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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_TERMINAL_ATTRIBUTES_H
     18 #define LATINIME_TERMINAL_ATTRIBUTES_H
     19 
     20 #include "unigram_dictionary.h"
     21 
     22 namespace latinime {
     23 
     24 /**
     25  * This class encapsulates information about a terminal that allows to
     26  * retrieve local node attributes like the list of shortcuts without
     27  * exposing the format structure to the client.
     28  */
     29 class TerminalAttributes {
     30  public:
     31     class ShortcutIterator {
     32         const uint8_t* const mDict;
     33         bool mHasNextShortcutTarget;
     34         int mPos;
     35 
     36      public:
     37         ShortcutIterator(const uint8_t* dict, const int pos, const uint8_t flags) : mDict(dict),
     38                 mPos(pos) {
     39             mHasNextShortcutTarget = (0 != (flags & UnigramDictionary::FLAG_HAS_SHORTCUT_TARGETS));
     40         }
     41 
     42         inline bool hasNextShortcutTarget() const {
     43             return mHasNextShortcutTarget;
     44         }
     45 
     46         // Gets the shortcut target itself as a uint16_t string. For parameters and return value
     47         // see BinaryFormat::getWordAtAddress.
     48         // TODO: make the output an uint32_t* to handle the whole unicode range.
     49         inline int getNextShortcutTarget(const int maxDepth, uint16_t* outWord) {
     50             const int shortcutFlags = BinaryFormat::getFlagsAndForwardPointer(mDict, &mPos);
     51             mHasNextShortcutTarget =
     52                     0 != (shortcutFlags & UnigramDictionary::FLAG_ATTRIBUTE_HAS_NEXT);
     53             unsigned int i;
     54             for (i = 0; i < MAX_WORD_LENGTH_INTERNAL; ++i) {
     55                 const int charCode = BinaryFormat::getCharCodeAndForwardPointer(mDict, &mPos);
     56                 if (NOT_A_CHARACTER == charCode) break;
     57                 outWord[i] = (uint16_t)charCode;
     58             }
     59             mPos += BinaryFormat::CHARACTER_ARRAY_TERMINATOR_SIZE;
     60             return i;
     61         }
     62     };
     63 
     64  private:
     65     const uint8_t* const mDict;
     66     const uint8_t mFlags;
     67     const int mStartPos;
     68 
     69  public:
     70     TerminalAttributes(const uint8_t* const dict, const uint8_t flags, const int pos) :
     71             mDict(dict), mFlags(flags), mStartPos(pos) {
     72     }
     73 
     74     inline ShortcutIterator getShortcutIterator() const {
     75         // The size of the shortcuts is stored here so that the whole shortcut chunk can be
     76         // skipped quickly, so we ignore it.
     77         return ShortcutIterator(mDict, mStartPos + BinaryFormat::SHORTCUT_LIST_SIZE_SIZE, mFlags);
     78     }
     79 };
     80 } // namespace latinime
     81 
     82 #endif // LATINIME_TERMINAL_ATTRIBUTES_H
     83