1 /*
2  * Copyright (C) 2018 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 "chre/util/dynamic_vector_base.h"
18 
19 #include <cstdint>
20 #include <cstring>
21 
22 #include "chre/util/container_support.h"
23 
24 namespace chre {
25 
DynamicVectorBase(DynamicVectorBase && other)26 DynamicVectorBase::DynamicVectorBase(DynamicVectorBase&& other)
27     : mData(other.mData),
28       mSize(other.mSize),
29       mCapacity(other.mCapacity) {
30   other.mData = nullptr;
31   other.mSize = 0;
32   other.mCapacity = 0;
33 }
34 
doReserve(size_t newCapacity,size_t elementSize)35 bool DynamicVectorBase::doReserve(size_t newCapacity, size_t elementSize) {
36   bool success = (newCapacity <= mCapacity);
37   if (!success) {
38     void *newData = memoryAlloc(newCapacity * elementSize);
39     if (newData != nullptr) {
40       memcpy(newData, mData, mSize * elementSize);
41       memoryFree(mData);
42       mData = newData;
43       mCapacity = newCapacity;
44       success = true;
45     }
46   }
47 
48   return success;
49 }
50 
doPrepareForPush(size_t elementSize)51 bool DynamicVectorBase::doPrepareForPush(size_t elementSize) {
52   return doReserve(getNextGrowthCapacity(), elementSize);
53 }
54 
getNextGrowthCapacity() const55 size_t DynamicVectorBase::getNextGrowthCapacity() const {
56   size_t newCapacity;
57   if (mCapacity == 0) {
58     newCapacity = 1;
59   } else if (mSize == mCapacity) {
60     newCapacity = mCapacity * 2;
61   } else {
62     newCapacity = mCapacity;
63   }
64 
65   return newCapacity;
66 }
67 
doErase(size_t index,size_t elementSize)68 void DynamicVectorBase::doErase(size_t index, size_t elementSize) {
69   mSize--;
70   size_t moveAmount = (mSize - index) * elementSize;
71   memmove(static_cast<uint8_t *>(mData) + (index * elementSize),
72           static_cast<uint8_t *>(mData) + ((index + 1) * elementSize),
73           moveAmount);
74 }
75 
doPushBack(const void * element,size_t elementSize)76 bool DynamicVectorBase::doPushBack(const void *element, size_t elementSize) {
77   bool spaceAvailable = doPrepareForPush(elementSize);
78   if (spaceAvailable) {
79     memcpy(static_cast<uint8_t *>(mData) + (mSize * elementSize),
80            element, elementSize);
81     mSize++;
82   }
83 
84   return spaceAvailable;
85 }
86 
87 }  // namespace chre
88