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.

manifest/content_id_test.cc

@@ -0,0 +1,79 @@
+// 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 "manifest/content_id.h"
+
+#include "gtest/gtest.h"
+
+namespace cdc_ft {
+
+namespace {
+
+using StringList = std::vector<absl::string_view>;
+
+static constexpr char kData[] = "Hey Google, tell me a joke.";
+static constexpr size_t kHashSize = 20;
+static constexpr char kHash[kHashSize + 1] =
+    "\x12\xe8\x41\x41\x39\x93\x13\x82\x34\xd0\xfe\xcb\x4e\xcf\x6a\x4c\xfd\x74"
+    "\x55\x27";
+static constexpr char kHashHex[] = "12e841413993138234d0fecb4ecf6a4cfd745527";
+
+TEST(ContentIdTest, StringToContentId) {
+  ContentIdProto content_id = ContentId::FromDataString(std::string(kData));
+  EXPECT_EQ(content_id.blake3_sum_160().size(), kHashSize);
+  EXPECT_EQ(content_id.blake3_sum_160(), absl::string_view(kHash, kHashSize));
+}
+
+TEST(ContentIdTest, StringViewToContentId) {
+  ContentIdProto content_id =
+      ContentId::FromDataString(absl::string_view(kData));
+  EXPECT_EQ(content_id.blake3_sum_160().size(), kHashSize);
+  EXPECT_EQ(content_id.blake3_sum_160(), absl::string_view(kHash, kHashSize));
+}
+
+TEST(ContentIdTest, PtrToContentId) {
+  absl::string_view data(kData);
+  ContentIdProto content_id = ContentId::FromArray(data.data(), data.size());
+  EXPECT_EQ(content_id.blake3_sum_160().size(), kHashSize);
+  EXPECT_EQ(content_id.blake3_sum_160(), absl::string_view(kHash, kHashSize));
+}
+
+TEST(ContentIdTest, ToHexString) {
+  ContentIdProto content_id =
+      ContentId::FromDataString(absl::string_view(kData));
+  std::string hash_str = ContentId::ToHexString(content_id);
+  EXPECT_EQ(hash_str.size(), 2 * kHashSize);
+  EXPECT_EQ(hash_str, kHashHex);
+}
+
+TEST(ContentIdTest, FromHexString) {
+  ContentIdProto content_id;
+  EXPECT_TRUE(ContentId::FromHexString(kHashHex, &content_id));
+  EXPECT_EQ(content_id.blake3_sum_160(), kHash);
+}
+
+TEST(ContentIdTest, GetByte) {
+  ContentIdProto content_id;
+  EXPECT_EQ(ContentId::GetByte(content_id, 0), 0);
+  EXPECT_EQ(ContentId::GetByte(content_id, 1000), 0);
+
+  EXPECT_TRUE(ContentId::FromHexString(kHashHex, &content_id));
+  EXPECT_EQ(ContentId::GetByte(content_id, 0), static_cast<uint8_t>(kHash[0]));
+  EXPECT_EQ(ContentId::GetByte(content_id, 1), static_cast<uint8_t>(kHash[1]));
+  EXPECT_EQ(ContentId::GetByte(content_id, 20), 0);
+}
+
+}  // namespace
+
+}  // namespace cdc_ft