2 * Copyright (C) 2016 The Android Open Source Project
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
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
19 #include <android-base/logging.h>
20 #include <android-base/strings.h>
23 #define LOG_TAG "preopt2cachename"
26 static const char* kDalvikCacheDir = "/data/dalvik-cache/";
27 static const char* kCacheSuffix = "@classes.dex";
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) {
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();
40 return split_file_location[split_file_location.size() - 2];
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) {
52 size_t ext_start = odex_file_location.rfind('.');
53 if (ext_start == std::string::npos || ext_start < file_location_start) {
56 std::string apk_name = odex_file_location.substr(file_location_start + 1,
57 ext_start - file_location_start);
59 // Replace extension with .apk.
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!";
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);
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 << "'";
90 cache_file += apk_name;
91 cache_file += kCacheSuffix;
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);
101 LOG(ERROR) << "Unable to determine isa for odex file '" << odex_file_location << "', skipping";
104 output_file_location += isa;
105 output_file_location += '/';
106 return OdexFilenameToCacheFile(odex_file_location, output_file_location);
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[]) {
115 LOG(ERROR) << "usage: preopt2cachename preopt-location";
118 std::string odex_file_location(argv[1]);
119 std::string output_file_location(kDalvikCacheDir);
120 if (!OdexToCacheFile(odex_file_location, output_file_location)) {
123 std::cout << output_file_location;