add leveldb

lib/leveldb/util/env.cc

@@ -0,0 +1,108 @@
+// 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.
+
+#include "leveldb/env.h"
+
+#include <cstdarg>
+
+// This workaround can be removed when leveldb::Env::DeleteFile is removed.
+// See env.h for justification.
+#if defined(_WIN32) && defined(LEVELDB_DELETEFILE_UNDEFINED)
+#undef DeleteFile
+#endif
+
+namespace leveldb {
+
+Env::Env() = default;
+
+Env::~Env() = default;
+
+Status Env::NewAppendableFile(const std::string& fname, WritableFile** result) {
+  return Status::NotSupported("NewAppendableFile", fname);
+}
+
+Status Env::RemoveDir(const std::string& dirname) { return DeleteDir(dirname); }
+Status Env::DeleteDir(const std::string& dirname) { return RemoveDir(dirname); }
+
+Status Env::RemoveFile(const std::string& fname) { return DeleteFile(fname); }
+Status Env::DeleteFile(const std::string& fname) { return RemoveFile(fname); }
+
+SequentialFile::~SequentialFile() = default;
+
+RandomAccessFile::~RandomAccessFile() = default;
+
+WritableFile::~WritableFile() = default;
+
+Logger::~Logger() = default;
+
+FileLock::~FileLock() = default;
+
+void Log(Logger* info_log, const char* format, ...) {
+  if (info_log != nullptr) {
+    std::va_list ap;
+    va_start(ap, format);
+    info_log->Logv(format, ap);
+    va_end(ap);
+  }
+}
+
+static Status DoWriteStringToFile(Env* env, const Slice& data,
+                                  const std::string& fname, bool should_sync) {
+  WritableFile* file;
+  Status s = env->NewWritableFile(fname, &file);
+  if (!s.ok()) {
+    return s;
+  }
+  s = file->Append(data);
+  if (s.ok() && should_sync) {
+    s = file->Sync();
+  }
+  if (s.ok()) {
+    s = file->Close();
+  }
+  delete file;  // Will auto-close if we did not close above
+  if (!s.ok()) {
+    env->RemoveFile(fname);
+  }
+  return s;
+}
+
+Status WriteStringToFile(Env* env, const Slice& data,
+                         const std::string& fname) {
+  return DoWriteStringToFile(env, data, fname, false);
+}
+
+Status WriteStringToFileSync(Env* env, const Slice& data,
+                             const std::string& fname) {
+  return DoWriteStringToFile(env, data, fname, true);
+}
+
+Status ReadFileToString(Env* env, const std::string& fname, std::string* data) {
+  data->clear();
+  SequentialFile* file;
+  Status s = env->NewSequentialFile(fname, &file);
+  if (!s.ok()) {
+    return s;
+  }
+  static const int kBufferSize = 8192;
+  char* space = new char[kBufferSize];
+  while (true) {
+    Slice fragment;
+    s = file->Read(kBufferSize, &fragment, space);
+    if (!s.ok()) {
+      break;
+    }
+    data->append(fragment.data(), fragment.size());
+    if (fragment.empty()) {
+      break;
+    }
+  }
+  delete[] space;
+  delete file;
+  return s;
+}
+
+EnvWrapper::~EnvWrapper() {}
+
+}  // namespace leveldb