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_host/fragmented_load_transaction.h"
18 
19 #include <algorithm>
20 
21 namespace android {
22 namespace chre {
23 
24 namespace {
25 
26 /**
27  * Returns a vector containing a specific subarray of the original vector.
28  *
29  * If the ending index of the subarray exceeds that of the source vector,
30  * the size will be truncated to the last element of the source vector.
31  *
32  * @param source the source vector
33  * @param start the starting index of the subarray
34  * @param size the size of the subarray
35  *
36  * @return the vector containing the subarray
37  */
getSubVector(const std::vector<uint8_t> & source,size_t start,size_t size)38 inline std::vector<uint8_t> getSubVector(
39     const std::vector<uint8_t>& source, size_t start, size_t size) {
40   size_t end = std::min(source.size(), start + size);
41   return (source.size() == 0) ?
42       std::vector<uint8_t>() :
43       std::vector<uint8_t>(
44           source.begin() + start, source.begin() + end); // [start, end)
45 }
46 
47 } // anonymous namespace
48 
FragmentedLoadTransaction(uint32_t transactionId,uint64_t appId,uint32_t appVersion,uint32_t targetApiVersion,const std::vector<uint8_t> & appBinary,size_t fragmentSize)49 FragmentedLoadTransaction::FragmentedLoadTransaction(
50     uint32_t transactionId, uint64_t appId, uint32_t appVersion,
51     uint32_t targetApiVersion, const std::vector<uint8_t>& appBinary,
52     size_t fragmentSize) {
53   mTransactionId = transactionId;
54 
55   // Start with fragmentId at 1 since 0 is used to indicate
56   // legacy behavior at CHRE
57   size_t fragmentId = 1;
58   size_t byteIndex = 0;
59   do {
60     if (fragmentId == 1) {
61       mFragmentRequests.emplace_back(
62           fragmentId++, transactionId, appId, appVersion, targetApiVersion,
63           appBinary.size(), getSubVector(appBinary, byteIndex, fragmentSize));
64     } else {
65       mFragmentRequests.emplace_back(
66           fragmentId++, transactionId,
67           getSubVector(appBinary, byteIndex, fragmentSize));
68     }
69 
70     byteIndex += fragmentSize;
71   } while (byteIndex < appBinary.size());
72 }
73 
getNextRequest()74 const FragmentedLoadRequest& FragmentedLoadTransaction::getNextRequest() {
75   return mFragmentRequests.at(mCurrentRequestIndex++);
76 }
77 
isComplete() const78 bool FragmentedLoadTransaction::isComplete() const {
79   return (mCurrentRequestIndex >= mFragmentRequests.size());
80 }
81 
82 }  // namespace chre
83 }  // namespace android
84