1 /*
2  * Copyright (C) 2015 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 package com.android.camera.debug;
18 
19 import com.android.camera.async.MainThread;
20 
21 import java.util.Arrays;
22 import java.util.Collections;
23 import java.util.List;
24 import java.util.Objects;
25 
26 /**
27  * Helpful logging extensions for including more detailed info about
28  * the objects and threads involved in the logging.
29  */
30 public class LogUtil {
31     /**
32      * Prefixes a message with with a hashcode tag of the object,
33      * and a [ui] tag if the method was executed on the main thread.
34      */
addTags(Object object, String msg)35     public static String addTags(Object object, String msg) {
36         return hashCodeTag(object) + mainThreadTag() + " " + msg;
37     }
38 
39     /**
40      * Prefixes a message with the bracketed tags specified in the
41      * tag list, along with a hashcode tag of the object, and a
42      * [ui] tag if the method was executed on the main thread.
43      */
addTags(Object object, String msg, String tagList)44     public static String addTags(Object object, String msg, String tagList) {
45         return hashCodeTag(object) + mainThreadTag() + formatTags(tagList) + " " + msg;
46     }
47 
formatTags(String tagList)48     private static String formatTags(String tagList) {
49         // Split on common "divider" characters:
50         // * All whitespace, except spaces: \x00-\x1F
51         // * () Characters: \x28-\x29
52         // * , Character: \x2C
53         // * / Character: \x2F
54         // * ;<=>? Characters: \x3B-\x3F
55         // * [\] Characters: \x5B-\x5D
56         // * {|} Characters: \x7B-\x7D
57         List<String> tags = Arrays.asList(tagList.split("[\\x00-\\x1F\\x28-\\x29\\x2C\\x2F"
58               + "\\x3B-\\x3F\\x5B-\\x5D\\x7B-\\x7D]"));
59         Collections.sort(tags);
60         String result = "";
61         // Convert all non-empty entries to tags.
62         for (String tag : tags) {
63             String trimmed = tag.trim();
64             if(trimmed.length() > 0) {
65                 result += "[" + trimmed + "]";
66             }
67         }
68         return result;
69     }
70 
hashCodeTag(Object object)71     private static String hashCodeTag(Object object) {
72         final String tag;
73         if (object == null) {
74             tag = "null";
75         } else {
76             tag = Integer.toHexString(Objects.hashCode(object));
77         }
78         return String.format("[%-9s]", "@" + tag);
79     }
80 
mainThreadTag()81     private static String mainThreadTag() {
82         return MainThread.isMainThread() ? "[ui]" : "";
83     }
84 }
85