Home | History | Annotate | Download | only in iot 
      1 /*
      2  * Copyright (C) 2017 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 "BootParameters.h"
     18 
     19 #define LOG_TAG "BootParameters"
     20 
     21 #include <fcntl.h>
     22 
     23 #include <string>
     24 
     25 #include <android-base/file.h>
     26 #include <base/json/json_parser.h>
     27 #include <base/json/json_reader.h>
     28 #include <base/json/json_value_converter.h>
     29 #include <utils/Log.h>
     30 
     31 using android::base::RemoveFileIfExists;
     32 using android::base::ReadFileToString;
     33 using base::JSONReader;
     34 using base::JSONValueConverter;
     35 using base::Value;
     36 
     37 namespace android {
     38 
     39 namespace {
     40 
     41 // Brightness and volume are stored as integer strings in next_boot.json.
     42 // They are divided by this constant to produce the actual float values in
     43 // range [0.0, 1.0]. This constant must match its counterpart in
     44 // DeviceManager.
     45 constexpr const float kFloatScaleFactor = 1000.0f;
     46 
     47 constexpr const char* kNextBootFile = "/data/misc/bootanimation/next_boot.json";
     48 constexpr const char* kLastBootFile = "/data/misc/bootanimation/last_boot.json";
     49 
     50 void swapBootConfigs() {
     51     // rename() will fail if next_boot.json doesn't exist, so delete
     52     // last_boot.json manually first.
     53     std::string err;
     54     if (!RemoveFileIfExists(kLastBootFile, &err))
     55         ALOGE("Unable to delete last boot file: %s", err.c_str());
     56 
     57     if (rename(kNextBootFile, kLastBootFile) && errno != ENOENT)
     58         ALOGE("Unable to swap boot files: %s", strerror(errno));
     59 
     60     int fd = open(kNextBootFile, O_CREAT, DEFFILEMODE);
     61     if (fd == -1) {
     62         ALOGE("Unable to create next boot file: %s", strerror(errno));
     63     } else {
     64         // Make next_boot.json writable to everyone so DeviceManagementService
     65         // can save saved_parameters there.
     66         if (fchmod(fd, DEFFILEMODE))
     67             ALOGE("Unable to set next boot file permissions: %s", strerror(errno));
     68         close(fd);
     69     }
     70 }
     71 
     72 }  // namespace
     73 
     74 BootParameters::SavedBootParameters::SavedBootParameters()
     75     : brightness(-kFloatScaleFactor), volume(-kFloatScaleFactor) {}
     76 
     77 void BootParameters::SavedBootParameters::RegisterJSONConverter(
     78         JSONValueConverter<SavedBootParameters>* converter) {
     79     converter->RegisterIntField("brightness", &SavedBootParameters::brightness);
     80     converter->RegisterIntField("volume", &SavedBootParameters::volume);
     81     converter->RegisterRepeatedString("param_names",
     82                                       &SavedBootParameters::param_names);
     83     converter->RegisterRepeatedString("param_values",
     84                                       &SavedBootParameters::param_values);
     85 }
     86 
     87 BootParameters::BootParameters() {
     88     swapBootConfigs();
     89     loadParameters();
     90 }
     91 
     92 void BootParameters::loadParameters() {
     93     std::string contents;
     94     if (!ReadFileToString(kLastBootFile, &contents)) {
     95         if (errno != ENOENT)
     96             ALOGE("Unable to read from %s: %s", kLastBootFile, strerror(errno));
     97 
     98         return;
     99     }
    100 
    101     std::unique_ptr<Value> json = JSONReader::Read(contents);
    102     if (json.get() == nullptr) {
    103         return;
    104     }
    105 
    106     JSONValueConverter<SavedBootParameters> converter;
    107     if (converter.Convert(*(json.get()), &mRawParameters)) {
    108         mBrightness = mRawParameters.brightness / kFloatScaleFactor;
    109         mVolume = mRawParameters.volume / kFloatScaleFactor;
    110 
    111         if (mRawParameters.param_names.size() == mRawParameters.param_values.size()) {
    112             for (size_t i = 0; i < mRawParameters.param_names.size(); i++) {
    113                 mParameters.push_back({
    114                         .key = mRawParameters.param_names[i]->c_str(),
    115                         .value = mRawParameters.param_values[i]->c_str()
    116                 });
    117             }
    118         } else {
    119             ALOGW("Parameter names and values size mismatch");
    120         }
    121     }
    122 }
    123 
    124 }  // namespace android
    125