1 files changed, 110 insertions, 0 deletions
diff --git a/src/rocksdb/env/file_system.cc b/src/rocksdb/env/file_system.cc
new file mode 100644
index 000000000..646e6e3d1
--- /dev/null
+++ b/src/rocksdb/env/file_system.cc
@@ -0,0 +1,110 @@
+// Copyright (c) 2019-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+//
+#include "env/composite_env_wrapper.h"
+#include "rocksdb/file_system.h"
+#include "options/db_options.h"
+#include "rocksdb/utilities/object_registry.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+FileSystem::FileSystem() {}
+
+FileSystem::~FileSystem() {}
+
+Status FileSystem::Load(const std::string& value,
+                        std::shared_ptr<FileSystem>* result) {
+  Status s;
+#ifndef ROCKSDB_LITE
+  s = ObjectRegistry::NewInstance()->NewSharedObject<FileSystem>(value, result);
+#else
+  (void)result;
+  s = Status::NotSupported("Cannot load FileSystem in LITE mode: ", value);
+#endif
+  return s;
+}
+
+FileOptions FileSystem::OptimizeForLogRead(
+              const FileOptions& file_options) const {
+  FileOptions optimized_file_options(file_options);
+  optimized_file_options.use_direct_reads = false;
+  return optimized_file_options;
+}
+
+FileOptions FileSystem::OptimizeForManifestRead(
+    const FileOptions& file_options) const {
+  FileOptions optimized_file_options(file_options);
+  optimized_file_options.use_direct_reads = false;
+  return optimized_file_options;
+}
+
+FileOptions FileSystem::OptimizeForLogWrite(const FileOptions& file_options,
+                                           const DBOptions& db_options) const {
+  FileOptions optimized_file_options(file_options);
+  optimized_file_options.bytes_per_sync = db_options.wal_bytes_per_sync;
+  optimized_file_options.writable_file_max_buffer_size =
+      db_options.writable_file_max_buffer_size;
+  return optimized_file_options;
+}
+
+FileOptions FileSystem::OptimizeForManifestWrite(
+    const FileOptions& file_options) const {
+  return file_options;
+}
+
+FileOptions FileSystem::OptimizeForCompactionTableWrite(
+    const FileOptions& file_options,
+    const ImmutableDBOptions& db_options) const {
+  FileOptions optimized_file_options(file_options);
+  optimized_file_options.use_direct_writes =
+      db_options.use_direct_io_for_flush_and_compaction;
+  return optimized_file_options;
+}
+
+FileOptions FileSystem::OptimizeForCompactionTableRead(
+    const FileOptions& file_options,
+    const ImmutableDBOptions& db_options) const {
+  FileOptions optimized_file_options(file_options);
+  optimized_file_options.use_direct_reads = db_options.use_direct_reads;
+  return optimized_file_options;
+}
+
+Status ReadFileToString(FileSystem* fs, const std::string& fname,
+                        std::string* data) {
+  FileOptions soptions;
+  data->clear();
+  std::unique_ptr<FSSequentialFile> file;
+  Status s = fs->NewSequentialFile(fname, soptions, &file, nullptr);
+  if (!s.ok()) {
+    return s;
+  }
+  static const int kBufferSize = 8192;
+  char* space = new char[kBufferSize];
+  while (true) {
+    Slice fragment;
+    s = file->Read(kBufferSize, IOOptions(), &fragment, space,
+                   nullptr);
+    if (!s.ok()) {
+      break;
+    }
+    data->append(fragment.data(), fragment.size());
+    if (fragment.empty()) {
+      break;
+    }
+  }
+  delete[] space;
+  return s;
+}
+
+#ifdef OS_WIN
+std::shared_ptr<FileSystem> FileSystem::Default() {
+  static LegacyFileSystemWrapper default_fs(Env::Default());
+  static std::shared_ptr<LegacyFileSystemWrapper> default_fs_ptr(
+      &default_fs, [](LegacyFileSystemWrapper*) {});
+  return default_fs_ptr;
+}
+#endif
+
+}  // namespace ROCKSDB_NAMESPACE