[DESCRIPTION]
Android O版本、AndroidN版本
1.ROM过大可以通过调整--compiler-filter,减少apk生成odex文件所占据空间的大小,通常来说odex+vdex文件越大,说明dex2oat优化的类越多越彻底,性能也相对较好;
2.Apk安装时间过长可以通过调整--compiler-filter,加快安装;
[SOLUTION]
修改dex2oat的--compiler-filter选项;
oat_location_为要修改apk的关键字,通常使用包名,比如微信:com.tencent.mm;
/art/dex2oat/dex2oat.cc
void ParseArgs(int argc, char** argv) {
original_argc = argc;
original_argv = argv;
InitLogging(argv, Runtime::Abort);
// Skip over argv[0].
argv++;
argc--;
if (argc == 0) {
Usage("No arguments specified");
}
……
} else if (option.starts_with("--dirty-image-objects=")) {
dirty_image_objects_filename_ = option.substr(strlen("--dirty-image-objects=")).data();
} else if (!compiler_options_->ParseCompilerOption(option, Usage)) {
Usage("Unknown argument %s", option.data());
}
}
/** MTK begin */
if(oat_location_ != "" && (oat_location_.find("mtk14456") != std::string::npos || oat_location_.find("com.tencent.mm")!= std::string::npos)){
LOG(INFO) << "MTK oat_location_=" << oat_location_ << ",SetCompilerFilter=CompilerOptions::kQuicken";
compiler_options_->SetCompilerFilter(CompilerFilter::kQuicken);
}
/** MTK end */
ProcessOptions(parser_options.get());
// Insert some compiler things.
InsertCompileOptions(argc, argv);
}
下面以Android O版本,微信6.6.2为例:
步骤:
1.下载weixin.apk,重命名为weixin.zip;解压缩,把所有的dex文件push到sdcard
2.adb shell,然后执行下面的命令:
./system/bin/dex2oat --oat-file=/sdcard/mtk14456tools_everything.odex --dex-file=/sdcard/classes.dex --dex-file=/sdcard/classes2.dex --dex-file=/sdcard/classes3.dex --dex-file=/sdcard/classes4.dex --dex-file=/sdcard/classes5.dex --compiler-filter=everything
--compiler-filter参数如下:
--compiler-filter=(assume-verified|extract|verify|quicken|space-profile|space|speed-profile|speed|everything-profile|everything)
通过上面可以得出下面数据:
Time为安装apk时dex2oat的时间;
Odex表示生成odex文件的大小;
Vdex表示生成vdex文件的大小;
表格统计数据是根据下面log和生成在sdcard的odex和vdex得出:
01-01 00:33:58.596 4332-4332/? I/dex2oat: StrippedCommandLine:./system/bin/dex2oat --oat-file=/sdcard/mtk14456tools_everything.odex --dex-file=/sdcard/classes.dex --dex-file=/sdcard/classes2.dex --dex-file=/sdcard/classes3.dex --dex-file=/sdcard/classes4.dex --dex-file=/sdcard/classes5.dex --compiler-filter=everything
01-01 00:34:51.958 4332-4332/? I/dex2oat: dex2oat took 53.364s (341.743s cpu) (threads: 8) arena alloc=27MB (28629200B) java alloc=24MB (25341840B) native alloc=128MB (135004032B) free=29MB (31195264B)