1 /*
2  * Copyright (C) 2013, 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_DYNAMIC_PT_READING_UTILS_H
18 #define LATINIME_DYNAMIC_PT_READING_UTILS_H
19 
20 #include <cstdint>
21 
22 #include "defines.h"
23 
24 namespace latinime {
25 
26 class DynamicPtReadingUtils {
27  public:
28     typedef uint8_t NodeFlags;
29 
30     static const int DICT_OFFSET_INVALID;
31     static const int DICT_OFFSET_ZERO_OFFSET;
32 
33     static int getForwardLinkPosition(const uint8_t *const buffer, const int pos);
34 
isValidForwardLinkPosition(const int forwardLinkAddress)35     static AK_FORCE_INLINE bool isValidForwardLinkPosition(const int forwardLinkAddress) {
36         return forwardLinkAddress != 0;
37     }
38 
39     static int getParentPtNodePosOffsetAndAdvancePosition(const uint8_t *const buffer,
40             int *const pos);
41 
42     static int getParentPtNodePos(const int parentOffset, const int ptNodePos);
43 
44     static int readChildrenPositionAndAdvancePosition(const uint8_t *const buffer, int *const pos);
45 
46     /**
47      * Node Flags
48      */
isMoved(const NodeFlags flags)49     static AK_FORCE_INLINE bool isMoved(const NodeFlags flags) {
50         return FLAG_IS_MOVED == (MASK_MOVED & flags);
51     }
52 
isDeleted(const NodeFlags flags)53     static AK_FORCE_INLINE bool isDeleted(const NodeFlags flags) {
54         return FLAG_IS_DELETED == (MASK_MOVED & flags);
55     }
56 
willBecomeNonTerminal(const NodeFlags flags)57     static AK_FORCE_INLINE bool willBecomeNonTerminal(const NodeFlags flags) {
58         return FLAG_WILL_BECOME_NON_TERMINAL == (MASK_MOVED & flags);
59     }
60 
updateAndGetFlags(const NodeFlags originalFlags,const bool isMoved,const bool isDeleted,const bool willBecomeNonTerminal)61     static AK_FORCE_INLINE NodeFlags updateAndGetFlags(const NodeFlags originalFlags,
62             const bool isMoved, const bool isDeleted, const bool willBecomeNonTerminal) {
63         NodeFlags flags = originalFlags;
64         flags = willBecomeNonTerminal ?
65                 ((flags & (~MASK_MOVED)) | FLAG_WILL_BECOME_NON_TERMINAL) : flags;
66         flags = isMoved ? ((flags & (~MASK_MOVED)) | FLAG_IS_MOVED) : flags;
67         flags = isDeleted ? ((flags & (~MASK_MOVED)) | FLAG_IS_DELETED) : flags;
68         flags = (!isMoved && !isDeleted && !willBecomeNonTerminal) ?
69                 ((flags & (~MASK_MOVED)) | FLAG_IS_NOT_MOVED) : flags;
70         return flags;
71     }
72 
73  private:
74     DISALLOW_IMPLICIT_CONSTRUCTORS(DynamicPtReadingUtils);
75 
76     static const NodeFlags MASK_MOVED;
77     static const NodeFlags FLAG_IS_NOT_MOVED;
78     static const NodeFlags FLAG_IS_MOVED;
79     static const NodeFlags FLAG_IS_DELETED;
80     static const NodeFlags FLAG_WILL_BECOME_NON_TERMINAL;
81 };
82 } // namespace latinime
83 #endif /* LATINIME_DYNAMIC_PT_READING_UTILS_H */
84