summaryrefslogtreecommitdiffstats
path: root/netwerk/url-classifier/UrlClassifierExceptionListService.sys.mjs
blob: 8c2bc8a3aac1818a2fa01ff52f0466a5d11db973 (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
/* 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/. */

export function UrlClassifierExceptionListService() {}

const lazy = {};

ChromeUtils.defineESModuleGetters(lazy, {
  RemoteSettings: "resource://services-settings/remote-settings.sys.mjs",
});

const COLLECTION_NAME = "url-classifier-skip-urls";

class Feature {
  constructor(name, prefName) {
    this.name = name;
    this.prefName = prefName;
    this.observers = new Set();
    this.prefValue = null;
    this.remoteEntries = null;

    if (prefName) {
      this.prefValue = Services.prefs.getStringPref(this.prefName, null);
      Services.prefs.addObserver(prefName, this);
    }
  }

  async addAndRunObserver(observer) {
    this.observers.add(observer);
    this.notifyObservers(observer);
  }

  removeObserver(observer) {
    this.observers.delete(observer);
  }

  observe(subject, topic, data) {
    if (topic != "nsPref:changed" || data != this.prefName) {
      console.error(`Unexpected event ${topic} with ${data}`);
      return;
    }

    this.prefValue = Services.prefs.getStringPref(this.prefName, null);
    this.notifyObservers();
  }

  onRemoteSettingsUpdate(entries) {
    this.remoteEntries = [];

    for (let entry of entries) {
      if (entry.feature == this.name) {
        this.remoteEntries.push(entry.pattern.toLowerCase());
      }
    }
  }

  notifyObservers(observer = null) {
    let entries = [];
    if (this.prefValue) {
      entries = this.prefValue.split(",");
    }

    if (this.remoteEntries) {
      for (let entry of this.remoteEntries) {
        entries.push(entry);
      }
    }

    let entriesAsString = entries.join(",").toLowerCase();
    if (observer) {
      observer.onExceptionListUpdate(entriesAsString);
    } else {
      for (let obs of this.observers) {
        obs.onExceptionListUpdate(entriesAsString);
      }
    }
  }
}

UrlClassifierExceptionListService.prototype = {
  classID: Components.ID("{b9f4fd03-9d87-4bfd-9958-85a821750ddc}"),
  QueryInterface: ChromeUtils.generateQI([
    "nsIUrlClassifierExceptionListService",
  ]),

  features: {},
  _initialized: false,

  async lazyInit() {
    if (this._initialized) {
      return;
    }

    let rs = lazy.RemoteSettings(COLLECTION_NAME);
    rs.on("sync", event => {
      let {
        data: { current },
      } = event;
      this.entries = current || [];
      this.onUpdateEntries(current);
    });

    this._initialized = true;

    // If the remote settings list hasn't been populated yet we have to make sure
    // to do it before firing the first notification.
    // This has to be run after _initialized is set because we'll be
    // blocked while getting entries from RemoteSetting, and we don't want
    // LazyInit is executed again.
    try {
      // The data will be initially available from the local DB (via a
      // resource:// URI).
      this.entries = await rs.get();
    } catch (e) {}

    // RemoteSettings.get() could return null, ensure passing a list to
    // onUpdateEntries.
    if (!this.entries) {
      this.entries = [];
    }

    this.onUpdateEntries(this.entries);
  },

  onUpdateEntries(entries) {
    for (let key of Object.keys(this.features)) {
      let feature = this.features[key];
      feature.onRemoteSettingsUpdate(entries);
      feature.notifyObservers();
    }
  },

  registerAndRunExceptionListObserver(feature, prefName, observer) {
    // We don't await this; the caller is C++ and won't await this function,
    // and because we prevent re-entering into this method, once it's been
    // called once any subsequent calls will early-return anyway - so
    // awaiting that would be meaningless. Instead, `Feature` implementations
    // make sure not to call into observers until they have data, and we
    // make sure to let feature instances know whether we have data
    // immediately.
    this.lazyInit();

    if (!this.features[feature]) {
      let featureObj = new Feature(feature, prefName);
      this.features[feature] = featureObj;
      // If we've previously initialized, we need to pass the entries
      // we already have to the new feature.
      if (this.entries) {
        featureObj.onRemoteSettingsUpdate(this.entries);
      }
    }
    this.features[feature].addAndRunObserver(observer);
  },

  unregisterExceptionListObserver(feature, observer) {
    if (!this.features[feature]) {
      return;
    }
    this.features[feature].removeObserver(observer);
  },

  clear() {
    this.features = {};
    this._initialized = false;
    this.entries = null;
  },
};