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      1 /*
      2  * Copyright (C) 2012 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef LATINIME_DIC_TRAVERSE_SESSION_H
     18 #define LATINIME_DIC_TRAVERSE_SESSION_H
     19 
     20 #include <vector>
     21 
     22 #include "defines.h"
     23 #include "jni.h"
     24 #include "suggest/core/dicnode/dic_nodes_cache.h"
     25 #include "suggest/core/dictionary/multi_bigram_map.h"
     26 #include "suggest/core/layout/proximity_info_state.h"
     27 
     28 namespace latinime {
     29 
     30 class Dictionary;
     31 class DictionaryStructureWithBufferPolicy;
     32 class PrevWordsInfo;
     33 class ProximityInfo;
     34 class SuggestOptions;
     35 
     36 class DicTraverseSession {
     37  public:
     38 
     39     // A factory method for DicTraverseSession
     40     static AK_FORCE_INLINE void *getSessionInstance(JNIEnv *env, jstring localeStr,
     41             jlong dictSize) {
     42         // To deal with the trade-off between accuracy and memory space, large cache is used for
     43         // dictionaries larger that the threshold
     44         return new DicTraverseSession(env, localeStr,
     45                 dictSize >= DICTIONARY_SIZE_THRESHOLD_TO_USE_LARGE_CACHE_FOR_SUGGESTION);
     46     }
     47 
     48     static AK_FORCE_INLINE void releaseSessionInstance(DicTraverseSession *traverseSession) {
     49         delete traverseSession;
     50     }
     51 
     52     AK_FORCE_INLINE DicTraverseSession(JNIEnv *env, jstring localeStr, bool usesLargeCache)
     53             : mProximityInfo(nullptr), mDictionary(nullptr), mSuggestOptions(nullptr),
     54               mDicNodesCache(usesLargeCache), mMultiBigramMap(), mInputSize(0), mMaxPointerCount(1),
     55               mMultiWordCostMultiplier(1.0f) {
     56         // NOTE: mProximityInfoStates is an array of instances.
     57         // No need to initialize it explicitly here.
     58         for (size_t i = 0; i < NELEMS(mPrevWordsPtNodePos); ++i) {
     59             mPrevWordsPtNodePos[i] = NOT_A_DICT_POS;
     60         }
     61     }
     62 
     63     // Non virtual inline destructor -- never inherit this class
     64     AK_FORCE_INLINE ~DicTraverseSession() {}
     65 
     66     void init(const Dictionary *dictionary, const PrevWordsInfo *const prevWordsInfo,
     67             const SuggestOptions *const suggestOptions);
     68     // TODO: Remove and merge into init
     69     void setupForGetSuggestions(const ProximityInfo *pInfo, const int *inputCodePoints,
     70             const int inputSize, const int *const inputXs, const int *const inputYs,
     71             const int *const times, const int *const pointerIds, const float maxSpatialDistance,
     72             const int maxPointerCount);
     73     void resetCache(const int thresholdForNextActiveDicNodes, const int maxWords);
     74 
     75     const DictionaryStructureWithBufferPolicy *getDictionaryStructurePolicy() const;
     76 
     77     //--------------------
     78     // getters and setters
     79     //--------------------
     80     const ProximityInfo *getProximityInfo() const { return mProximityInfo; }
     81     const SuggestOptions *getSuggestOptions() const { return mSuggestOptions; }
     82     const int *getPrevWordsPtNodePos() const { return mPrevWordsPtNodePos; }
     83     DicNodesCache *getDicTraverseCache() { return &mDicNodesCache; }
     84     MultiBigramMap *getMultiBigramMap() { return &mMultiBigramMap; }
     85     const ProximityInfoState *getProximityInfoState(int id) const {
     86         return &mProximityInfoStates[id];
     87     }
     88     int getInputSize() const { return mInputSize; }
     89 
     90     bool isOnlyOnePointerUsed(int *pointerId) const {
     91         // Not in the dictionary word
     92         int usedPointerCount = 0;
     93         int usedPointerId = 0;
     94         for (int i = 0; i < mMaxPointerCount; ++i) {
     95             if (mProximityInfoStates[i].isUsed()) {
     96                 ++usedPointerCount;
     97                 usedPointerId = i;
     98             }
     99         }
    100         if (usedPointerCount != 1) {
    101             return false;
    102         }
    103         if (pointerId) {
    104             *pointerId = usedPointerId;
    105         }
    106         return true;
    107     }
    108 
    109     ProximityType getProximityTypeG(const DicNode *const dicNode, const int childCodePoint) const {
    110         ProximityType proximityType = UNRELATED_CHAR;
    111         for (int i = 0; i < MAX_POINTER_COUNT_G; ++i) {
    112             if (!mProximityInfoStates[i].isUsed()) {
    113                 continue;
    114             }
    115             const int pointerId = dicNode->getInputIndex(i);
    116             proximityType = mProximityInfoStates[i].getProximityTypeG(pointerId, childCodePoint);
    117             ASSERT(proximityType == UNRELATED_CHAR || proximityType == MATCH_CHAR);
    118             // TODO: Make this more generic
    119             // Currently we assume there are only two types here -- UNRELATED_CHAR
    120             // and MATCH_CHAR
    121             if (proximityType != UNRELATED_CHAR) {
    122                 return proximityType;
    123             }
    124         }
    125         return proximityType;
    126     }
    127 
    128     AK_FORCE_INLINE bool isCacheBorderForTyping(const int inputSize) const {
    129         return mDicNodesCache.isCacheBorderForTyping(inputSize);
    130     }
    131 
    132     /**
    133      * Returns whether or not it is possible to continue suggestion from the previous search.
    134      */
    135     // TODO: Remove. No need to check once the session is fully implemented.
    136     bool isContinuousSuggestionPossible() const {
    137         if (!mDicNodesCache.hasCachedDicNodesForContinuousSuggestion()) {
    138             return false;
    139         }
    140         ASSERT(mMaxPointerCount <= MAX_POINTER_COUNT_G);
    141         for (int i = 0; i < mMaxPointerCount; ++i) {
    142             const ProximityInfoState *const pInfoState = getProximityInfoState(i);
    143             // If a proximity info state is not continuous suggestion possible,
    144             // do not continue searching.
    145             if (pInfoState->isUsed() && !pInfoState->isContinuousSuggestionPossible()) {
    146                 return false;
    147             }
    148         }
    149         return true;
    150     }
    151 
    152     bool isTouchPositionCorrectionEnabled() const {
    153         return mProximityInfoStates[0].touchPositionCorrectionEnabled();
    154     }
    155 
    156     float getMultiWordCostMultiplier() const {
    157         return mMultiWordCostMultiplier;
    158     }
    159 
    160  private:
    161     DISALLOW_IMPLICIT_CONSTRUCTORS(DicTraverseSession);
    162     // threshold to start caching
    163     static const int CACHE_START_INPUT_LENGTH_THRESHOLD;
    164     static const int DICTIONARY_SIZE_THRESHOLD_TO_USE_LARGE_CACHE_FOR_SUGGESTION;
    165     void initializeProximityInfoStates(const int *const inputCodePoints, const int *const inputXs,
    166             const int *const inputYs, const int *const times, const int *const pointerIds,
    167             const int inputSize, const float maxSpatialDistance, const int maxPointerCount);
    168 
    169     int mPrevWordsPtNodePos[MAX_PREV_WORD_COUNT_FOR_N_GRAM];
    170     const ProximityInfo *mProximityInfo;
    171     const Dictionary *mDictionary;
    172     const SuggestOptions *mSuggestOptions;
    173 
    174     DicNodesCache mDicNodesCache;
    175     // Temporary cache for bigram frequencies
    176     MultiBigramMap mMultiBigramMap;
    177     ProximityInfoState mProximityInfoStates[MAX_POINTER_COUNT_G];
    178 
    179     int mInputSize;
    180     int mMaxPointerCount;
    181 
    182     /////////////////////////////////
    183     // Configuration per dictionary
    184     float mMultiWordCostMultiplier;
    185 
    186 };
    187 } // namespace latinime
    188 #endif // LATINIME_DIC_TRAVERSE_SESSION_H
    189