1 files changed, 124 insertions, 0 deletions
diff --git a/src/rocksdb/file/file_util.cc b/src/rocksdb/file/file_util.cc
new file mode 100644
index 000000000..c231bf7d1
--- /dev/null
+++ b/src/rocksdb/file/file_util.cc
@@ -0,0 +1,124 @@
+//  Copyright (c) 2011-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 "file/file_util.h"
+
+#include <string>
+#include <algorithm>
+
+#include "file/random_access_file_reader.h"
+#include "file/sequence_file_reader.h"
+#include "file/sst_file_manager_impl.h"
+#include "file/writable_file_writer.h"
+#include "rocksdb/env.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+// Utility function to copy a file up to a specified length
+Status CopyFile(FileSystem* fs, const std::string& source,
+                const std::string& destination, uint64_t size, bool use_fsync) {
+  const FileOptions soptions;
+  Status s;
+  std::unique_ptr<SequentialFileReader> src_reader;
+  std::unique_ptr<WritableFileWriter> dest_writer;
+
+  {
+    std::unique_ptr<FSSequentialFile> srcfile;
+    s = fs->NewSequentialFile(source, soptions, &srcfile, nullptr);
+    if (!s.ok()) {
+      return s;
+    }
+    std::unique_ptr<FSWritableFile> destfile;
+    s = fs->NewWritableFile(destination, soptions, &destfile, nullptr);
+    if (!s.ok()) {
+      return s;
+    }
+
+    if (size == 0) {
+      // default argument means copy everything
+      s = fs->GetFileSize(source, IOOptions(), &size, nullptr);
+      if (!s.ok()) {
+        return s;
+      }
+    }
+    src_reader.reset(new SequentialFileReader(std::move(srcfile), source));
+    dest_writer.reset(
+        new WritableFileWriter(std::move(destfile), destination, soptions));
+  }
+
+  char buffer[4096];
+  Slice slice;
+  while (size > 0) {
+    size_t bytes_to_read = std::min(sizeof(buffer), static_cast<size_t>(size));
+    s = src_reader->Read(bytes_to_read, &slice, buffer);
+    if (!s.ok()) {
+      return s;
+    }
+    if (slice.size() == 0) {
+      return Status::Corruption("file too small");
+    }
+    s = dest_writer->Append(slice);
+    if (!s.ok()) {
+      return s;
+    }
+    size -= slice.size();
+  }
+  return dest_writer->Sync(use_fsync);
+}
+
+// Utility function to create a file with the provided contents
+Status CreateFile(FileSystem* fs, const std::string& destination,
+                  const std::string& contents, bool use_fsync) {
+  const EnvOptions soptions;
+  Status s;
+  std::unique_ptr<WritableFileWriter> dest_writer;
+
+  std::unique_ptr<FSWritableFile> destfile;
+  s = fs->NewWritableFile(destination, soptions, &destfile, nullptr);
+  if (!s.ok()) {
+    return s;
+  }
+  dest_writer.reset(
+      new WritableFileWriter(std::move(destfile), destination, soptions));
+  s = dest_writer->Append(Slice(contents));
+  if (!s.ok()) {
+    return s;
+  }
+  return dest_writer->Sync(use_fsync);
+}
+
+Status DeleteDBFile(const ImmutableDBOptions* db_options,
+                    const std::string& fname, const std::string& dir_to_sync,
+                    const bool force_bg, const bool force_fg) {
+#ifndef ROCKSDB_LITE
+  SstFileManagerImpl* sfm =
+      static_cast<SstFileManagerImpl*>(db_options->sst_file_manager.get());
+  if (sfm && !force_fg) {
+    return sfm->ScheduleFileDeletion(fname, dir_to_sync, force_bg);
+  } else {
+    return db_options->env->DeleteFile(fname);
+  }
+#else
+  (void)dir_to_sync;
+  (void)force_bg;
+  (void)force_fg;
+  // SstFileManager is not supported in ROCKSDB_LITE
+  // Delete file immediately
+  return db_options->env->DeleteFile(fname);
+#endif
+}
+
+bool IsWalDirSameAsDBPath(const ImmutableDBOptions* db_options) {
+  bool same = false;
+  assert(!db_options->db_paths.empty());
+  Status s = db_options->env->AreFilesSame(db_options->wal_dir,
+                                           db_options->db_paths[0].path, &same);
+  if (s.IsNotSupported()) {
+    same = db_options->wal_dir == db_options->db_paths[0].path;
+  }
+  return same;
+}
+
+}  // namespace ROCKSDB_NAMESPACE