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#ifndef MOZC_DICTIONARY_SYSTEM_CODEC_INTERFACE_H_
#define MOZC_DICTIONARY_SYSTEM_CODEC_INTERFACE_H_

#include <string>
#include <vector>

#include "base/port.h"
#include "base/string_piece.h"

namespace mozc {
namespace dictionary {

struct TokenInfo;

// TODO(hidehiko): Use StringPiece.
class SystemDictionaryCodecInterface {
 public:
  // Get section name functions are expected not to be called so often

  // Return section name for key trie
  virtual const string GetSectionNameForKey() const = 0;

  // Return section name for value trie
  virtual const string GetSectionNameForValue() const = 0;

  // Return section name for tokens array
  virtual const string GetSectionNameForTokens() const = 0;

  // Return section name for frequent pos map
  virtual const string GetSectionNameForPos() const = 0;

  // Encode value(word) string
  virtual void EncodeValue(const StringPiece src, string *dst) const = 0;

  // Decode value(word) string
  virtual void DecodeValue(const StringPiece src, string *dst) const = 0;

  // Encode key(reading) string
  virtual void EncodeKey(const StringPiece src, string *dst) const = 0;

  // Decode key(reading) string
  virtual void DecodeKey(const StringPiece src, string *dst) const = 0;

  // Returns the length of encoded key string.
  virtual size_t GetEncodedKeyLength(const StringPiece src) const = 0;

  // Returns the length of decoded key string.
  virtual size_t GetDecodedKeyLength(const StringPiece src) const = 0;

  // Encode tokens(word info) for a certain key
  virtual void EncodeTokens(
      const vector<TokenInfo> &tokens, string *output) const = 0;

  // Decode token(word info) for a certain key
  virtual void DecodeTokens(
      const uint8 *ptr, vector<TokenInfo> *tokens) const = 0;

  // Decode a token. If the token is the last one, returns false,
  // otherwise true.
  virtual bool DecodeToken(
      const uint8 *ptr, TokenInfo *token_info, int *read_bytes) const = 0;

  // Read a token for reverse lookup
  // If the token have value id, assign it to |value_id|
  // otherwise assign -1
  // Return false if a token is the last token for a certain key
  virtual bool ReadTokenForReverseLookup(
      const uint8 *ptr, int *value_id, int *read_bytes) const = 0;

  // Return termination flag for tokens
  virtual uint8 GetTokensTerminationFlag() const  = 0;

 protected:
  SystemDictionaryCodecInterface() {}
  virtual ~SystemDictionaryCodecInterface() {}

 private:
  DISALLOW_COPY_AND_ASSIGN(SystemDictionaryCodecInterface);
};

class SystemDictionaryCodecFactory {
 public:
  static SystemDictionaryCodecInterface *GetCodec();
  static void SetCodec(SystemDictionaryCodecInterface *codec);

 private:
  DISALLOW_IMPLICIT_CONSTRUCTORS(SystemDictionaryCodecFactory);
};

}  // namespace dictionary
}  // namespace

#endif  // MOZC_DICTIONARY_SYSTEM_CODEC_INTERFACE_H_