src/dictionary/system/codec.h

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#ifndef MOZC_DICTIONARY_SYSTEM_CODEC_H_
#define MOZC_DICTIONARY_SYSTEM_CODEC_H_

#include <string>
#include <vector>

#include "base/port.h"
#include "base/string_piece.h"
#include "dictionary/system/codec_interface.h"

namespace mozc {
namespace dictionary {

class SystemDictionaryCodec : public SystemDictionaryCodecInterface {
 public:
  SystemDictionaryCodec();

  virtual ~SystemDictionaryCodec();

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

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

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

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

  // Compresses key string into small bytes.
  virtual void EncodeKey(const StringPiece src, string *dst) const;

  // Decompress key string
  virtual void DecodeKey(const StringPiece src, string *dst) const;

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

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

  // Compresses value string into small bytes.
  virtual void EncodeValue(const StringPiece src, string *dst) const;

  // Decompress value string
  virtual void DecodeValue(const StringPiece src, string *dst) const;

  // Compress tokens
  virtual void EncodeTokens(
      const vector<TokenInfo> &tokens, string *output) const;

  // Decompress tokens
  virtual void DecodeTokens(const uint8 *ptr, vector<TokenInfo> *tokens) const;

  // Decompress a token.
  virtual bool DecodeToken(
      const uint8 *ptr, TokenInfo *token_info, int *read_bytes) const;

  // Read a token for reverse lookup
  // If the token have value id, assign it to |id_in_value_trie|
  // 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;

  virtual uint8 GetTokensTerminationFlag() const;

 private:
  void EncodeToken(
      const vector<TokenInfo> &tokens, int index, string *output) const;

  DISALLOW_COPY_AND_ASSIGN(SystemDictionaryCodec);
};
}  // namespace dictionary
}  // namespace mozc

#endif  // MOZC_DICTIONARY_SYSTEM_CODEC_H_