Add spellcheck and word suggestion to the prediction service

third_party/android_prediction/suggest/core/session/dic_traverse_session.h

Index: third_party/android_prediction/suggest/core/session/dic_traverse_session.h
diff --git a/third_party/android_prediction/suggest/core/session/dic_traverse_session.h b/third_party/android_prediction/suggest/core/session/dic_traverse_session.h
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index 0000000000000000000000000000000000000000..d74846e88caab0fd986a3da179639c1e25822a63
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+/*
+ * Copyright (C) 2012 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.
+ */
+
+#ifndef LATINIME_DIC_TRAVERSE_SESSION_H
+#define LATINIME_DIC_TRAVERSE_SESSION_H
+
+#include <vector>
+
+#include "third_party/android_prediction/defines.h"
+#include "third_party/android_prediction/suggest/core/dicnode/dic_nodes_cache.h"
+#include "third_party/android_prediction/suggest/core/dictionary/multi_bigram_map.h"
+#include "third_party/android_prediction/suggest/core/layout/proximity_info_state.h"
+
+namespace latinime {
+
+class Dictionary;
+class DictionaryStructureWithBufferPolicy;
+class PrevWordsInfo;
+class ProximityInfo;
+class SuggestOptions;
+
+class DicTraverseSession {
+ public:
+
+    // A factory method for DicTraverseSession
+    static AK_FORCE_INLINE void *getSessionInstance(std::string localeStr,
+            long dictSize) {
+        // To deal with the trade-off between accuracy and memory space, large cache is used for
+        // dictionaries larger that the threshold
+        return new DicTraverseSession(localeStr,
+                dictSize >= DICTIONARY_SIZE_THRESHOLD_TO_USE_LARGE_CACHE_FOR_SUGGESTION);
+    }
+
+    static AK_FORCE_INLINE void releaseSessionInstance(DicTraverseSession *traverseSession) {
+        delete traverseSession;
+    }
+
+    AK_FORCE_INLINE DicTraverseSession(std::string localeStr, bool usesLargeCache)
+            : mProximityInfo(nullptr), mDictionary(nullptr), mSuggestOptions(nullptr),
+              mDicNodesCache(usesLargeCache), mMultiBigramMap(), mInputSize(0), mMaxPointerCount(1),
+              mMultiWordCostMultiplier(1.0f) {
+        // NOTE: mProximityInfoStates is an array of instances.
+        // No need to initialize it explicitly here.
+        for (size_t i = 0; i < NELEMS(mPrevWordsPtNodePos); ++i) {
+            mPrevWordsPtNodePos[i] = NOT_A_DICT_POS;
+        }
+    }
+
+    // Non virtual inline destructor -- never inherit this class
+    AK_FORCE_INLINE ~DicTraverseSession() {}
+
+    void init(const Dictionary *dictionary, const PrevWordsInfo *const prevWordsInfo,
+            const SuggestOptions *const suggestOptions);
+    // TODO: Remove and merge into init
+    void setupForGetSuggestions(const ProximityInfo *pInfo, const int *inputCodePoints,
+            const int inputSize, const int *const inputXs, const int *const inputYs,
+            const int *const times, const int *const pointerIds, const float maxSpatialDistance,
+            const int maxPointerCount);
+    void resetCache(const int thresholdForNextActiveDicNodes, const int maxWords);
+
+    const DictionaryStructureWithBufferPolicy *getDictionaryStructurePolicy() const;
+
+    //--------------------
+    // getters and setters
+    //--------------------
+    const ProximityInfo *getProximityInfo() const { return mProximityInfo; }
+    const SuggestOptions *getSuggestOptions() const { return mSuggestOptions; }
+    const int *getPrevWordsPtNodePos() const { return mPrevWordsPtNodePos; }
+    DicNodesCache *getDicTraverseCache() { return &mDicNodesCache; }
+    MultiBigramMap *getMultiBigramMap() { return &mMultiBigramMap; }
+    const ProximityInfoState *getProximityInfoState(int id) const {
+        return &mProximityInfoStates[id];
+    }
+    int getInputSize() const { return mInputSize; }
+
+    bool isOnlyOnePointerUsed(int *pointerId) const {
+        // Not in the dictionary word
+        int usedPointerCount = 0;
+        int usedPointerId = 0;
+        for (int i = 0; i < mMaxPointerCount; ++i) {
+            if (mProximityInfoStates[i].isUsed()) {
+                ++usedPointerCount;
+                usedPointerId = i;
+            }
+        }
+        if (usedPointerCount != 1) {
+            return false;
+        }
+        if (pointerId) {
+            *pointerId = usedPointerId;
+        }
+        return true;
+    }
+
+    ProximityType getProximityTypeG(const DicNode *const dicNode, const int childCodePoint) const {
+        ProximityType proximityType = UNRELATED_CHAR;
+        for (int i = 0; i < MAX_POINTER_COUNT_G; ++i) {
+            if (!mProximityInfoStates[i].isUsed()) {
+                continue;
+            }
+            const int pointerId = dicNode->getInputIndex(i);
+            proximityType = mProximityInfoStates[i].getProximityTypeG(pointerId, childCodePoint);
+            ASSERT(proximityType == UNRELATED_CHAR || proximityType == MATCH_CHAR);
+            // TODO: Make this more generic
+            // Currently we assume there are only two types here -- UNRELATED_CHAR
+            // and MATCH_CHAR
+            if (proximityType != UNRELATED_CHAR) {
+                return proximityType;
+            }
+        }
+        return proximityType;
+    }
+
+    AK_FORCE_INLINE bool isCacheBorderForTyping(const int inputSize) const {
+        return mDicNodesCache.isCacheBorderForTyping(inputSize);
+    }
+
+    /**
+     * Returns whether or not it is possible to continue suggestion from the previous search.
+     */
+    // TODO: Remove. No need to check once the session is fully implemented.
+    bool isContinuousSuggestionPossible() const {
+        if (!mDicNodesCache.hasCachedDicNodesForContinuousSuggestion()) {
+            return false;
+        }
+        ASSERT(mMaxPointerCount <= MAX_POINTER_COUNT_G);
+        for (int i = 0; i < mMaxPointerCount; ++i) {
+            const ProximityInfoState *const pInfoState = getProximityInfoState(i);
+            // If a proximity info state is not continuous suggestion possible,
+            // do not continue searching.
+            if (pInfoState->isUsed() && !pInfoState->isContinuousSuggestionPossible()) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    bool isTouchPositionCorrectionEnabled() const {
+        return mProximityInfoStates[0].touchPositionCorrectionEnabled();
+    }
+
+    float getMultiWordCostMultiplier() const {
+        return mMultiWordCostMultiplier;
+    }
+
+ private:
+    DISALLOW_IMPLICIT_CONSTRUCTORS(DicTraverseSession);
+    // threshold to start caching
+    static const int CACHE_START_INPUT_LENGTH_THRESHOLD;
+    static const int DICTIONARY_SIZE_THRESHOLD_TO_USE_LARGE_CACHE_FOR_SUGGESTION;
+    void initializeProximityInfoStates(const int *const inputCodePoints, const int *const inputXs,
+            const int *const inputYs, const int *const times, const int *const pointerIds,
+            const int inputSize, const float maxSpatialDistance, const int maxPointerCount);
+
+    int mPrevWordsPtNodePos[MAX_PREV_WORD_COUNT_FOR_N_GRAM];
+    const ProximityInfo *mProximityInfo;
+    const Dictionary *mDictionary;
+    const SuggestOptions *mSuggestOptions;
+
+    DicNodesCache mDicNodesCache;
+    // Temporary cache for bigram frequencies
+    MultiBigramMap mMultiBigramMap;
+    ProximityInfoState mProximityInfoStates[MAX_POINTER_COUNT_G];
+
+    int mInputSize;
+    int mMaxPointerCount;
+
+    /////////////////////////////////
+    // Configuration per dictionary
+    float mMultiWordCostMultiplier;
+
+};
+} // namespace latinime
+#endif // LATINIME_DIC_TRAVERSE_SESSION_H