Home | History | Annotate | Download | only in dicnode 
      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_NODES_CACHE_H
     18 #define LATINIME_DIC_NODES_CACHE_H
     19 
     20 #include <stdint.h>
     21 
     22 #include "defines.h"
     23 #include "suggest/core/dicnode/dic_node_priority_queue.h"
     24 
     25 namespace latinime {
     26 
     27 class DicNode;
     28 
     29 /**
     30  * Class for controlling dicNode search priority queue and lexicon trie traversal.
     31  */
     32 class DicNodesCache {
     33  public:
     34     AK_FORCE_INLINE explicit DicNodesCache(const bool usesLargeCapacityCache)
     35             : mUsesLargeCapacityCache(usesLargeCapacityCache),
     36               mDicNodePriorityQueue0(getCacheCapacity()),
     37               mDicNodePriorityQueue1(getCacheCapacity()),
     38               mDicNodePriorityQueue2(getCacheCapacity()),
     39               mDicNodePriorityQueueForTerminal(MAX_RESULTS),
     40               mActiveDicNodes(&mDicNodePriorityQueue0),
     41               mNextActiveDicNodes(&mDicNodePriorityQueue1),
     42               mCachedDicNodesForContinuousSuggestion(&mDicNodePriorityQueue2),
     43               mTerminalDicNodes(&mDicNodePriorityQueueForTerminal),
     44               mInputIndex(0), mLastCachedInputIndex(0) {}
     45 
     46     AK_FORCE_INLINE virtual ~DicNodesCache() {}
     47 
     48     AK_FORCE_INLINE void reset(const int nextActiveSize, const int terminalSize) {
     49         mInputIndex = 0;
     50         mLastCachedInputIndex = 0;
     51         // We want to use the max capacity for the current active dic node queue.
     52         mActiveDicNodes->clearAndResizeToCapacity();
     53         // nextActiveSize is used to limit the next iteration's active dic node size.
     54         const int nextActiveSizeFittingToTheCapacity = min(nextActiveSize, getCacheCapacity());
     55         mNextActiveDicNodes->clearAndResize(nextActiveSizeFittingToTheCapacity);
     56         mTerminalDicNodes->clearAndResize(terminalSize);
     57         // We want to use the max capacity for the cached dic nodes that will be used for the
     58         // continuous suggestion.
     59         mCachedDicNodesForContinuousSuggestion->clearAndResizeToCapacity();
     60     }
     61 
     62     AK_FORCE_INLINE void continueSearch() {
     63         resetTemporaryCaches();
     64         restoreActiveDicNodesFromCache();
     65     }
     66 
     67     AK_FORCE_INLINE void advanceActiveDicNodes() {
     68         if (DEBUG_DICT) {
     69             AKLOGI("Advance active %d nodes.", mNextActiveDicNodes->getSize());
     70         }
     71         if (DEBUG_DICT_FULL) {
     72             mNextActiveDicNodes->dump();
     73         }
     74         mNextActiveDicNodes =
     75                 moveNodesAndReturnReusableEmptyQueue(mNextActiveDicNodes, &mActiveDicNodes);
     76     }
     77 
     78     DicNode *setCommitPoint(int commitPoint);
     79 
     80     int activeSize() const { return mActiveDicNodes->getSize(); }
     81     int terminalSize() const { return mTerminalDicNodes->getSize(); }
     82     bool isLookAheadCorrectionInputIndex(const int inputIndex) const {
     83         return inputIndex == mInputIndex - 1;
     84     }
     85     void advanceInputIndex(const int inputSize) {
     86         if (mInputIndex < inputSize) {
     87             mInputIndex++;
     88         }
     89     }
     90 
     91     AK_FORCE_INLINE void copyPushTerminal(DicNode *dicNode) {
     92         mTerminalDicNodes->copyPush(dicNode);
     93     }
     94 
     95     AK_FORCE_INLINE void copyPushActive(DicNode *dicNode) {
     96         mActiveDicNodes->copyPush(dicNode);
     97     }
     98 
     99     AK_FORCE_INLINE bool copyPushContinue(DicNode *dicNode) {
    100         return mCachedDicNodesForContinuousSuggestion->copyPush(dicNode);
    101     }
    102 
    103     AK_FORCE_INLINE void copyPushNextActive(DicNode *dicNode) {
    104         DicNode *pushedDicNode = mNextActiveDicNodes->copyPush(dicNode);
    105         if (!pushedDicNode) {
    106             if (dicNode->isCached()) {
    107                 dicNode->remove();
    108             }
    109             // We simply drop any dic node that was not cached, ignoring the slim chance
    110             // that one of its children represents what the user really wanted.
    111         }
    112     }
    113 
    114     void popTerminal(DicNode *dest) {
    115         mTerminalDicNodes->copyPop(dest);
    116     }
    117 
    118     void popActive(DicNode *dest) {
    119         mActiveDicNodes->copyPop(dest);
    120     }
    121 
    122     bool hasCachedDicNodesForContinuousSuggestion() const {
    123         return mCachedDicNodesForContinuousSuggestion
    124                 && mCachedDicNodesForContinuousSuggestion->getSize() > 0;
    125     }
    126 
    127     AK_FORCE_INLINE bool isCacheBorderForTyping(const int inputSize) const {
    128         // TODO: Move this variable to header
    129         static const int CACHE_BACK_LENGTH = 3;
    130         const int cacheInputIndex = inputSize - CACHE_BACK_LENGTH;
    131         const bool shouldCache = (cacheInputIndex == mInputIndex)
    132                 && (cacheInputIndex != mLastCachedInputIndex);
    133         return shouldCache;
    134     }
    135 
    136     AK_FORCE_INLINE void updateLastCachedInputIndex() {
    137         mLastCachedInputIndex = mInputIndex;
    138     }
    139 
    140  private:
    141     DISALLOW_COPY_AND_ASSIGN(DicNodesCache);
    142 
    143     AK_FORCE_INLINE void restoreActiveDicNodesFromCache() {
    144         if (DEBUG_DICT) {
    145             AKLOGI("Restore %d nodes. inputIndex = %d.",
    146                     mCachedDicNodesForContinuousSuggestion->getSize(), mLastCachedInputIndex);
    147         }
    148         if (DEBUG_DICT_FULL || DEBUG_CACHE) {
    149             mCachedDicNodesForContinuousSuggestion->dump();
    150         }
    151         mInputIndex = mLastCachedInputIndex;
    152         mCachedDicNodesForContinuousSuggestion = moveNodesAndReturnReusableEmptyQueue(
    153                 mCachedDicNodesForContinuousSuggestion, &mActiveDicNodes);
    154     }
    155 
    156     AK_FORCE_INLINE static DicNodePriorityQueue *moveNodesAndReturnReusableEmptyQueue(
    157             DicNodePriorityQueue *src, DicNodePriorityQueue **dest) {
    158         const int srcMaxSize = src->getMaxSize();
    159         const int destMaxSize = (*dest)->getMaxSize();
    160         DicNodePriorityQueue *tmp = *dest;
    161         *dest = src;
    162         (*dest)->setMaxSize(destMaxSize);
    163         tmp->clearAndResize(srcMaxSize);
    164         return tmp;
    165     }
    166 
    167     AK_FORCE_INLINE int getCacheCapacity() const {
    168         return mUsesLargeCapacityCache ?
    169                 LARGE_PRIORITY_QUEUE_CAPACITY : SMALL_PRIORITY_QUEUE_CAPACITY;
    170     }
    171 
    172     AK_FORCE_INLINE void resetTemporaryCaches() {
    173         mActiveDicNodes->clear();
    174         mNextActiveDicNodes->clear();
    175         mTerminalDicNodes->clear();
    176     }
    177 
    178     static const int LARGE_PRIORITY_QUEUE_CAPACITY;
    179     static const int SMALL_PRIORITY_QUEUE_CAPACITY;
    180 
    181     const bool mUsesLargeCapacityCache;
    182     // Instances
    183     DicNodePriorityQueue mDicNodePriorityQueue0;
    184     DicNodePriorityQueue mDicNodePriorityQueue1;
    185     DicNodePriorityQueue mDicNodePriorityQueue2;
    186     DicNodePriorityQueue mDicNodePriorityQueueForTerminal;
    187 
    188     // Active dicNodes currently being expanded.
    189     DicNodePriorityQueue *mActiveDicNodes;
    190     // Next dicNodes to be expanded.
    191     DicNodePriorityQueue *mNextActiveDicNodes;
    192     // Cached dicNodes used for continuous suggestion.
    193     DicNodePriorityQueue *mCachedDicNodesForContinuousSuggestion;
    194     // Current top terminal dicNodes.
    195     DicNodePriorityQueue *mTerminalDicNodes;
    196     int mInputIndex;
    197     int mLastCachedInputIndex;
    198 };
    199 } // namespace latinime
    200 #endif // LATINIME_DIC_NODES_CACHE_H
    201