summaryrefslogtreecommitdiff
path: root/modules/ProfileAge.jsm
blob: f6030e2da35fa6671282ddbacfb49764f59e2f10 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

"use strict";

this.EXPORTED_SYMBOLS = ["ProfileAge"];

const {classes: Cc, interfaces: Ci, results: Cr, utils: Cu} = Components;

Cu.import("resource://gre/modules/Promise.jsm");
Cu.import("resource://gre/modules/osfile.jsm")
Cu.import("resource://gre/modules/Task.jsm");
Cu.import("resource://gre/modules/Log.jsm");
Cu.import("resource://services-common/utils.js");

/**
 * Profile access to times.json (eg, creation/reset time).
 * This is separate from the provider to simplify testing and enable extraction
 * to a shared location in the future.
 */
this.ProfileAge = function(profile, log) {
  this.profilePath = profile || OS.Constants.Path.profileDir;
  if (!this.profilePath) {
    throw new Error("No profile directory.");
  }
  this._log = log || {"debug": function (s) { dump(s + "\n"); }};
}
this.ProfileAge.prototype = {
  /**
   * There are three ways we can get our creation time:
   *
   * 1. From our own saved value (to avoid redundant work).
   * 2. From the on-disk JSON file.
   * 3. By calculating it from the filesystem.
   *
   * If we have to calculate, we write out the file; if we have
   * to touch the file, we persist in-memory.
   *
   * @return a promise that resolves to the profile's creation time.
   */
  get created() {
    function onSuccess(times) {
      if (times.created) {
        return times.created;
      }
      return onFailure.call(this, null, times);
    }

    function onFailure(err, times) {
      return this.computeAndPersistCreated(times)
                 .then(function onSuccess(created) {
                         return created;
                       }.bind(this));
    }

    return this.getTimes()
               .then(onSuccess.bind(this),
                     onFailure.bind(this));
  },

  /**
   * Explicitly make `file`, a filename, a full path
   * relative to our profile path.
   */
  getPath: function (file) {
    return OS.Path.join(this.profilePath, file);
  },

  /**
   * Return a promise which resolves to the JSON contents
   * of the time file, using the already read value if possible.
   */
  getTimes: function (file="times.json") {
    if (this._times) {
      return Promise.resolve(this._times);
    }
    return this.readTimes(file).then(
      times => {
        return this.times = times || {};
      }
    );
  },

  /**
   * Return a promise which resolves to the JSON contents
   * of the time file in this accessor's profile.
   */
  readTimes: function (file="times.json") {
    return CommonUtils.readJSON(this.getPath(file));
  },

  /**
   * Return a promise representing the writing of `contents`
   * to `file` in the specified profile.
   */
  writeTimes: function (contents, file="times.json") {
    return CommonUtils.writeJSON(contents, this.getPath(file));
  },

  /**
   * Merge existing contents with a 'created' field, writing them
   * to the specified file. Promise, naturally.
   */
  computeAndPersistCreated: function (existingContents, file="times.json") {
    let path = this.getPath(file);
    function onOldest(oldest) {
      let contents = existingContents || {};
      contents.created = oldest;
      this._times = contents;
      return this.writeTimes(contents, path)
                 .then(function onSuccess() {
                   return oldest;
                 });
    }

    return this.getOldestProfileTimestamp()
               .then(onOldest.bind(this));
  },

  /**
   * Traverse the contents of the profile directory, finding the oldest file
   * and returning its creation timestamp.
   */
  getOldestProfileTimestamp: function () {
    let self = this;
    let oldest = Date.now() + 1000;
    let iterator = new OS.File.DirectoryIterator(this.profilePath);
    self._log.debug("Iterating over profile " + this.profilePath);
    if (!iterator) {
      throw new Error("Unable to fetch oldest profile entry: no profile iterator.");
    }

    function onEntry(entry) {
      function onStatSuccess(info) {
        // OS.File doesn't seem to be behaving. See Bug 827148.
        // Let's do the best we can. This whole function is defensive.
        let date = info.winBirthDate || info.macBirthDate;
        if (!date || !date.getTime()) {
          // OS.File will only return file creation times of any kind on Mac
          // and Windows, where birthTime is defined.
          // That means we're unable to function on Linux, so we use mtime
          // instead.
          self._log.debug("No birth date. Using mtime.");
          date = info.lastModificationDate;
        }

        if (date) {
          let timestamp = date.getTime();
          self._log.debug("Using date: " + entry.path + " = " + date);
          if (timestamp < oldest) {
            oldest = timestamp;
          }
        }
      }

      function onStatFailure(e) {
        // Never mind.
        self._log.debug("Stat failure", e);
      }

      return OS.File.stat(entry.path)
                    .then(onStatSuccess, onStatFailure);
    }

    let promise = iterator.forEach(onEntry);

    function onSuccess() {
      iterator.close();
      return oldest;
    }

    function onFailure(reason) {
      iterator.close();
      throw new Error("Unable to fetch oldest profile entry: " + reason);
    }

    return promise.then(onSuccess, onFailure);
  },

  /**
   * Record (and persist) when a profile reset happened.  We just store a
   * single value - the timestamp of the most recent reset - but there is scope
   * to keep a list of reset times should our health-reporter successor
   * be able to make use of that.
   * Returns a promise that is resolved once the file has been written.
   */
  recordProfileReset: function (time=Date.now(), file="times.json") {
    return this.getTimes(file).then(
      times => {
        times.reset = time;
        return this.writeTimes(times, file);
      }
    );
  },

  /* Returns a promise that resolves to the time the profile was reset,
   * or undefined if not recorded.
   */
  get reset() {
    return this.getTimes().then(
      times => times.reset
    );
  },
}