1 /*
2  * Copyright 2016, 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 package com.android.managedprovisioning.common;
17 
18 import android.content.Context;
19 import android.content.SharedPreferences;
20 import android.support.annotation.VisibleForTesting;
21 
22 public class ManagedProvisioningSharedPreferences {
23     public static final long DEFAULT_PROVISIONING_ID = 0L;
24 
25     @VisibleForTesting
26     static final String KEY_PROVISIONING_ID = "provisioning_id";
27 
28     @VisibleForTesting
29     static final String SHARED_PREFERENCE = "managed_profile_shared_preferences";
30 
31     /**
32      * It's a process-wise in-memory write lock. No other processes will write the same file.
33      */
34     private static final Object sWriteLock = new Object();
35 
36     private final SharedPreferences mSharedPreferences;
37 
ManagedProvisioningSharedPreferences(Context context)38     public ManagedProvisioningSharedPreferences(Context context) {
39         mSharedPreferences = context.getSharedPreferences(SHARED_PREFERENCE, Context.MODE_PRIVATE);
40     }
41 
42     @VisibleForTesting
getProvisioningId()43     public long getProvisioningId() {
44         return mSharedPreferences.getLong(KEY_PROVISIONING_ID, DEFAULT_PROVISIONING_ID);
45     }
46 
47     /**
48      * Can assume the id is unique across all provisioning sessions
49      * @return a new provisioning id by incrementing the current id
50      */
incrementAndGetProvisioningId()51     public long incrementAndGetProvisioningId() {
52         synchronized (sWriteLock) {
53             long provisioningId = getProvisioningId();
54             provisioningId++;
55             // commit synchronously
56             mSharedPreferences.edit().putLong(KEY_PROVISIONING_ID, provisioningId).commit();
57             return provisioningId;
58         }
59     }
60 }
61