text: // Copyright (c) 2011 The LevelDB Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file. See the AUTHORS file for names of contributors.
  //
  // Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
  
  #include <memory>
  #include <string>
  #include <vector>
  #include <algorithm>
  
  #include "env/mock_env.h"
  #include "rocksdb/env.h"
  #include "test_util/testharness.h"
  
  namespace ROCKSDB_NAMESPACE {
  
  // Normalizes trivial differences across Envs such that these test cases can
  // run on all Envs.
  class NormalizingEnvWrapper : public EnvWrapper {
   public:
    explicit NormalizingEnvWrapper(Env* base) : EnvWrapper(base) {}
  
    // Removes . and .. from directory listing
    Status GetChildren(const std::string& dir,
                       std::vector<std::string>* result) override {
      Status status = EnvWrapper::GetChildren(dir, result);
      if (status.ok()) {
        result->erase(std::remove_if(result->begin(), result->end(),
                                     [](const std::string& s) {
                                       return s == "." || s == "..";
                                     }),
                      result->end());
      }
      return status;
    }
  
    // Removes . and .. from directory listing
    Status GetChildrenFileAttributes(
        const std::string& dir, std::vector<FileAttributes>* result) override {
      Status status = EnvWrapper::GetChildrenFileAttributes(dir, result);
      if (status.ok()) {
        result->erase(std::remove_if(result->begin(), result->end(),
                                     [](const FileAttributes& fa) {
                                       return fa.name == "." || fa.name == "..";
                                     }),
                      result->end());
      }
      return status;
    }
  };
  
  class EnvBasicTestWithParam : public testing::Test,
                                public ::testing::WithParamInterface<Env*> {
   public:
    Env* env_;
    const EnvOptions soptions_;
    std::string test_dir_;
  
    EnvBasicTestWithParam() : env_(GetParam()) {
      test_dir_ = test::PerThreadDBPath(env_, "env_basic_test");
    }
  
    void SetUp() override { env_->CreateDirIfMissing(test_dir_); }
  
    void TearDown() override {
      std::vector<std::string> files;
      env_->GetChildren(test_dir_, &files);
      for (const auto& file : files) {
        // don't know whether it's file or directory, try both. The tests must
        // only create files or empty directories, so one must succeed, else the
        // directory's corrupted.
        Status s = env_->DeleteFile(test_dir_ + "/" + file);
        if (!s.ok()) {
          ASSERT_OK(env_->DeleteDir(test_dir_ + "/" + file));
        }
      }
    }
  };
  
  class EnvMoreTestWithParam : public EnvBasicTestWithParam {};
  
  static std::unique_ptr<Env> def_env(new NormalizingEnvWrapper(Env::Default()));
  INSTANTIATE_TEST_CASE_P(EnvDefault, EnvBasicTestWithParam,
                          ::testing::Values(def_env.get()));
  INSTANTIATE_TEST_CASE_P(EnvDefault, EnvMoreTestWithParam,
                          ::testing::Values(def_env.get()));
  
  static std::unique_ptr<Env> mock_env(new MockEnv(Env::Default()));
  INSTANTIATE_TEST_CASE_P(MockEnv, EnvBasicTestWithParam,
                          ::testing::Values(mock_env.get()));
  #ifndef ROCKSDB_LITE
  static std::unique_ptr<Env> mem_env(NewMemEnv(Env::Default()));
  INSTANTIATE_TEST_CASE_P(MemEnv, EnvBasicTestWithParam,
                          ::testing::Values(mem_env.get()));
  
  namespace {
  
  // Returns a vector of 0 or 1 Env*, depending whether an Env is registered for
  // TEST_ENV_URI.
  //
  // The purpose of returning an empty vector (instead of nullptr) is that gtest
  // ValuesIn() will skip running tests when given an empty collection.
  std::vector<Env*> GetCustomEnvs() {
    static Env* custom_env;
    static bool init = false;
    if (!init) {
      init = true;
      const char* uri = getenv("TEST_ENV_URI");
      if (uri != nullptr) {
        Env::LoadEnv(uri, &custom_env);
      }
    }
  
    std::vector<Env*> res;
    if (custom_env != nullptr) {
      res.emplace_back(custom_env);
    }
    return res;
  }
  
  }  // anonymous namespace
  
  INSTANTIATE_TEST_CASE_P(CustomEnv, EnvBasicTestWithParam,
                          ::testing::ValuesIn(GetCustomEnvs()));
  
  INSTANTIATE_TEST_CASE_P(CustomEnv, EnvMoreTestWithParam,
                          ::testing::ValuesIn(GetCustomEnvs()));
  
  #endif  // ROCKSDB_LITE
  
  TEST_P(EnvBasicTestWithParam, Basics) {
    uint64_t file_size;
    std::unique_ptr<WritableFile> writable_file;
    std::vector<std::string> children;
  
    // Check that the directory is empty.
    ASSERT_EQ(Status::NotFound(), env_->FileExists(test_dir_ + "/non_existent"));
    ASSERT_TRUE(!env_->GetFileSize(test_dir_ + "/non_existent", &file_size).ok());
    ASSERT_OK(env_->GetChildren(test_dir_, &children));
    ASSERT_EQ(0U, children.size());
  
    // Create a file.
    ASSERT_OK(env_->NewWritableFile(test_dir_ + "/f", &writable_file, soptions_));
    ASSERT_OK(writable_file->Close());
    writable_file.reset();
  
    // Check that the file exists.
    ASSERT_OK(env_->FileExists(test_dir_ + "/f"));
    ASSERT_OK(env_->GetFileSize(test_dir_ + "/f", &file_size));
    ASSERT_EQ(0U, file_size);
    ASSERT_OK(env_->GetChildren(test_dir_, &children));
    ASSERT_EQ(1U, children.size());
    ASSERT_EQ("f", children[0]);
    ASSERT_OK(env_->DeleteFile(test_dir_ + "/f"));
  
    // Write to the file.
    ASSERT_OK(
        env_->NewWritableFile(test_dir_ + "/f1", &writable_file, soptions_));
    ASSERT_OK(writable_file->Append("abc"));
    ASSERT_OK(writable_file->Close());
    writable_file.reset();
    ASSERT_OK(
        env_->NewWritableFile(test_dir_ + "/f2", &writable_file, soptions_));
    ASSERT_OK(writable_file->Close());
    writable_file.reset();
  
    // Check for expected size.
    ASSERT_OK(env_->GetFileSize(test_dir_ + "/f1", &file_size));
    ASSERT_EQ(3U, file_size);
  
    // Check that renaming works.
    ASSERT_TRUE(
        !env_->RenameFile(test_dir_ + "/non_existent", test_dir_ + "/g").ok());
    ASSERT_OK(env_->RenameFile(test_dir_ + "/f1", test_dir_ + "/g"));
    ASSERT_EQ(Status::NotFound(), env_->FileExists(test_dir_ + "/f1"));
    ASSERT_OK(env_->FileExists(test_dir_ + "/g"));
    ASSERT_OK(env_->GetFileSize(test_dir_ + "/g", &file_size));
    ASSERT_EQ(3U, file_size);
  
    // Check that renaming overwriting works
    ASSERT_OK(env_->RenameFile(test_dir_ + "/f2", test_dir_ + "/g"));
    ASSERT_OK(env_->GetFileSize(test_dir_ + "/g", &file_size));
    ASSERT_EQ(0U, file_size);
  
    // Check that opening non-existent file fails.
    std::unique_ptr<SequentialFile> seq_file;
    std::unique_ptr<RandomAccessFile> rand_file;
    ASSERT_TRUE(!env_->NewSequentialFile(test_dir_ + "/non_existent", &seq_file,
                                         soptions_)
                     .ok());
    ASSERT_TRUE(!seq_file);
    ASSERT_TRUE(!env_->NewRandomAccessFile(test_dir_ + "/non_existent",
                                           &rand_file, soptions_)
                     .ok());
    ASSERT_TRUE(!rand_file);
  
    // Check that deleting works.
    ASSERT_TRUE(!env_->DeleteFile(test_dir_ + "/non_existent").ok());
    ASSERT_OK(env_->DeleteFile(test_dir_ + "/g"));
    ASSERT_EQ(Status::NotFound(), env_->FileExists(test_dir_ + "/g"));
    ASSERT_OK(env_->GetChildren(test_dir_, &children));
    ASSERT_EQ(0U, children.size());
    ASSERT_TRUE(
        env_->GetChildren(test_dir_ + "/non_existent", &children).IsNotFound());
  }
  
  TEST_P(EnvBasicTestWithParam, ReadWrite) {
    std::unique_ptr<WritableFile> writable_file;
    std::unique_ptr<SequentialFile> seq_file;
    std::unique_ptr<RandomAccessFile> rand_file;
    Slice result;
    char scratch[100];
  
    ASSERT_OK(env_->NewWritableFile(test_dir_ + "/f", &writable_file, soptions_));
    ASSERT_OK(writable_file->Append("hello "));
    ASSERT_OK(writable_file->Append("world"));
    ASSERT_OK(writable_file->Close());
    writable_file.reset();
  
    // Read sequentially.
    ASSERT_OK(env_->NewSequentialFile(test_dir_ + "/f", &seq_file, soptions_));
    ASSERT_OK(seq_file->Read(5, &result, scratch));  // Read "hello".
    ASSERT_EQ(0, result.compare("hello"));
    ASSERT_OK(seq_file->Skip(1));
    ASSERT_OK(seq_file->Read(1000, &result, scratch));  // Read "world".
    ASSERT_EQ(0, result.compare("world"));
    ASSERT_OK(seq_file->Read(1000, &result, scratch));  // Try reading past EOF.
    ASSERT_EQ(0U, result.size());
    ASSERT_OK(seq_file->Skip(100));  // Try to skip past end of file.
    ASSERT_OK(seq_file->Read(1000, &result, scratch));
    ASSERT_EQ(0U, result.size());
  
    // Random reads.
    ASSERT_OK(env_->NewRandomAccessFile(test_dir_ + "/f", &rand_file, soptions_));
    ASSERT_OK(rand_file->Read(6, 5, &result, scratch));  // Read "world".
    ASSERT_EQ(0, result.compare("world"));
    ASSERT_OK(rand_file->Read(0, 5, &result, scratch));  // Read "hello".
    ASSERT_EQ(0, result.compare("hello"));
    ASSERT_OK(rand_file->Read(10, 100, &result, scratch));  // Read "d".
    ASSERT_EQ(0, result.compare("d"));
  
    // Too high offset.
    ASSERT_TRUE(rand_file->Read(1000, 5, &result, scratch).ok());
  }
  
  TEST_P(EnvBasicTestWithParam, Misc) {
    std::unique_ptr<WritableFile> writable_file;
    ASSERT_OK(env_->NewWritableFile(test_dir_ + "/b", &writable_file, soptions_));
  
    // These are no-ops, but we test they return success.
    ASSERT_OK(writable_file->Sync());
    ASSERT_OK(writable_file->Flush());
    ASSERT_OK(writable_file->Close());
    writable_file.reset();
  }
  
  TEST_P(EnvBasicTestWithParam, LargeWrite) {
    const size_t kWriteSize = 300 * 1024;
    char* scratch = new char[kWriteSize * 2];
  
    std::string write_data;
    for (size_t i = 0; i < kWriteSize; ++i) {
      write_data.append(1, static_cast<char>(i));
    }
  
    std::unique_ptr<WritableFile> writable_file;
    ASSERT_OK(env_->NewWritableFile(test_dir_ + "/f", &writable_file, soptions_));
    ASSERT_OK(writable_file->Append("foo"));
    ASSERT_OK(writable_file->Append(write_data));
    ASSERT_OK(writable_file->Close());
    writable_file.reset();
  
    std::unique_ptr<SequentialFile> seq_file;
    Slice result;
    ASSERT_OK(env_->NewSequentialFile(test_dir_ + "/f", &seq_file, soptions_));
    ASSERT_OK(seq_file->Read(3, &result, scratch));  // Read "foo".
    ASSERT_EQ(0, result.compare("foo"));
  
    size_t read = 0;
    std::string read_data;
    while (read < kWriteSize) {
      ASSERT_OK(seq_file->Read(kWriteSize - read, &result, scratch));
      read_data.append(result.data(), result.size());
      read += result.size();
    }
    ASSERT_TRUE(write_data == read_data);
    delete [] scratch;
  }
  
  TEST_P(EnvMoreTestWithParam, GetModTime) {
    ASSERT_OK(env_->CreateDirIfMissing(test_dir_ + "/dir1"));
    uint64_t mtime1 = 0x0;
    ASSERT_OK(env_->GetFileModificationTime(test_dir_ + "/dir1", &mtime1));
  }
  
  TEST_P(EnvMoreTestWithParam, MakeDir) {
    ASSERT_OK(env_->CreateDir(test_dir_ + "/j"));
    ASSERT_OK(env_->FileExists(test_dir_ + "/j"));
    std::vector<std::string> children;
    env_->GetChildren(test_dir_, &children);
    ASSERT_EQ(1U, children.size());
    // fail because file already exists
    ASSERT_TRUE(!env_->CreateDir(test_dir_ + "/j").ok());
    ASSERT_OK(env_->CreateDirIfMissing(test_dir_ + "/j"));
    ASSERT_OK(env_->DeleteDir(test_dir_ + "/j"));
    ASSERT_EQ(Status::NotFound(), env_->FileExists(test_dir_ + "/j"));
  }
  
  TEST_P(EnvMoreTestWithParam, GetChildren) {
    // empty folder returns empty vector
    std::vector<std::string> children;
    std::vector<Env::FileAttributes> childAttr;
    ASSERT_OK(env_->CreateDirIfMissing(test_dir_));
    ASSERT_OK(env_->GetChildren(test_dir_, &children));
    ASSERT_OK(env_->FileExists(test_dir_));
    ASSERT_OK(env_->GetChildrenFileAttributes(test_dir_, &childAttr));
    ASSERT_EQ(0U, children.size());
    ASSERT_EQ(0U, childAttr.size());
  
    // folder with contents returns relative path to test dir
    ASSERT_OK(env_->CreateDirIfMissing(test_dir_ + "/niu"));
    ASSERT_OK(env_->CreateDirIfMissing(test_dir_ + "/you"));
    ASSERT_OK(env_->CreateDirIfMissing(test_dir_ + "/guo"));
    ASSERT_OK(env_->GetChildren(test_dir_, &children));
    ASSERT_OK(env_->GetChildrenFileAttributes(test_dir_, &childAttr));
    ASSERT_EQ(3U, children.size());
    ASSERT_EQ(3U, childAttr.size());
    for (auto each : children) {
      env_->DeleteDir(test_dir_ + "/" + each);
    }  // necessary for default POSIX env
  
    // non-exist directory returns IOError
    ASSERT_OK(env_->DeleteDir(test_dir_));
    ASSERT_TRUE(!env_->FileExists(test_dir_).ok());
    ASSERT_TRUE(!env_->GetChildren(test_dir_, &children).ok());
    ASSERT_TRUE(!env_->GetChildrenFileAttributes(test_dir_, &childAttr).ok());
  
    // if dir is a file, returns IOError
    ASSERT_OK(env_->CreateDir(test_dir_));
    std::unique_ptr<WritableFile> writable_file;
    ASSERT_OK(
        env_->NewWritableFile(test_dir_ + "/file", &writable_file, soptions_));
    ASSERT_OK(writable_file->Close());
    writable_file.reset();
    ASSERT_TRUE(!env_->GetChildren(test_dir_ + "/file", &children).ok());
    ASSERT_EQ(0U, children.size());
  }
  
  }  // namespace ROCKSDB_NAMESPACE
  int main(int argc, char** argv) {
    ::testing::InitGoogleTest(&argc, argv);
    return RUN_ALL_TESTS();
  }
  