tolower(c); });
+  std::regex re("(https?)://([^:^?/]+)(?::([0-9]+))?.*");
+  std::smatch match;
+  if (!std::regex_match(url_copy, match, re))
+    return absl::Status(
+        absl::StatusCode::kInvalidArgument,
+        absl::StrFormat("'%s' is not a valid url.", url_string.c_str()));
+  Url url;
+  url.protocol = match[1].str();
+  url.host = match[2].str();
+  if (match.size() == 4 && match[3].length() > 0)
+    url.port = match[3].str();
+  else if (url.protocol.back() == 's')
+    url.port = "443";
+  else
+    url.port = "80";
+  return url;
+}
+
+Url::Url() = default;
+
+Url::Url(std::string protocol, std::string host, std::string port)
+    : protocol(protocol), host(host), port(port) {}
+
+Url::~Url() = default;
+
+bool operator==(const Url& lhs, const Url& rhs) {
+  return lhs.host == rhs.host && lhs.port == rhs.port &&
+         lhs.protocol == rhs.protocol;
+}
+
+}  // namespace cdc_ft