aria2/src/bencode.h

/* <!-- copyright */
/*
 * aria2 - The high speed download utility
 *
 * Copyright (C) 2006 Tatsuhiro Tsujikawa
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * In addition, as a special exception, the copyright holders give
 * permission to link the code of portions of this program with the
 * OpenSSL library under certain conditions as described in each
 * individual source file, and distribute linked combinations
 * including the two.
 * You must obey the GNU General Public License in all respects
 * for all of the code used other than OpenSSL.  If you modify
 * file(s) with this exception, you may extend this exception to your
 * version of the file(s), but you are not obligated to do so.  If you
 * do not wish to do so, delete this exception statement from your
 * version.  If you delete this exception statement from all source
 * files in the program, then also delete it here.
 */
/* copyright --> */
#ifndef _D_BENCODE_H_
#define _D_BENCODE_H_

#include "common.h"

#include <string>
#include <map>
#include <deque>
#include <iosfwd>

#include "SharedHandle.h"
#include "RecoverableException.h"

namespace aria2 {

namespace bencode {

class BDE;

class BDE {
public:
  typedef std::map<std::string, BDE> Dict;
  typedef std::deque<BDE> List;
  typedef int64_t Integer;
private:
  enum TYPE{
    TYPE_NONE,
    TYPE_INTEGER,
    TYPE_STRING,
    TYPE_DICT,
    TYPE_LIST,
  };

  TYPE _type;
  SharedHandle<Dict> _dict;
  SharedHandle<List> _list;
  SharedHandle<std::string> _string;
  SharedHandle<Integer> _integer;

public:
  BDE() throw();

  static BDE dict() throw();

  static BDE list() throw();

  static const BDE none;

  // Test for Null data
  // Return true if the type of this object is None.
  bool isNone() const throw();

  //////////////////////////////////////////////////////////////////////////////
  // Integer Interface

  BDE(Integer integer) throw();

  // Returns true if the type of this object is Integer.
  bool isInteger() const throw();

  // Returns Integer. Requires this object to be Integer.
  Integer i() const throw(RecoverableException);

  //////////////////////////////////////////////////////////////////////////////
  // String Interface

  BDE(const std::string& string) throw();

  // Made explicit to avoid ambiguity with BDE(Integer).
  explicit BDE(const char* cstring) throw();

  BDE(const char* data, size_t length) throw();

  BDE(const unsigned char* data, size_t length) throw();

  // Returns true if the type of this object is String.
  bool isString() const throw();

  // Returns std::string. Requires this object to be String
  const std::string& s() const throw(RecoverableException);

  // Returns std::string.data() casted to unsigned char*.
  // Use s().size() to get length.
  const unsigned char* uc() const throw(RecoverableException);

  //////////////////////////////////////////////////////////////////////////////
  // Dictionary Interface

  // Returns true if the type of this object is Dict.
  bool isDict() const throw();

  // Returns the reference to BDE object associated with given key.
  // If the key is not found, new pair with that key is created using default
  // values, which is then returned. In other words, this is the same behavior
  // of std::map's operator[].
  // Requires this object to be Dict.
  BDE& operator[](const std::string& key) throw(RecoverableException);

  // Returns the const reference to BDE ojbect associated with given key.
  // If the key is not found, BDE::none is returned.
  // Requires this object to be Dict.
  const BDE& operator[](const std::string& key) const
    throw(RecoverableException);

  // Returns true if the given key is found in dict.
  // Requires this object to be Dict.
  bool containsKey(const std::string& key) const throw(RecoverableException);

  // Removes specified key from dict.
  // Requires this object to be Dict.
  void removeKey(const std::string& key) const throw(RecoverableException);

  // Returns a read/write iterator that points to the first pair in the dict.
  // Requires this object to be Dict.
  Dict::iterator dictBegin() throw(RecoverableException);

  // Returns a read/write read-only iterator that points to the first pair in
  // the dict.
  // Requires this object to be Dict.
  Dict::const_iterator dictBegin() const throw(RecoverableException);

  // Returns a read/write read-only iterator that points to one past the last
  // pair in the dict.
  // Requires this object to be Dict.
  Dict::iterator dictEnd() throw(RecoverableException);

  // Returns a read/write read-only iterator that points to one past the last
  // pair in the dict.
  // Requires this object to be Dict.
  Dict::const_iterator dictEnd() const throw(RecoverableException);

  //////////////////////////////////////////////////////////////////////////////
  // List Interface

  // Returns true if the type of this object is List.
  bool isList() const throw();

  // Appends given bde to list. Required the type of this object to be List.
  void append(const BDE& bde) throw(RecoverableException);

  // Alias for append()
  void operator<<(const BDE& bde) throw(RecoverableException);

  // Returns the reference of the object at the given index. Required this
  // object to be List.
  BDE& operator[](size_t index) throw(RecoverableException);

  // Returns the const reference of the object at the given index.
  // Required this object to be List.
  const BDE& operator[](size_t index) const throw(RecoverableException);

  // Returns a read/write iterator that points to the first object in list.
  // Required this object to be List.
  List::iterator listBegin() throw(RecoverableException);

  // Returns a read/write read-only iterator that points to the first object
  // in list. Required this object to be List.
  List::const_iterator listBegin() const throw(RecoverableException);

  // Returns a read/write iterator that points to the one past the last object
  // in list. Required this object to be List.
  List::iterator listEnd() throw(RecoverableException);

  // Returns a read/write read-only iterator that points to the one past the
  // last object in list. Required this object to be List.
  List::const_iterator listEnd() const throw(RecoverableException);

  // For List type: Returns size of list.
  // For Dict type: Returns size of dict.
  size_t size() const throw(RecoverableException);

  // For List type: Returns true if size of list is 0.
  // For Dict type: Returns true if size of dict is 0.
  bool empty() const throw(RecoverableException);
};

BDE decode(std::istream& in) throw(RecoverableException);

// Decode the data in s.
BDE decode(const std::string& s) throw(RecoverableException);

BDE decode(const unsigned char* data, size_t length)
  throw(RecoverableException);

BDE decodeFromFile(const std::string& filename) throw(RecoverableException);

std::string encode(const BDE& bde) throw();

} // namespace bencode

} // namespace aria2

#endif // _D_BENCODE_H_