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 "idmap2/BinaryStreamVisitor.h"
18 
19 #include <algorithm>
20 #include <cstring>
21 #include <string>
22 
23 #include "android-base/macros.h"
24 
25 namespace android::idmap2 {
26 
Write16(uint16_t value)27 void BinaryStreamVisitor::Write16(uint16_t value) {
28   uint16_t x = htodl(value);
29   stream_.write(reinterpret_cast<char*>(&x), sizeof(uint16_t));
30 }
31 
Write32(uint32_t value)32 void BinaryStreamVisitor::Write32(uint32_t value) {
33   uint32_t x = htodl(value);
34   stream_.write(reinterpret_cast<char*>(&x), sizeof(uint32_t));
35 }
36 
WriteString(const StringPiece & value)37 void BinaryStreamVisitor::WriteString(const StringPiece& value) {
38   char buf[kIdmapStringLength];
39   memset(buf, 0, sizeof(buf));
40   memcpy(buf, value.data(), std::min(value.size(), sizeof(buf)));
41   stream_.write(buf, sizeof(buf));
42 }
43 
visit(const Idmap & idmap ATTRIBUTE_UNUSED)44 void BinaryStreamVisitor::visit(const Idmap& idmap ATTRIBUTE_UNUSED) {
45   // nothing to do
46 }
47 
visit(const IdmapHeader & header)48 void BinaryStreamVisitor::visit(const IdmapHeader& header) {
49   Write32(header.GetMagic());
50   Write32(header.GetVersion());
51   Write32(header.GetTargetCrc());
52   Write32(header.GetOverlayCrc());
53   WriteString(header.GetTargetPath());
54   WriteString(header.GetOverlayPath());
55 }
56 
visit(const IdmapData & data ATTRIBUTE_UNUSED)57 void BinaryStreamVisitor::visit(const IdmapData& data ATTRIBUTE_UNUSED) {
58   // nothing to do
59 }
60 
visit(const IdmapData::Header & header)61 void BinaryStreamVisitor::visit(const IdmapData::Header& header) {
62   Write16(header.GetTargetPackageId());
63   Write16(header.GetTypeCount());
64 }
65 
visit(const IdmapData::TypeEntry & type_entry)66 void BinaryStreamVisitor::visit(const IdmapData::TypeEntry& type_entry) {
67   const uint16_t entryCount = type_entry.GetEntryCount();
68 
69   Write16(type_entry.GetTargetTypeId());
70   Write16(type_entry.GetOverlayTypeId());
71   Write16(entryCount);
72   Write16(type_entry.GetEntryOffset());
73   for (uint16_t i = 0; i < entryCount; i++) {
74     EntryId entry_id = type_entry.GetEntry(i);
75     Write32(entry_id != kNoEntry ? static_cast<uint32_t>(entry_id) : kPadding);
76   }
77 }
78 
79 }  // namespace android::idmap2
80