summaryrefslogtreecommitdiffstats
path: root/toolkit/modules/sessionstore/SessionHistory.sys.mjs
blob: b4dc428742da0c21996350e1cabf7488a2487587 (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
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
/* 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/. */

const lazy = {};

ChromeUtils.defineESModuleGetters(lazy, {
  E10SUtils: "resource://gre/modules/E10SUtils.sys.mjs",
});

function debug(msg) {
  Services.console.logStringMessage("SessionHistory: " + msg);
}

/**
 * The external API exported by this module.
 */
export var SessionHistory = Object.freeze({
  isEmpty(docShell) {
    return SessionHistoryInternal.isEmpty(docShell);
  },

  collect(docShell, aFromIdx = -1) {
    if (Services.appinfo.sessionHistoryInParent) {
      throw new Error("Use SessionHistory.collectFromParent instead");
    }
    return SessionHistoryInternal.collect(docShell, aFromIdx);
  },

  collectFromParent(uri, documentHasChildNodes, history, aFromIdx = -1) {
    return SessionHistoryInternal.collectCommon(
      uri,
      documentHasChildNodes,
      history,
      aFromIdx
    );
  },

  restore(docShell, tabData) {
    if (Services.appinfo.sessionHistoryInParent) {
      throw new Error("Use SessionHistory.restoreFromParent instead");
    }
    return SessionHistoryInternal.restore(
      docShell.QueryInterface(Ci.nsIWebNavigation).sessionHistory
        .legacySHistory,
      tabData
    );
  },

  restoreFromParent(history, tabData) {
    return SessionHistoryInternal.restore(history, tabData);
  },
});

/**
 * The internal API for the SessionHistory module.
 */
var SessionHistoryInternal = {
  /**
   * Mapping from legacy docshellIDs to docshellUUIDs.
   */
  _docshellUUIDMap: new Map(),

  /**
   * Returns whether the given docShell's session history is empty.
   *
   * @param docShell
   *        The docShell that owns the session history.
   */
  isEmpty(docShell) {
    let webNavigation = docShell.QueryInterface(Ci.nsIWebNavigation);
    let history = webNavigation.sessionHistory;
    if (!webNavigation.currentURI) {
      return true;
    }
    let uri = webNavigation.currentURI.spec;
    return uri == "about:blank" && history.count == 0;
  },

  /**
   * Collects session history data for a given docShell.
   *
   * @param docShell
   *        The docShell that owns the session history.
   * @param aFromIdx
   *        The starting local index to collect the history from.
   * @return An object reprereseting a partial global history update.
   */
  collect(docShell, aFromIdx = -1) {
    let webNavigation = docShell.QueryInterface(Ci.nsIWebNavigation);
    let uri = webNavigation.currentURI.displaySpec;
    let body = webNavigation.document.body;
    let history = webNavigation.sessionHistory;
    return this.collectCommon(
      uri,
      body && body.hasChildNodes(),
      history.legacySHistory,
      aFromIdx
    );
  },

  collectCommon(uri, documentHasChildNodes, shistory, aFromIdx) {
    let data = {
      entries: [],
      requestedIndex: shistory.requestedIndex + 1,
    };

    // We want to keep track how many entries we *could* have collected and
    // how many we skipped, so we can sanitiy-check the current history index
    // and also determine whether we need to get any fallback data or not.
    let skippedCount = 0,
      entryCount = 0;

    if (shistory && shistory.count > 0) {
      let count = shistory.count;
      for (; entryCount < count; entryCount++) {
        let shEntry = shistory.getEntryAtIndex(entryCount);
        if (entryCount <= aFromIdx) {
          skippedCount++;
          continue;
        }
        let entry = this.serializeEntry(shEntry);
        data.entries.push(entry);
      }

      // Ensure the index isn't out of bounds if an exception was thrown above.
      data.index = Math.min(shistory.index + 1, entryCount);
    }

    // If either the session history isn't available yet or doesn't have any
    // valid entries, make sure we at least include the current page,
    // unless of course we just skipped all entries because aFromIdx was big enough.
    if (!data.entries.length && (skippedCount != entryCount || aFromIdx < 0)) {
      // We landed here because the history is inaccessible or there are no
      // history entries. In that case we should at least record the docShell's
      // current URL as a single history entry. If the URL is not about:blank
      // or it's a blank tab that was modified (like a custom newtab page),
      // record it. For about:blank we explicitly want an empty array without
      // an 'index' property to denote that there are no history entries.
      if (uri != "about:blank" || documentHasChildNodes) {
        data.entries.push({
          url: uri,
          triggeringPrincipal_base64: lazy.E10SUtils.SERIALIZED_SYSTEMPRINCIPAL,
        });
        data.index = 1;
      }
    }

    data.fromIdx = aFromIdx;

    return data;
  },

  /**
   * Get an object that is a serialized representation of a History entry.
   *
   * @param shEntry
   *        nsISHEntry instance
   * @return object
   */
  serializeEntry(shEntry) {
    let entry = { url: shEntry.URI.displaySpec, title: shEntry.title };

    if (shEntry.isSubFrame) {
      entry.subframe = true;
    }

    entry.cacheKey = shEntry.cacheKey;
    entry.ID = shEntry.ID;
    entry.docshellUUID = shEntry.docshellID.toString();

    // We will include the property only if it's truthy to save a couple of
    // bytes when the resulting object is stringified and saved to disk.
    if (shEntry.referrerInfo) {
      entry.referrerInfo = lazy.E10SUtils.serializeReferrerInfo(
        shEntry.referrerInfo
      );
    }

    if (shEntry.originalURI) {
      entry.originalURI = shEntry.originalURI.spec;
    }

    if (shEntry.resultPrincipalURI) {
      entry.resultPrincipalURI = shEntry.resultPrincipalURI.spec;

      // For downgrade compatibility we store the loadReplace property as it
      // would be stored before result principal URI introduction so that
      // the old code can still create URL based principals for channels
      // correctly.  When resultPrincipalURI is non-null and not equal to
      // channel's orignalURI in the new code, it's equal to setting
      // LOAD_REPLACE in the old code.  Note that we only do 'the best we can'
      // here to derivate the 'old' loadReplace flag value.
      entry.loadReplace = entry.resultPrincipalURI != entry.originalURI;
    } else {
      // We want to store the property to let the backward compatibility code,
      // when reading the stored session, work. When this property is undefined
      // that code will derive the result principal URI from the load replace
      // flag.
      entry.resultPrincipalURI = null;
    }

    if (shEntry.loadReplace) {
      // Storing under a new property name, since it has changed its meaning
      // with the result principal URI introduction.
      entry.loadReplace2 = shEntry.loadReplace;
    }

    if (shEntry.isSrcdocEntry) {
      entry.srcdocData = shEntry.srcdocData;
      entry.isSrcdocEntry = shEntry.isSrcdocEntry;
    }

    if (shEntry.baseURI) {
      entry.baseURI = shEntry.baseURI.spec;
    }

    if (shEntry.contentType) {
      entry.contentType = shEntry.contentType;
    }

    if (shEntry.scrollRestorationIsManual) {
      entry.scrollRestorationIsManual = true;
    } else {
      let x = {},
        y = {};
      shEntry.getScrollPosition(x, y);
      if (x.value !== 0 || y.value !== 0) {
        entry.scroll = x.value + "," + y.value;
      }

      let layoutHistoryState = shEntry.layoutHistoryState;
      if (layoutHistoryState && layoutHistoryState.hasStates) {
        let presStates = layoutHistoryState
          .getKeys()
          .map(key => this._getSerializablePresState(layoutHistoryState, key))
          .filter(
            presState =>
              // Only keep presState entries that contain more than the key itself.
              Object.getOwnPropertyNames(presState).length > 1
          );

        if (presStates.length) {
          entry.presState = presStates;
        }
      }
    }

    // Collect triggeringPrincipal data for the current history entry.
    if (shEntry.principalToInherit) {
      entry.principalToInherit_base64 = lazy.E10SUtils.serializePrincipal(
        shEntry.principalToInherit
      );
    }

    if (shEntry.partitionedPrincipalToInherit) {
      entry.partitionedPrincipalToInherit_base64 = lazy.E10SUtils.serializePrincipal(
        shEntry.partitionedPrincipalToInherit
      );
    }

    entry.hasUserInteraction = shEntry.hasUserInteraction;

    if (shEntry.triggeringPrincipal) {
      entry.triggeringPrincipal_base64 = lazy.E10SUtils.serializePrincipal(
        shEntry.triggeringPrincipal
      );
    }

    if (shEntry.csp) {
      entry.csp = lazy.E10SUtils.serializeCSP(shEntry.csp);
    }

    entry.docIdentifier = shEntry.bfcacheID;

    if (shEntry.stateData != null) {
      let stateData = shEntry.stateData;
      entry.structuredCloneState = stateData.getDataAsBase64();
      entry.structuredCloneVersion = stateData.formatVersion;
    }

    if (shEntry.wireframe != null) {
      entry.wireframe = shEntry.wireframe;
    }

    if (shEntry.childCount > 0 && !shEntry.hasDynamicallyAddedChild()) {
      let children = [];
      for (let i = 0; i < shEntry.childCount; i++) {
        let child = shEntry.GetChildAt(i);

        if (child) {
          children.push(this.serializeEntry(child));
        }
      }

      if (children.length) {
        entry.children = children;
      }
    }

    entry.persist = shEntry.persist;

    return entry;
  },

  /**
   * Get an object that is a serializable representation of a PresState.
   *
   * @param layoutHistoryState
   *        nsILayoutHistoryState instance
   * @param stateKey
   *        The state key of the presState to be retrieved.
   * @return object
   */
  _getSerializablePresState(layoutHistoryState, stateKey) {
    let presState = { stateKey };
    let x = {},
      y = {},
      scrollOriginDowngrade = {},
      res = {};

    layoutHistoryState.getPresState(stateKey, x, y, scrollOriginDowngrade, res);
    if (x.value !== 0 || y.value !== 0) {
      presState.scroll = x.value + "," + y.value;
    }
    if (scrollOriginDowngrade.value === false) {
      presState.scrollOriginDowngrade = scrollOriginDowngrade.value;
    }
    if (res.value != 1.0) {
      presState.res = res.value;
    }

    return presState;
  },

  /**
   * Restores session history data for a given docShell.
   *
   * @param history
   *        The session history object.
   * @param tabData
   *        The tabdata including all history entries.
   * @return A reference to the docShell's nsISHistory interface.
   */
  restore(history, tabData) {
    if (history.count > 0) {
      history.purgeHistory(history.count);
    }

    let idMap = { used: {} };
    let docIdentMap = {};
    for (let i = 0; i < tabData.entries.length; i++) {
      let entry = tabData.entries[i];
      // XXXzpao Wallpaper patch for bug 514751
      if (!entry.url) {
        continue;
      }
      let persist = "persist" in entry ? entry.persist : true;
      let shEntry = this.deserializeEntry(entry, idMap, docIdentMap, history);

      // To enable a smooth migration, we treat values of null/undefined as having
      // user interaction (because we don't want to hide all session history that was
      // added before we started recording user interaction).
      //
      // This attribute is only set on top-level SH history entries, so we set it
      // outside of deserializeEntry since that is called recursively.
      if (entry.hasUserInteraction == undefined) {
        shEntry.hasUserInteraction = true;
      } else {
        shEntry.hasUserInteraction = entry.hasUserInteraction;
      }

      history.addEntry(shEntry, persist);
    }

    // Select the right history entry.
    let index = tabData.index - 1;
    if (index < history.count && history.index != index) {
      history.index = index;
    }
    return history;
  },

  /**
   * Expands serialized history data into a session-history-entry instance.
   *
   * @param entry
   *        Object containing serialized history data for a URL
   * @param idMap
   *        Hash for ensuring unique frame IDs
   * @param docIdentMap
   *        Hash to ensure reuse of BFCache entries
   * @returns nsISHEntry
   */
  deserializeEntry(entry, idMap, docIdentMap, shistory) {
    var shEntry = shistory.createEntry();

    shEntry.URI = Services.io.newURI(entry.url);
    shEntry.title = entry.title || entry.url;
    if (entry.subframe) {
      shEntry.isSubFrame = entry.subframe || false;
    }
    shEntry.setLoadTypeAsHistory();
    if (entry.contentType) {
      shEntry.contentType = entry.contentType;
    }
    // Referrer information is now stored as a referrerInfo property. We should
    // also cope with the old format of passing `referrer` and `referrerPolicy`
    // separately.
    if (entry.referrerInfo) {
      shEntry.referrerInfo = lazy.E10SUtils.deserializeReferrerInfo(
        entry.referrerInfo
      );
    } else if (entry.referrer) {
      let ReferrerInfo = Components.Constructor(
        "@mozilla.org/referrer-info;1",
        "nsIReferrerInfo",
        "init"
      );
      shEntry.referrerInfo = new ReferrerInfo(
        entry.referrerPolicy,
        true,
        Services.io.newURI(entry.referrer)
      );
    }

    if (entry.originalURI) {
      shEntry.originalURI = Services.io.newURI(entry.originalURI);
    }
    if (typeof entry.resultPrincipalURI === "undefined" && entry.loadReplace) {
      // This is backward compatibility code for stored sessions saved prior to
      // introduction of the resultPrincipalURI property.  The equivalent of this
      // property non-null value used to be the URL while the LOAD_REPLACE flag
      // was set.
      shEntry.resultPrincipalURI = shEntry.URI;
    } else if (entry.resultPrincipalURI) {
      shEntry.resultPrincipalURI = Services.io.newURI(entry.resultPrincipalURI);
    }
    if (entry.loadReplace2) {
      shEntry.loadReplace = entry.loadReplace2;
    }
    if (entry.isSrcdocEntry) {
      shEntry.srcdocData = entry.srcdocData;
    }
    if (entry.baseURI) {
      shEntry.baseURI = Services.io.newURI(entry.baseURI);
    }

    if (entry.cacheKey) {
      shEntry.cacheKey = entry.cacheKey;
    }

    if (entry.ID) {
      // get a new unique ID for this frame (since the one from the last
      // start might already be in use)
      var id = idMap[entry.ID] || 0;
      if (!id) {
        // eslint-disable-next-line no-empty
        for (id = Date.now(); id in idMap.used; id++) {}
        idMap[entry.ID] = id;
        idMap.used[id] = true;
      }
      shEntry.ID = id;
    }

    // If we have the legacy docshellID on our entry, upgrade it to a
    // docshellUUID by going through the mapping.
    if (entry.docshellID) {
      if (!this._docshellUUIDMap.has(entry.docshellID)) {
        // Convert the nsID to a string so that the docshellUUID property
        // is correctly stored as a string.
        this._docshellUUIDMap.set(
          entry.docshellID,
          Services.uuid.generateUUID().toString()
        );
      }
      entry.docshellUUID = this._docshellUUIDMap.get(entry.docshellID);
      delete entry.docshellID;
    }

    if (entry.docshellUUID) {
      shEntry.docshellID = Components.ID(entry.docshellUUID);
    }

    if (entry.structuredCloneState && entry.structuredCloneVersion) {
      var stateData = Cc[
        "@mozilla.org/docshell/structured-clone-container;1"
      ].createInstance(Ci.nsIStructuredCloneContainer);

      stateData.initFromBase64(
        entry.structuredCloneState,
        entry.structuredCloneVersion
      );
      shEntry.stateData = stateData;
    }

    if (entry.scrollRestorationIsManual) {
      shEntry.scrollRestorationIsManual = true;
    } else {
      if (entry.scroll) {
        shEntry.setScrollPosition(
          ...this._deserializeScrollPosition(entry.scroll)
        );
      }

      if (entry.presState) {
        let layoutHistoryState = shEntry.initLayoutHistoryState();

        for (let presState of entry.presState) {
          this._deserializePresState(layoutHistoryState, presState);
        }
      }
    }

    let childDocIdents = {};
    if (entry.docIdentifier) {
      // If we have a serialized document identifier, try to find an SHEntry
      // which matches that doc identifier and adopt that SHEntry's
      // BFCacheEntry.  If we don't find a match, insert shEntry as the match
      // for the document identifier.
      let matchingEntry = docIdentMap[entry.docIdentifier];
      if (!matchingEntry) {
        matchingEntry = { shEntry, childDocIdents };
        docIdentMap[entry.docIdentifier] = matchingEntry;
      } else {
        shEntry.adoptBFCacheEntry(matchingEntry.shEntry);
        childDocIdents = matchingEntry.childDocIdents;
      }
    }

    // Every load must have a triggeringPrincipal to load otherwise we prevent it,
    // this code *must* always return a valid principal:
    shEntry.triggeringPrincipal = lazy.E10SUtils.deserializePrincipal(
      entry.triggeringPrincipal_base64,
      () => {
        // This callback fires when we failed to deserialize the principal (or we don't have one)
        // and this ensures we always have a principal returned from this function.
        // We must always have a triggering principal for a load to work.
        // A null principal won't always work however is safe to use.
        debug(
          "Couldn't deserialize the triggeringPrincipal, falling back to NullPrincipal"
        );
        return Services.scriptSecurityManager.createNullPrincipal({});
      }
    );
    // As both partitionedPrincipal and principalToInherit are both not required to load
    // it's ok to keep these undefined when we don't have a previously defined principal.
    if (entry.partitionedPrincipalToInherit_base64) {
      shEntry.partitionedPrincipalToInherit = lazy.E10SUtils.deserializePrincipal(
        entry.partitionedPrincipalToInherit_base64
      );
    }
    if (entry.principalToInherit_base64) {
      shEntry.principalToInherit = lazy.E10SUtils.deserializePrincipal(
        entry.principalToInherit_base64
      );
    }
    if (entry.csp) {
      shEntry.csp = lazy.E10SUtils.deserializeCSP(entry.csp);
    }
    if (entry.wireframe) {
      shEntry.wireframe = entry.wireframe;
    }

    if (entry.children) {
      for (var i = 0; i < entry.children.length; i++) {
        // XXXzpao Wallpaper patch for bug 514751
        if (!entry.children[i].url) {
          continue;
        }

        // We're getting sessionrestore.js files with a cycle in the
        // doc-identifier graph, likely due to bug 698656.  (That is, we have
        // an entry where doc identifier A is an ancestor of doc identifier B,
        // and another entry where doc identifier B is an ancestor of A.)
        //
        // If we were to respect these doc identifiers, we'd create a cycle in
        // the SHEntries themselves, which causes the docshell to loop forever
        // when it looks for the root SHEntry.
        //
        // So as a hack to fix this, we restrict the scope of a doc identifier
        // to be a node's siblings and cousins, and pass childDocIdents, not
        // aDocIdents, to _deserializeHistoryEntry.  That is, we say that two
        // SHEntries with the same doc identifier have the same document iff
        // they have the same parent or their parents have the same document.

        shEntry.AddChild(
          this.deserializeEntry(
            entry.children[i],
            idMap,
            childDocIdents,
            shistory
          ),
          i
        );
      }
    }

    return shEntry;
  },

  /**
   * Expands serialized PresState data and adds it to the given nsILayoutHistoryState.
   *
   * @param layoutHistoryState
   *        nsILayoutHistoryState instance
   * @param presState
   *        Object containing serialized PresState data.
   */
  _deserializePresState(layoutHistoryState, presState) {
    let stateKey = presState.stateKey;
    let scrollOriginDowngrade =
      typeof presState.scrollOriginDowngrade == "boolean"
        ? presState.scrollOriginDowngrade
        : true;
    let res = presState.res || 1.0;

    layoutHistoryState.addNewPresState(
      stateKey,
      ...this._deserializeScrollPosition(presState.scroll),
      scrollOriginDowngrade,
      res
    );
  },

  /**
   * Expands serialized scroll position data into an array containing the x and y coordinates,
   * defaulting to 0,0 if no scroll position was found.
   *
   * @param scroll
   *        Object containing serialized scroll position data.
   * @return An array containing the scroll position's x and y coordinates.
   */
  _deserializeScrollPosition(scroll = "0,0") {
    return scroll.split(",").map(pos => parseInt(pos, 10) || 0);
  },
};