Read speed of SharedPreferences

Question

How fast are SharedPreferences? Is there a way to put them in memory for reading? I have a small amount of data that a ListView has to query to d

Answer 1

According to this link, getSharedPreferences is not that much heavy because it opens file only when you call getSharedPreferences first time:

// There are 1000 String values in preferences

SharedPreferences first = context.getSharedPreferences("com.example.app", Context.MODE_PRIVATE);
// call time = 4 milliseconds

SharedPreferences second = context.getSharedPreferences("com.example.app", Context.MODE_PRIVATE);
// call time = 0 milliseconds

SharedPreferences third = context.getSharedPreferences("com.example.app", Context.MODE_PRIVATE);
// call time = 0 milliseconds

But using get methods will take some time for the first time you call it:

first.getString("key", null)
// call time = 147 milliseconds

first.getString("key", null)
// call time = 0 milliseconds

second.getString("key", null)
// call time = 0 milliseconds

third.getString("key", null)
// call time = 0 milliseconds