vChewing-macOS/Source/Engine/ParselessPhraseDB.h

61 lines
2.3 KiB
C++

// Copyright (c) 2022 and onwards The McBopomofo Authors.
//
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
#ifndef SOURCE_ENGINE_PARSELESSPHRASEDB_H_
#define SOURCE_ENGINE_PARSELESSPHRASEDB_H_
#include <cstddef>
#include <string>
#include <vector>
namespace McBopomofo {
constexpr std::string_view SORTED_PRAGMA_HEADER
= "# format org.openvanilla.mcbopomofo.sorted\n";
// Defines phrase database that consists of (key, value, score) rows that are
// pre-sorted by the byte value of the keys. It is way faster than FastLM
// because it does not need to parse anything. Instead, it relies on the fact
// that the database is already sorted, and binary search is used to find the
// rows.
class ParselessPhraseDB {
public:
ParselessPhraseDB(
const char* buf, size_t length, bool validate_pragma = false);
// Find the rows that match the key. Note that prefix match is used. If you
// need exact match, the key will need to have a delimiter (usually a space)
// at the end.
std::vector<std::string_view> findRows(const std::string_view& key);
const char* findFirstMatchingLine(const std::string_view& key);
private:
const char* begin_;
const char* end_;
};
}; // namespace McBopomofo
#endif // SOURCE_ENGINE_PARSELESSPHRASEDB_H_