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 30 // Returns the ISA extracted from the file_location. 31 // file_location is formatted like /system/app/<app_name>/oat/<isa>/<app_name>.{odex,vdex} 32 // for all functions. We return an empty string "" in error cases. 33 static std::string ExtractISA(const std::string& file_location) { 34 std::vector<std::string> split_file_location = android::base::Split(file_location, "/"); 35 if (split_file_location.size() <= 1) { 36 return ""; 37 } else if (split_file_location.size() != 7) { 38 LOG(WARNING) << "Unexpected length for file-location. We expected 7 segments but found " 39 << split_file_location.size(); 40 } 41 return split_file_location[split_file_location.size() - 2]; 42 } 43 44 // Returns the apk name extracted from the file_location. 45 // file_location is formatted like /system/app/<app_name>/oat/<isa>/<app_name>.{odex,vdex}. 46 // We return the final <app_name> with the .{odex,vdex} replaced with .apk. 47 static std::string ExtractAPKName(const std::string& file_location) { 48 // Find and copy filename. 49 size_t file_location_start = file_location.rfind('/'); 50 if (file_location_start == std::string::npos) { 51 return ""; 52 } 53 size_t ext_start = file_location.rfind('.'); 54 if (ext_start == std::string::npos || ext_start < file_location_start) { 55 return ""; 56 } 57 std::string apk_name = file_location.substr(file_location_start + 1, 58 ext_start - file_location_start); 59 60 // Replace extension with .apk. 61 apk_name += "apk"; 62 return apk_name; 63 } 64 65 // The cache file name is /data/dalvik-cache/<isa>/ prior to this function 66 static bool SystemBFilenameToCacheFile(const std::string& file_location, 67 /*in-out*/std::string& cache_file) { 68 // Skip the first '/' in file_location. 69 size_t initial_position = file_location[0] == '/' ? 1 : 0; 70 size_t apk_position = file_location.find("/oat", initial_position); 71 if (apk_position == std::string::npos) { 72 LOG(ERROR) << "Unable to find oat directory!"; 73 return false; 74 } 75 76 size_t cache_file_position = cache_file.size(); 77 cache_file += file_location.substr(initial_position, apk_position); 78 // '/' -> '@' up to where the apk would be. 79 cache_file_position = cache_file.find('/', cache_file_position); 80 while (cache_file_position != std::string::npos) { 81 cache_file[cache_file_position] = '@'; 82 cache_file_position = cache_file.find('/', cache_file_position); 83 } 84 85 // Add <apk_name>. 86 std::string apk_name = ExtractAPKName(file_location); 87 if (apk_name.empty()) { 88 LOG(ERROR) << "Unable to determine apk name from file name '" << file_location << "'"; 89 return false; 90 } 91 cache_file += apk_name; 92 if (file_location.size() >= 5 && 93 file_location.substr(file_location.size() - 5) == std::string(".vdex")) { 94 cache_file += kVdexCacheSuffix; 95 } else { 96 cache_file += kOdexCacheSuffix; 97 } 98 return true; 99 } 100 101 // Do the overall transformation from file_location to output_file_location. Prior to this the 102 // output_file_location is empty. 103 static bool SystemBFileToCacheFile(const std::string& file_location, 104 /*out*/std::string& output_file_location) { 105 std::string isa = ExtractISA(file_location); 106 if (isa.empty()) { 107 LOG(ERROR) << "Unable to determine isa for file '" << file_location << "', skipping"; 108 return false; 109 } 110 output_file_location += isa; 111 output_file_location += '/'; 112 return SystemBFilenameToCacheFile(file_location, output_file_location); 113 } 114 115 // This program is used to determine where in the /data directory the runtime will search for an 116 // odex file if it is unable to find one at the given 'preopt-name' location. This is used to allow 117 // us to store these preopted files in the unused system_b partition and copy them out on first 118 // boot of the device. 119 int main(int argc, char *argv[]) { 120 if (argc != 2) { 121 LOG(ERROR) << "usage: preopt2cachename preopt-location"; 122 return 2; 123 } 124 std::string file_location(argv[1]); 125 std::string output_file_location(kDalvikCacheDir); 126 if (!SystemBFileToCacheFile(file_location, output_file_location)) { 127 return 1; 128 } else { 129 std::cout << output_file_location; 130 } 131 return 0; 132 } 133
