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 #include "dictionary/structure/pt_common/dynamic_pt_reading_utils.h"
18 
19 #include "defines.h"
20 #include "dictionary/utils/byte_array_utils.h"
21 
22 namespace latinime {
23 
24 const DynamicPtReadingUtils::NodeFlags DynamicPtReadingUtils::MASK_MOVED = 0xC0;
25 const DynamicPtReadingUtils::NodeFlags DynamicPtReadingUtils::FLAG_IS_NOT_MOVED = 0xC0;
26 const DynamicPtReadingUtils::NodeFlags DynamicPtReadingUtils::FLAG_IS_MOVED = 0x40;
27 const DynamicPtReadingUtils::NodeFlags DynamicPtReadingUtils::FLAG_IS_DELETED = 0x80;
28 const DynamicPtReadingUtils::NodeFlags DynamicPtReadingUtils::FLAG_WILL_BECOME_NON_TERMINAL = 0x00;
29 
30 // TODO: Make DICT_OFFSET_ZERO_OFFSET = 0.
31 // Currently, DICT_OFFSET_INVALID is 0 in Java side but offset can be 0 during GC. So, the maximum
32 // value of offsets, which is 0x7FFFFF is used to represent 0 offset.
33 const int DynamicPtReadingUtils::DICT_OFFSET_INVALID = 0;
34 const int DynamicPtReadingUtils::DICT_OFFSET_ZERO_OFFSET = 0x7FFFFF;
35 
getForwardLinkPosition(const uint8_t * const buffer,const int pos)36 /* static */ int DynamicPtReadingUtils::getForwardLinkPosition(const uint8_t *const buffer,
37         const int pos) {
38     int linkAddressPos = pos;
39     return ByteArrayUtils::readSint24AndAdvancePosition(buffer, &linkAddressPos);
40 }
41 
getParentPtNodePosOffsetAndAdvancePosition(const uint8_t * const buffer,int * const pos)42 /* static */ int DynamicPtReadingUtils::getParentPtNodePosOffsetAndAdvancePosition(
43         const uint8_t *const buffer, int *const pos) {
44     return ByteArrayUtils::readSint24AndAdvancePosition(buffer, pos);
45 }
46 
getParentPtNodePos(const int parentOffset,const int ptNodePos)47 /* static */ int DynamicPtReadingUtils::getParentPtNodePos(const int parentOffset,
48         const int ptNodePos) {
49     if (parentOffset == DICT_OFFSET_INVALID) {
50         return NOT_A_DICT_POS;
51     } else if (parentOffset == DICT_OFFSET_ZERO_OFFSET) {
52         return ptNodePos;
53     } else {
54         return parentOffset + ptNodePos;
55     }
56 }
57 
readChildrenPositionAndAdvancePosition(const uint8_t * const buffer,int * const pos)58 /* static */ int DynamicPtReadingUtils::readChildrenPositionAndAdvancePosition(
59         const uint8_t *const buffer, int *const pos) {
60     const int base = *pos;
61     const int offset = ByteArrayUtils::readSint24AndAdvancePosition(buffer, pos);
62     if (offset == DICT_OFFSET_INVALID) {
63         // The PtNode does not have children.
64         return NOT_A_DICT_POS;
65     } else if (offset == DICT_OFFSET_ZERO_OFFSET) {
66         return base;
67     } else {
68         return base + offset;
69     }
70 }
71 
72 } // namespace latinime
73