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/log_test.cc

@@ -0,0 +1,134 @@
+// 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/log.h"
+
+#include "absl/strings/match.h"
+#include "common/path.h"
+#include "common/status_test_macros.h"
+#include "gtest/gtest.h"
+
+namespace cdc_ft {
+namespace {
+
+constexpr char kLogMessage[] = "Test log";
+
+class TestLog : public Log {
+ public:
+  explicit TestLog(LogLevel log_level) : Log(log_level) {}
+
+  LogLevel LastLevel() const { return last_level_; }
+  const std::string& LastFunc() const { return last_func_; }
+  const std::string& LastMessage() const { return last_message_; }
+
+ protected:
+  void WriteLogMessage(LogLevel level, const char* file, int line,
+                       const char* func, const char* message) override {
+    constexpr char expected_file[] = "log_test.cc";
+    // The full filename depends on the compiler invocation, so we just compare
+    // the basename.
+    EXPECT_TRUE(absl::StrContains(file, expected_file))
+        << "File name '" << file << "' does not contain expected name '"
+        << expected_file << "'.";
+    EXPECT_GT(line, 0);
+    last_level_ = level;
+    last_func_ = func;
+    last_message_ = message;
+  }
+
+ private:
+  LogLevel last_level_;
+  std::string last_func_;
+  std::string last_message_;
+};
+
+class LogTest : public ::testing::Test {
+ public:
+  void SetUp() override {
+    Log::Initialize(std::make_unique<TestLog>(LogLevel::kInfo));
+  }
+
+  void TearDown() override { Log::Shutdown(); }
+
+ protected:
+  TestLog* Log() const { return static_cast<TestLog*>(Log::Instance()); }
+};
+
+TEST_F(LogTest, LogMessage) {
+  LOG_INFO(kLogMessage);
+  EXPECT_EQ(kLogMessage, Log()->LastMessage());
+}
+
+TEST_F(LogTest, LogFormattedMessage) {
+  LOG_INFO("Test %i %s", 123, "message");
+  EXPECT_EQ("Test 123 message", Log()->LastMessage());
+}
+
+TEST_F(LogTest, IgnoresBelowLogLevel) {
+  EXPECT_EQ(Log()->GetLogLevel(), LogLevel::kInfo);
+  LOG_DEBUG(kLogMessage);
+  EXPECT_EQ("", Log()->LastMessage());
+
+  Log()->SetLogLevel(LogLevel::kDebug);
+  LOG_DEBUG(kLogMessage);
+  EXPECT_EQ(kLogMessage, Log()->LastMessage());
+}
+
+TEST_F(LogTest, VerbosityToLogLevel) {
+  EXPECT_EQ(Log::VerbosityToLogLevel(0), LogLevel::kWarning);
+  EXPECT_EQ(Log::VerbosityToLogLevel(1), LogLevel::kWarning);
+  EXPECT_EQ(Log::VerbosityToLogLevel(2), LogLevel::kInfo);
+  EXPECT_EQ(Log::VerbosityToLogLevel(3), LogLevel::kDebug);
+  EXPECT_EQ(Log::VerbosityToLogLevel(4), LogLevel::kVerbose);
+  EXPECT_EQ(Log::VerbosityToLogLevel(5), LogLevel::kVerbose);
+}
+
+TEST(FileLogTest, LogToFile) {
+  std::string tmp_dir = path::GetTempDir();
+  std::string log_path = path::Join(tmp_dir, "__log_unittest.log");
+  Log::Initialize(std::make_unique<FileLog>(LogLevel::kInfo, log_path.c_str()));
+  LOG_ERROR("Error");
+  LOG_INFO("Info");
+  LOG_DEBUG("Debug");
+  Log::Shutdown();
+
+  std::vector<std::string> lines;
+  ASSERT_OK(
+      path::ReadAllLines(log_path, &lines, path::ReadFlags::kRemoveEmpty));
+  ASSERT_EQ(lines.size(), 2);
+
+  EXPECT_TRUE(absl::StrContains(lines[0], "ERROR")) << lines[0];
+  EXPECT_TRUE(absl::StrContains(lines[0], "log_test.cc")) << lines[0];
+  EXPECT_TRUE(absl::StrContains(lines[0], "Error")) << lines[0];
+
+  EXPECT_TRUE(absl::StrContains(lines[1], "INFO")) << lines[1];
+  EXPECT_TRUE(absl::StrContains(lines[1], "log_test.cc")) << lines[1];
+  EXPECT_TRUE(absl::StrContains(lines[1], "Info")) << lines[1];
+
+  // Check date and time.
+  int yy, mo, da, hh, mm, ss, msec;
+  int scan_res = sscanf(lines[0].c_str(), "%04d-%02d-%02d %02d:%02d:%02d.%03d",
+                        &yy, &mo, &da, &hh, &mm, &ss, &msec);
+  EXPECT_EQ(scan_res, 7) << lines[0];
+}
+
+TEST(NoLogTest, LogNotInitialized) {
+  // Using the log before initializing it should not trigger an assertion.
+  LOG_ERROR("Error");
+  LOG_INFO("Info");
+  LOG_DEBUG("Debug");
+}
+
+}  // namespace
+}  // namespace cdc_ft