file.h

// Copyright 2014 Google Inc. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd

#ifndef PACKAGER_FILE_FILE_H_
#define PACKAGER_FILE_FILE_H_

#include <stdint.h>

#include <string>

#include "packager/base/macros.h"
#include "packager/file/public/buffer_callback_params.h"

namespace shaka {

extern const char* kCallbackFilePrefix;
extern const char* kLocalFilePrefix;
extern const char* kMemoryFilePrefix;
extern const char* kUdpFilePrefix;
const int64_t kWholeFile = -1;

class File {
 public:
  static File* Open(const char* file_name, const char* mode);

  static File* OpenWithNoBuffering(const char* file_name, const char* mode);

  static bool Delete(const char* file_name);

  virtual bool Close() = 0;

  virtual int64_t Read(void* buffer, uint64_t length) = 0;

  virtual int64_t Write(const void* buffer, uint64_t length) = 0;

  virtual int64_t Size() = 0;

  virtual bool Flush() = 0;

  virtual bool Seek(uint64_t position) = 0;

  virtual bool Tell(uint64_t* position) = 0;

  const std::string& file_name() const { return file_name_; }

  // ************************************************************
  // * Static Methods: File-on-the-filesystem status
  // ************************************************************

  static int64_t GetFileSize(const char* file_name);

  static bool ReadFileToString(const char* file_name, std::string* contents);

  static bool WriteStringToFile(const char* file_name,
                                const std::string& contents);

  static bool WriteFileAtomically(const char* file_name,
                                  const std::string& contents);

  static bool Copy(const char* from_file_name, const char* to_file_name);

  static int64_t CopyFile(File* source, File* destination);

  static int64_t CopyFile(File* source, File* destination, int64_t max_copy);

  static bool IsLocalRegularFile(const char* file_name);

  static std::string MakeCallbackFileName(
      const BufferCallbackParams& callback_params,
      const std::string& name);

  static bool ParseCallbackFileName(
      const std::string& callback_file_name,
      const BufferCallbackParams** callback_params,
      std::string* name);

 protected:
  explicit File(const std::string& file_name) : file_name_(file_name) {}
  virtual ~File() {}

  virtual bool Open() = 0;

 private:
  friend class ThreadedIoFile;

  // This is a file factory method, it creates a proper file, e.g.
  // LocalFile, MemFile based on prefix.
  static File* Create(const char* file_name, const char* mode);

  static File* CreateInternalFile(const char* file_name, const char* mode);

  // Note that the file type prefix has been stripped off.
  std::string file_name_;

  DISALLOW_COPY_AND_ASSIGN(File);
};

}  // namespace shaka

#endif  // PACKAGER_FILE_FILE_H_