netwerk/cache/nsDiskCacheMap.cpp@6474c204b198
netwerk/cache/nsDiskCacheMap.cpp
Wed, 31 Dec 2014 06:09:35 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 06:09:35 +0100
- changeset 0
- 6474c204b198
- permissions
- -rw-r--r--
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2 /* vim:set ts=4 sw=4 sts=4 cin et: */
3 /* This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
7 #include "nsCache.h"
8 #include "nsDiskCacheMap.h"
9 #include "nsDiskCacheBinding.h"
10 #include "nsDiskCacheEntry.h"
11 #include "nsDiskCacheDevice.h"
12 #include "nsCacheService.h"
14 #include <string.h>
15 #include "nsPrintfCString.h"
17 #include "nsISerializable.h"
18 #include "nsSerializationHelper.h"
20 #include "mozilla/MemoryReporting.h"
21 #include "mozilla/Telemetry.h"
22 #include "mozilla/VisualEventTracer.h"
23 #include <algorithm>
25 using namespace mozilla;
27 /******************************************************************************
28 * nsDiskCacheMap
29 *****************************************************************************/
31 /**
32 * File operations
33 */
35 nsresult
36 nsDiskCacheMap::Open(nsIFile * cacheDirectory,
37 nsDiskCache::CorruptCacheInfo * corruptInfo,
38 bool reportCacheCleanTelemetryData)
39 {
40 NS_ENSURE_ARG_POINTER(corruptInfo);
42 // Assume we have an unexpected error until we find otherwise.
43 *corruptInfo = nsDiskCache::kUnexpectedError;
44 NS_ENSURE_ARG_POINTER(cacheDirectory);
45 if (mMapFD) return NS_ERROR_ALREADY_INITIALIZED;
47 mCacheDirectory = cacheDirectory; // save a reference for ourselves
49 // create nsIFile for _CACHE_MAP_
50 nsresult rv;
51 nsCOMPtr<nsIFile> file;
52 rv = cacheDirectory->Clone(getter_AddRefs(file));
53 rv = file->AppendNative(NS_LITERAL_CSTRING("_CACHE_MAP_"));
54 NS_ENSURE_SUCCESS(rv, rv);
56 // open the file - restricted to user, the data could be confidential
57 rv = file->OpenNSPRFileDesc(PR_RDWR | PR_CREATE_FILE, 00600, &mMapFD);
58 if (NS_FAILED(rv)) {
59 *corruptInfo = nsDiskCache::kOpenCacheMapError;
60 NS_WARNING("Could not open cache map file");
61 return NS_ERROR_FILE_CORRUPTED;
62 }
64 bool cacheFilesExist = CacheFilesExist();
65 rv = NS_ERROR_FILE_CORRUPTED; // presume the worst
66 uint32_t mapSize = PR_Available(mMapFD);
68 if (NS_FAILED(InitCacheClean(cacheDirectory,
69 corruptInfo,
70 reportCacheCleanTelemetryData))) {
71 // corruptInfo is set in the call to InitCacheClean
72 goto error_exit;
73 }
75 // check size of map file
76 if (mapSize == 0) { // creating a new _CACHE_MAP_
78 // block files shouldn't exist if we're creating the _CACHE_MAP_
79 if (cacheFilesExist) {
80 *corruptInfo = nsDiskCache::kBlockFilesShouldNotExist;
81 goto error_exit;
82 }
84 if (NS_FAILED(CreateCacheSubDirectories())) {
85 *corruptInfo = nsDiskCache::kCreateCacheSubdirectories;
86 goto error_exit;
87 }
89 // create the file - initialize in memory
90 memset(&mHeader, 0, sizeof(nsDiskCacheHeader));
91 mHeader.mVersion = nsDiskCache::kCurrentVersion;
92 mHeader.mRecordCount = kMinRecordCount;
93 mRecordArray = (nsDiskCacheRecord *)
94 PR_CALLOC(mHeader.mRecordCount * sizeof(nsDiskCacheRecord));
95 if (!mRecordArray) {
96 *corruptInfo = nsDiskCache::kOutOfMemory;
97 rv = NS_ERROR_OUT_OF_MEMORY;
98 goto error_exit;
99 }
100 } else if (mapSize >= sizeof(nsDiskCacheHeader)) { // read existing _CACHE_MAP_
102 // if _CACHE_MAP_ exists, so should the block files
103 if (!cacheFilesExist) {
104 *corruptInfo = nsDiskCache::kBlockFilesShouldExist;
105 goto error_exit;
106 }
108 CACHE_LOG_DEBUG(("CACHE: nsDiskCacheMap::Open [this=%p] reading map", this));
110 // read the header
111 uint32_t bytesRead = PR_Read(mMapFD, &mHeader, sizeof(nsDiskCacheHeader));
112 if (sizeof(nsDiskCacheHeader) != bytesRead) {
113 *corruptInfo = nsDiskCache::kHeaderSizeNotRead;
114 goto error_exit;
115 }
116 mHeader.Unswap();
118 if (mHeader.mIsDirty) {
119 *corruptInfo = nsDiskCache::kHeaderIsDirty;
120 goto error_exit;
121 }
123 if (mHeader.mVersion != nsDiskCache::kCurrentVersion) {
124 *corruptInfo = nsDiskCache::kVersionMismatch;
125 goto error_exit;
126 }
128 uint32_t recordArraySize =
129 mHeader.mRecordCount * sizeof(nsDiskCacheRecord);
130 if (mapSize < recordArraySize + sizeof(nsDiskCacheHeader)) {
131 *corruptInfo = nsDiskCache::kRecordsIncomplete;
132 goto error_exit;
133 }
135 // Get the space for the records
136 mRecordArray = (nsDiskCacheRecord *) PR_MALLOC(recordArraySize);
137 if (!mRecordArray) {
138 *corruptInfo = nsDiskCache::kOutOfMemory;
139 rv = NS_ERROR_OUT_OF_MEMORY;
140 goto error_exit;
141 }
143 // Read the records
144 bytesRead = PR_Read(mMapFD, mRecordArray, recordArraySize);
145 if (bytesRead < recordArraySize) {
146 *corruptInfo = nsDiskCache::kNotEnoughToRead;
147 goto error_exit;
148 }
150 // Unswap each record
151 int32_t total = 0;
152 for (int32_t i = 0; i < mHeader.mRecordCount; ++i) {
153 if (mRecordArray[i].HashNumber()) {
154 #if defined(IS_LITTLE_ENDIAN)
155 mRecordArray[i].Unswap();
156 #endif
157 total ++;
158 }
159 }
161 // verify entry count
162 if (total != mHeader.mEntryCount) {
163 *corruptInfo = nsDiskCache::kEntryCountIncorrect;
164 goto error_exit;
165 }
167 } else {
168 *corruptInfo = nsDiskCache::kHeaderIncomplete;
169 goto error_exit;
170 }
172 rv = OpenBlockFiles(corruptInfo);
173 if (NS_FAILED(rv)) {
174 // corruptInfo is set in the call to OpenBlockFiles
175 goto error_exit;
176 }
178 // set dirty bit and flush header
179 mHeader.mIsDirty = true;
180 rv = FlushHeader();
181 if (NS_FAILED(rv)) {
182 *corruptInfo = nsDiskCache::kFlushHeaderError;
183 goto error_exit;
184 }
186 Telemetry::Accumulate(Telemetry::HTTP_DISK_CACHE_OVERHEAD,
187 (uint32_t)SizeOfExcludingThis(moz_malloc_size_of));
189 *corruptInfo = nsDiskCache::kNotCorrupt;
190 return NS_OK;
192 error_exit:
193 (void) Close(false);
195 return rv;
196 }
199 nsresult
200 nsDiskCacheMap::Close(bool flush)
201 {
202 nsCacheService::AssertOwnsLock();
203 nsresult rv = NS_OK;
205 // Cancel any pending cache validation event, the FlushRecords call below
206 // will validate the cache.
207 if (mCleanCacheTimer) {
208 mCleanCacheTimer->Cancel();
209 }
211 // If cache map file and its block files are still open, close them
212 if (mMapFD) {
213 // close block files
214 rv = CloseBlockFiles(flush);
215 if (NS_SUCCEEDED(rv) && flush && mRecordArray) {
216 // write the map records
217 rv = FlushRecords(false); // don't bother swapping buckets back
218 if (NS_SUCCEEDED(rv)) {
219 // clear dirty bit
220 mHeader.mIsDirty = false;
221 rv = FlushHeader();
222 }
223 }
224 if ((PR_Close(mMapFD) != PR_SUCCESS) && (NS_SUCCEEDED(rv)))
225 rv = NS_ERROR_UNEXPECTED;
227 mMapFD = nullptr;
228 }
230 if (mCleanFD) {
231 PR_Close(mCleanFD);
232 mCleanFD = nullptr;
233 }
235 PR_FREEIF(mRecordArray);
236 PR_FREEIF(mBuffer);
237 mBufferSize = 0;
238 return rv;
239 }
242 nsresult
243 nsDiskCacheMap::Trim()
244 {
245 nsresult rv, rv2 = NS_OK;
246 for (int i=0; i < kNumBlockFiles; ++i) {
247 rv = mBlockFile[i].Trim();
248 if (NS_FAILED(rv)) rv2 = rv; // if one or more errors, report at least one
249 }
250 // Try to shrink the records array
251 rv = ShrinkRecords();
252 if (NS_FAILED(rv)) rv2 = rv; // if one or more errors, report at least one
253 return rv2;
254 }
257 nsresult
258 nsDiskCacheMap::FlushHeader()
259 {
260 if (!mMapFD) return NS_ERROR_NOT_AVAILABLE;
262 // seek to beginning of cache map
263 int32_t filePos = PR_Seek(mMapFD, 0, PR_SEEK_SET);
264 if (filePos != 0) return NS_ERROR_UNEXPECTED;
266 // write the header
267 mHeader.Swap();
268 int32_t bytesWritten = PR_Write(mMapFD, &mHeader, sizeof(nsDiskCacheHeader));
269 mHeader.Unswap();
270 if (sizeof(nsDiskCacheHeader) != bytesWritten) {
271 return NS_ERROR_UNEXPECTED;
272 }
274 PRStatus err = PR_Sync(mMapFD);
275 if (err != PR_SUCCESS) return NS_ERROR_UNEXPECTED;
277 // If we have a clean header then revalidate the cache clean file
278 if (!mHeader.mIsDirty) {
279 RevalidateCache();
280 }
282 return NS_OK;
283 }
286 nsresult
287 nsDiskCacheMap::FlushRecords(bool unswap)
288 {
289 if (!mMapFD) return NS_ERROR_NOT_AVAILABLE;
291 // seek to beginning of buckets
292 int32_t filePos = PR_Seek(mMapFD, sizeof(nsDiskCacheHeader), PR_SEEK_SET);
293 if (filePos != sizeof(nsDiskCacheHeader))
294 return NS_ERROR_UNEXPECTED;
296 #if defined(IS_LITTLE_ENDIAN)
297 // Swap each record
298 for (int32_t i = 0; i < mHeader.mRecordCount; ++i) {
299 if (mRecordArray[i].HashNumber())
300 mRecordArray[i].Swap();
301 }
302 #endif
304 int32_t recordArraySize = sizeof(nsDiskCacheRecord) * mHeader.mRecordCount;
306 int32_t bytesWritten = PR_Write(mMapFD, mRecordArray, recordArraySize);
307 if (bytesWritten != recordArraySize)
308 return NS_ERROR_UNEXPECTED;
310 #if defined(IS_LITTLE_ENDIAN)
311 if (unswap) {
312 // Unswap each record
313 for (int32_t i = 0; i < mHeader.mRecordCount; ++i) {
314 if (mRecordArray[i].HashNumber())
315 mRecordArray[i].Unswap();
316 }
317 }
318 #endif
320 return NS_OK;
321 }
324 /**
325 * Record operations
326 */
328 uint32_t
329 nsDiskCacheMap::GetBucketRank(uint32_t bucketIndex, uint32_t targetRank)
330 {
331 nsDiskCacheRecord * records = GetFirstRecordInBucket(bucketIndex);
332 uint32_t rank = 0;
334 for (int i = mHeader.mBucketUsage[bucketIndex]-1; i >= 0; i--) {
335 if ((rank < records[i].EvictionRank()) &&
336 ((targetRank == 0) || (records[i].EvictionRank() < targetRank)))
337 rank = records[i].EvictionRank();
338 }
339 return rank;
340 }
342 nsresult
343 nsDiskCacheMap::GrowRecords()
344 {
345 if (mHeader.mRecordCount >= mMaxRecordCount)
346 return NS_OK;
347 CACHE_LOG_DEBUG(("CACHE: GrowRecords\n"));
349 // Resize the record array
350 int32_t newCount = mHeader.mRecordCount << 1;
351 if (newCount > mMaxRecordCount)
352 newCount = mMaxRecordCount;
353 nsDiskCacheRecord *newArray = (nsDiskCacheRecord *)
354 PR_REALLOC(mRecordArray, newCount * sizeof(nsDiskCacheRecord));
355 if (!newArray)
356 return NS_ERROR_OUT_OF_MEMORY;
358 // Space out the buckets
359 uint32_t oldRecordsPerBucket = GetRecordsPerBucket();
360 uint32_t newRecordsPerBucket = newCount / kBuckets;
361 // Work from back to space out each bucket to the new array
362 for (int bucketIndex = kBuckets - 1; bucketIndex >= 0; --bucketIndex) {
363 // Move bucket
364 nsDiskCacheRecord *newRecords = newArray + bucketIndex * newRecordsPerBucket;
365 const uint32_t count = mHeader.mBucketUsage[bucketIndex];
366 memmove(newRecords,
367 newArray + bucketIndex * oldRecordsPerBucket,
368 count * sizeof(nsDiskCacheRecord));
369 // clear unused records
370 memset(newRecords + count, 0,
371 (newRecordsPerBucket - count) * sizeof(nsDiskCacheRecord));
372 }
374 // Set as the new record array
375 mRecordArray = newArray;
376 mHeader.mRecordCount = newCount;
378 InvalidateCache();
380 return NS_OK;
381 }
383 nsresult
384 nsDiskCacheMap::ShrinkRecords()
385 {
386 if (mHeader.mRecordCount <= kMinRecordCount)
387 return NS_OK;
388 CACHE_LOG_DEBUG(("CACHE: ShrinkRecords\n"));
390 // Verify if we can shrink the record array: all buckets must be less than
391 // 1/2 filled
392 uint32_t maxUsage = 0, bucketIndex;
393 for (bucketIndex = 0; bucketIndex < kBuckets; ++bucketIndex) {
394 if (maxUsage < mHeader.mBucketUsage[bucketIndex])
395 maxUsage = mHeader.mBucketUsage[bucketIndex];
396 }
397 // Determine new bucket size, halve size until maxUsage
398 uint32_t oldRecordsPerBucket = GetRecordsPerBucket();
399 uint32_t newRecordsPerBucket = oldRecordsPerBucket;
400 while (maxUsage < (newRecordsPerBucket >> 1))
401 newRecordsPerBucket >>= 1;
402 if (newRecordsPerBucket < (kMinRecordCount / kBuckets))
403 newRecordsPerBucket = (kMinRecordCount / kBuckets);
404 NS_ASSERTION(newRecordsPerBucket <= oldRecordsPerBucket,
405 "ShrinkRecords() can't grow records!");
406 if (newRecordsPerBucket == oldRecordsPerBucket)
407 return NS_OK;
408 // Move the buckets close to each other
409 for (bucketIndex = 1; bucketIndex < kBuckets; ++bucketIndex) {
410 // Move bucket
411 memmove(mRecordArray + bucketIndex * newRecordsPerBucket,
412 mRecordArray + bucketIndex * oldRecordsPerBucket,
413 newRecordsPerBucket * sizeof(nsDiskCacheRecord));
414 }
416 // Shrink the record array memory block itself
417 uint32_t newCount = newRecordsPerBucket * kBuckets;
418 nsDiskCacheRecord* newArray = (nsDiskCacheRecord *)
419 PR_REALLOC(mRecordArray, newCount * sizeof(nsDiskCacheRecord));
420 if (!newArray)
421 return NS_ERROR_OUT_OF_MEMORY;
423 // Set as the new record array
424 mRecordArray = newArray;
425 mHeader.mRecordCount = newCount;
427 InvalidateCache();
429 return NS_OK;
430 }
432 nsresult
433 nsDiskCacheMap::AddRecord( nsDiskCacheRecord * mapRecord,
434 nsDiskCacheRecord * oldRecord)
435 {
436 CACHE_LOG_DEBUG(("CACHE: AddRecord [%x]\n", mapRecord->HashNumber()));
438 const uint32_t hashNumber = mapRecord->HashNumber();
439 const uint32_t bucketIndex = GetBucketIndex(hashNumber);
440 const uint32_t count = mHeader.mBucketUsage[bucketIndex];
442 oldRecord->SetHashNumber(0); // signify no record
444 if (count == GetRecordsPerBucket()) {
445 // Ignore failure to grow the record space, we will then reuse old records
446 GrowRecords();
447 }
449 nsDiskCacheRecord * records = GetFirstRecordInBucket(bucketIndex);
450 if (count < GetRecordsPerBucket()) {
451 // stick the new record at the end
452 records[count] = *mapRecord;
453 mHeader.mEntryCount++;
454 mHeader.mBucketUsage[bucketIndex]++;
455 if (mHeader.mEvictionRank[bucketIndex] < mapRecord->EvictionRank())
456 mHeader.mEvictionRank[bucketIndex] = mapRecord->EvictionRank();
457 InvalidateCache();
458 } else {
459 // Find the record with the highest eviction rank
460 nsDiskCacheRecord * mostEvictable = &records[0];
461 for (int i = count-1; i > 0; i--) {
462 if (records[i].EvictionRank() > mostEvictable->EvictionRank())
463 mostEvictable = &records[i];
464 }
465 *oldRecord = *mostEvictable; // i == GetRecordsPerBucket(), so
466 // evict the mostEvictable
467 *mostEvictable = *mapRecord; // replace it with the new record
468 // check if we need to update mostEvictable entry in header
469 if (mHeader.mEvictionRank[bucketIndex] < mapRecord->EvictionRank())
470 mHeader.mEvictionRank[bucketIndex] = mapRecord->EvictionRank();
471 if (oldRecord->EvictionRank() >= mHeader.mEvictionRank[bucketIndex])
472 mHeader.mEvictionRank[bucketIndex] = GetBucketRank(bucketIndex, 0);
473 InvalidateCache();
474 }
476 NS_ASSERTION(mHeader.mEvictionRank[bucketIndex] == GetBucketRank(bucketIndex, 0),
477 "eviction rank out of sync");
478 return NS_OK;
479 }
482 nsresult
483 nsDiskCacheMap::UpdateRecord( nsDiskCacheRecord * mapRecord)
484 {
485 CACHE_LOG_DEBUG(("CACHE: UpdateRecord [%x]\n", mapRecord->HashNumber()));
487 const uint32_t hashNumber = mapRecord->HashNumber();
488 const uint32_t bucketIndex = GetBucketIndex(hashNumber);
489 nsDiskCacheRecord * records = GetFirstRecordInBucket(bucketIndex);
491 for (int i = mHeader.mBucketUsage[bucketIndex]-1; i >= 0; i--) {
492 if (records[i].HashNumber() == hashNumber) {
493 const uint32_t oldRank = records[i].EvictionRank();
495 // stick the new record here
496 records[i] = *mapRecord;
498 // update eviction rank in header if necessary
499 if (mHeader.mEvictionRank[bucketIndex] < mapRecord->EvictionRank())
500 mHeader.mEvictionRank[bucketIndex] = mapRecord->EvictionRank();
501 else if (mHeader.mEvictionRank[bucketIndex] == oldRank)
502 mHeader.mEvictionRank[bucketIndex] = GetBucketRank(bucketIndex, 0);
504 InvalidateCache();
506 NS_ASSERTION(mHeader.mEvictionRank[bucketIndex] == GetBucketRank(bucketIndex, 0),
507 "eviction rank out of sync");
508 return NS_OK;
509 }
510 }
511 NS_NOTREACHED("record not found");
512 return NS_ERROR_UNEXPECTED;
513 }
516 nsresult
517 nsDiskCacheMap::FindRecord( uint32_t hashNumber, nsDiskCacheRecord * result)
518 {
519 const uint32_t bucketIndex = GetBucketIndex(hashNumber);
520 nsDiskCacheRecord * records = GetFirstRecordInBucket(bucketIndex);
522 for (int i = mHeader.mBucketUsage[bucketIndex]-1; i >= 0; i--) {
523 if (records[i].HashNumber() == hashNumber) {
524 *result = records[i]; // copy the record
525 NS_ASSERTION(result->ValidRecord(), "bad cache map record");
526 return NS_OK;
527 }
528 }
529 return NS_ERROR_CACHE_KEY_NOT_FOUND;
530 }
533 nsresult
534 nsDiskCacheMap::DeleteRecord( nsDiskCacheRecord * mapRecord)
535 {
536 CACHE_LOG_DEBUG(("CACHE: DeleteRecord [%x]\n", mapRecord->HashNumber()));
538 const uint32_t hashNumber = mapRecord->HashNumber();
539 const uint32_t bucketIndex = GetBucketIndex(hashNumber);
540 nsDiskCacheRecord * records = GetFirstRecordInBucket(bucketIndex);
541 uint32_t last = mHeader.mBucketUsage[bucketIndex]-1;
543 for (int i = last; i >= 0; i--) {
544 if (records[i].HashNumber() == hashNumber) {
545 // found it, now delete it.
546 uint32_t evictionRank = records[i].EvictionRank();
547 NS_ASSERTION(evictionRank == mapRecord->EvictionRank(),
548 "evictionRank out of sync");
549 // if not the last record, shift last record into opening
550 records[i] = records[last];
551 records[last].SetHashNumber(0); // clear last record
552 mHeader.mBucketUsage[bucketIndex] = last;
553 mHeader.mEntryCount--;
555 // update eviction rank
556 uint32_t bucketIndex = GetBucketIndex(mapRecord->HashNumber());
557 if (mHeader.mEvictionRank[bucketIndex] <= evictionRank) {
558 mHeader.mEvictionRank[bucketIndex] = GetBucketRank(bucketIndex, 0);
559 }
561 InvalidateCache();
563 NS_ASSERTION(mHeader.mEvictionRank[bucketIndex] ==
564 GetBucketRank(bucketIndex, 0), "eviction rank out of sync");
565 return NS_OK;
566 }
567 }
568 return NS_ERROR_UNEXPECTED;
569 }
572 int32_t
573 nsDiskCacheMap::VisitEachRecord(uint32_t bucketIndex,
574 nsDiskCacheRecordVisitor * visitor,
575 uint32_t evictionRank)
576 {
577 int32_t rv = kVisitNextRecord;
578 uint32_t count = mHeader.mBucketUsage[bucketIndex];
579 nsDiskCacheRecord * records = GetFirstRecordInBucket(bucketIndex);
581 // call visitor for each entry (matching any eviction rank)
582 for (int i = count-1; i >= 0; i--) {
583 if (evictionRank > records[i].EvictionRank()) continue;
585 rv = visitor->VisitRecord(&records[i]);
586 if (rv == kStopVisitingRecords)
587 break; // Stop visiting records
589 if (rv == kDeleteRecordAndContinue) {
590 --count;
591 records[i] = records[count];
592 records[count].SetHashNumber(0);
593 InvalidateCache();
594 }
595 }
597 if (mHeader.mBucketUsage[bucketIndex] - count != 0) {
598 mHeader.mEntryCount -= mHeader.mBucketUsage[bucketIndex] - count;
599 mHeader.mBucketUsage[bucketIndex] = count;
600 // recalc eviction rank
601 mHeader.mEvictionRank[bucketIndex] = GetBucketRank(bucketIndex, 0);
602 }
603 NS_ASSERTION(mHeader.mEvictionRank[bucketIndex] ==
604 GetBucketRank(bucketIndex, 0), "eviction rank out of sync");
606 return rv;
607 }
610 /**
611 * VisitRecords
612 *
613 * Visit every record in cache map in the most convenient order
614 */
615 nsresult
616 nsDiskCacheMap::VisitRecords( nsDiskCacheRecordVisitor * visitor)
617 {
618 for (int bucketIndex = 0; bucketIndex < kBuckets; ++bucketIndex) {
619 if (VisitEachRecord(bucketIndex, visitor, 0) == kStopVisitingRecords)
620 break;
621 }
622 return NS_OK;
623 }
626 /**
627 * EvictRecords
628 *
629 * Just like VisitRecords, but visits the records in order of their eviction rank
630 */
631 nsresult
632 nsDiskCacheMap::EvictRecords( nsDiskCacheRecordVisitor * visitor)
633 {
634 uint32_t tempRank[kBuckets];
635 int bucketIndex = 0;
637 // copy eviction rank array
638 for (bucketIndex = 0; bucketIndex < kBuckets; ++bucketIndex)
639 tempRank[bucketIndex] = mHeader.mEvictionRank[bucketIndex];
641 // Maximum number of iterations determined by number of records
642 // as a safety limiter for the loop. Use a copy of mHeader.mEntryCount since
643 // the value could decrease if some entry is evicted.
644 int32_t entryCount = mHeader.mEntryCount;
645 for (int n = 0; n < entryCount; ++n) {
647 // find bucket with highest eviction rank
648 uint32_t rank = 0;
649 for (int i = 0; i < kBuckets; ++i) {
650 if (rank < tempRank[i]) {
651 rank = tempRank[i];
652 bucketIndex = i;
653 }
654 }
656 if (rank == 0) break; // we've examined all the records
658 // visit records in bucket with eviction ranks >= target eviction rank
659 if (VisitEachRecord(bucketIndex, visitor, rank) == kStopVisitingRecords)
660 break;
662 // find greatest rank less than 'rank'
663 tempRank[bucketIndex] = GetBucketRank(bucketIndex, rank);
664 }
665 return NS_OK;
666 }
670 nsresult
671 nsDiskCacheMap::OpenBlockFiles(nsDiskCache::CorruptCacheInfo * corruptInfo)
672 {
673 NS_ENSURE_ARG_POINTER(corruptInfo);
675 // create nsIFile for block file
676 nsCOMPtr<nsIFile> blockFile;
677 nsresult rv = NS_OK;
678 *corruptInfo = nsDiskCache::kUnexpectedError;
680 for (int i = 0; i < kNumBlockFiles; ++i) {
681 rv = GetBlockFileForIndex(i, getter_AddRefs(blockFile));
682 if (NS_FAILED(rv)) {
683 *corruptInfo = nsDiskCache::kCouldNotGetBlockFileForIndex;
684 break;
685 }
687 uint32_t blockSize = GetBlockSizeForIndex(i+1); // +1 to match file selectors 1,2,3
688 uint32_t bitMapSize = GetBitMapSizeForIndex(i+1);
689 rv = mBlockFile[i].Open(blockFile, blockSize, bitMapSize, corruptInfo);
690 if (NS_FAILED(rv)) {
691 // corruptInfo was set inside the call to mBlockFile[i].Open
692 break;
693 }
694 }
695 // close all files in case of any error
696 if (NS_FAILED(rv))
697 (void)CloseBlockFiles(false); // we already have an error to report
699 return rv;
700 }
703 nsresult
704 nsDiskCacheMap::CloseBlockFiles(bool flush)
705 {
706 nsresult rv, rv2 = NS_OK;
707 for (int i=0; i < kNumBlockFiles; ++i) {
708 rv = mBlockFile[i].Close(flush);
709 if (NS_FAILED(rv)) rv2 = rv; // if one or more errors, report at least one
710 }
711 return rv2;
712 }
715 bool
716 nsDiskCacheMap::CacheFilesExist()
717 {
718 nsCOMPtr<nsIFile> blockFile;
719 nsresult rv;
721 for (int i = 0; i < kNumBlockFiles; ++i) {
722 bool exists;
723 rv = GetBlockFileForIndex(i, getter_AddRefs(blockFile));
724 if (NS_FAILED(rv)) return false;
726 rv = blockFile->Exists(&exists);
727 if (NS_FAILED(rv) || !exists) return false;
728 }
730 return true;
731 }
734 nsresult
735 nsDiskCacheMap::CreateCacheSubDirectories()
736 {
737 if (!mCacheDirectory)
738 return NS_ERROR_UNEXPECTED;
740 for (int32_t index = 0 ; index < 16 ; index++) {
741 nsCOMPtr<nsIFile> file;
742 nsresult rv = mCacheDirectory->Clone(getter_AddRefs(file));
743 if (NS_FAILED(rv))
744 return rv;
746 rv = file->AppendNative(nsPrintfCString("%X", index));
747 if (NS_FAILED(rv))
748 return rv;
750 rv = file->Create(nsIFile::DIRECTORY_TYPE, 0700);
751 if (NS_FAILED(rv))
752 return rv;
753 }
755 return NS_OK;
756 }
759 nsDiskCacheEntry *
760 nsDiskCacheMap::ReadDiskCacheEntry(nsDiskCacheRecord * record)
761 {
762 CACHE_LOG_DEBUG(("CACHE: ReadDiskCacheEntry [%x]\n", record->HashNumber()));
764 nsresult rv = NS_ERROR_UNEXPECTED;
765 nsDiskCacheEntry * diskEntry = nullptr;
766 uint32_t metaFile = record->MetaFile();
767 int32_t bytesRead = 0;
769 if (!record->MetaLocationInitialized()) return nullptr;
771 if (metaFile == 0) { // entry/metadata stored in separate file
772 // open and read the file
773 nsCOMPtr<nsIFile> file;
774 rv = GetLocalFileForDiskCacheRecord(record,
775 nsDiskCache::kMetaData,
776 false,
777 getter_AddRefs(file));
778 NS_ENSURE_SUCCESS(rv, nullptr);
780 CACHE_LOG_DEBUG(("CACHE: nsDiskCacheMap::ReadDiskCacheEntry"
781 "[this=%p] reading disk cache entry", this));
783 PRFileDesc * fd = nullptr;
785 // open the file - restricted to user, the data could be confidential
786 rv = file->OpenNSPRFileDesc(PR_RDONLY, 00600, &fd);
787 NS_ENSURE_SUCCESS(rv, nullptr);
789 int32_t fileSize = PR_Available(fd);
790 if (fileSize < 0) {
791 // an error occurred. We could call PR_GetError(), but how would that help?
792 rv = NS_ERROR_UNEXPECTED;
793 } else {
794 rv = EnsureBuffer(fileSize);
795 if (NS_SUCCEEDED(rv)) {
796 bytesRead = PR_Read(fd, mBuffer, fileSize);
797 if (bytesRead < fileSize) {
798 rv = NS_ERROR_UNEXPECTED;
799 }
800 }
801 }
802 PR_Close(fd);
803 NS_ENSURE_SUCCESS(rv, nullptr);
805 } else if (metaFile < (kNumBlockFiles + 1)) {
806 // entry/metadata stored in cache block file
808 // allocate buffer
809 uint32_t blockCount = record->MetaBlockCount();
810 bytesRead = blockCount * GetBlockSizeForIndex(metaFile);
812 rv = EnsureBuffer(bytesRead);
813 NS_ENSURE_SUCCESS(rv, nullptr);
815 // read diskEntry, note when the blocks are at the end of file,
816 // bytesRead may be less than blockSize*blockCount.
817 // But the bytesRead should at least agree with the real disk entry size.
818 rv = mBlockFile[metaFile - 1].ReadBlocks(mBuffer,
819 record->MetaStartBlock(),
820 blockCount,
821 &bytesRead);
822 NS_ENSURE_SUCCESS(rv, nullptr);
823 }
824 diskEntry = (nsDiskCacheEntry *)mBuffer;
825 diskEntry->Unswap(); // disk to memory
826 // Check if calculated size agrees with bytesRead
827 if (bytesRead < 0 || (uint32_t)bytesRead < diskEntry->Size())
828 return nullptr;
830 // Return the buffer containing the diskEntry structure
831 return diskEntry;
832 }
835 /**
836 * CreateDiskCacheEntry(nsCacheEntry * entry)
837 *
838 * Prepare an nsCacheEntry for writing to disk
839 */
840 nsDiskCacheEntry *
841 nsDiskCacheMap::CreateDiskCacheEntry(nsDiskCacheBinding * binding,
842 uint32_t * aSize)
843 {
844 nsCacheEntry * entry = binding->mCacheEntry;
845 if (!entry) return nullptr;
847 // Store security info, if it is serializable
848 nsCOMPtr<nsISupports> infoObj = entry->SecurityInfo();
849 nsCOMPtr<nsISerializable> serializable = do_QueryInterface(infoObj);
850 if (infoObj && !serializable) return nullptr;
851 if (serializable) {
852 nsCString info;
853 nsresult rv = NS_SerializeToString(serializable, info);
854 if (NS_FAILED(rv)) return nullptr;
855 rv = entry->SetMetaDataElement("security-info", info.get());
856 if (NS_FAILED(rv)) return nullptr;
857 }
859 uint32_t keySize = entry->Key()->Length() + 1;
860 uint32_t metaSize = entry->MetaDataSize();
861 uint32_t size = sizeof(nsDiskCacheEntry) + keySize + metaSize;
863 if (aSize) *aSize = size;
865 nsresult rv = EnsureBuffer(size);
866 if (NS_FAILED(rv)) return nullptr;
868 nsDiskCacheEntry *diskEntry = (nsDiskCacheEntry *)mBuffer;
869 diskEntry->mHeaderVersion = nsDiskCache::kCurrentVersion;
870 diskEntry->mMetaLocation = binding->mRecord.MetaLocation();
871 diskEntry->mFetchCount = entry->FetchCount();
872 diskEntry->mLastFetched = entry->LastFetched();
873 diskEntry->mLastModified = entry->LastModified();
874 diskEntry->mExpirationTime = entry->ExpirationTime();
875 diskEntry->mDataSize = entry->DataSize();
876 diskEntry->mKeySize = keySize;
877 diskEntry->mMetaDataSize = metaSize;
879 memcpy(diskEntry->Key(), entry->Key()->get(), keySize);
881 rv = entry->FlattenMetaData(diskEntry->MetaData(), metaSize);
882 if (NS_FAILED(rv)) return nullptr;
884 return diskEntry;
885 }
888 nsresult
889 nsDiskCacheMap::WriteDiskCacheEntry(nsDiskCacheBinding * binding)
890 {
891 CACHE_LOG_DEBUG(("CACHE: WriteDiskCacheEntry [%x]\n",
892 binding->mRecord.HashNumber()));
894 mozilla::eventtracer::AutoEventTracer writeDiskCacheEntry(
895 binding->mCacheEntry,
896 mozilla::eventtracer::eExec,
897 mozilla::eventtracer::eDone,
898 "net::cache::WriteDiskCacheEntry");
900 nsresult rv = NS_OK;
901 uint32_t size;
902 nsDiskCacheEntry * diskEntry = CreateDiskCacheEntry(binding, &size);
903 if (!diskEntry) return NS_ERROR_UNEXPECTED;
905 uint32_t fileIndex = CalculateFileIndex(size);
907 // Deallocate old storage if necessary
908 if (binding->mRecord.MetaLocationInitialized()) {
909 // we have existing storage
911 if ((binding->mRecord.MetaFile() == 0) &&
912 (fileIndex == 0)) { // keeping the separate file
913 // just decrement total
914 DecrementTotalSize(binding->mRecord.MetaFileSize());
915 NS_ASSERTION(binding->mRecord.MetaFileGeneration() == binding->mGeneration,
916 "generations out of sync");
917 } else {
918 rv = DeleteStorage(&binding->mRecord, nsDiskCache::kMetaData);
919 NS_ENSURE_SUCCESS(rv, rv);
920 }
921 }
923 binding->mRecord.SetEvictionRank(ULONG_MAX - SecondsFromPRTime(PR_Now()));
924 // write entry data to disk cache block file
925 diskEntry->Swap();
927 if (fileIndex != 0) {
928 while (1) {
929 uint32_t blockSize = GetBlockSizeForIndex(fileIndex);
930 uint32_t blocks = ((size - 1) / blockSize) + 1;
932 int32_t startBlock;
933 rv = mBlockFile[fileIndex - 1].WriteBlocks(diskEntry, size, blocks,
934 &startBlock);
935 if (NS_SUCCEEDED(rv)) {
936 // update binding and cache map record
937 binding->mRecord.SetMetaBlocks(fileIndex, startBlock, blocks);
939 rv = UpdateRecord(&binding->mRecord);
940 NS_ENSURE_SUCCESS(rv, rv);
942 // XXX we should probably write out bucket ourselves
944 IncrementTotalSize(blocks, blockSize);
945 break;
946 }
948 if (fileIndex == kNumBlockFiles) {
949 fileIndex = 0; // write data to separate file
950 break;
951 }
953 // try next block file
954 fileIndex++;
955 }
956 }
958 if (fileIndex == 0) {
959 // Write entry data to separate file
960 uint32_t metaFileSizeK = ((size + 0x03FF) >> 10); // round up to nearest 1k
961 if (metaFileSizeK > kMaxDataSizeK)
962 metaFileSizeK = kMaxDataSizeK;
964 binding->mRecord.SetMetaFileGeneration(binding->mGeneration);
965 binding->mRecord.SetMetaFileSize(metaFileSizeK);
966 rv = UpdateRecord(&binding->mRecord);
967 NS_ENSURE_SUCCESS(rv, rv);
969 nsCOMPtr<nsIFile> localFile;
970 rv = GetLocalFileForDiskCacheRecord(&binding->mRecord,
971 nsDiskCache::kMetaData,
972 true,
973 getter_AddRefs(localFile));
974 NS_ENSURE_SUCCESS(rv, rv);
976 // open the file
977 PRFileDesc * fd;
978 // open the file - restricted to user, the data could be confidential
979 rv = localFile->OpenNSPRFileDesc(PR_RDWR | PR_TRUNCATE | PR_CREATE_FILE, 00600, &fd);
980 NS_ENSURE_SUCCESS(rv, rv);
982 // write the file
983 int32_t bytesWritten = PR_Write(fd, diskEntry, size);
985 PRStatus err = PR_Close(fd);
986 if ((bytesWritten != (int32_t)size) || (err != PR_SUCCESS)) {
987 return NS_ERROR_UNEXPECTED;
988 }
990 IncrementTotalSize(metaFileSizeK);
991 }
993 return rv;
994 }
997 nsresult
998 nsDiskCacheMap::ReadDataCacheBlocks(nsDiskCacheBinding * binding, char * buffer, uint32_t size)
999 {
1000 CACHE_LOG_DEBUG(("CACHE: ReadDataCacheBlocks [%x size=%u]\n",
1001 binding->mRecord.HashNumber(), size));
1003 uint32_t fileIndex = binding->mRecord.DataFile();
1004 int32_t readSize = size;
1006 nsresult rv = mBlockFile[fileIndex - 1].ReadBlocks(buffer,
1007 binding->mRecord.DataStartBlock(),
1008 binding->mRecord.DataBlockCount(),
1009 &readSize);
1010 NS_ENSURE_SUCCESS(rv, rv);
1011 if (readSize < (int32_t)size) {
1012 rv = NS_ERROR_UNEXPECTED;
1013 }
1014 return rv;
1015 }
1018 nsresult
1019 nsDiskCacheMap::WriteDataCacheBlocks(nsDiskCacheBinding * binding, char * buffer, uint32_t size)
1020 {
1021 CACHE_LOG_DEBUG(("CACHE: WriteDataCacheBlocks [%x size=%u]\n",
1022 binding->mRecord.HashNumber(), size));
1024 mozilla::eventtracer::AutoEventTracer writeDataCacheBlocks(
1025 binding->mCacheEntry,
1026 mozilla::eventtracer::eExec,
1027 mozilla::eventtracer::eDone,
1028 "net::cache::WriteDataCacheBlocks");
1030 nsresult rv = NS_OK;
1032 // determine block file & number of blocks
1033 uint32_t fileIndex = CalculateFileIndex(size);
1034 uint32_t blockCount = 0;
1035 int32_t startBlock = 0;
1037 if (size > 0) {
1038 // if fileIndex is 0, bad things happen below, which makes gcc 4.7
1039 // complain, but it's not supposed to happen. See bug 854105.
1040 MOZ_ASSERT(fileIndex);
1041 while (fileIndex) {
1042 uint32_t blockSize = GetBlockSizeForIndex(fileIndex);
1043 blockCount = ((size - 1) / blockSize) + 1;
1045 rv = mBlockFile[fileIndex - 1].WriteBlocks(buffer, size, blockCount,
1046 &startBlock);
1047 if (NS_SUCCEEDED(rv)) {
1048 IncrementTotalSize(blockCount, blockSize);
1049 break;
1050 }
1052 if (fileIndex == kNumBlockFiles)
1053 return rv;
1055 fileIndex++;
1056 }
1057 }
1059 // update binding and cache map record
1060 binding->mRecord.SetDataBlocks(fileIndex, startBlock, blockCount);
1061 if (!binding->mDoomed) {
1062 rv = UpdateRecord(&binding->mRecord);
1063 }
1064 return rv;
1065 }
1068 nsresult
1069 nsDiskCacheMap::DeleteStorage(nsDiskCacheRecord * record)
1070 {
1071 nsresult rv1 = DeleteStorage(record, nsDiskCache::kData);
1072 nsresult rv2 = DeleteStorage(record, nsDiskCache::kMetaData);
1073 return NS_FAILED(rv1) ? rv1 : rv2;
1074 }
1077 nsresult
1078 nsDiskCacheMap::DeleteStorage(nsDiskCacheRecord * record, bool metaData)
1079 {
1080 CACHE_LOG_DEBUG(("CACHE: DeleteStorage [%x %u]\n", record->HashNumber(),
1081 metaData));
1083 nsresult rv = NS_ERROR_UNEXPECTED;
1084 uint32_t fileIndex = metaData ? record->MetaFile() : record->DataFile();
1085 nsCOMPtr<nsIFile> file;
1087 if (fileIndex == 0) {
1088 // delete the file
1089 uint32_t sizeK = metaData ? record->MetaFileSize() : record->DataFileSize();
1090 // XXX if sizeK == USHRT_MAX, stat file for actual size
1092 rv = GetFileForDiskCacheRecord(record, metaData, false, getter_AddRefs(file));
1093 if (NS_SUCCEEDED(rv)) {
1094 rv = file->Remove(false); // false == non-recursive
1095 }
1096 DecrementTotalSize(sizeK);
1098 } else if (fileIndex < (kNumBlockFiles + 1)) {
1099 // deallocate blocks
1100 uint32_t startBlock = metaData ? record->MetaStartBlock() : record->DataStartBlock();
1101 uint32_t blockCount = metaData ? record->MetaBlockCount() : record->DataBlockCount();
1103 rv = mBlockFile[fileIndex - 1].DeallocateBlocks(startBlock, blockCount);
1104 DecrementTotalSize(blockCount, GetBlockSizeForIndex(fileIndex));
1105 }
1106 if (metaData) record->ClearMetaLocation();
1107 else record->ClearDataLocation();
1109 return rv;
1110 }
1113 nsresult
1114 nsDiskCacheMap::GetFileForDiskCacheRecord(nsDiskCacheRecord * record,
1115 bool meta,
1116 bool createPath,
1117 nsIFile ** result)
1118 {
1119 if (!mCacheDirectory) return NS_ERROR_NOT_AVAILABLE;
1121 nsCOMPtr<nsIFile> file;
1122 nsresult rv = mCacheDirectory->Clone(getter_AddRefs(file));
1123 if (NS_FAILED(rv)) return rv;
1125 uint32_t hash = record->HashNumber();
1127 // The file is stored under subdirectories according to the hash number:
1128 // 0x01234567 -> 0/12/
1129 rv = file->AppendNative(nsPrintfCString("%X", hash >> 28));
1130 if (NS_FAILED(rv)) return rv;
1131 rv = file->AppendNative(nsPrintfCString("%02X", (hash >> 20) & 0xFF));
1132 if (NS_FAILED(rv)) return rv;
1134 bool exists;
1135 if (createPath && (NS_FAILED(file->Exists(&exists)) || !exists)) {
1136 rv = file->Create(nsIFile::DIRECTORY_TYPE, 0700);
1137 if (NS_FAILED(rv)) return rv;
1138 }
1140 int16_t generation = record->Generation();
1141 char name[32];
1142 // Cut the beginning of the hash that was used in the path
1143 ::sprintf(name, "%05X%c%02X", hash & 0xFFFFF, (meta ? 'm' : 'd'),
1144 generation);
1145 rv = file->AppendNative(nsDependentCString(name));
1146 if (NS_FAILED(rv)) return rv;
1148 NS_IF_ADDREF(*result = file);
1149 return rv;
1150 }
1153 nsresult
1154 nsDiskCacheMap::GetLocalFileForDiskCacheRecord(nsDiskCacheRecord * record,
1155 bool meta,
1156 bool createPath,
1157 nsIFile ** result)
1158 {
1159 nsCOMPtr<nsIFile> file;
1160 nsresult rv = GetFileForDiskCacheRecord(record,
1161 meta,
1162 createPath,
1163 getter_AddRefs(file));
1164 if (NS_FAILED(rv)) return rv;
1166 NS_IF_ADDREF(*result = file);
1167 return rv;
1168 }
1171 nsresult
1172 nsDiskCacheMap::GetBlockFileForIndex(uint32_t index, nsIFile ** result)
1173 {
1174 if (!mCacheDirectory) return NS_ERROR_NOT_AVAILABLE;
1176 nsCOMPtr<nsIFile> file;
1177 nsresult rv = mCacheDirectory->Clone(getter_AddRefs(file));
1178 if (NS_FAILED(rv)) return rv;
1180 char name[32];
1181 ::sprintf(name, "_CACHE_%03d_", index + 1);
1182 rv = file->AppendNative(nsDependentCString(name));
1183 if (NS_FAILED(rv)) return rv;
1185 NS_IF_ADDREF(*result = file);
1187 return rv;
1188 }
1191 uint32_t
1192 nsDiskCacheMap::CalculateFileIndex(uint32_t size)
1193 {
1194 // We prefer to use block file with larger block if the wasted space would
1195 // be the same. E.g. store entry with size of 3073 bytes in 1 4K-block
1196 // instead of in 4 1K-blocks.
1198 if (size <= 3 * BLOCK_SIZE_FOR_INDEX(1)) return 1;
1199 if (size <= 3 * BLOCK_SIZE_FOR_INDEX(2)) return 2;
1200 if (size <= 4 * BLOCK_SIZE_FOR_INDEX(3)) return 3;
1201 return 0;
1202 }
1204 nsresult
1205 nsDiskCacheMap::EnsureBuffer(uint32_t bufSize)
1206 {
1207 if (mBufferSize < bufSize) {
1208 char * buf = (char *)PR_REALLOC(mBuffer, bufSize);
1209 if (!buf) {
1210 mBufferSize = 0;
1211 return NS_ERROR_OUT_OF_MEMORY;
1212 }
1213 mBuffer = buf;
1214 mBufferSize = bufSize;
1215 }
1216 return NS_OK;
1217 }
1219 void
1220 nsDiskCacheMap::NotifyCapacityChange(uint32_t capacity)
1221 {
1222 // Heuristic 1. average cache entry size is probably around 1KB
1223 // Heuristic 2. we don't want more than 32MB reserved to store the record
1224 // map in memory.
1225 const int32_t RECORD_COUNT_LIMIT = 32 * 1024 * 1024 / sizeof(nsDiskCacheRecord);
1226 int32_t maxRecordCount = std::min(int32_t(capacity), RECORD_COUNT_LIMIT);
1227 if (mMaxRecordCount < maxRecordCount) {
1228 // We can only grow
1229 mMaxRecordCount = maxRecordCount;
1230 }
1231 }
1233 size_t
1234 nsDiskCacheMap::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf)
1235 {
1236 size_t usage = aMallocSizeOf(mRecordArray);
1238 usage += aMallocSizeOf(mBuffer);
1239 usage += aMallocSizeOf(mMapFD);
1240 usage += aMallocSizeOf(mCleanFD);
1241 usage += aMallocSizeOf(mCacheDirectory);
1242 usage += aMallocSizeOf(mCleanCacheTimer);
1244 for (int i = 0; i < kNumBlockFiles; i++) {
1245 usage += mBlockFile[i].SizeOfExcludingThis(aMallocSizeOf);
1246 }
1248 return usage;
1249 }
1251 nsresult
1252 nsDiskCacheMap::InitCacheClean(nsIFile * cacheDirectory,
1253 nsDiskCache::CorruptCacheInfo * corruptInfo,
1254 bool reportCacheCleanTelemetryData)
1255 {
1256 // The _CACHE_CLEAN_ file will be used in the future to determine
1257 // if the cache is clean or not.
1258 bool cacheCleanFileExists = false;
1259 nsCOMPtr<nsIFile> cacheCleanFile;
1260 nsresult rv = cacheDirectory->GetParent(getter_AddRefs(cacheCleanFile));
1261 if (NS_SUCCEEDED(rv)) {
1262 rv = cacheCleanFile->AppendNative(
1263 NS_LITERAL_CSTRING("_CACHE_CLEAN_"));
1264 if (NS_SUCCEEDED(rv)) {
1265 // Check if the file already exists, if it does, we will later read the
1266 // value and report it to telemetry.
1267 cacheCleanFile->Exists(&cacheCleanFileExists);
1268 }
1269 }
1270 if (NS_FAILED(rv)) {
1271 NS_WARNING("Could not build cache clean file path");
1272 *corruptInfo = nsDiskCache::kCacheCleanFilePathError;
1273 return rv;
1274 }
1276 // Make sure the _CACHE_CLEAN_ file exists
1277 rv = cacheCleanFile->OpenNSPRFileDesc(PR_RDWR | PR_CREATE_FILE,
1278 00600, &mCleanFD);
1279 if (NS_FAILED(rv)) {
1280 NS_WARNING("Could not open cache clean file");
1281 *corruptInfo = nsDiskCache::kCacheCleanOpenFileError;
1282 return rv;
1283 }
1285 if (cacheCleanFileExists) {
1286 char clean = '0';
1287 int32_t bytesRead = PR_Read(mCleanFD, &clean, 1);
1288 if (bytesRead != 1) {
1289 NS_WARNING("Could not read _CACHE_CLEAN_ file contents");
1290 } else if (reportCacheCleanTelemetryData) {
1291 Telemetry::Accumulate(Telemetry::DISK_CACHE_REDUCTION_TRIAL,
1292 clean == '1' ? 1 : 0);
1293 }
1294 }
1296 // Create a timer that will be used to validate the cache
1297 // as long as an activity threshold was met
1298 mCleanCacheTimer = do_CreateInstance("@mozilla.org/timer;1", &rv);
1299 if (NS_SUCCEEDED(rv)) {
1300 mCleanCacheTimer->SetTarget(nsCacheService::GlobalInstance()->mCacheIOThread);
1301 rv = ResetCacheTimer();
1302 }
1304 if (NS_FAILED(rv)) {
1305 NS_WARNING("Could not create cache clean timer");
1306 mCleanCacheTimer = nullptr;
1307 *corruptInfo = nsDiskCache::kCacheCleanTimerError;
1308 return rv;
1309 }
1311 return NS_OK;
1312 }
1314 nsresult
1315 nsDiskCacheMap::WriteCacheClean(bool clean)
1316 {
1317 nsCacheService::AssertOwnsLock();
1318 if (!mCleanFD) {
1319 NS_WARNING("Cache clean file is not open!");
1320 return NS_ERROR_FAILURE;
1321 }
1323 CACHE_LOG_DEBUG(("CACHE: WriteCacheClean: %d\n", clean? 1 : 0));
1324 // I'm using a simple '1' or '0' to denote cache clean
1325 // since it can be edited easily by any text editor for testing.
1326 char data = clean? '1' : '0';
1327 int32_t filePos = PR_Seek(mCleanFD, 0, PR_SEEK_SET);
1328 if (filePos != 0) {
1329 NS_WARNING("Could not seek in cache clean file!");
1330 return NS_ERROR_FAILURE;
1331 }
1332 int32_t bytesWritten = PR_Write(mCleanFD, &data, 1);
1333 if (bytesWritten != 1) {
1334 NS_WARNING("Could not write cache clean file!");
1335 return NS_ERROR_FAILURE;
1336 }
1337 PRStatus err = PR_Sync(mCleanFD);
1338 if (err != PR_SUCCESS) {
1339 NS_WARNING("Could not flush cache clean file!");
1340 }
1342 return NS_OK;
1343 }
1345 nsresult
1346 nsDiskCacheMap::InvalidateCache()
1347 {
1348 nsCacheService::AssertOwnsLock();
1349 CACHE_LOG_DEBUG(("CACHE: InvalidateCache\n"));
1350 nsresult rv;
1352 if (!mIsDirtyCacheFlushed) {
1353 rv = WriteCacheClean(false);
1354 if (NS_FAILED(rv)) {
1355 Telemetry::Accumulate(Telemetry::DISK_CACHE_INVALIDATION_SUCCESS, 0);
1356 return rv;
1357 }
1359 Telemetry::Accumulate(Telemetry::DISK_CACHE_INVALIDATION_SUCCESS, 1);
1360 mIsDirtyCacheFlushed = true;
1361 }
1363 rv = ResetCacheTimer();
1364 NS_ENSURE_SUCCESS(rv, rv);
1366 return NS_OK;
1367 }
1369 nsresult
1370 nsDiskCacheMap::ResetCacheTimer(int32_t timeout)
1371 {
1372 mCleanCacheTimer->Cancel();
1373 nsresult rv =
1374 mCleanCacheTimer->InitWithFuncCallback(RevalidateTimerCallback,
1375 nullptr, timeout,
1376 nsITimer::TYPE_ONE_SHOT);
1377 NS_ENSURE_SUCCESS(rv, rv);
1378 mLastInvalidateTime = PR_IntervalNow();
1380 return rv;
1381 }
1383 void
1384 nsDiskCacheMap::RevalidateTimerCallback(nsITimer *aTimer, void *arg)
1385 {
1386 nsCacheServiceAutoLock lock(LOCK_TELEM(NSDISKCACHEMAP_REVALIDATION));
1387 if (!nsCacheService::gService->mDiskDevice ||
1388 !nsCacheService::gService->mDiskDevice->Initialized()) {
1389 return;
1390 }
1392 nsDiskCacheMap *diskCacheMap =
1393 &nsCacheService::gService->mDiskDevice->mCacheMap;
1395 // If we have less than kRevalidateCacheTimeout since the last timer was
1396 // issued then another thread called InvalidateCache. This won't catch
1397 // all cases where we wanted to cancel the timer, but under the lock it
1398 // is always OK to revalidate as long as IsCacheInSafeState() returns
1399 // true. We just want to avoid revalidating when we can to reduce IO
1400 // and this check will do that.
1401 uint32_t delta =
1402 PR_IntervalToMilliseconds(PR_IntervalNow() -
1403 diskCacheMap->mLastInvalidateTime) +
1404 kRevalidateCacheTimeoutTolerance;
1405 if (delta < kRevalidateCacheTimeout) {
1406 diskCacheMap->ResetCacheTimer();
1407 return;
1408 }
1410 nsresult rv = diskCacheMap->RevalidateCache();
1411 if (NS_FAILED(rv)) {
1412 diskCacheMap->ResetCacheTimer(kRevalidateCacheErrorTimeout);
1413 }
1414 }
1416 bool
1417 nsDiskCacheMap::IsCacheInSafeState()
1418 {
1419 return nsCacheService::GlobalInstance()->IsDoomListEmpty();
1420 }
1422 nsresult
1423 nsDiskCacheMap::RevalidateCache()
1424 {
1425 CACHE_LOG_DEBUG(("CACHE: RevalidateCache\n"));
1426 nsresult rv;
1428 if (!IsCacheInSafeState()) {
1429 Telemetry::Accumulate(Telemetry::DISK_CACHE_REVALIDATION_SAFE, 0);
1430 CACHE_LOG_DEBUG(("CACHE: Revalidation should not performed because "
1431 "cache not in a safe state\n"));
1432 // Normally we would return an error here, but there is a bug where
1433 // the doom list sometimes gets an entry 'stuck' and doens't clear it
1434 // until browser shutdown. So we allow revalidation for the time being
1435 // to get proper telemetry data of how much the cache corruption plan
1436 // would help.
1437 } else {
1438 Telemetry::Accumulate(Telemetry::DISK_CACHE_REVALIDATION_SAFE, 1);
1439 }
1441 // We want this after the lock to prove that flushing a file isn't that expensive
1442 Telemetry::AutoTimer<Telemetry::NETWORK_DISK_CACHE_REVALIDATION> totalTimer;
1444 // If telemetry data shows it is worth it, we'll be flushing headers and
1445 // records before flushing the clean cache file.
1447 // Write out the _CACHE_CLEAN_ file with '1'
1448 rv = WriteCacheClean(true);
1449 if (NS_FAILED(rv)) {
1450 Telemetry::Accumulate(Telemetry::DISK_CACHE_REVALIDATION_SUCCESS, 0);
1451 return rv;
1452 }
1454 Telemetry::Accumulate(Telemetry::DISK_CACHE_REVALIDATION_SUCCESS, 1);
1455 mIsDirtyCacheFlushed = false;
1457 return NS_OK;
1458 }
