shaka-packager/packager/media/formats/webvtt/text_readers.h

92 lines
2.3 KiB
C++

// Copyright 2017 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_MEDIA_FORMATS_WEBVTT_TEXT_READERS_H_
#define PACKAGER_MEDIA_FORMATS_WEBVTT_TEXT_READERS_H_
#include <memory>
#include <string>
#include <vector>
#include "packager/file/file_closer.h"
#include "packager/status.h"
namespace shaka {
class File;
namespace media {
/// Class to read character-by-character from a file.
class FileReader {
public:
/// Create a new file reader by opening a file. If the file fails to open (in
/// readonly mode) a non-ok status will be returned. If the file successfully
/// opens, |out| will be set to a new FileReader and an ok status will be
/// returned.
static Status Open(const std::string& filename,
std::unique_ptr<FileReader>* out);
/// Read the next character from the file. If there is a next character,
/// |out| will be set and true will be returned. If there is no next
/// character false will be returned.
bool Next(char* out);
private:
explicit FileReader(std::unique_ptr<File, FileCloser> file);
FileReader(const FileReader& reader) = delete;
FileReader operator=(const FileReader& reader) = delete;
std::unique_ptr<File, FileCloser> file_;
};
class PeekingReader {
public:
explicit PeekingReader(std::unique_ptr<FileReader> source);
bool Peek(char* out);
bool Next(char* out);
private:
PeekingReader(const PeekingReader&) = delete;
PeekingReader operator=(const PeekingReader&) = delete;
std::unique_ptr<FileReader> source_;
char cached_next_ = 0;
bool has_cached_next_ = false;
};
class LineReader {
public:
explicit LineReader(std::unique_ptr<FileReader> source);
bool Next(std::string* out);
private:
LineReader(const LineReader&) = delete;
LineReader operator=(const LineReader&) = delete;
PeekingReader source_;
};
class BlockReader {
public:
explicit BlockReader(std::unique_ptr<FileReader> source);
bool Next(std::vector<std::string>* out);
private:
BlockReader(const BlockReader&) = delete;
BlockReader operator=(const BlockReader&) = delete;
LineReader source_;
};
} // namespace media
} // namespace shaka
#endif // MEDIA_FORMATS_WEBVTT_TEXT_READERS_H_