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