/*
* Copyright (C) 2009 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* This class defines AtomDictBase class which is the base class for all atom
* dictionaries. Atom dictionaries are managed by the decoder class
* MatrixSearch.
*
* When the user appends a new character to the Pinyin string, all enabled atom
* dictionaries' extend_dict() will be called at least once to get candidates
* ended in this step (the information of starting step is also given in the
* parameter). Usually, when extend_dict() is called, a MileStoneHandle object
* returned by a previous calling for a earlier step is given to speed up the
* look-up process, and a new MileStoneHandle object will be returned if
* the extension is successful.
*
* A returned MileStoneHandle object should keep alive until Function
* reset_milestones() is called and this object is noticed to be reset.
*
* Usually, the atom dictionary can use step information to manage its
* MileStoneHandle objects, or it can make the objects in ascendant order to
* make the reset easier.
*
* When the decoder loads the dictionary, it will give a starting lemma id for
* this atom dictionary to map a inner id to a global id. Global ids should be
* used when an atom dictionary talks to any component outside.
*/
#ifndef PINYINIME_INCLUDE_ATOMDICTBASE_H__
#define PINYINIME_INCLUDE_ATOMDICTBASE_H__
#include <stdlib.h>
#include "./dictdef.h"
#include "./searchutility.h"
namespace ime_pinyin {
class AtomDictBase {
public:
virtual ~AtomDictBase() {}
/**
* Load an atom dictionary from a file.
*
* @param file_name The file name to load dictionary.
* @param start_id The starting id used for this atom dictionary.
* @param end_id The end id (included) which can be used for this atom
* dictionary. User dictionary will always use the last id space, so it can
* ignore this paramter. All other atom dictionaries should check this
* parameter.
* @return True if succeed.
*/
virtual bool load_dict(const char *file_name, LemmaIdType start_id,
LemmaIdType end_id) = 0;
/**
* Close this atom dictionary.
*
* @return True if succeed.
*/
virtual bool close_dict() = 0;
/**
* Get the total number of lemmas in this atom dictionary.
*
* @return The total number of lemmas.
*/
virtual size_t number_of_lemmas() = 0;
/**
* This function is called by the decoder when user deletes a character from
* the input string, or begins a new input string.
*
* Different atom dictionaries may implement this function in different way.
* an atom dictionary can use one of these two parameters (or both) to reset
* its corresponding MileStoneHandle objects according its detailed
* implementation.
*
* For example, if an atom dictionary uses step information to manage its
* MileStoneHandle objects, parameter from_step can be used to identify which
* objects should be reset; otherwise, if another atom dictionary does not
* use the detailed step information, it only uses ascendant handles
* (according to step. For the same step, earlier call, smaller handle), it
* can easily reset those MileStoneHandle which are larger than from_handle.
*
* The decoder always reset the decoding state by step. So when it begins
* resetting, it will call reset_milestones() of its atom dictionaries with
* the step information, and the MileStoneHandle objects returned by the
* earliest calling of extend_dict() for that step.
*
* If an atom dictionary does not implement incremental search, this function
* can be totally ignored.
*
* @param from_step From which step(included) the MileStoneHandle
* objects should be reset.
* @param from_handle The ealiest MileStoneHandle object for step from_step
*/
virtual void reset_milestones(uint16 from_step,
MileStoneHandle from_handle) = 0;
/**
* Used to extend in this dictionary. The handle returned should keep valid
* until reset_milestones() is called.
*
* @param from_handle Its previous returned extended handle without the new
* spelling id, it can be used to speed up the extending.
* @param dep The paramter used for extending.
* @param lpi_items Used to fill in the lemmas matched.
* @param lpi_max The length of the buffer
* @param lpi_num Used to return the newly added items.
* @return The new mile stone for this extending. 0 if fail.
*/
virtual MileStoneHandle extend_dict(MileStoneHandle from_handle,
const DictExtPara *dep,
LmaPsbItem *lpi_items,
size_t lpi_max, size_t *lpi_num) = 0;
/**
* Get lemma items with scores according to a spelling id stream.
* This atom dictionary does not need to sort the returned items.
*
* @param splid_str The spelling id stream buffer.
* @param splid_str_len The length of the spelling id stream buffer.
* @param lpi_items Used to return matched lemma items with scores.
* @param lpi_max The maximum size of the buffer to return result.
* @return The number of matched items which have been filled in to lpi_items.
*/
virtual size_t get_lpis(const uint16 *splid_str, uint16 splid_str_len,
LmaPsbItem *lpi_items, size_t lpi_max) = 0;
/**
* Get a lemma string (The Chinese string) by the given lemma id.
*
* @param id_lemma The lemma id to get the string.
* @param str_buf The buffer to return the Chinese string.
* @param str_max The maximum size of the buffer.
* @return The length of the string, 0 if fail.
*/
virtual uint16 get_lemma_str(LemmaIdType id_lemma, char16 *str_buf,
uint16 str_max) = 0;
/**
* Get the full spelling ids for the given lemma id.
* If the given buffer is too short, return 0.
*
* @param splids Used to return the spelling ids.
* @param splids_max The maximum buffer length of splids.
* @param arg_valid Used to indicate if the incoming parameters have been
* initialized are valid. If it is true, the splids and splids_max are valid
* and there may be half ids in splids to be updated to full ids. In this
* case, splids_max is the number of valid ids in splids.
* @return The number of ids in the buffer.
*/
virtual uint16 get_lemma_splids(LemmaIdType id_lemma, uint16 *splids,
uint16 splids_max, bool arg_valid) = 0;
/**
* Function used for prediction.
* No need to sort the newly added items.
*
* @param last_hzs The last n Chinese chracters(called Hanzi), its length
* should be less than or equal to kMaxPredictSize.
* @param hzs_len specifies the length(<= kMaxPredictSize) of the history.
* @param npre_items Used used to return the result.
* @param npre_max The length of the buffer to return result
* @param b4_used Number of prediction result (from npre_items[-b4_used])
* from other atom dictionaries. A atom ditionary can just ignore it.
* @return The number of prediction result from this atom dictionary.
*/
virtual size_t predict(const char16 last_hzs[], uint16 hzs_len,
NPredictItem *npre_items, size_t npre_max,
size_t b4_used) = 0;
/**
* Add a lemma to the dictionary. If the dictionary allows to add new
* items and this item does not exist, add it.
*
* @param lemma_str The Chinese string of the lemma.
* @param splids The spelling ids of the lemma.
* @param lemma_len The length of the Chinese lemma.
* @param count The frequency count for this lemma.
*/
virtual LemmaIdType put_lemma(char16 lemma_str[], uint16 splids[],
uint16 lemma_len, uint16 count) = 0;
/**
* Update a lemma's occuring count.
*
* @param lemma_id The lemma id to update.
* @param delta_count The frequnecy count to ajust.
* @param selected Indicate whether this lemma is selected by user and
* submitted to target edit box.
* @return The id if succeed, 0 if fail.
*/
virtual LemmaIdType update_lemma(LemmaIdType lemma_id, int16 delta_count,
bool selected) = 0;
/**
* Get the lemma id for the given lemma.
*
* @param lemma_str The Chinese string of the lemma.
* @param splids The spelling ids of the lemma.
* @param lemma_len The length of the lemma.
* @return The matched lemma id, or 0 if fail.
*/
virtual LemmaIdType get_lemma_id(char16 lemma_str[], uint16 splids[],
uint16 lemma_len) = 0;
/**
* Get the lemma score.
*
* @param lemma_id The lemma id to get score.
* @return The score of the lemma, or 0 if fail.
*/
virtual LmaScoreType get_lemma_score(LemmaIdType lemma_id) = 0;
/**
* Get the lemma score.
*
* @param lemma_str The Chinese string of the lemma.
* @param splids The spelling ids of the lemma.
* @param lemma_len The length of the lemma.
* @return The score of the lamm, or 0 if fail.
*/
virtual LmaScoreType get_lemma_score(char16 lemma_str[], uint16 splids[],
uint16 lemma_len) = 0;
/**
* If the dictionary allowed, remove a lemma from it.
*
* @param lemma_id The id of the lemma to remove.
* @return True if succeed.
*/
virtual bool remove_lemma(LemmaIdType lemma_id) = 0;
/**
* Get the total occuring count of this atom dictionary.
*
* @return The total occuring count of this atom dictionary.
*/
virtual size_t get_total_lemma_count() = 0;
/**
* Set the total occuring count of other atom dictionaries.
*
* @param count The total occuring count of other atom dictionaies.
*/
virtual void set_total_lemma_count_of_others(size_t count) = 0;
/**
* Notify this atom dictionary to flush the cached data to persistent storage
* if necessary.
*/
virtual void flush_cache() = 0;
};
}
#endif // PINYINIME_INCLUDE_ATOMDICTBASE_H__