1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "net/disk_cache/entry_impl.h" 6 7 #include "base/hash.h" 8 #include "base/message_loop/message_loop.h" 9 #include "base/metrics/histogram.h" 10 #include "base/strings/string_util.h" 11 #include "net/base/io_buffer.h" 12 #include "net/base/net_errors.h" 13 #include "net/disk_cache/backend_impl.h" 14 #include "net/disk_cache/bitmap.h" 15 #include "net/disk_cache/cache_util.h" 16 #include "net/disk_cache/disk_format.h" 17 #include "net/disk_cache/histogram_macros.h" 18 #include "net/disk_cache/net_log_parameters.h" 19 #include "net/disk_cache/sparse_control.h" 20 21 using base::Time; 22 using base::TimeDelta; 23 using base::TimeTicks; 24 25 namespace { 26 27 // Index for the file used to store the key, if any (files_[kKeyFileIndex]). 28 const int kKeyFileIndex = 3; 29 30 // This class implements FileIOCallback to buffer the callback from a file IO 31 // operation from the actual net class. 32 class SyncCallback: public disk_cache::FileIOCallback { 33 public: 34 // |end_event_type| is the event type to log on completion. Logs nothing on 35 // discard, or when the NetLog is not set to log all events. 36 SyncCallback(disk_cache::EntryImpl* entry, net::IOBuffer* buffer, 37 const net::CompletionCallback& callback, 38 net::NetLog::EventType end_event_type) 39 : entry_(entry), callback_(callback), buf_(buffer), 40 start_(TimeTicks::Now()), end_event_type_(end_event_type) { 41 entry->AddRef(); 42 entry->IncrementIoCount(); 43 } 44 virtual ~SyncCallback() {} 45 46 virtual void OnFileIOComplete(int bytes_copied) OVERRIDE; 47 void Discard(); 48 49 private: 50 disk_cache::EntryImpl* entry_; 51 net::CompletionCallback callback_; 52 scoped_refptr<net::IOBuffer> buf_; 53 TimeTicks start_; 54 const net::NetLog::EventType end_event_type_; 55 56 DISALLOW_COPY_AND_ASSIGN(SyncCallback); 57 }; 58 59 void SyncCallback::OnFileIOComplete(int bytes_copied) { 60 entry_->DecrementIoCount(); 61 if (!callback_.is_null()) { 62 if (entry_->net_log().IsLoggingAllEvents()) { 63 entry_->net_log().EndEvent( 64 end_event_type_, 65 disk_cache::CreateNetLogReadWriteCompleteCallback(bytes_copied)); 66 } 67 entry_->ReportIOTime(disk_cache::EntryImpl::kAsyncIO, start_); 68 buf_ = NULL; // Release the buffer before invoking the callback. 69 callback_.Run(bytes_copied); 70 } 71 entry_->Release(); 72 delete this; 73 } 74 75 void SyncCallback::Discard() { 76 callback_.Reset(); 77 buf_ = NULL; 78 OnFileIOComplete(0); 79 } 80 81 const int kMaxBufferSize = 1024 * 1024; // 1 MB. 82 83 } // namespace 84 85 namespace disk_cache { 86 87 // This class handles individual memory buffers that store data before it is 88 // sent to disk. The buffer can start at any offset, but if we try to write to 89 // anywhere in the first 16KB of the file (kMaxBlockSize), we set the offset to 90 // zero. The buffer grows up to a size determined by the backend, to keep the 91 // total memory used under control. 92 class EntryImpl::UserBuffer { 93 public: 94 explicit UserBuffer(BackendImpl* backend) 95 : backend_(backend->GetWeakPtr()), offset_(0), grow_allowed_(true) { 96 buffer_.reserve(kMaxBlockSize); 97 } 98 ~UserBuffer() { 99 if (backend_.get()) 100 backend_->BufferDeleted(capacity() - kMaxBlockSize); 101 } 102 103 // Returns true if we can handle writing |len| bytes to |offset|. 104 bool PreWrite(int offset, int len); 105 106 // Truncates the buffer to |offset| bytes. 107 void Truncate(int offset); 108 109 // Writes |len| bytes from |buf| at the given |offset|. 110 void Write(int offset, IOBuffer* buf, int len); 111 112 // Returns true if we can read |len| bytes from |offset|, given that the 113 // actual file has |eof| bytes stored. Note that the number of bytes to read 114 // may be modified by this method even though it returns false: that means we 115 // should do a smaller read from disk. 116 bool PreRead(int eof, int offset, int* len); 117 118 // Read |len| bytes from |buf| at the given |offset|. 119 int Read(int offset, IOBuffer* buf, int len); 120 121 // Prepare this buffer for reuse. 122 void Reset(); 123 124 char* Data() { return buffer_.size() ? &buffer_[0] : NULL; } 125 int Size() { return static_cast<int>(buffer_.size()); } 126 int Start() { return offset_; } 127 int End() { return offset_ + Size(); } 128 129 private: 130 int capacity() { return static_cast<int>(buffer_.capacity()); } 131 bool GrowBuffer(int required, int limit); 132 133 base::WeakPtr<BackendImpl> backend_; 134 int offset_; 135 std::vector<char> buffer_; 136 bool grow_allowed_; 137 DISALLOW_COPY_AND_ASSIGN(UserBuffer); 138 }; 139 140 bool EntryImpl::UserBuffer::PreWrite(int offset, int len) { 141 DCHECK_GE(offset, 0); 142 DCHECK_GE(len, 0); 143 DCHECK_GE(offset + len, 0); 144 145 // We don't want to write before our current start. 146 if (offset < offset_) 147 return false; 148 149 // Lets get the common case out of the way. 150 if (offset + len <= capacity()) 151 return true; 152 153 // If we are writing to the first 16K (kMaxBlockSize), we want to keep the 154 // buffer offset_ at 0. 155 if (!Size() && offset > kMaxBlockSize) 156 return GrowBuffer(len, kMaxBufferSize); 157 158 int required = offset - offset_ + len; 159 return GrowBuffer(required, kMaxBufferSize * 6 / 5); 160 } 161 162 void EntryImpl::UserBuffer::Truncate(int offset) { 163 DCHECK_GE(offset, 0); 164 DCHECK_GE(offset, offset_); 165 DVLOG(3) << "Buffer truncate at " << offset << " current " << offset_; 166 167 offset -= offset_; 168 if (Size() >= offset) 169 buffer_.resize(offset); 170 } 171 172 void EntryImpl::UserBuffer::Write(int offset, IOBuffer* buf, int len) { 173 DCHECK_GE(offset, 0); 174 DCHECK_GE(len, 0); 175 DCHECK_GE(offset + len, 0); 176 DCHECK_GE(offset, offset_); 177 DVLOG(3) << "Buffer write at " << offset << " current " << offset_; 178 179 if (!Size() && offset > kMaxBlockSize) 180 offset_ = offset; 181 182 offset -= offset_; 183 184 if (offset > Size()) 185 buffer_.resize(offset); 186 187 if (!len) 188 return; 189 190 char* buffer = buf->data(); 191 int valid_len = Size() - offset; 192 int copy_len = std::min(valid_len, len); 193 if (copy_len) { 194 memcpy(&buffer_[offset], buffer, copy_len); 195 len -= copy_len; 196 buffer += copy_len; 197 } 198 if (!len) 199 return; 200 201 buffer_.insert(buffer_.end(), buffer, buffer + len); 202 } 203 204 bool EntryImpl::UserBuffer::PreRead(int eof, int offset, int* len) { 205 DCHECK_GE(offset, 0); 206 DCHECK_GT(*len, 0); 207 208 if (offset < offset_) { 209 // We are reading before this buffer. 210 if (offset >= eof) 211 return true; 212 213 // If the read overlaps with the buffer, change its length so that there is 214 // no overlap. 215 *len = std::min(*len, offset_ - offset); 216 *len = std::min(*len, eof - offset); 217 218 // We should read from disk. 219 return false; 220 } 221 222 if (!Size()) 223 return false; 224 225 // See if we can fulfill the first part of the operation. 226 return (offset - offset_ < Size()); 227 } 228 229 int EntryImpl::UserBuffer::Read(int offset, IOBuffer* buf, int len) { 230 DCHECK_GE(offset, 0); 231 DCHECK_GT(len, 0); 232 DCHECK(Size() || offset < offset_); 233 234 int clean_bytes = 0; 235 if (offset < offset_) { 236 // We don't have a file so lets fill the first part with 0. 237 clean_bytes = std::min(offset_ - offset, len); 238 memset(buf->data(), 0, clean_bytes); 239 if (len == clean_bytes) 240 return len; 241 offset = offset_; 242 len -= clean_bytes; 243 } 244 245 int start = offset - offset_; 246 int available = Size() - start; 247 DCHECK_GE(start, 0); 248 DCHECK_GE(available, 0); 249 len = std::min(len, available); 250 memcpy(buf->data() + clean_bytes, &buffer_[start], len); 251 return len + clean_bytes; 252 } 253 254 void EntryImpl::UserBuffer::Reset() { 255 if (!grow_allowed_) { 256 if (backend_.get()) 257 backend_->BufferDeleted(capacity() - kMaxBlockSize); 258 grow_allowed_ = true; 259 std::vector<char> tmp; 260 buffer_.swap(tmp); 261 buffer_.reserve(kMaxBlockSize); 262 } 263 offset_ = 0; 264 buffer_.clear(); 265 } 266 267 bool EntryImpl::UserBuffer::GrowBuffer(int required, int limit) { 268 DCHECK_GE(required, 0); 269 int current_size = capacity(); 270 if (required <= current_size) 271 return true; 272 273 if (required > limit) 274 return false; 275 276 if (!backend_.get()) 277 return false; 278 279 int to_add = std::max(required - current_size, kMaxBlockSize * 4); 280 to_add = std::max(current_size, to_add); 281 required = std::min(current_size + to_add, limit); 282 283 grow_allowed_ = backend_->IsAllocAllowed(current_size, required); 284 if (!grow_allowed_) 285 return false; 286 287 DVLOG(3) << "Buffer grow to " << required; 288 289 buffer_.reserve(required); 290 return true; 291 } 292 293 // ------------------------------------------------------------------------ 294 295 EntryImpl::EntryImpl(BackendImpl* backend, Addr address, bool read_only) 296 : entry_(NULL, Addr(0)), node_(NULL, Addr(0)), 297 backend_(backend->GetWeakPtr()), doomed_(false), read_only_(read_only), 298 dirty_(false) { 299 entry_.LazyInit(backend->File(address), address); 300 for (int i = 0; i < kNumStreams; i++) { 301 unreported_size_[i] = 0; 302 } 303 } 304 305 void EntryImpl::DoomImpl() { 306 if (doomed_ || !backend_.get()) 307 return; 308 309 SetPointerForInvalidEntry(backend_->GetCurrentEntryId()); 310 backend_->InternalDoomEntry(this); 311 } 312 313 int EntryImpl::ReadDataImpl(int index, int offset, IOBuffer* buf, int buf_len, 314 const CompletionCallback& callback) { 315 if (net_log_.IsLoggingAllEvents()) { 316 net_log_.BeginEvent( 317 net::NetLog::TYPE_ENTRY_READ_DATA, 318 CreateNetLogReadWriteDataCallback(index, offset, buf_len, false)); 319 } 320 321 int result = InternalReadData(index, offset, buf, buf_len, callback); 322 323 if (result != net::ERR_IO_PENDING && net_log_.IsLoggingAllEvents()) { 324 net_log_.EndEvent( 325 net::NetLog::TYPE_ENTRY_READ_DATA, 326 CreateNetLogReadWriteCompleteCallback(result)); 327 } 328 return result; 329 } 330 331 int EntryImpl::WriteDataImpl(int index, int offset, IOBuffer* buf, int buf_len, 332 const CompletionCallback& callback, 333 bool truncate) { 334 if (net_log_.IsLoggingAllEvents()) { 335 net_log_.BeginEvent( 336 net::NetLog::TYPE_ENTRY_WRITE_DATA, 337 CreateNetLogReadWriteDataCallback(index, offset, buf_len, truncate)); 338 } 339 340 int result = InternalWriteData(index, offset, buf, buf_len, callback, 341 truncate); 342 343 if (result != net::ERR_IO_PENDING && net_log_.IsLoggingAllEvents()) { 344 net_log_.EndEvent( 345 net::NetLog::TYPE_ENTRY_WRITE_DATA, 346 CreateNetLogReadWriteCompleteCallback(result)); 347 } 348 return result; 349 } 350 351 int EntryImpl::ReadSparseDataImpl(int64 offset, IOBuffer* buf, int buf_len, 352 const CompletionCallback& callback) { 353 DCHECK(node_.Data()->dirty || read_only_); 354 int result = InitSparseData(); 355 if (net::OK != result) 356 return result; 357 358 TimeTicks start = TimeTicks::Now(); 359 result = sparse_->StartIO(SparseControl::kReadOperation, offset, buf, buf_len, 360 callback); 361 ReportIOTime(kSparseRead, start); 362 return result; 363 } 364 365 int EntryImpl::WriteSparseDataImpl(int64 offset, IOBuffer* buf, int buf_len, 366 const CompletionCallback& callback) { 367 DCHECK(node_.Data()->dirty || read_only_); 368 int result = InitSparseData(); 369 if (net::OK != result) 370 return result; 371 372 TimeTicks start = TimeTicks::Now(); 373 result = sparse_->StartIO(SparseControl::kWriteOperation, offset, buf, 374 buf_len, callback); 375 ReportIOTime(kSparseWrite, start); 376 return result; 377 } 378 379 int EntryImpl::GetAvailableRangeImpl(int64 offset, int len, int64* start) { 380 int result = InitSparseData(); 381 if (net::OK != result) 382 return result; 383 384 return sparse_->GetAvailableRange(offset, len, start); 385 } 386 387 void EntryImpl::CancelSparseIOImpl() { 388 if (!sparse_.get()) 389 return; 390 391 sparse_->CancelIO(); 392 } 393 394 int EntryImpl::ReadyForSparseIOImpl(const CompletionCallback& callback) { 395 DCHECK(sparse_.get()); 396 return sparse_->ReadyToUse(callback); 397 } 398 399 uint32 EntryImpl::GetHash() { 400 return entry_.Data()->hash; 401 } 402 403 bool EntryImpl::CreateEntry(Addr node_address, const std::string& key, 404 uint32 hash) { 405 Trace("Create entry In"); 406 EntryStore* entry_store = entry_.Data(); 407 RankingsNode* node = node_.Data(); 408 memset(entry_store, 0, sizeof(EntryStore) * entry_.address().num_blocks()); 409 memset(node, 0, sizeof(RankingsNode)); 410 if (!node_.LazyInit(backend_->File(node_address), node_address)) 411 return false; 412 413 entry_store->rankings_node = node_address.value(); 414 node->contents = entry_.address().value(); 415 416 entry_store->hash = hash; 417 entry_store->creation_time = Time::Now().ToInternalValue(); 418 entry_store->key_len = static_cast<int32>(key.size()); 419 if (entry_store->key_len > kMaxInternalKeyLength) { 420 Addr address(0); 421 if (!CreateBlock(entry_store->key_len + 1, &address)) 422 return false; 423 424 entry_store->long_key = address.value(); 425 File* key_file = GetBackingFile(address, kKeyFileIndex); 426 key_ = key; 427 428 size_t offset = 0; 429 if (address.is_block_file()) 430 offset = address.start_block() * address.BlockSize() + kBlockHeaderSize; 431 432 if (!key_file || !key_file->Write(key.data(), key.size(), offset)) { 433 DeleteData(address, kKeyFileIndex); 434 return false; 435 } 436 437 if (address.is_separate_file()) 438 key_file->SetLength(key.size() + 1); 439 } else { 440 memcpy(entry_store->key, key.data(), key.size()); 441 entry_store->key[key.size()] = '\0'; 442 } 443 backend_->ModifyStorageSize(0, static_cast<int32>(key.size())); 444 CACHE_UMA(COUNTS, "KeySize", 0, static_cast<int32>(key.size())); 445 node->dirty = backend_->GetCurrentEntryId(); 446 Log("Create Entry "); 447 return true; 448 } 449 450 bool EntryImpl::IsSameEntry(const std::string& key, uint32 hash) { 451 if (entry_.Data()->hash != hash || 452 static_cast<size_t>(entry_.Data()->key_len) != key.size()) 453 return false; 454 455 return (key.compare(GetKey()) == 0); 456 } 457 458 void EntryImpl::InternalDoom() { 459 net_log_.AddEvent(net::NetLog::TYPE_ENTRY_DOOM); 460 DCHECK(node_.HasData()); 461 if (!node_.Data()->dirty) { 462 node_.Data()->dirty = backend_->GetCurrentEntryId(); 463 node_.Store(); 464 } 465 doomed_ = true; 466 } 467 468 void EntryImpl::DeleteEntryData(bool everything) { 469 DCHECK(doomed_ || !everything); 470 471 if (GetEntryFlags() & PARENT_ENTRY) { 472 // We have some child entries that must go away. 473 SparseControl::DeleteChildren(this); 474 } 475 476 if (GetDataSize(0)) 477 CACHE_UMA(COUNTS, "DeleteHeader", 0, GetDataSize(0)); 478 if (GetDataSize(1)) 479 CACHE_UMA(COUNTS, "DeleteData", 0, GetDataSize(1)); 480 for (int index = 0; index < kNumStreams; index++) { 481 Addr address(entry_.Data()->data_addr[index]); 482 if (address.is_initialized()) { 483 backend_->ModifyStorageSize(entry_.Data()->data_size[index] - 484 unreported_size_[index], 0); 485 entry_.Data()->data_addr[index] = 0; 486 entry_.Data()->data_size[index] = 0; 487 entry_.Store(); 488 DeleteData(address, index); 489 } 490 } 491 492 if (!everything) 493 return; 494 495 // Remove all traces of this entry. 496 backend_->RemoveEntry(this); 497 498 // Note that at this point node_ and entry_ are just two blocks of data, and 499 // even if they reference each other, nobody should be referencing them. 500 501 Addr address(entry_.Data()->long_key); 502 DeleteData(address, kKeyFileIndex); 503 backend_->ModifyStorageSize(entry_.Data()->key_len, 0); 504 505 backend_->DeleteBlock(entry_.address(), true); 506 entry_.Discard(); 507 508 if (!LeaveRankingsBehind()) { 509 backend_->DeleteBlock(node_.address(), true); 510 node_.Discard(); 511 } 512 } 513 514 CacheAddr EntryImpl::GetNextAddress() { 515 return entry_.Data()->next; 516 } 517 518 void EntryImpl::SetNextAddress(Addr address) { 519 DCHECK_NE(address.value(), entry_.address().value()); 520 entry_.Data()->next = address.value(); 521 bool success = entry_.Store(); 522 DCHECK(success); 523 } 524 525 bool EntryImpl::LoadNodeAddress() { 526 Addr address(entry_.Data()->rankings_node); 527 if (!node_.LazyInit(backend_->File(address), address)) 528 return false; 529 return node_.Load(); 530 } 531 532 bool EntryImpl::Update() { 533 DCHECK(node_.HasData()); 534 535 if (read_only_) 536 return true; 537 538 RankingsNode* rankings = node_.Data(); 539 if (!rankings->dirty) { 540 rankings->dirty = backend_->GetCurrentEntryId(); 541 if (!node_.Store()) 542 return false; 543 } 544 return true; 545 } 546 547 void EntryImpl::SetDirtyFlag(int32 current_id) { 548 DCHECK(node_.HasData()); 549 if (node_.Data()->dirty && current_id != node_.Data()->dirty) 550 dirty_ = true; 551 552 if (!current_id) 553 dirty_ = true; 554 } 555 556 void EntryImpl::SetPointerForInvalidEntry(int32 new_id) { 557 node_.Data()->dirty = new_id; 558 node_.Store(); 559 } 560 561 bool EntryImpl::LeaveRankingsBehind() { 562 return !node_.Data()->contents; 563 } 564 565 // This only includes checks that relate to the first block of the entry (the 566 // first 256 bytes), and values that should be set from the entry creation. 567 // Basically, even if there is something wrong with this entry, we want to see 568 // if it is possible to load the rankings node and delete them together. 569 bool EntryImpl::SanityCheck() { 570 if (!entry_.VerifyHash()) 571 return false; 572 573 EntryStore* stored = entry_.Data(); 574 if (!stored->rankings_node || stored->key_len <= 0) 575 return false; 576 577 if (stored->reuse_count < 0 || stored->refetch_count < 0) 578 return false; 579 580 Addr rankings_addr(stored->rankings_node); 581 if (!rankings_addr.SanityCheckForRankings()) 582 return false; 583 584 Addr next_addr(stored->next); 585 if (next_addr.is_initialized() && !next_addr.SanityCheckForEntryV2()) { 586 STRESS_NOTREACHED(); 587 return false; 588 } 589 STRESS_DCHECK(next_addr.value() != entry_.address().value()); 590 591 if (stored->state > ENTRY_DOOMED || stored->state < ENTRY_NORMAL) 592 return false; 593 594 Addr key_addr(stored->long_key); 595 if ((stored->key_len <= kMaxInternalKeyLength && key_addr.is_initialized()) || 596 (stored->key_len > kMaxInternalKeyLength && !key_addr.is_initialized())) 597 return false; 598 599 if (!key_addr.SanityCheckV2()) 600 return false; 601 602 if (key_addr.is_initialized() && 603 ((stored->key_len < kMaxBlockSize && key_addr.is_separate_file()) || 604 (stored->key_len >= kMaxBlockSize && key_addr.is_block_file()))) 605 return false; 606 607 int num_blocks = NumBlocksForEntry(stored->key_len); 608 if (entry_.address().num_blocks() != num_blocks) 609 return false; 610 611 return true; 612 } 613 614 bool EntryImpl::DataSanityCheck() { 615 EntryStore* stored = entry_.Data(); 616 Addr key_addr(stored->long_key); 617 618 // The key must be NULL terminated. 619 if (!key_addr.is_initialized() && stored->key[stored->key_len]) 620 return false; 621 622 if (stored->hash != base::Hash(GetKey())) 623 return false; 624 625 for (int i = 0; i < kNumStreams; i++) { 626 Addr data_addr(stored->data_addr[i]); 627 int data_size = stored->data_size[i]; 628 if (data_size < 0) 629 return false; 630 if (!data_size && data_addr.is_initialized()) 631 return false; 632 if (!data_addr.SanityCheckV2()) 633 return false; 634 if (!data_size) 635 continue; 636 if (data_size <= kMaxBlockSize && data_addr.is_separate_file()) 637 return false; 638 if (data_size > kMaxBlockSize && data_addr.is_block_file()) 639 return false; 640 } 641 return true; 642 } 643 644 void EntryImpl::FixForDelete() { 645 EntryStore* stored = entry_.Data(); 646 Addr key_addr(stored->long_key); 647 648 if (!key_addr.is_initialized()) 649 stored->key[stored->key_len] = '\0'; 650 651 for (int i = 0; i < kNumStreams; i++) { 652 Addr data_addr(stored->data_addr[i]); 653 int data_size = stored->data_size[i]; 654 if (data_addr.is_initialized()) { 655 if ((data_size <= kMaxBlockSize && data_addr.is_separate_file()) || 656 (data_size > kMaxBlockSize && data_addr.is_block_file()) || 657 !data_addr.SanityCheckV2()) { 658 STRESS_NOTREACHED(); 659 // The address is weird so don't attempt to delete it. 660 stored->data_addr[i] = 0; 661 // In general, trust the stored size as it should be in sync with the 662 // total size tracked by the backend. 663 } 664 } 665 if (data_size < 0) 666 stored->data_size[i] = 0; 667 } 668 entry_.Store(); 669 } 670 671 void EntryImpl::IncrementIoCount() { 672 backend_->IncrementIoCount(); 673 } 674 675 void EntryImpl::DecrementIoCount() { 676 if (backend_.get()) 677 backend_->DecrementIoCount(); 678 } 679 680 void EntryImpl::OnEntryCreated(BackendImpl* backend) { 681 // Just grab a reference to the backround queue. 682 background_queue_ = backend->GetBackgroundQueue(); 683 } 684 685 void EntryImpl::SetTimes(base::Time last_used, base::Time last_modified) { 686 node_.Data()->last_used = last_used.ToInternalValue(); 687 node_.Data()->last_modified = last_modified.ToInternalValue(); 688 node_.set_modified(); 689 } 690 691 void EntryImpl::ReportIOTime(Operation op, const base::TimeTicks& start) { 692 if (!backend_.get()) 693 return; 694 695 switch (op) { 696 case kRead: 697 CACHE_UMA(AGE_MS, "ReadTime", 0, start); 698 break; 699 case kWrite: 700 CACHE_UMA(AGE_MS, "WriteTime", 0, start); 701 break; 702 case kSparseRead: 703 CACHE_UMA(AGE_MS, "SparseReadTime", 0, start); 704 break; 705 case kSparseWrite: 706 CACHE_UMA(AGE_MS, "SparseWriteTime", 0, start); 707 break; 708 case kAsyncIO: 709 CACHE_UMA(AGE_MS, "AsyncIOTime", 0, start); 710 break; 711 case kReadAsync1: 712 CACHE_UMA(AGE_MS, "AsyncReadDispatchTime", 0, start); 713 break; 714 case kWriteAsync1: 715 CACHE_UMA(AGE_MS, "AsyncWriteDispatchTime", 0, start); 716 break; 717 default: 718 NOTREACHED(); 719 } 720 } 721 722 void EntryImpl::BeginLogging(net::NetLog* net_log, bool created) { 723 DCHECK(!net_log_.net_log()); 724 net_log_ = net::BoundNetLog::Make( 725 net_log, net::NetLog::SOURCE_DISK_CACHE_ENTRY); 726 net_log_.BeginEvent( 727 net::NetLog::TYPE_DISK_CACHE_ENTRY_IMPL, 728 CreateNetLogEntryCreationCallback(this, created)); 729 } 730 731 const net::BoundNetLog& EntryImpl::net_log() const { 732 return net_log_; 733 } 734 735 // static 736 int EntryImpl::NumBlocksForEntry(int key_size) { 737 // The longest key that can be stored using one block. 738 int key1_len = 739 static_cast<int>(sizeof(EntryStore) - offsetof(EntryStore, key)); 740 741 if (key_size < key1_len || key_size > kMaxInternalKeyLength) 742 return 1; 743 744 return ((key_size - key1_len) / 256 + 2); 745 } 746 747 // ------------------------------------------------------------------------ 748 749 void EntryImpl::Doom() { 750 if (background_queue_.get()) 751 background_queue_->DoomEntryImpl(this); 752 } 753 754 void EntryImpl::Close() { 755 if (background_queue_.get()) 756 background_queue_->CloseEntryImpl(this); 757 } 758 759 std::string EntryImpl::GetKey() const { 760 CacheEntryBlock* entry = const_cast<CacheEntryBlock*>(&entry_); 761 int key_len = entry->Data()->key_len; 762 if (key_len <= kMaxInternalKeyLength) 763 return std::string(entry->Data()->key); 764 765 // We keep a copy of the key so that we can always return it, even if the 766 // backend is disabled. 767 if (!key_.empty()) 768 return key_; 769 770 Addr address(entry->Data()->long_key); 771 DCHECK(address.is_initialized()); 772 size_t offset = 0; 773 if (address.is_block_file()) 774 offset = address.start_block() * address.BlockSize() + kBlockHeaderSize; 775 776 COMPILE_ASSERT(kNumStreams == kKeyFileIndex, invalid_key_index); 777 File* key_file = const_cast<EntryImpl*>(this)->GetBackingFile(address, 778 kKeyFileIndex); 779 if (!key_file) 780 return std::string(); 781 782 ++key_len; // We store a trailing \0 on disk that we read back below. 783 if (!offset && key_file->GetLength() != static_cast<size_t>(key_len)) 784 return std::string(); 785 786 if (!key_file->Read(WriteInto(&key_, key_len), key_len, offset)) 787 key_.clear(); 788 return key_; 789 } 790 791 Time EntryImpl::GetLastUsed() const { 792 CacheRankingsBlock* node = const_cast<CacheRankingsBlock*>(&node_); 793 return Time::FromInternalValue(node->Data()->last_used); 794 } 795 796 Time EntryImpl::GetLastModified() const { 797 CacheRankingsBlock* node = const_cast<CacheRankingsBlock*>(&node_); 798 return Time::FromInternalValue(node->Data()->last_modified); 799 } 800 801 int32 EntryImpl::GetDataSize(int index) const { 802 if (index < 0 || index >= kNumStreams) 803 return 0; 804 805 CacheEntryBlock* entry = const_cast<CacheEntryBlock*>(&entry_); 806 return entry->Data()->data_size[index]; 807 } 808 809 int EntryImpl::ReadData(int index, int offset, IOBuffer* buf, int buf_len, 810 const CompletionCallback& callback) { 811 if (callback.is_null()) 812 return ReadDataImpl(index, offset, buf, buf_len, callback); 813 814 DCHECK(node_.Data()->dirty || read_only_); 815 if (index < 0 || index >= kNumStreams) 816 return net::ERR_INVALID_ARGUMENT; 817 818 int entry_size = entry_.Data()->data_size[index]; 819 if (offset >= entry_size || offset < 0 || !buf_len) 820 return 0; 821 822 if (buf_len < 0) 823 return net::ERR_INVALID_ARGUMENT; 824 825 if (!background_queue_.get()) 826 return net::ERR_UNEXPECTED; 827 828 background_queue_->ReadData(this, index, offset, buf, buf_len, callback); 829 return net::ERR_IO_PENDING; 830 } 831 832 int EntryImpl::WriteData(int index, int offset, IOBuffer* buf, int buf_len, 833 const CompletionCallback& callback, bool truncate) { 834 if (callback.is_null()) 835 return WriteDataImpl(index, offset, buf, buf_len, callback, truncate); 836 837 DCHECK(node_.Data()->dirty || read_only_); 838 if (index < 0 || index >= kNumStreams) 839 return net::ERR_INVALID_ARGUMENT; 840 841 if (offset < 0 || buf_len < 0) 842 return net::ERR_INVALID_ARGUMENT; 843 844 if (!background_queue_.get()) 845 return net::ERR_UNEXPECTED; 846 847 background_queue_->WriteData(this, index, offset, buf, buf_len, truncate, 848 callback); 849 return net::ERR_IO_PENDING; 850 } 851 852 int EntryImpl::ReadSparseData(int64 offset, IOBuffer* buf, int buf_len, 853 const CompletionCallback& callback) { 854 if (callback.is_null()) 855 return ReadSparseDataImpl(offset, buf, buf_len, callback); 856 857 if (!background_queue_.get()) 858 return net::ERR_UNEXPECTED; 859 860 background_queue_->ReadSparseData(this, offset, buf, buf_len, callback); 861 return net::ERR_IO_PENDING; 862 } 863 864 int EntryImpl::WriteSparseData(int64 offset, IOBuffer* buf, int buf_len, 865 const CompletionCallback& callback) { 866 if (callback.is_null()) 867 return WriteSparseDataImpl(offset, buf, buf_len, callback); 868 869 if (!background_queue_.get()) 870 return net::ERR_UNEXPECTED; 871 872 background_queue_->WriteSparseData(this, offset, buf, buf_len, callback); 873 return net::ERR_IO_PENDING; 874 } 875 876 int EntryImpl::GetAvailableRange(int64 offset, int len, int64* start, 877 const CompletionCallback& callback) { 878 if (!background_queue_.get()) 879 return net::ERR_UNEXPECTED; 880 881 background_queue_->GetAvailableRange(this, offset, len, start, callback); 882 return net::ERR_IO_PENDING; 883 } 884 885 bool EntryImpl::CouldBeSparse() const { 886 if (sparse_.get()) 887 return true; 888 889 scoped_ptr<SparseControl> sparse; 890 sparse.reset(new SparseControl(const_cast<EntryImpl*>(this))); 891 return sparse->CouldBeSparse(); 892 } 893 894 void EntryImpl::CancelSparseIO() { 895 if (background_queue_.get()) 896 background_queue_->CancelSparseIO(this); 897 } 898 899 int EntryImpl::ReadyForSparseIO(const CompletionCallback& callback) { 900 if (!sparse_.get()) 901 return net::OK; 902 903 if (!background_queue_.get()) 904 return net::ERR_UNEXPECTED; 905 906 background_queue_->ReadyForSparseIO(this, callback); 907 return net::ERR_IO_PENDING; 908 } 909 910 // When an entry is deleted from the cache, we clean up all the data associated 911 // with it for two reasons: to simplify the reuse of the block (we know that any 912 // unused block is filled with zeros), and to simplify the handling of write / 913 // read partial information from an entry (don't have to worry about returning 914 // data related to a previous cache entry because the range was not fully 915 // written before). 916 EntryImpl::~EntryImpl() { 917 if (!backend_.get()) { 918 entry_.clear_modified(); 919 node_.clear_modified(); 920 return; 921 } 922 Log("~EntryImpl in"); 923 924 // Save the sparse info to disk. This will generate IO for this entry and 925 // maybe for a child entry, so it is important to do it before deleting this 926 // entry. 927 sparse_.reset(); 928 929 // Remove this entry from the list of open entries. 930 backend_->OnEntryDestroyBegin(entry_.address()); 931 932 if (doomed_) { 933 DeleteEntryData(true); 934 } else { 935 #if defined(NET_BUILD_STRESS_CACHE) 936 SanityCheck(); 937 #endif 938 net_log_.AddEvent(net::NetLog::TYPE_ENTRY_CLOSE); 939 bool ret = true; 940 for (int index = 0; index < kNumStreams; index++) { 941 if (user_buffers_[index].get()) { 942 if (!(ret = Flush(index, 0))) 943 LOG(ERROR) << "Failed to save user data"; 944 } 945 if (unreported_size_[index]) { 946 backend_->ModifyStorageSize( 947 entry_.Data()->data_size[index] - unreported_size_[index], 948 entry_.Data()->data_size[index]); 949 } 950 } 951 952 if (!ret) { 953 // There was a failure writing the actual data. Mark the entry as dirty. 954 int current_id = backend_->GetCurrentEntryId(); 955 node_.Data()->dirty = current_id == 1 ? -1 : current_id - 1; 956 node_.Store(); 957 } else if (node_.HasData() && !dirty_ && node_.Data()->dirty) { 958 node_.Data()->dirty = 0; 959 node_.Store(); 960 } 961 } 962 963 Trace("~EntryImpl out 0x%p", reinterpret_cast<void*>(this)); 964 net_log_.EndEvent(net::NetLog::TYPE_DISK_CACHE_ENTRY_IMPL); 965 backend_->OnEntryDestroyEnd(); 966 } 967 968 // ------------------------------------------------------------------------ 969 970 int EntryImpl::InternalReadData(int index, int offset, 971 IOBuffer* buf, int buf_len, 972 const CompletionCallback& callback) { 973 DCHECK(node_.Data()->dirty || read_only_); 974 DVLOG(2) << "Read from " << index << " at " << offset << " : " << buf_len; 975 if (index < 0 || index >= kNumStreams) 976 return net::ERR_INVALID_ARGUMENT; 977 978 int entry_size = entry_.Data()->data_size[index]; 979 if (offset >= entry_size || offset < 0 || !buf_len) 980 return 0; 981 982 if (buf_len < 0) 983 return net::ERR_INVALID_ARGUMENT; 984 985 if (!backend_.get()) 986 return net::ERR_UNEXPECTED; 987 988 TimeTicks start = TimeTicks::Now(); 989 990 if (offset + buf_len > entry_size) 991 buf_len = entry_size - offset; 992 993 UpdateRank(false); 994 995 backend_->OnEvent(Stats::READ_DATA); 996 backend_->OnRead(buf_len); 997 998 Addr address(entry_.Data()->data_addr[index]); 999 int eof = address.is_initialized() ? entry_size : 0; 1000 if (user_buffers_[index].get() && 1001 user_buffers_[index]->PreRead(eof, offset, &buf_len)) { 1002 // Complete the operation locally. 1003 buf_len = user_buffers_[index]->Read(offset, buf, buf_len); 1004 ReportIOTime(kRead, start); 1005 return buf_len; 1006 } 1007 1008 address.set_value(entry_.Data()->data_addr[index]); 1009 DCHECK(address.is_initialized()); 1010 if (!address.is_initialized()) { 1011 DoomImpl(); 1012 return net::ERR_FAILED; 1013 } 1014 1015 File* file = GetBackingFile(address, index); 1016 if (!file) { 1017 DoomImpl(); 1018 LOG(ERROR) << "No file for " << std::hex << address.value(); 1019 return net::ERR_FILE_NOT_FOUND; 1020 } 1021 1022 size_t file_offset = offset; 1023 if (address.is_block_file()) { 1024 DCHECK_LE(offset + buf_len, kMaxBlockSize); 1025 file_offset += address.start_block() * address.BlockSize() + 1026 kBlockHeaderSize; 1027 } 1028 1029 SyncCallback* io_callback = NULL; 1030 if (!callback.is_null()) { 1031 io_callback = new SyncCallback(this, buf, callback, 1032 net::NetLog::TYPE_ENTRY_READ_DATA); 1033 } 1034 1035 TimeTicks start_async = TimeTicks::Now(); 1036 1037 bool completed; 1038 if (!file->Read(buf->data(), buf_len, file_offset, io_callback, &completed)) { 1039 if (io_callback) 1040 io_callback->Discard(); 1041 DoomImpl(); 1042 return net::ERR_CACHE_READ_FAILURE; 1043 } 1044 1045 if (io_callback && completed) 1046 io_callback->Discard(); 1047 1048 if (io_callback) 1049 ReportIOTime(kReadAsync1, start_async); 1050 1051 ReportIOTime(kRead, start); 1052 return (completed || callback.is_null()) ? buf_len : net::ERR_IO_PENDING; 1053 } 1054 1055 int EntryImpl::InternalWriteData(int index, int offset, 1056 IOBuffer* buf, int buf_len, 1057 const CompletionCallback& callback, 1058 bool truncate) { 1059 DCHECK(node_.Data()->dirty || read_only_); 1060 DVLOG(2) << "Write to " << index << " at " << offset << " : " << buf_len; 1061 if (index < 0 || index >= kNumStreams) 1062 return net::ERR_INVALID_ARGUMENT; 1063 1064 if (offset < 0 || buf_len < 0) 1065 return net::ERR_INVALID_ARGUMENT; 1066 1067 if (!backend_.get()) 1068 return net::ERR_UNEXPECTED; 1069 1070 int max_file_size = backend_->MaxFileSize(); 1071 1072 // offset or buf_len could be negative numbers. 1073 if (offset > max_file_size || buf_len > max_file_size || 1074 offset + buf_len > max_file_size) { 1075 int size = offset + buf_len; 1076 if (size <= max_file_size) 1077 size = kint32max; 1078 backend_->TooMuchStorageRequested(size); 1079 return net::ERR_FAILED; 1080 } 1081 1082 TimeTicks start = TimeTicks::Now(); 1083 1084 // Read the size at this point (it may change inside prepare). 1085 int entry_size = entry_.Data()->data_size[index]; 1086 bool extending = entry_size < offset + buf_len; 1087 truncate = truncate && entry_size > offset + buf_len; 1088 Trace("To PrepareTarget 0x%x", entry_.address().value()); 1089 if (!PrepareTarget(index, offset, buf_len, truncate)) 1090 return net::ERR_FAILED; 1091 1092 Trace("From PrepareTarget 0x%x", entry_.address().value()); 1093 if (extending || truncate) 1094 UpdateSize(index, entry_size, offset + buf_len); 1095 1096 UpdateRank(true); 1097 1098 backend_->OnEvent(Stats::WRITE_DATA); 1099 backend_->OnWrite(buf_len); 1100 1101 if (user_buffers_[index].get()) { 1102 // Complete the operation locally. 1103 user_buffers_[index]->Write(offset, buf, buf_len); 1104 ReportIOTime(kWrite, start); 1105 return buf_len; 1106 } 1107 1108 Addr address(entry_.Data()->data_addr[index]); 1109 if (offset + buf_len == 0) { 1110 if (truncate) { 1111 DCHECK(!address.is_initialized()); 1112 } 1113 return 0; 1114 } 1115 1116 File* file = GetBackingFile(address, index); 1117 if (!file) 1118 return net::ERR_FILE_NOT_FOUND; 1119 1120 size_t file_offset = offset; 1121 if (address.is_block_file()) { 1122 DCHECK_LE(offset + buf_len, kMaxBlockSize); 1123 file_offset += address.start_block() * address.BlockSize() + 1124 kBlockHeaderSize; 1125 } else if (truncate || (extending && !buf_len)) { 1126 if (!file->SetLength(offset + buf_len)) 1127 return net::ERR_FAILED; 1128 } 1129 1130 if (!buf_len) 1131 return 0; 1132 1133 SyncCallback* io_callback = NULL; 1134 if (!callback.is_null()) { 1135 io_callback = new SyncCallback(this, buf, callback, 1136 net::NetLog::TYPE_ENTRY_WRITE_DATA); 1137 } 1138 1139 TimeTicks start_async = TimeTicks::Now(); 1140 1141 bool completed; 1142 if (!file->Write(buf->data(), buf_len, file_offset, io_callback, 1143 &completed)) { 1144 if (io_callback) 1145 io_callback->Discard(); 1146 return net::ERR_CACHE_WRITE_FAILURE; 1147 } 1148 1149 if (io_callback && completed) 1150 io_callback->Discard(); 1151 1152 if (io_callback) 1153 ReportIOTime(kWriteAsync1, start_async); 1154 1155 ReportIOTime(kWrite, start); 1156 return (completed || callback.is_null()) ? buf_len : net::ERR_IO_PENDING; 1157 } 1158 1159 // ------------------------------------------------------------------------ 1160 1161 bool EntryImpl::CreateDataBlock(int index, int size) { 1162 DCHECK(index >= 0 && index < kNumStreams); 1163 1164 Addr address(entry_.Data()->data_addr[index]); 1165 if (!CreateBlock(size, &address)) 1166 return false; 1167 1168 entry_.Data()->data_addr[index] = address.value(); 1169 entry_.Store(); 1170 return true; 1171 } 1172 1173 bool EntryImpl::CreateBlock(int size, Addr* address) { 1174 DCHECK(!address->is_initialized()); 1175 if (!backend_.get()) 1176 return false; 1177 1178 FileType file_type = Addr::RequiredFileType(size); 1179 if (EXTERNAL == file_type) { 1180 if (size > backend_->MaxFileSize()) 1181 return false; 1182 if (!backend_->CreateExternalFile(address)) 1183 return false; 1184 } else { 1185 int num_blocks = Addr::RequiredBlocks(size, file_type); 1186 1187 if (!backend_->CreateBlock(file_type, num_blocks, address)) 1188 return false; 1189 } 1190 return true; 1191 } 1192 1193 // Note that this method may end up modifying a block file so upon return the 1194 // involved block will be free, and could be reused for something else. If there 1195 // is a crash after that point (and maybe before returning to the caller), the 1196 // entry will be left dirty... and at some point it will be discarded; it is 1197 // important that the entry doesn't keep a reference to this address, or we'll 1198 // end up deleting the contents of |address| once again. 1199 void EntryImpl::DeleteData(Addr address, int index) { 1200 DCHECK(backend_.get()); 1201 if (!address.is_initialized()) 1202 return; 1203 if (address.is_separate_file()) { 1204 int failure = !DeleteCacheFile(backend_->GetFileName(address)); 1205 CACHE_UMA(COUNTS, "DeleteFailed", 0, failure); 1206 if (failure) { 1207 LOG(ERROR) << "Failed to delete " << 1208 backend_->GetFileName(address).value() << " from the cache."; 1209 } 1210 if (files_[index].get()) 1211 files_[index] = NULL; // Releases the object. 1212 } else { 1213 backend_->DeleteBlock(address, true); 1214 } 1215 } 1216 1217 void EntryImpl::UpdateRank(bool modified) { 1218 if (!backend_.get()) 1219 return; 1220 1221 if (!doomed_) { 1222 // Everything is handled by the backend. 1223 backend_->UpdateRank(this, modified); 1224 return; 1225 } 1226 1227 Time current = Time::Now(); 1228 node_.Data()->last_used = current.ToInternalValue(); 1229 1230 if (modified) 1231 node_.Data()->last_modified = current.ToInternalValue(); 1232 } 1233 1234 File* EntryImpl::GetBackingFile(Addr address, int index) { 1235 if (!backend_.get()) 1236 return NULL; 1237 1238 File* file; 1239 if (address.is_separate_file()) 1240 file = GetExternalFile(address, index); 1241 else 1242 file = backend_->File(address); 1243 return file; 1244 } 1245 1246 File* EntryImpl::GetExternalFile(Addr address, int index) { 1247 DCHECK(index >= 0 && index <= kKeyFileIndex); 1248 if (!files_[index].get()) { 1249 // For a key file, use mixed mode IO. 1250 scoped_refptr<File> file(new File(kKeyFileIndex == index)); 1251 if (file->Init(backend_->GetFileName(address))) 1252 files_[index].swap(file); 1253 } 1254 return files_[index].get(); 1255 } 1256 1257 // We keep a memory buffer for everything that ends up stored on a block file 1258 // (because we don't know yet the final data size), and for some of the data 1259 // that end up on external files. This function will initialize that memory 1260 // buffer and / or the files needed to store the data. 1261 // 1262 // In general, a buffer may overlap data already stored on disk, and in that 1263 // case, the contents of the buffer are the most accurate. It may also extend 1264 // the file, but we don't want to read from disk just to keep the buffer up to 1265 // date. This means that as soon as there is a chance to get confused about what 1266 // is the most recent version of some part of a file, we'll flush the buffer and 1267 // reuse it for the new data. Keep in mind that the normal use pattern is quite 1268 // simple (write sequentially from the beginning), so we optimize for handling 1269 // that case. 1270 bool EntryImpl::PrepareTarget(int index, int offset, int buf_len, 1271 bool truncate) { 1272 if (truncate) 1273 return HandleTruncation(index, offset, buf_len); 1274 1275 if (!offset && !buf_len) 1276 return true; 1277 1278 Addr address(entry_.Data()->data_addr[index]); 1279 if (address.is_initialized()) { 1280 if (address.is_block_file() && !MoveToLocalBuffer(index)) 1281 return false; 1282 1283 if (!user_buffers_[index].get() && offset < kMaxBlockSize) { 1284 // We are about to create a buffer for the first 16KB, make sure that we 1285 // preserve existing data. 1286 if (!CopyToLocalBuffer(index)) 1287 return false; 1288 } 1289 } 1290 1291 if (!user_buffers_[index].get()) 1292 user_buffers_[index].reset(new UserBuffer(backend_.get())); 1293 1294 return PrepareBuffer(index, offset, buf_len); 1295 } 1296 1297 // We get to this function with some data already stored. If there is a 1298 // truncation that results on data stored internally, we'll explicitly 1299 // handle the case here. 1300 bool EntryImpl::HandleTruncation(int index, int offset, int buf_len) { 1301 Addr address(entry_.Data()->data_addr[index]); 1302 1303 int current_size = entry_.Data()->data_size[index]; 1304 int new_size = offset + buf_len; 1305 1306 if (!new_size) { 1307 // This is by far the most common scenario. 1308 backend_->ModifyStorageSize(current_size - unreported_size_[index], 0); 1309 entry_.Data()->data_addr[index] = 0; 1310 entry_.Data()->data_size[index] = 0; 1311 unreported_size_[index] = 0; 1312 entry_.Store(); 1313 DeleteData(address, index); 1314 1315 user_buffers_[index].reset(); 1316 return true; 1317 } 1318 1319 // We never postpone truncating a file, if there is one, but we may postpone 1320 // telling the backend about the size reduction. 1321 if (user_buffers_[index].get()) { 1322 DCHECK_GE(current_size, user_buffers_[index]->Start()); 1323 if (!address.is_initialized()) { 1324 // There is no overlap between the buffer and disk. 1325 if (new_size > user_buffers_[index]->Start()) { 1326 // Just truncate our buffer. 1327 DCHECK_LT(new_size, user_buffers_[index]->End()); 1328 user_buffers_[index]->Truncate(new_size); 1329 return true; 1330 } 1331 1332 // Just discard our buffer. 1333 user_buffers_[index]->Reset(); 1334 return PrepareBuffer(index, offset, buf_len); 1335 } 1336 1337 // There is some overlap or we need to extend the file before the 1338 // truncation. 1339 if (offset > user_buffers_[index]->Start()) 1340 user_buffers_[index]->Truncate(new_size); 1341 UpdateSize(index, current_size, new_size); 1342 if (!Flush(index, 0)) 1343 return false; 1344 user_buffers_[index].reset(); 1345 } 1346 1347 // We have data somewhere, and it is not in a buffer. 1348 DCHECK(!user_buffers_[index].get()); 1349 DCHECK(address.is_initialized()); 1350 1351 if (new_size > kMaxBlockSize) 1352 return true; // Let the operation go directly to disk. 1353 1354 return ImportSeparateFile(index, offset + buf_len); 1355 } 1356 1357 bool EntryImpl::CopyToLocalBuffer(int index) { 1358 Addr address(entry_.Data()->data_addr[index]); 1359 DCHECK(!user_buffers_[index].get()); 1360 DCHECK(address.is_initialized()); 1361 1362 int len = std::min(entry_.Data()->data_size[index], kMaxBlockSize); 1363 user_buffers_[index].reset(new UserBuffer(backend_.get())); 1364 user_buffers_[index]->Write(len, NULL, 0); 1365 1366 File* file = GetBackingFile(address, index); 1367 int offset = 0; 1368 1369 if (address.is_block_file()) 1370 offset = address.start_block() * address.BlockSize() + kBlockHeaderSize; 1371 1372 if (!file || 1373 !file->Read(user_buffers_[index]->Data(), len, offset, NULL, NULL)) { 1374 user_buffers_[index].reset(); 1375 return false; 1376 } 1377 return true; 1378 } 1379 1380 bool EntryImpl::MoveToLocalBuffer(int index) { 1381 if (!CopyToLocalBuffer(index)) 1382 return false; 1383 1384 Addr address(entry_.Data()->data_addr[index]); 1385 entry_.Data()->data_addr[index] = 0; 1386 entry_.Store(); 1387 DeleteData(address, index); 1388 1389 // If we lose this entry we'll see it as zero sized. 1390 int len = entry_.Data()->data_size[index]; 1391 backend_->ModifyStorageSize(len - unreported_size_[index], 0); 1392 unreported_size_[index] = len; 1393 return true; 1394 } 1395 1396 bool EntryImpl::ImportSeparateFile(int index, int new_size) { 1397 if (entry_.Data()->data_size[index] > new_size) 1398 UpdateSize(index, entry_.Data()->data_size[index], new_size); 1399 1400 return MoveToLocalBuffer(index); 1401 } 1402 1403 bool EntryImpl::PrepareBuffer(int index, int offset, int buf_len) { 1404 DCHECK(user_buffers_[index].get()); 1405 if ((user_buffers_[index]->End() && offset > user_buffers_[index]->End()) || 1406 offset > entry_.Data()->data_size[index]) { 1407 // We are about to extend the buffer or the file (with zeros), so make sure 1408 // that we are not overwriting anything. 1409 Addr address(entry_.Data()->data_addr[index]); 1410 if (address.is_initialized() && address.is_separate_file()) { 1411 if (!Flush(index, 0)) 1412 return false; 1413 // There is an actual file already, and we don't want to keep track of 1414 // its length so we let this operation go straight to disk. 1415 // The only case when a buffer is allowed to extend the file (as in fill 1416 // with zeros before the start) is when there is no file yet to extend. 1417 user_buffers_[index].reset(); 1418 return true; 1419 } 1420 } 1421 1422 if (!user_buffers_[index]->PreWrite(offset, buf_len)) { 1423 if (!Flush(index, offset + buf_len)) 1424 return false; 1425 1426 // Lets try again. 1427 if (offset > user_buffers_[index]->End() || 1428 !user_buffers_[index]->PreWrite(offset, buf_len)) { 1429 // We cannot complete the operation with a buffer. 1430 DCHECK(!user_buffers_[index]->Size()); 1431 DCHECK(!user_buffers_[index]->Start()); 1432 user_buffers_[index].reset(); 1433 } 1434 } 1435 return true; 1436 } 1437 1438 bool EntryImpl::Flush(int index, int min_len) { 1439 Addr address(entry_.Data()->data_addr[index]); 1440 DCHECK(user_buffers_[index].get()); 1441 DCHECK(!address.is_initialized() || address.is_separate_file()); 1442 DVLOG(3) << "Flush"; 1443 1444 int size = std::max(entry_.Data()->data_size[index], min_len); 1445 if (size && !address.is_initialized() && !CreateDataBlock(index, size)) 1446 return false; 1447 1448 if (!entry_.Data()->data_size[index]) { 1449 DCHECK(!user_buffers_[index]->Size()); 1450 return true; 1451 } 1452 1453 address.set_value(entry_.Data()->data_addr[index]); 1454 1455 int len = user_buffers_[index]->Size(); 1456 int offset = user_buffers_[index]->Start(); 1457 if (!len && !offset) 1458 return true; 1459 1460 if (address.is_block_file()) { 1461 DCHECK_EQ(len, entry_.Data()->data_size[index]); 1462 DCHECK(!offset); 1463 offset = address.start_block() * address.BlockSize() + kBlockHeaderSize; 1464 } 1465 1466 File* file = GetBackingFile(address, index); 1467 if (!file) 1468 return false; 1469 1470 if (!file->Write(user_buffers_[index]->Data(), len, offset, NULL, NULL)) 1471 return false; 1472 user_buffers_[index]->Reset(); 1473 1474 return true; 1475 } 1476 1477 void EntryImpl::UpdateSize(int index, int old_size, int new_size) { 1478 if (entry_.Data()->data_size[index] == new_size) 1479 return; 1480 1481 unreported_size_[index] += new_size - old_size; 1482 entry_.Data()->data_size[index] = new_size; 1483 entry_.set_modified(); 1484 } 1485 1486 int EntryImpl::InitSparseData() { 1487 if (sparse_.get()) 1488 return net::OK; 1489 1490 // Use a local variable so that sparse_ never goes from 'valid' to NULL. 1491 scoped_ptr<SparseControl> sparse(new SparseControl(this)); 1492 int result = sparse->Init(); 1493 if (net::OK == result) 1494 sparse_.swap(sparse); 1495 1496 return result; 1497 } 1498 1499 void EntryImpl::SetEntryFlags(uint32 flags) { 1500 entry_.Data()->flags |= flags; 1501 entry_.set_modified(); 1502 } 1503 1504 uint32 EntryImpl::GetEntryFlags() { 1505 return entry_.Data()->flags; 1506 } 1507 1508 void EntryImpl::GetData(int index, char** buffer, Addr* address) { 1509 DCHECK(backend_.get()); 1510 if (user_buffers_[index].get() && user_buffers_[index]->Size() && 1511 !user_buffers_[index]->Start()) { 1512 // The data is already in memory, just copy it and we're done. 1513 int data_len = entry_.Data()->data_size[index]; 1514 if (data_len <= user_buffers_[index]->Size()) { 1515 DCHECK(!user_buffers_[index]->Start()); 1516 *buffer = new char[data_len]; 1517 memcpy(*buffer, user_buffers_[index]->Data(), data_len); 1518 return; 1519 } 1520 } 1521 1522 // Bad news: we'd have to read the info from disk so instead we'll just tell 1523 // the caller where to read from. 1524 *buffer = NULL; 1525 address->set_value(entry_.Data()->data_addr[index]); 1526 if (address->is_initialized()) { 1527 // Prevent us from deleting the block from the backing store. 1528 backend_->ModifyStorageSize(entry_.Data()->data_size[index] - 1529 unreported_size_[index], 0); 1530 entry_.Data()->data_addr[index] = 0; 1531 entry_.Data()->data_size[index] = 0; 1532 } 1533 } 1534 1535 void EntryImpl::Log(const char* msg) { 1536 int dirty = 0; 1537 if (node_.HasData()) { 1538 dirty = node_.Data()->dirty; 1539 } 1540 1541 Trace("%s 0x%p 0x%x 0x%x", msg, reinterpret_cast<void*>(this), 1542 entry_.address().value(), node_.address().value()); 1543 1544 Trace(" data: 0x%x 0x%x 0x%x", entry_.Data()->data_addr[0], 1545 entry_.Data()->data_addr[1], entry_.Data()->long_key); 1546 1547 Trace(" doomed: %d 0x%x", doomed_, dirty); 1548 } 1549 1550 } // namespace disk_cache 1551