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
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
content / browser / code_cache / generated_code_cache.cc [blame]
// Copyright 2018 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/342213636): Remove this and spanify to fix the errors.
#pragma allow_unsafe_buffers
#endif
#include "content/browser/code_cache/generated_code_cache.h"
#include <iostream>
#include <string_view>
#include "base/feature_list.h"
#include "base/functional/bind.h"
#include "base/functional/callback_helpers.h"
#include "base/memory/ptr_util.h"
#include "base/metrics/histogram_functions.h"
#include "base/metrics/histogram_macros.h"
#include "base/not_fatal_until.h"
#include "base/numerics/byte_conversions.h"
#include "base/strings/strcat.h"
#include "base/strings/string_number_conversions.h"
#include "base/time/time.h"
#include "components/services/storage/public/cpp/big_io_buffer.h"
#include "content/common/features.h"
#include "content/public/browser/content_browser_client.h"
#include "content/public/common/content_client.h"
#include "content/public/common/url_constants.h"
#include "crypto/sha2.h"
#include "net/base/completion_once_callback.h"
#include "net/base/features.h"
#include "net/base/network_isolation_key.h"
#include "net/base/url_util.h"
#include "net/http/http_cache.h"
#include "third_party/blink/public/common/scheme_registry.h"
#include "url/gurl.h"
using storage::BigIOBuffer;
namespace content {
namespace {
constexpr char kPrefix[] = "_key";
constexpr char kSeparator[] = " \n";
// We always expect to receive valid URLs that can be used as keys to the code
// cache. The relevant checks (for ex: resource_url is valid, origin_lock is
// not opque etc.,) must be done prior to requesting the code cache.
//
// This function doesn't enforce anything in the production code. It is here
// to make the assumptions explicit and to catch any errors when DCHECKs are
// enabled.
void CheckValidKeys(const GURL& resource_url,
const GURL& origin_lock,
GeneratedCodeCache::CodeCacheType cache_type) {
// If the resource url is invalid don't cache the code.
DCHECK(resource_url.is_valid());
bool resource_url_is_chrome_or_chrome_untrusted =
resource_url.SchemeIs(content::kChromeUIScheme) ||
resource_url.SchemeIs(content::kChromeUIUntrustedScheme);
DCHECK(resource_url.SchemeIsHTTPOrHTTPS() ||
resource_url_is_chrome_or_chrome_untrusted ||
blink::CommonSchemeRegistry::IsExtensionScheme(resource_url.scheme()));
// |origin_lock| should be either empty or should have
// Http/Https/chrome/chrome-untrusted schemes and it should not be a URL with
// opaque origin. Empty origin_locks are allowed when the renderer is not
// locked to an origin.
bool origin_lock_is_chrome_or_chrome_untrusted =
origin_lock.SchemeIs(content::kChromeUIScheme) ||
origin_lock.SchemeIs(content::kChromeUIUntrustedScheme);
DCHECK(
origin_lock.is_empty() ||
((origin_lock.SchemeIsHTTPOrHTTPS() ||
origin_lock_is_chrome_or_chrome_untrusted ||
blink::CommonSchemeRegistry::IsExtensionScheme(origin_lock.scheme())) &&
!url::Origin::Create(origin_lock).opaque()));
// The chrome and chrome-untrusted schemes are only used with the WebUI
// code cache type.
DCHECK_EQ(origin_lock_is_chrome_or_chrome_untrusted,
cache_type == GeneratedCodeCache::kWebUIJavaScript);
DCHECK_EQ(resource_url_is_chrome_or_chrome_untrusted,
cache_type == GeneratedCodeCache::kWebUIJavaScript);
}
// Generates the cache key for the given |resource_url|, |origin_lock| and
// |nik|.
// |resource_url| is the url corresponding to the requested resource.
// |origin_lock| is the origin that the renderer which requested this
// resource is locked to.
// |nik| is the network isolation key that consists of top-level-site that
// initiated the request.
// For example, if SitePerProcess is enabled and http://script.com/script1.js is
// requested by http://example.com, then http://script.com/script.js is the
// resource_url and http://example.com is the origin_lock.
//
// This returns the key by concatenating the serialized url, origin lock and nik
// with a separator in between. |origin_lock| could be empty when renderer is
// not locked to an origin (ex: SitePerProcess is disabled) and it is safe to
// use only |resource_url| as the key in such cases.
// TODO(wjmaclean): Either convert this to use a SiteInfo object, or convert it
// to something not based on URLs.
std::string GetCacheKey(const GURL& resource_url,
const GURL& origin_lock,
const net::NetworkIsolationKey& nik,
GeneratedCodeCache::CodeCacheType cache_type) {
CheckValidKeys(resource_url, origin_lock, cache_type);
// Add a prefix _ so it can't be parsed as a valid URL.
std::string key(kPrefix);
// Remove reference, username and password sections of the URL.
key.append(net::SimplifyUrlForRequest(resource_url).spec());
// Add a separator between URL and origin to avoid any possibility of
// attacks by crafting the URL. URLs do not contain any control ASCII
// characters, and also space is encoded. So use ' \n' as a seperator.
key.append(kSeparator);
if (origin_lock.is_valid())
key.append(net::SimplifyUrlForRequest(origin_lock).spec());
if (net::HttpCache::IsSplitCacheEnabled() &&
base::FeatureList::IsEnabled(
net::features::kSplitCodeCacheByNetworkIsolationKey)) {
// TODO(crbug.com/40232395): Transient NIKs return nullopt when
// their ToCacheKeyString() method is invoked, as they generally shouldn't
// be written to disk. This code is currently reached for transient NIKs,
// which needs to be fixed.
if (!nik.IsTransient()) {
key.append(kSeparator);
key.append(*nik.ToCacheKeyString());
}
}
return key;
}
constexpr size_t kResponseTimeSizeInBytes = sizeof(int64_t);
constexpr size_t kDataSizeInBytes = sizeof(uint32_t);
constexpr size_t kHeaderSizeInBytes =
kResponseTimeSizeInBytes + kDataSizeInBytes;
// The SHA-256 checksum is used as the key for the de-duplicated code data. We
// must convert the checksum to a string key in a way that is guaranteed not to
// match a key generated by |GetCacheKey|. A simple way to do this is to convert
// it to a hex number string, which is twice as long as the checksum.
constexpr size_t kSHAKeySizeInBytes = 2 * crypto::kSHA256Length;
// This is the threshold for storing the header and cached code in stream 0,
// which is read into memory on opening an entry. JavaScript code caching stores
// time stamps with no data, or timestamps with just a tag, and we observe many
// 8 and 16 byte reads and writes. Make the threshold larger to speed up small
// code entries too.
constexpr size_t kInlineDataLimit = 4096;
// This is the maximum size for code that will be stored under the key generated
// by |GetCacheKey|. Each origin will get its own copy of the generated code for
// a given resource. Code that is larger than this limit will be stored under a
// key derived from the code checksum, and each origin using a given resource
// gets its own small entry under the key generated by |GetCacheKey| that holds
// the hash, enabling a two stage lookup. This limit was determined empirically
// by a Finch experiment.
constexpr size_t kDedicatedDataLimit = 16384;
void WriteCommonDataHeader(net::IOBufferWithSize* buffer,
const base::Time& response_time,
uint32_t data_size) {
auto header = buffer->span().first<kHeaderSizeInBytes>();
auto [header_time, header_size] = header.split_at<kResponseTimeSizeInBytes>();
header_time.copy_from(base::I64ToLittleEndian(
response_time.ToDeltaSinceWindowsEpoch().InMicroseconds()));
header_size.copy_from(base::U32ToLittleEndian(data_size));
}
void ReadCommonDataHeader(net::IOBufferWithSize* buffer,
base::Time* response_time,
uint32_t* data_size) {
auto header = buffer->span().first<kHeaderSizeInBytes>();
auto [header_time, header_size] = header.split_at<kResponseTimeSizeInBytes>();
int64_t raw_response_time = base::I64FromLittleEndian(header_time);
*response_time = base::Time::FromDeltaSinceWindowsEpoch(
base::Microseconds(raw_response_time));
*data_size = base::U32FromLittleEndian(header_size);
}
static_assert(mojo_base::BigBuffer::kMaxInlineBytes <=
std::numeric_limits<int>::max(),
"Buffer size calculations may overflow int");
net::CacheType CodeCacheTypeToNetCacheType(
GeneratedCodeCache::CodeCacheType type) {
switch (type) {
case GeneratedCodeCache::CodeCacheType::kJavaScript:
return net::GENERATED_BYTE_CODE_CACHE;
case GeneratedCodeCache::CodeCacheType::kWebAssembly:
return net::GENERATED_NATIVE_CODE_CACHE;
case GeneratedCodeCache::CodeCacheType::kWebUIJavaScript:
return net::GENERATED_WEBUI_BYTE_CODE_CACHE;
}
NOTREACHED_IN_MIGRATION();
}
void CollectStatisticsForEmbedderWebUIPages(
const GURL& resource_url,
const GURL& origin_lock,
GeneratedCodeCache::CacheEntryStatus entry_status) {
const content::ContentBrowserClient* browser_client =
GetContentClient()->browser();
CHECK(browser_client);
const std::string resource_hostname =
browser_client->GetWebUIHostnameForCodeCacheMetrics(resource_url);
const std::string origin_hostname =
browser_client->GetWebUIHostnameForCodeCacheMetrics(origin_lock);
if (!resource_hostname.empty()) {
base::UmaHistogramEnumeration(
base::StrCat({"SiteIsolatedCodeCache.JS.WebUI.",
std::move(resource_hostname), ".Resource.Behaviour"}),
entry_status);
}
if (!origin_hostname.empty()) {
base::UmaHistogramEnumeration(
base::StrCat({"SiteIsolatedCodeCache.JS.WebUI.",
std::move(origin_hostname), ".Origin.Behaviour"}),
entry_status);
}
}
} // namespace
bool GeneratedCodeCache::IsValidHeader(
scoped_refptr<net::IOBufferWithSize> small_buffer) const {
size_t buffer_size = small_buffer->size();
if (buffer_size < kHeaderSizeInBytes) {
return false;
}
base::Time response_time;
uint32_t data_size = 0;
ReadCommonDataHeader(small_buffer.get(), &response_time, &data_size);
if (data_size <= kInlineDataLimit) {
return buffer_size == kHeaderSizeInBytes + data_size;
}
if (!ShouldDeduplicateEntry(data_size)) {
return buffer_size == kHeaderSizeInBytes;
}
return buffer_size == kHeaderSizeInBytes + kSHAKeySizeInBytes;
}
void GeneratedCodeCache::ReportPeriodicalHistograms() {
DCHECK_EQ(cache_type_, CodeCacheType::kJavaScript);
base::UmaHistogramCustomCounts(
"SiteIsolatedCodeCache.JS.PotentialMemoryBackedCodeCacheSize2",
lru_cache_.GetSize(),
/*min=*/0,
/*exclusive_max=*/kLruCacheCapacity,
/*buckets=*/50);
}
std::string GeneratedCodeCache::GetResourceURLFromKey(const std::string& key) {
constexpr size_t kPrefixStringLen = std::size(kPrefix) - 1;
// |key| may not have a prefix and separator (e.g. for deduplicated entries).
// In that case, return an empty string.
const size_t separator_index = key.find(kSeparator);
if (key.length() < kPrefixStringLen || separator_index == std::string::npos) {
return std::string();
}
std::string resource_url =
key.substr(kPrefixStringLen, separator_index - kPrefixStringLen);
return resource_url;
}
void GeneratedCodeCache::CollectStatistics(
const GURL& resource_url,
const GURL& origin_lock,
GeneratedCodeCache::CacheEntryStatus status) {
switch (cache_type_) {
case GeneratedCodeCache::CodeCacheType::kJavaScript:
UMA_HISTOGRAM_ENUMERATION("SiteIsolatedCodeCache.JS.Behaviour", status);
break;
case GeneratedCodeCache::CodeCacheType::kWebUIJavaScript:
UMA_HISTOGRAM_ENUMERATION("SiteIsolatedCodeCache.JS.Behaviour", status);
UMA_HISTOGRAM_ENUMERATION("SiteIsolatedCodeCache.JS.WebUI.Behaviour",
status);
CollectStatisticsForEmbedderWebUIPages(resource_url, origin_lock, status);
break;
case GeneratedCodeCache::CodeCacheType::kWebAssembly:
UMA_HISTOGRAM_ENUMERATION("SiteIsolatedCodeCache.WASM.Behaviour", status);
break;
}
}
// Stores the information about a pending request while disk backend is
// being initialized or another request for the same key is live.
class GeneratedCodeCache::PendingOperation {
public:
PendingOperation(Operation op,
const GURL& resource_url,
const GURL& origin_lock,
const std::string& key,
scoped_refptr<net::IOBufferWithSize> small_buffer,
scoped_refptr<BigIOBuffer> large_buffer)
: op_(op),
resource_url_(resource_url),
origin_lock_(origin_lock),
key_(key),
small_buffer_(small_buffer),
large_buffer_(large_buffer) {
DCHECK(Operation::kWrite == op_ || Operation::kWriteWithSHAKey == op_);
}
PendingOperation(Operation op,
const GURL& resource_url,
const GURL& origin_lock,
const std::string& key,
ReadDataCallback read_callback)
: op_(op),
resource_url_(resource_url),
origin_lock_(origin_lock),
key_(key),
read_callback_(std::move(read_callback)) {
DCHECK_EQ(Operation::kFetch, op_);
}
PendingOperation(Operation op,
const GURL& resource_url,
const GURL& origin_lock,
const std::string& key,
const base::Time& response_time,
const base::TimeTicks start_time,
scoped_refptr<net::IOBufferWithSize> small_buffer,
scoped_refptr<BigIOBuffer> large_buffer,
ReadDataCallback read_callback)
: op_(op),
resource_url_(resource_url),
origin_lock_(origin_lock),
key_(key),
response_time_(response_time),
start_time_(start_time),
small_buffer_(small_buffer),
large_buffer_(large_buffer),
read_callback_(std::move(read_callback)) {
DCHECK_EQ(Operation::kFetchWithSHAKey, op_);
}
PendingOperation(Operation op,
const GURL& resource_url,
const GURL& origin_lock,
const std::string& key)
: op_(op),
resource_url_(resource_url),
origin_lock_(origin_lock),
key_(key) {
DCHECK_EQ(Operation::kDelete, op_);
}
PendingOperation(Operation op, GetBackendCallback backend_callback)
: op_(op), backend_callback_(std::move(backend_callback)) {
DCHECK_EQ(Operation::kGetBackend, op_);
}
~PendingOperation();
Operation operation() const { return op_; }
const std::string& key() const { return key_; }
const GURL& resource_url() const { return resource_url_; }
const GURL& origin_lock() const { return origin_lock_; }
scoped_refptr<net::IOBufferWithSize> small_buffer() { return small_buffer_; }
scoped_refptr<BigIOBuffer> large_buffer() { return large_buffer_; }
ReadDataCallback TakeReadCallback() { return std::move(read_callback_); }
void RunReadCallback(GeneratedCodeCache* code_cache,
base::Time response_time,
mojo_base::BigBuffer data) {
if (code_cache->cache_type_ == CodeCacheType::kJavaScript) {
const bool code_cache_hit = data.size() > 0;
const bool in_memory_code_cache_hit = code_cache->lru_cache_.Has(key_);
if (code_cache_hit && !in_memory_code_cache_hit) {
code_cache->lru_cache_.Put(key_, response_time, base::make_span(data));
}
if (!base::FeatureList::IsEnabled(features::kInMemoryCodeCache)) {
if (code_cache_hit && in_memory_code_cache_hit) {
base::UmaHistogramTimes(
"SiteIsolatedCodeCache.JS.MemoryBackedCodeCachePotentialImpact",
base::TimeTicks::Now() - start_time_);
}
base::UmaHistogramBoolean("SiteIsolatedCodeCache.JS.Hit",
code_cache_hit);
base::UmaHistogramBoolean(
"SiteIsolatedCodeCache.JS.PotentialMemoryBackedCodeCacheHit",
in_memory_code_cache_hit);
}
}
std::move(read_callback_).Run(response_time, std::move(data));
}
GetBackendCallback TakeBackendCallback() {
return std::move(backend_callback_);
}
// These are called by Fetch operations to hold the buffers we create once the
// entry is opened.
void set_small_buffer(scoped_refptr<net::IOBufferWithSize> small_buffer) {
DCHECK_EQ(Operation::kFetch, op_);
small_buffer_ = small_buffer;
}
void set_large_buffer(scoped_refptr<BigIOBuffer> large_buffer) {
DCHECK_EQ(Operation::kFetch, op_);
large_buffer_ = large_buffer;
}
// This returns the site-specific response time for merged code entries.
const base::Time& response_time() const {
DCHECK_EQ(Operation::kFetchWithSHAKey, op_);
return response_time_;
}
base::TimeTicks start_time() const { return start_time_; }
// These are called by write and fetch operations to track buffer completions
// and signal when the operation has finished, and whether it was successful.
bool succeeded() const { return succeeded_; }
bool AddBufferCompletion(bool succeeded) {
DCHECK(op_ == Operation::kWrite || op_ == Operation::kWriteWithSHAKey ||
op_ == Operation::kFetch || op_ == Operation::kFetchWithSHAKey);
if (!succeeded)
succeeded_ = false;
DCHECK_GT(2, completions_);
completions_++;
return completions_ == 2;
}
private:
const Operation op_;
const GURL resource_url_;
const GURL origin_lock_;
const std::string key_;
const base::Time response_time_;
const base::TimeTicks start_time_ = base::TimeTicks::Now();
scoped_refptr<net::IOBufferWithSize> small_buffer_;
scoped_refptr<BigIOBuffer> large_buffer_;
ReadDataCallback read_callback_;
GetBackendCallback backend_callback_;
int completions_ = 0;
bool succeeded_ = true;
};
GeneratedCodeCache::PendingOperation::~PendingOperation() = default;
GeneratedCodeCache::GeneratedCodeCache(const base::FilePath& path,
int max_size_bytes,
CodeCacheType cache_type)
: backend_state_(kInitializing),
path_(path),
max_size_bytes_(max_size_bytes),
cache_type_(cache_type),
lru_cache_(max_size_bytes == 0
? kLruCacheCapacity
: std::min<int64_t>(kLruCacheCapacity, max_size_bytes)) {
CreateBackend();
if (cache_type == CodeCacheType::kJavaScript) {
histograms_timer_.Start(
FROM_HERE, base::Minutes(5),
base::BindRepeating(&GeneratedCodeCache::ReportPeriodicalHistograms,
base::Unretained(this)));
}
}
GeneratedCodeCache::~GeneratedCodeCache() = default;
void GeneratedCodeCache::GetBackend(GetBackendCallback callback) {
switch (backend_state_) {
case kFailed:
std::move(callback).Run(nullptr);
return;
case kInitialized:
std::move(callback).Run(backend_.get());
return;
case kInitializing:
pending_ops_.emplace(std::make_unique<PendingOperation>(
Operation::kGetBackend, std::move(callback)));
return;
}
}
void GeneratedCodeCache::WriteEntry(const GURL& url,
const GURL& origin_lock,
const net::NetworkIsolationKey& nik,
const base::Time& response_time,
mojo_base::BigBuffer data) {
if (backend_state_ == kFailed) {
// Silently fail the request.
CollectStatistics(url, origin_lock, CacheEntryStatus::kError);
return;
}
// Reject buffers that are large enough to cause overflow problems.
if (data.size() >= std::numeric_limits<int32_t>::max())
return;
const std::string key = GetCacheKey(url, origin_lock, nik, cache_type_);
if (cache_type_ == CodeCacheType::kJavaScript) {
lru_cache_.Put(key, response_time, base::make_span(data));
}
scoped_refptr<net::IOBufferWithSize> small_buffer;
scoped_refptr<BigIOBuffer> large_buffer;
const uint32_t data_size = static_cast<uint32_t>(data.size());
// We have three different cache entry layouts, depending on data size.
if (data_size <= kInlineDataLimit) {
// 1. Inline
// [stream0] response time, size, data
// [stream1] <empty>
small_buffer = base::MakeRefCounted<net::IOBufferWithSize>(
kHeaderSizeInBytes + data.size());
// Copy |data| into the small buffer.
small_buffer->span().subspan(kHeaderSizeInBytes).copy_from(data);
// Write 0 bytes and truncate stream 1 to clear any stale data.
large_buffer = base::MakeRefCounted<BigIOBuffer>(mojo_base::BigBuffer());
} else if (!ShouldDeduplicateEntry(data_size)) {
// 2. Dedicated
// [stream0] response time, size
// [stream1] data
small_buffer =
base::MakeRefCounted<net::IOBufferWithSize>(kHeaderSizeInBytes);
large_buffer = base::MakeRefCounted<BigIOBuffer>(std::move(data));
} else {
// 3. Indirect
// [stream0] response time, size, checksum
// [stream1] <empty>
// [stream0 (checksum key entry)] <empty>
// [stream1 (checksum key entry)] data
// Make a copy of the data before hashing. A compromised renderer could
// change shared memory before we can compute the hash and write the data.
// TODO(crbug.com/40151989) Eliminate this copy when the shared memory can't
// be written by the sender.
mojo_base::BigBuffer copy({data.data(), data.size()});
if (copy.size() != data.size())
return;
data = mojo_base::BigBuffer(); // Release the old buffer.
uint8_t result[crypto::kSHA256Length];
crypto::SHA256HashString(
std::string_view(reinterpret_cast<char*>(copy.data()), copy.size()),
result, std::size(result));
std::string checksum_key = base::HexEncode(result);
DCHECK_EQ(kSHAKeySizeInBytes, checksum_key.length());
small_buffer = base::MakeRefCounted<net::IOBufferWithSize>(
kHeaderSizeInBytes + checksum_key.length());
// Copy |checksum_key| into the small buffer.
small_buffer->span()
.subspan(kHeaderSizeInBytes)
.copy_from(base::as_byte_span(checksum_key));
// Write 0 bytes and truncate stream 1 to clear any stale data.
large_buffer = base::MakeRefCounted<BigIOBuffer>(mojo_base::BigBuffer());
// Issue another write operation for the code, with the checksum as the key
// and nothing in the header.
auto small_buffer2 = base::MakeRefCounted<net::IOBufferWithSize>(0);
auto large_buffer2 = base::MakeRefCounted<BigIOBuffer>(std::move(copy));
auto op2 = std::make_unique<PendingOperation>(
Operation::kWriteWithSHAKey, url, origin_lock, checksum_key,
small_buffer2, large_buffer2);
EnqueueOperation(std::move(op2));
}
WriteCommonDataHeader(small_buffer.get(), response_time, data_size);
// Create the write operation.
auto op = std::make_unique<PendingOperation>(
Operation::kWrite, url, origin_lock, key, small_buffer, large_buffer);
EnqueueOperation(std::move(op));
}
void GeneratedCodeCache::FetchEntry(const GURL& url,
const GURL& origin_lock,
const net::NetworkIsolationKey& nik,
ReadDataCallback read_data_callback) {
if (backend_state_ == kFailed) {
CollectStatistics(url, origin_lock, CacheEntryStatus::kError);
// Fail the request.
std::move(read_data_callback).Run(base::Time(), mojo_base::BigBuffer());
return;
}
std::string key = GetCacheKey(url, origin_lock, nik, cache_type_);
auto op = std::make_unique<PendingOperation>(
Operation::kFetch, url, origin_lock, key, std::move(read_data_callback));
EnqueueOperation(std::move(op));
}
void GeneratedCodeCache::DeleteEntry(const GURL& url,
const GURL& origin_lock,
const net::NetworkIsolationKey& nik) {
if (backend_state_ == kFailed) {
// Silently fail.
CollectStatistics(url, origin_lock, CacheEntryStatus::kError);
return;
}
std::string key = GetCacheKey(url, origin_lock, nik, cache_type_);
auto op = std::make_unique<PendingOperation>(Operation::kDelete, url,
origin_lock, key);
EnqueueOperation(std::move(op));
lru_cache_.Delete(key);
}
void GeneratedCodeCache::CreateBackend() {
// If the initialization of the existing cache fails, this call would delete
// all the contents and recreates a new one.
disk_cache::BackendResult result = disk_cache::CreateCacheBackend(
CodeCacheTypeToNetCacheType(cache_type_), net::CACHE_BACKEND_SIMPLE,
/*file_operations=*/nullptr, path_, max_size_bytes_,
disk_cache::ResetHandling::kResetOnError, /*net_log=*/nullptr,
base::BindOnce(&GeneratedCodeCache::DidCreateBackend,
weak_ptr_factory_.GetWeakPtr()));
if (result.net_error != net::ERR_IO_PENDING) {
DidCreateBackend(std::move(result));
}
}
void GeneratedCodeCache::DidCreateBackend(disk_cache::BackendResult result) {
if (result.net_error != net::OK) {
backend_state_ = kFailed;
} else {
backend_ = std::move(result.backend);
backend_state_ = kInitialized;
}
IssuePendingOperations();
}
void GeneratedCodeCache::EnqueueOperation(
std::unique_ptr<PendingOperation> op) {
if (backend_state_ != kInitialized) {
// Insert it into the list of pending operations while the backend is
// still being opened.
pending_ops_.emplace(std::move(op));
return;
}
EnqueueOperationAndIssueIfNext(std::move(op));
}
void GeneratedCodeCache::IssuePendingOperations() {
// Issue any operations that were received while creating the backend.
while (!pending_ops_.empty()) {
// Take ownership of the next PendingOperation here. |op| will either be
// moved onto a queue in active_entries_map_ or issued and completed in
// |DoPendingGetBackend|.
std::unique_ptr<PendingOperation> op = std::move(pending_ops_.front());
pending_ops_.pop();
// Properly enqueue/dequeue ops for Write, Fetch, and Delete.
if (op->operation() != Operation::kGetBackend) {
EnqueueOperationAndIssueIfNext(std::move(op));
} else {
// There is no queue for get backend operations. Issue them immediately.
IssueOperation(op.get());
}
}
}
void GeneratedCodeCache::IssueOperation(PendingOperation* op) {
switch (op->operation()) {
case kFetch:
case kFetchWithSHAKey:
FetchEntryImpl(op);
break;
case kWrite:
case kWriteWithSHAKey:
WriteEntryImpl(op);
break;
case kDelete:
DeleteEntryImpl(op);
break;
case kGetBackend:
DoPendingGetBackend(op);
break;
}
}
void GeneratedCodeCache::WriteEntryImpl(PendingOperation* op) {
DCHECK(Operation::kWrite == op->operation() ||
Operation::kWriteWithSHAKey == op->operation());
if (backend_state_ != kInitialized) {
// Silently fail the request.
CloseOperationAndIssueNext(op);
return;
}
disk_cache::EntryResult result = backend_->OpenOrCreateEntry(
op->key(), net::LOW,
base::BindOnce(&GeneratedCodeCache::OpenCompleteForWrite,
weak_ptr_factory_.GetWeakPtr(), op));
if (result.net_error() != net::ERR_IO_PENDING) {
OpenCompleteForWrite(op, std::move(result));
}
}
void GeneratedCodeCache::OpenCompleteForWrite(
PendingOperation* op,
disk_cache::EntryResult entry_result) {
DCHECK(Operation::kWrite == op->operation() ||
Operation::kWriteWithSHAKey == op->operation());
if (entry_result.net_error() != net::OK) {
CollectStatistics(op->resource_url(), op->origin_lock(),
CacheEntryStatus::kError);
CloseOperationAndIssueNext(op);
return;
}
if (entry_result.opened()) {
CollectStatistics(op->resource_url(), op->origin_lock(),
CacheEntryStatus::kUpdate);
} else {
CollectStatistics(op->resource_url(), op->origin_lock(),
CacheEntryStatus::kCreate);
}
disk_cache::ScopedEntryPtr entry(entry_result.ReleaseEntry());
// There should be a valid entry if the open was successful.
DCHECK(entry);
// For merged entries, don't write if the entry already exists.
if (op->operation() == Operation::kWriteWithSHAKey) {
int small_size = entry->GetDataSize(kSmallDataStream);
int large_size = entry->GetDataSize(kLargeDataStream);
if (small_size == 0 && large_size == op->large_buffer()->size()) {
// Skip overwriting with identical data.
CloseOperationAndIssueNext(op);
return;
}
// Otherwise, there shouldn't be any data for this entry yet.
DCHECK_EQ(0, small_size);
DCHECK_EQ(0, large_size);
}
// Write the small data first, truncating.
auto small_buffer = op->small_buffer();
int result = entry->WriteData(
kSmallDataStream, 0, small_buffer.get(), small_buffer->size(),
base::BindOnce(&GeneratedCodeCache::WriteSmallBufferComplete,
weak_ptr_factory_.GetWeakPtr(), op),
true);
if (result != net::ERR_IO_PENDING) {
WriteSmallBufferComplete(op, result);
}
// Write the large data, truncating.
auto large_buffer = op->large_buffer();
result = entry->WriteData(
kLargeDataStream, 0, large_buffer.get(), large_buffer->size(),
base::BindOnce(&GeneratedCodeCache::WriteLargeBufferComplete,
weak_ptr_factory_.GetWeakPtr(), op),
true);
if (result != net::ERR_IO_PENDING) {
WriteLargeBufferComplete(op, result);
}
}
void GeneratedCodeCache::WriteSmallBufferComplete(PendingOperation* op,
int rv) {
DCHECK(Operation::kWrite == op->operation() ||
Operation::kWriteWithSHAKey == op->operation());
if (op->AddBufferCompletion(rv == op->small_buffer()->size())) {
WriteComplete(op);
}
}
void GeneratedCodeCache::WriteLargeBufferComplete(PendingOperation* op,
int rv) {
DCHECK(Operation::kWrite == op->operation() ||
Operation::kWriteWithSHAKey == op->operation());
if (op->AddBufferCompletion(rv == op->large_buffer()->size())) {
WriteComplete(op);
}
}
void GeneratedCodeCache::WriteComplete(PendingOperation* op) {
DCHECK(Operation::kWrite == op->operation() ||
Operation::kWriteWithSHAKey == op->operation());
if (!op->succeeded()) {
// The write failed; record the failure and doom the entry here.
CollectStatistics(op->resource_url(), op->origin_lock(),
CacheEntryStatus::kWriteFailed);
DoomEntry(op);
}
CloseOperationAndIssueNext(op);
}
void GeneratedCodeCache::FetchEntryImpl(PendingOperation* op) {
DCHECK(Operation::kFetch == op->operation() ||
Operation::kFetchWithSHAKey == op->operation());
if (base::FeatureList::IsEnabled(features::kInMemoryCodeCache)) {
if (auto result = lru_cache_.Get(op->key())) {
op->RunReadCallback(this, result->response_time, std::move(result->data));
CloseOperationAndIssueNext(op);
return;
}
}
if (backend_state_ != kInitialized) {
op->RunReadCallback(this, base::Time(), mojo_base::BigBuffer());
CloseOperationAndIssueNext(op);
return;
}
// This is a part of loading cycle and hence should run with a high priority.
disk_cache::EntryResult result = backend_->OpenEntry(
op->key(), net::HIGHEST,
base::BindOnce(&GeneratedCodeCache::OpenCompleteForRead,
weak_ptr_factory_.GetWeakPtr(), op));
if (result.net_error() != net::ERR_IO_PENDING) {
OpenCompleteForRead(op, std::move(result));
}
}
void GeneratedCodeCache::OpenCompleteForRead(
PendingOperation* op,
disk_cache::EntryResult entry_result) {
DCHECK(Operation::kFetch == op->operation() ||
Operation::kFetchWithSHAKey == op->operation());
if (entry_result.net_error() != net::OK) {
CollectStatistics(op->resource_url(), op->origin_lock(),
CacheEntryStatus::kMiss);
op->RunReadCallback(this, base::Time(), mojo_base::BigBuffer());
CloseOperationAndIssueNext(op);
return;
}
disk_cache::ScopedEntryPtr entry(entry_result.ReleaseEntry());
// There should be a valid entry if the open was successful.
DCHECK(entry);
int small_size = entry->GetDataSize(kSmallDataStream);
int large_size = entry->GetDataSize(kLargeDataStream);
scoped_refptr<net::IOBufferWithSize> small_buffer;
scoped_refptr<BigIOBuffer> large_buffer;
if (op->operation() == Operation::kFetch) {
small_buffer = base::MakeRefCounted<net::IOBufferWithSize>(small_size);
op->set_small_buffer(small_buffer);
large_buffer = base::MakeRefCounted<BigIOBuffer>(large_size);
op->set_large_buffer(large_buffer);
} else {
small_buffer = op->small_buffer();
large_buffer = op->large_buffer();
DCHECK_EQ(small_size, small_buffer->size());
DCHECK_EQ(large_size, large_buffer->size());
}
// Read the small data first.
int result = entry->ReadData(
kSmallDataStream, 0, small_buffer.get(), small_buffer->size(),
base::BindOnce(&GeneratedCodeCache::ReadSmallBufferComplete,
weak_ptr_factory_.GetWeakPtr(), op));
if (result != net::ERR_IO_PENDING) {
ReadSmallBufferComplete(op, result);
}
// Skip the large read if data is in the small read.
if (large_size == 0)
return;
// Read the large data.
result = entry->ReadData(
kLargeDataStream, 0, large_buffer.get(), large_buffer->size(),
base::BindOnce(&GeneratedCodeCache::ReadLargeBufferComplete,
weak_ptr_factory_.GetWeakPtr(), op));
if (result != net::ERR_IO_PENDING) {
ReadLargeBufferComplete(op, result);
}
}
void GeneratedCodeCache::ReadSmallBufferComplete(PendingOperation* op, int rv) {
DCHECK(Operation::kFetch == op->operation() ||
Operation::kFetchWithSHAKey == op->operation());
bool no_header = op->operation() == Operation::kFetchWithSHAKey;
bool succeeded = (rv == op->small_buffer()->size() &&
(no_header || IsValidHeader(op->small_buffer())));
CollectStatistics(
op->resource_url(), op->origin_lock(),
succeeded ? CacheEntryStatus::kHit : CacheEntryStatus::kMiss);
if (op->AddBufferCompletion(succeeded))
ReadComplete(op);
// Small reads must finish now since no large read is pending.
if (op->large_buffer()->size() == 0)
ReadLargeBufferComplete(op, 0);
}
void GeneratedCodeCache::ReadLargeBufferComplete(PendingOperation* op, int rv) {
DCHECK(Operation::kFetch == op->operation() ||
Operation::kFetchWithSHAKey == op->operation());
if (op->AddBufferCompletion(rv == op->large_buffer()->size()))
ReadComplete(op);
}
void GeneratedCodeCache::ReadComplete(PendingOperation* op) {
DCHECK(Operation::kFetch == op->operation() ||
Operation::kFetchWithSHAKey == op->operation());
if (!op->succeeded()) {
op->RunReadCallback(this, base::Time(), mojo_base::BigBuffer());
// Doom this entry since it is inaccessible.
DoomEntry(op);
} else {
if (op->operation() != Operation::kFetchWithSHAKey) {
base::Time response_time;
uint32_t data_size = 0;
ReadCommonDataHeader(op->small_buffer().get(), &response_time,
&data_size);
if (data_size <= kInlineDataLimit) {
// Small data. Copy the data from the small buffer.
DCHECK_EQ(0, op->large_buffer()->size());
mojo_base::BigBuffer data(
op->small_buffer()->span().subspan(kHeaderSizeInBytes, data_size));
op->RunReadCallback(this, response_time, std::move(data));
} else if (!ShouldDeduplicateEntry(data_size)) {
// Large data below the merging threshold, or deduplication is disabled.
// Return the large buffer.
op->RunReadCallback(this, response_time,
op->large_buffer()->TakeBuffer());
} else {
// Very large data. Create the second fetch using the checksum as key.
DCHECK_EQ(static_cast<int>(kHeaderSizeInBytes + kSHAKeySizeInBytes),
op->small_buffer()->size());
std::string checksum_key(
op->small_buffer()->data() + kHeaderSizeInBytes,
kSHAKeySizeInBytes);
auto small_buffer = base::MakeRefCounted<net::IOBufferWithSize>(0);
auto large_buffer = base::MakeRefCounted<BigIOBuffer>(data_size);
auto op2 = std::make_unique<PendingOperation>(
Operation::kFetchWithSHAKey, op->resource_url(), op->origin_lock(),
checksum_key, response_time, op->start_time(), small_buffer,
large_buffer, op->TakeReadCallback());
EnqueueOperation(std::move(op2));
}
} else {
// Large merged code data with no header. |op| holds the response time.
op->RunReadCallback(this, op->response_time(),
op->large_buffer()->TakeBuffer());
}
}
CloseOperationAndIssueNext(op);
}
void GeneratedCodeCache::DeleteEntryImpl(PendingOperation* op) {
DCHECK_EQ(Operation::kDelete, op->operation());
DoomEntry(op);
CloseOperationAndIssueNext(op);
}
void GeneratedCodeCache::DoomEntry(PendingOperation* op) {
// Write, Fetch, and Delete may all doom an entry.
DCHECK_NE(Operation::kGetBackend, op->operation());
// Entries shouldn't be doomed if the backend hasn't been initialized.
DCHECK_EQ(kInitialized, backend_state_);
CollectStatistics(op->resource_url(), op->origin_lock(),
CacheEntryStatus::kClear);
backend_->DoomEntry(op->key(), net::LOWEST, net::CompletionOnceCallback());
}
void GeneratedCodeCache::IssueNextOperation(const std::string& key) {
auto it = active_entries_map_.find(key);
if (it == active_entries_map_.end())
return;
DCHECK(!it->second.empty());
IssueOperation(it->second.front().get());
}
void GeneratedCodeCache::CloseOperationAndIssueNext(PendingOperation* op) {
// Dequeue op, keeping it alive long enough to issue another op.
std::unique_ptr<PendingOperation> keep_alive = DequeueOperation(op);
IssueNextOperation(op->key());
}
void GeneratedCodeCache::EnqueueOperationAndIssueIfNext(
std::unique_ptr<PendingOperation> op) {
// GetBackend ops have no key and shouldn't be enqueued here.
DCHECK_NE(Operation::kGetBackend, op->operation());
auto it = active_entries_map_.find(op->key());
bool can_issue = false;
if (it == active_entries_map_.end()) {
it = active_entries_map_.emplace(op->key(), PendingOperationQueue()).first;
can_issue = true;
}
const std::string& key = op->key();
it->second.emplace(std::move(op));
if (can_issue)
IssueNextOperation(key);
}
std::unique_ptr<GeneratedCodeCache::PendingOperation>
GeneratedCodeCache::DequeueOperation(PendingOperation* op) {
auto it = active_entries_map_.find(op->key());
CHECK(it != active_entries_map_.end(), base::NotFatalUntil::M130);
DCHECK(!it->second.empty());
std::unique_ptr<PendingOperation> result = std::move(it->second.front());
// |op| should be at the front.
DCHECK_EQ(op, result.get());
it->second.pop();
// Delete the queue if it becomes empty.
if (it->second.empty()) {
active_entries_map_.erase(it);
}
return result;
}
void GeneratedCodeCache::DoPendingGetBackend(PendingOperation* op) {
// |op| is kept alive in |IssuePendingOperations| for the duration of this
// call. We shouldn't access |op| after returning from this function.
DCHECK_EQ(kGetBackend, op->operation());
if (backend_state_ == kInitialized) {
op->TakeBackendCallback().Run(backend_.get());
} else {
DCHECK_EQ(backend_state_, kFailed);
op->TakeBackendCallback().Run(nullptr);
}
}
bool GeneratedCodeCache::IsDeduplicationEnabled() const {
// Deduplication is disabled in the WebUI code cache, as an additional defense
// against privilege escalation in case there is a bug in the deduplication
// logic.
return cache_type_ != kWebUIJavaScript;
}
bool GeneratedCodeCache::ShouldDeduplicateEntry(uint32_t data_size) const {
return data_size > kDedicatedDataLimit && IsDeduplicationEnabled();
}
void GeneratedCodeCache::SetLastUsedTimeForTest(
const GURL& resource_url,
const GURL& origin_lock,
const net::NetworkIsolationKey& nik,
base::Time time,
base::OnceClosure user_callback) {
// This is used only for tests. So reasonable to assume that backend is
// initialized here. All other operations handle the case when backend was not
// yet opened.
DCHECK_EQ(backend_state_, kInitialized);
auto split = base::SplitOnceCallback(std::move(user_callback));
disk_cache::EntryResultCallback callback = base::BindOnce(
&GeneratedCodeCache::OpenCompleteForSetLastUsedForTest,
weak_ptr_factory_.GetWeakPtr(), time, std::move(split.first));
std::string key = GetCacheKey(resource_url, origin_lock, nik, cache_type_);
disk_cache::EntryResult result =
backend_->OpenEntry(key, net::LOWEST, std::move(callback));
if (result.net_error() != net::ERR_IO_PENDING) {
OpenCompleteForSetLastUsedForTest(time, std::move(split.second),
std::move(result));
}
}
void GeneratedCodeCache::ClearInMemoryCache() {
lru_cache_.Clear();
}
void GeneratedCodeCache::OpenCompleteForSetLastUsedForTest(
base::Time time,
base::OnceClosure callback,
disk_cache::EntryResult result) {
DCHECK_EQ(result.net_error(), net::OK);
{
disk_cache::ScopedEntryPtr disk_entry(result.ReleaseEntry());
DCHECK(disk_entry);
disk_entry->SetLastUsedTimeForTest(time);
}
std::move(callback).Run();
}
void GeneratedCodeCache::CollectStatisticsForTest(
const GURL& resource_url,
const GURL& origin_lock,
GeneratedCodeCache::CacheEntryStatus status) {
CollectStatistics(resource_url, origin_lock, status);
}
} // namespace content