Cache the system version, numbers, and name, as the OS does not.

During startup, the system name and/or version is requested a number of times, and each call is 1ms or more.  Changed the numbers parsing to use std::string instead of NSString so that the static variable could be an std::string, avoiding having to make the conversion every function call.

BUG=None


Review URL: https://chromiumcodereview.appspot.com/11437046

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@172092 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 28 insertions, 19 deletions

diff --git a/base/sys_info_ios.mm b/base/sys_info_ios.mm
index 1ee0e54..7863f6b 100644
--- a/base/sys_info_ios.mm
+++ b/base/sys_info_ios.mm
@@ -18,16 +18,28 @@ namespace base {
 
 // static
 std::string SysInfo::OperatingSystemName() {
-  base::mac::ScopedNSAutoreleasePool pool;
+  static dispatch_once_t get_system_name_once;
+  static std::string* system_name;
+  dispatch_once(&get_system_name_once, ^{
+      base::mac::ScopedNSAutoreleasePool pool;
+      system_name = new std::string(
+          SysNSStringToUTF8([[UIDevice currentDevice] systemName]));
+  });
   // Examples of returned value: 'iPhone OS' on iPad 5.1.1
   // and iPhone 5.1.1.
-  return SysNSStringToUTF8([[UIDevice currentDevice] systemName]);
+  return *system_name;
 }
 
 // static
 std::string SysInfo::OperatingSystemVersion() {
-  base::mac::ScopedNSAutoreleasePool pool;
-  return SysNSStringToUTF8([[UIDevice currentDevice] systemVersion]);
+  static dispatch_once_t get_system_version_once;
+  static std::string* system_version;
+  dispatch_once(&get_system_version_once, ^{
+      base::mac::ScopedNSAutoreleasePool pool;
+      system_version = new std::string(
+          SysNSStringToUTF8([[UIDevice currentDevice] systemVersion]));
+  });
+  return *system_version;
 }
 
 // static
@@ -35,21 +47,18 @@ void SysInfo::OperatingSystemVersionNumbers(int32* major_version,
                                             int32* minor_version,
                                             int32* bugfix_version) {
   base::mac::ScopedNSAutoreleasePool pool;
-  NSString* version = [[UIDevice currentDevice] systemVersion];
-  NSArray* version_info = [version componentsSeparatedByString:@"."];
-  NSUInteger length = [version_info count];
-
-  *major_version = [[version_info objectAtIndex:0] intValue];
-
-  if (length >= 2)
-    *minor_version = [[version_info objectAtIndex:1] intValue];
-  else
-    *minor_version = 0;
-
-  if (length >= 3)
-    *bugfix_version = [[version_info objectAtIndex:2] intValue];
-  else
-    *bugfix_version = 0;
+  std::string system_version = OperatingSystemVersion();
+  if (!system_version.empty()) {
+    // Try to parse out the version numbers from the string.
+    int num_read = sscanf(system_version.c_str(), "%d.%d.%d", major_version,
+                          minor_version, bugfix_version);
+    if (num_read < 1)
+      *major_version = 0;
+    if (num_read < 2)
+      *minor_version = 0;
+    if (num_read < 3)
+      *bugfix_version = 0;
+  }
 }
 
 // static