1 /* 2 * Copyright (C) 2016 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 <iostream> 18 19 #include <android-base/logging.h> 20 #include <android-base/strings.h> 21 22 #ifndef LOG_TAG 23 #define LOG_TAG "preopt2cachename" 24 #endif 25 26 static const char* kDalvikCacheDir = "/data/dalvik-cache/"; 27 static const char* kOdexCacheSuffix = "@classes.dex"; 28 static const char* kVdexCacheSuffix = "@classes.vdex"; 29 static const char* kArtCacheSuffix = "@classes.art"; 30 31 // Returns the ISA extracted from the file_location. 32 // file_location is formatted like /system/app/<app_name>/oat/<isa>/<app_name>.{odex,vdex} 33 // for all functions. We return an empty string "" in error cases. 34 static std::string ExtractISA(const std::string& file_location) { 35 std::vector<std::string> split_file_location = android::base::Split(file_location, "/"); 36 if (split_file_location.size() <= 1) { 37 return ""; 38 } else if (split_file_location.size() != 7) { 39 LOG(WARNING) << "Unexpected length for file-location. We expected 7 segments but found " 40 << split_file_location.size(); 41 } 42 return split_file_location[split_file_location.size() - 2]; 43 } 44 45 // Returns the apk name extracted from the file_location. 46 // file_location is formatted like /system/app/<app_name>/oat/<isa>/<app_name>.{odex,vdex}. 47 // We return the final <app_name> with the .{odex,vdex} replaced with .apk. 48 static std::string ExtractAPKName(const std::string& file_location) { 49 // Find and copy filename. 50 size_t file_location_start = file_location.rfind('/'); 51 if (file_location_start == std::string::npos) { 52 return ""; 53 } 54 size_t ext_start = file_location.rfind('.'); 55 if (ext_start == std::string::npos || ext_start < file_location_start) { 56 return ""; 57 } 58 std::string apk_name = file_location.substr(file_location_start + 1, 59 ext_start - file_location_start); 60 61 // Replace extension with .apk. 62 apk_name += "apk"; 63 return apk_name; 64 } 65 66 // The cache file name is /data/dalvik-cache/<isa>/ prior to this function 67 static bool SystemBFilenameToCacheFile(const std::string& file_location, 68 /*in-out*/std::string& cache_file) { 69 // Skip the first '/' in file_location. 70 size_t initial_position = file_location[0] == '/' ? 1 : 0; 71 size_t apk_position = file_location.find("/oat", initial_position); 72 if (apk_position == std::string::npos) { 73 LOG(ERROR) << "Unable to find oat directory!"; 74 return false; 75 } 76 77 size_t cache_file_position = cache_file.size(); 78 cache_file += file_location.substr(initial_position, apk_position); 79 // '/' -> '@' up to where the apk would be. 80 cache_file_position = cache_file.find('/', cache_file_position); 81 while (cache_file_position != std::string::npos) { 82 cache_file[cache_file_position] = '@'; 83 cache_file_position = cache_file.find('/', cache_file_position); 84 } 85 86 // Add <apk_name>. 87 std::string apk_name = ExtractAPKName(file_location); 88 if (apk_name.empty()) { 89 LOG(ERROR) << "Unable to determine apk name from file name '" << file_location << "'"; 90 return false; 91 } 92 std::string::size_type pos = file_location.find_last_of("."); 93 if (pos == std::string::npos) { 94 LOG(ERROR) << "Invalid file location '" << file_location << "'"; 95 return false; 96 } 97 cache_file += apk_name; 98 std::string extension(file_location.substr(pos)); 99 if (extension == ".vdex") { 100 cache_file += kVdexCacheSuffix; 101 } else if (extension == ".art") { 102 cache_file += kArtCacheSuffix; 103 } else { 104 cache_file += kOdexCacheSuffix; 105 } 106 return true; 107 } 108 109 // Do the overall transformation from file_location to output_file_location. Prior to this the 110 // output_file_location is empty. 111 static bool SystemBFileToCacheFile(const std::string& file_location, 112 /*out*/std::string& output_file_location) { 113 std::string isa = ExtractISA(file_location); 114 if (isa.empty()) { 115 LOG(ERROR) << "Unable to determine isa for file '" << file_location << "', skipping"; 116 return false; 117 } 118 output_file_location += isa; 119 output_file_location += '/'; 120 return SystemBFilenameToCacheFile(file_location, output_file_location); 121 } 122 123 // This program is used to determine where in the /data directory the runtime will search for an 124 // odex file if it is unable to find one at the given 'preopt-name' location. This is used to allow 125 // us to store these preopted files in the unused system_b partition and copy them out on first 126 // boot of the device. 127 int main(int argc, char *argv[]) { 128 if (argc != 2) { 129 LOG(ERROR) << "usage: preopt2cachename preopt-location"; 130 return 2; 131 } 132 std::string file_location(argv[1]); 133 std::string output_file_location(kDalvikCacheDir); 134 if (!SystemBFileToCacheFile(file_location, output_file_location)) { 135 return 1; 136 } else { 137 std::cout << output_file_location; 138 } 139 return 0; 140 } 141
