base/sys_info_android.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/sys_info.h"
   6
   7 #include <sys/system_properties.h>
   8
   9 #include "base/android/sys_utils.h"
  10 #include "base/lazy_instance.h"
  11 #include "base/logging.h"
  12 #include "base/strings/string_number_conversions.h"
  13 #include "base/strings/string_piece.h"
  14 #include "base/strings/stringprintf.h"
  15 #include "base/sys_info_internal.h"
  16
  17 namespace {
  18
  19 // Default version of Android to fall back to when actual version numbers
  20 // cannot be acquired. This is an obviously invalid version number. Code
  21 // doing version comparison should treat it as so and fail all comparisons.
  22 const int kDefaultAndroidMajorVersion = 0;
  23 const int kDefaultAndroidMinorVersion = 0;
  24 const int kDefaultAndroidBugfixVersion = 0;
  25
  26 // Parse out the OS version numbers from the system properties.
  27 void ParseOSVersionNumbers(const char* os_version_str,
  28                            int32 *major_version,
  29                            int32 *minor_version,
  30                            int32 *bugfix_version) {
  31   if (os_version_str[0]) {
  32     // Try to parse out the version numbers from the string.
  33     int num_read = sscanf(os_version_str, "%d.%d.%d", major_version,
  34                           minor_version, bugfix_version);
  35
  36     if (num_read > 0) {
  37       // If we don't have a full set of version numbers, make the extras 0.
  38       if (num_read < 2) *minor_version = 0;
  39       if (num_read < 3) *bugfix_version = 0;
  40       return;
  41     }
  42   }
  43
  44   // For some reason, we couldn't parse the version number string.
  45   *major_version = kDefaultAndroidMajorVersion;
  46   *minor_version = kDefaultAndroidMinorVersion;
  47   *bugfix_version = kDefaultAndroidBugfixVersion;
  48 }
  49
  50 // Parses a system property (specified with unit 'k','m' or 'g').
  51 // Returns a value in bytes.
  52 // Returns -1 if the string could not be parsed.
  53 int64 ParseSystemPropertyBytes(const base::StringPiece& str) {
  54   const int64 KB = 1024;
  55   const int64 MB = 1024 * KB;
  56   const int64 GB = 1024 * MB;
  57   if (str.size() == 0u)
  58     return -1;
  59   int64 unit_multiplier = 1;
  60   size_t length = str.size();
  61   if (str[length - 1] == 'k') {
  62     unit_multiplier = KB;
  63     length--;
  64   } else if (str[length - 1] == 'm') {
  65     unit_multiplier = MB;
  66     length--;
  67   } else if (str[length - 1] == 'g') {
  68     unit_multiplier = GB;
  69     length--;
  70   }
  71   int64 result = 0;
  72   bool parsed = base::StringToInt64(str.substr(0, length), &result);
  73   bool negative = result <= 0;
  74   bool overflow = result >= std::numeric_limits<int64>::max() / unit_multiplier;
  75   if (!parsed || negative || overflow)
  76     return -1;
  77   return result * unit_multiplier;
  78 }
  79
  80 int GetDalvikHeapSizeMB() {
  81   char heap_size_str[PROP_VALUE_MAX];
  82   __system_property_get("dalvik.vm.heapsize", heap_size_str);
  83   // dalvik.vm.heapsize property is writable by a root user.
  84   // Clamp it to reasonable range as a sanity check,
  85   // a typical android device will never have less than 48MB.
  86   const int64 MB = 1024 * 1024;
  87   int64 result = ParseSystemPropertyBytes(heap_size_str);
  88   if (result == -1) {
  89      // We should consider not exposing these values if they are not reliable.
  90      LOG(ERROR) << "Can't parse dalvik.vm.heapsize: " << heap_size_str;
  91      result = base::SysInfo::AmountOfPhysicalMemoryMB() / 3;
  92   }
  93   result = std::min<int64>(std::max<int64>(32 * MB, result), 1024 * MB) / MB;
  94   return static_cast<int>(result);
  95 }
  96
  97 int GetDalvikHeapGrowthLimitMB() {
  98   char heap_size_str[PROP_VALUE_MAX];
  99   __system_property_get("dalvik.vm.heapgrowthlimit", heap_size_str);
 100   // dalvik.vm.heapgrowthlimit property is writable by a root user.
 101   // Clamp it to reasonable range as a sanity check,
 102   // a typical android device will never have less than 24MB.
 103   const int64 MB = 1024 * 1024;
 104   int64 result = ParseSystemPropertyBytes(heap_size_str);
 105   if (result == -1) {
 106      // We should consider not exposing these values if they are not reliable.
 107      LOG(ERROR) << "Can't parse dalvik.vm.heapgrowthlimit: " << heap_size_str;
 108      result = base::SysInfo::AmountOfPhysicalMemoryMB() / 6;
 109   }
 110   result = std::min<int64>(std::max<int64>(16 * MB, result), 512 * MB) / MB;
 111   return static_cast<int>(result);
 112 }
 113
 114 }  // anonymous namespace
 115
 116 namespace base {
 117
 118 std::string SysInfo::OperatingSystemName() {
 119   return "Android";
 120 }
 121
 122 std::string SysInfo::GetAndroidBuildCodename() {
 123   char os_version_codename_str[PROP_VALUE_MAX];
 124   __system_property_get("ro.build.version.codename", os_version_codename_str);
 125   return std::string(os_version_codename_str);
 126 }
 127
 128 std::string SysInfo::GetAndroidBuildID() {
 129   char os_build_id_str[PROP_VALUE_MAX];
 130   __system_property_get("ro.build.id", os_build_id_str);
 131   return std::string(os_build_id_str);
 132 }
 133
 134 std::string SysInfo::GetDeviceName() {
 135   char device_model_str[PROP_VALUE_MAX];
 136   __system_property_get("ro.product.model", device_model_str);
 137   return std::string(device_model_str);
 138 }
 139
 140 std::string SysInfo::OperatingSystemVersion() {
 141   int32 major, minor, bugfix;
 142   OperatingSystemVersionNumbers(&major, &minor, &bugfix);
 143   return StringPrintf("%d.%d.%d", major, minor, bugfix);
 144 }
 145
 146 void SysInfo::OperatingSystemVersionNumbers(int32* major_version,
 147                                             int32* minor_version,
 148                                             int32* bugfix_version) {
 149   // Read the version number string out from the properties.
 150   char os_version_str[PROP_VALUE_MAX];
 151   __system_property_get("ro.build.version.release", os_version_str);
 152
 153   // Parse out the numbers.
 154   ParseOSVersionNumbers(os_version_str, major_version, minor_version,
 155                         bugfix_version);
 156 }
 157
 158 int SysInfo::DalvikHeapSizeMB() {
 159   static int heap_size = GetDalvikHeapSizeMB();
 160   return heap_size;
 161 }
 162
 163 int SysInfo::DalvikHeapGrowthLimitMB() {
 164   static int heap_growth_limit = GetDalvikHeapGrowthLimitMB();
 165   return heap_growth_limit;
 166 }
 167
 168 static base::LazyInstance<
 169     base::internal::LazySysInfoValue<bool,
 170         android::SysUtils::IsLowEndDeviceFromJni> >::Leaky
 171     g_lazy_low_end_device = LAZY_INSTANCE_INITIALIZER;
 172
 173 bool SysInfo::IsLowEndDevice() {
 174   return g_lazy_low_end_device.Get().value();
 175 }
 176
 177
 178 }  // namespace base