fragmented_load_transaction.cc revision abe6dd64a5ae46024eecaddc8f1dbdff9a4d4da5 
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
21namespace android {
22namespace chre {
23
24namespace {
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 */
38inline 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
49FragmentedLoadTransaction::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
74const FragmentedLoadRequest& FragmentedLoadTransaction::getNextRequest() {
75  return mFragmentRequests.at(mCurrentRequestIndex++);
76}
77
78bool FragmentedLoadTransaction::isComplete() const {
79  return (mCurrentRequestIndex >= mFragmentRequests.size());
80}
81
82}  // namespace chre
83}  // namespace android
84