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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 "dictionary/utils/multi_bigram_map.h"
     24 #include "jni.h"
     25 #include "suggest/core/dicnode/dic_nodes_cache.h"
     26 #include "suggest/core/layout/proximity_info_state.h"
     27 #include "utils/int_array_view.h"
     28 
     29 namespace latinime {
     30 
     31 class Dictionary;
     32 class DictionaryStructureWithBufferPolicy;
     33 class NgramContext;
     34 class ProximityInfo;
     35 class SuggestOptions;
     36 
     37 class DicTraverseSession {
     38  public:
     39 
     40     // A factory method for DicTraverseSession
     41     static AK_FORCE_INLINE void *getSessionInstance(JNIEnv *env, jstring localeStr,
     42             jlong dictSize) {
     43         // To deal with the trade-off between accuracy and memory space, large cache is used for
     44         // dictionaries larger that the threshold
     45         return new DicTraverseSession(env, localeStr,
     46                 dictSize >= DICTIONARY_SIZE_THRESHOLD_TO_USE_LARGE_CACHE_FOR_SUGGESTION);
     47     }
     48 
     49     static AK_FORCE_INLINE void releaseSessionInstance(DicTraverseSession *traverseSession) {
     50         delete traverseSession;
     51     }
     52 
     53     AK_FORCE_INLINE DicTraverseSession(JNIEnv *env, jstring localeStr, bool usesLargeCache)
     54             : mPrevWordIdCount(0), mProximityInfo(nullptr), mDictionary(nullptr),
     55               mSuggestOptions(nullptr), mDicNodesCache(usesLargeCache), mMultiBigramMap(),
     56               mInputSize(0), mMaxPointerCount(1), mMultiWordCostMultiplier(1.0f) {
     57         // NOTE: mProximityInfoStates is an array of instances.
     58         // No need to initialize it explicitly here.
     59     }
     60 
     61     // Non virtual inline destructor -- never inherit this class
     62     AK_FORCE_INLINE ~DicTraverseSession() {}
     63 
     64     void init(const Dictionary *dictionary, const NgramContext *const ngramContext,
     65             const SuggestOptions *const suggestOptions);
     66     // TODO: Remove and merge into init
     67     void setupForGetSuggestions(const ProximityInfo *pInfo, const int *inputCodePoints,
     68             const int inputSize, const int *const inputXs, const int *const inputYs,
     69             const int *const times, const int *const pointerIds, const float maxSpatialDistance,
     70             const int maxPointerCount);
     71     void resetCache(const int thresholdForNextActiveDicNodes, const int maxWords);
     72 
     73     const DictionaryStructureWithBufferPolicy *getDictionaryStructurePolicy() const;
     74 
     75     //--------------------
     76     // getters and setters
     77     //--------------------
     78     const ProximityInfo *getProximityInfo() const { return mProximityInfo; }
     79     const SuggestOptions *getSuggestOptions() const { return mSuggestOptions; }
     80     const WordIdArrayView getPrevWordIds() const {
     81         return WordIdArrayView::fromArray(mPrevWordIdArray).limit(mPrevWordIdCount);
     82     }
     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     WordIdArray<MAX_PREV_WORD_COUNT_FOR_N_GRAM> mPrevWordIdArray;
    170     size_t mPrevWordIdCount;
    171     const ProximityInfo *mProximityInfo;
    172     const Dictionary *mDictionary;
    173     const SuggestOptions *mSuggestOptions;
    174 
    175     DicNodesCache mDicNodesCache;
    176     // Temporary cache for bigram frequencies
    177     MultiBigramMap mMultiBigramMap;
    178     ProximityInfoState mProximityInfoStates[MAX_POINTER_COUNT_G];
    179 
    180     int mInputSize;
    181     int mMaxPointerCount;
    182 
    183     /////////////////////////////////
    184     // Configuration per dictionary
    185     float mMultiWordCostMultiplier;
    186 
    187 };
    188 } // namespace latinime
    189 #endif // LATINIME_DIC_TRAVERSE_SESSION_H
    190