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/blockfile/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/blockfile/backend_impl.h" 14 #include "net/disk_cache/blockfile/bitmap.h" 15 #include "net/disk_cache/blockfile/disk_format.h" 16 #include "net/disk_cache/blockfile/histogram_macros.h" 17 #include "net/disk_cache/blockfile/sparse_control.h" 18 #include "net/disk_cache/cache_util.h" 19 #include "net/disk_cache/net_log_parameters.h" 20 21 // Provide a BackendImpl object to macros from histogram_macros.h. 22 #define CACHE_UMA_BACKEND_IMPL_OBJ backend_ 23 24 using base::Time; 25 using base::TimeDelta; 26 using base::TimeTicks; 27 28 namespace { 29 30 // Index for the file used to store the key, if any (files_[kKeyFileIndex]). 31 const int kKeyFileIndex = 3; 32 33 // This class implements FileIOCallback to buffer the callback from a file IO 34 // operation from the actual net class. 35 class SyncCallback: public disk_cache::FileIOCallback { 36 public: 37 // |end_event_type| is the event type to log on completion. Logs nothing on 38 // discard, or when the NetLog is not set to log all events. 39 SyncCallback(disk_cache::EntryImpl* entry, net::IOBuffer* buffer, 40 const net::CompletionCallback& callback, 41 net::NetLog::EventType end_event_type) 42 : entry_(entry), callback_(callback), buf_(buffer), 43 start_(TimeTicks::Now()), end_event_type_(end_event_type) { 44 entry->AddRef(); 45 entry->IncrementIoCount(); 46 } 47 virtual ~SyncCallback() {} 48 49 virtual void OnFileIOComplete(int bytes_copied) OVERRIDE; 50 void Discard(); 51 52 private: 53 disk_cache::EntryImpl* entry_; 54 net::CompletionCallback callback_; 55 scoped_refptr<net::IOBuffer> buf_; 56 TimeTicks start_; 57 const net::NetLog::EventType end_event_type_; 58 59 DISALLOW_COPY_AND_ASSIGN(SyncCallback); 60 }; 61 62 void SyncCallback::OnFileIOComplete(int bytes_copied) { 63 entry_->DecrementIoCount(); 64 if (!callback_.is_null()) { 65 if (entry_->net_log().IsLogging()) { 66 entry_->net_log().EndEvent( 67 end_event_type_, 68 disk_cache::CreateNetLogReadWriteCompleteCallback(bytes_copied)); 69 } 70 entry_->ReportIOTime(disk_cache::EntryImpl::kAsyncIO, start_); 71 buf_ = NULL; // Release the buffer before invoking the callback. 72 callback_.Run(bytes_copied); 73 } 74 entry_->Release(); 75 delete this; 76 } 77 78 void SyncCallback::Discard() { 79 callback_.Reset(); 80 buf_ = NULL; 81 OnFileIOComplete(0); 82 } 83 84 const int kMaxBufferSize = 1024 * 1024; // 1 MB. 85 86 } // namespace 87 88 namespace disk_cache { 89 90 // This class handles individual memory buffers that store data before it is 91 // sent to disk. The buffer can start at any offset, but if we try to write to 92 // anywhere in the first 16KB of the file (kMaxBlockSize), we set the offset to 93 // zero. The buffer grows up to a size determined by the backend, to keep the 94 // total memory used under control. 95 class EntryImpl::UserBuffer { 96 public: 97 explicit UserBuffer(BackendImpl* backend) 98 : backend_(backend->GetWeakPtr()), offset_(0), grow_allowed_(true) { 99 buffer_.reserve(kMaxBlockSize); 100 } 101 ~UserBuffer() { 102 if (backend_.get()) 103 backend_->BufferDeleted(capacity() - kMaxBlockSize); 104 } 105 106 // Returns true if we can handle writing |len| bytes to |offset|. 107 bool PreWrite(int offset, int len); 108 109 // Truncates the buffer to |offset| bytes. 110 void Truncate(int offset); 111 112 // Writes |len| bytes from |buf| at the given |offset|. 113 void Write(int offset, IOBuffer* buf, int len); 114 115 // Returns true if we can read |len| bytes from |offset|, given that the 116 // actual file has |eof| bytes stored. Note that the number of bytes to read 117 // may be modified by this method even though it returns false: that means we 118 // should do a smaller read from disk. 119 bool PreRead(int eof, int offset, int* len); 120 121 // Read |len| bytes from |buf| at the given |offset|. 122 int Read(int offset, IOBuffer* buf, int len); 123 124 // Prepare this buffer for reuse. 125 void Reset(); 126 127 char* Data() { return buffer_.size() ? &buffer_[0] : NULL; } 128 int Size() { return static_cast<int>(buffer_.size()); } 129 int Start() { return offset_; } 130 int End() { return offset_ + Size(); } 131 132 private: 133 int capacity() { return static_cast<int>(buffer_.capacity()); } 134 bool GrowBuffer(int required, int limit); 135 136 base::WeakPtr<BackendImpl> backend_; 137 int offset_; 138 std::vector<char> buffer_; 139 bool grow_allowed_; 140 DISALLOW_COPY_AND_ASSIGN(UserBuffer); 141 }; 142 143 bool EntryImpl::UserBuffer::PreWrite(int offset, int len) { 144 DCHECK_GE(offset, 0); 145 DCHECK_GE(len, 0); 146 DCHECK_GE(offset + len, 0); 147 148 // We don't want to write before our current start. 149 if (offset < offset_) 150 return false; 151 152 // Lets get the common case out of the way. 153 if (offset + len <= capacity()) 154 return true; 155 156 // If we are writing to the first 16K (kMaxBlockSize), we want to keep the 157 // buffer offset_ at 0. 158 if (!Size() && offset > kMaxBlockSize) 159 return GrowBuffer(len, kMaxBufferSize); 160 161 int required = offset - offset_ + len; 162 return GrowBuffer(required, kMaxBufferSize * 6 / 5); 163 } 164 165 void EntryImpl::UserBuffer::Truncate(int offset) { 166 DCHECK_GE(offset, 0); 167 DCHECK_GE(offset, offset_); 168 DVLOG(3) << "Buffer truncate at " << offset << " current " << offset_; 169 170 offset -= offset_; 171 if (Size() >= offset) 172 buffer_.resize(offset); 173 } 174 175 void EntryImpl::UserBuffer::Write(int offset, IOBuffer* buf, int len) { 176 DCHECK_GE(offset, 0); 177 DCHECK_GE(len, 0); 178 DCHECK_GE(offset + len, 0); 179 DCHECK_GE(offset, offset_); 180 DVLOG(3) << "Buffer write at " << offset << " current " << offset_; 181 182 if (!Size() && offset > kMaxBlockSize) 183 offset_ = offset; 184 185 offset -= offset_; 186 187 if (offset > Size()) 188 buffer_.resize(offset); 189 190 if (!len) 191 return; 192 193 char* buffer = buf->data(); 194 int valid_len = Size() - offset; 195 int copy_len = std::min(valid_len, len); 196 if (copy_len) { 197 memcpy(&buffer_[offset], buffer, copy_len); 198 len -= copy_len; 199 buffer += copy_len; 200 } 201 if (!len) 202 return; 203 204 buffer_.insert(buffer_.end(), buffer, buffer + len); 205 } 206 207 bool EntryImpl::UserBuffer::PreRead(int eof, int offset, int* len) { 208 DCHECK_GE(offset, 0); 209 DCHECK_GT(*len, 0); 210 211 if (offset < offset_) { 212 // We are reading before this buffer. 213 if (offset >= eof) 214 return true; 215 216 // If the read overlaps with the buffer, change its length so that there is 217 // no overlap. 218 *len = std::min(*len, offset_ - offset); 219 *len = std::min(*len, eof - offset); 220 221 // We should read from disk. 222 return false; 223 } 224 225 if (!Size()) 226 return false; 227 228 // See if we can fulfill the first part of the operation. 229 return (offset - offset_ < Size()); 230 } 231 232 int EntryImpl::UserBuffer::Read(int offset, IOBuffer* buf, int len) { 233 DCHECK_GE(offset, 0); 234 DCHECK_GT(len, 0); 235 DCHECK(Size() || offset < offset_); 236 237 int clean_bytes = 0; 238 if (offset < offset_) { 239 // We don't have a file so lets fill the first part with 0. 240 clean_bytes = std::min(offset_ - offset, len); 241 memset(buf->data(), 0, clean_bytes); 242 if (len == clean_bytes) 243 return len; 244 offset = offset_; 245 len -= clean_bytes; 246 } 247 248 int start = offset - offset_; 249 int available = Size() - start; 250 DCHECK_GE(start, 0); 251 DCHECK_GE(available, 0); 252 len = std::min(len, available); 253 memcpy(buf->data() + clean_bytes, &buffer_[start], len); 254 return len + clean_bytes; 255 } 256 257 void EntryImpl::UserBuffer::Reset() { 258 if (!grow_allowed_) { 259 if (backend_.get()) 260 backend_->BufferDeleted(capacity() - kMaxBlockSize); 261 grow_allowed_ = true; 262 std::vector<char> tmp; 263 buffer_.swap(tmp); 264 buffer_.reserve(kMaxBlockSize); 265 } 266 offset_ = 0; 267 buffer_.clear(); 268 } 269 270 bool EntryImpl::UserBuffer::GrowBuffer(int required, int limit) { 271 DCHECK_GE(required, 0); 272 int current_size = capacity(); 273 if (required <= current_size) 274 return true; 275 276 if (required > limit) 277 return false; 278 279 if (!backend_.get()) 280 return false; 281 282 int to_add = std::max(required - current_size, kMaxBlockSize * 4); 283 to_add = std::max(current_size, to_add); 284 required = std::min(current_size + to_add, limit); 285 286 grow_allowed_ = backend_->IsAllocAllowed(current_size, required); 287 if (!grow_allowed_) 288 return false; 289 290 DVLOG(3) << "Buffer grow to " << required; 291 292 buffer_.reserve(required); 293 return true; 294 } 295 296 // ------------------------------------------------------------------------ 297 298 EntryImpl::EntryImpl(BackendImpl* backend, Addr address, bool read_only) 299 : entry_(NULL, Addr(0)), node_(NULL, Addr(0)), 300 backend_(backend->GetWeakPtr()), doomed_(false), read_only_(read_only), 301 dirty_(false) { 302 entry_.LazyInit(backend->File(address), address); 303 for (int i = 0; i < kNumStreams; i++) { 304 unreported_size_[i] = 0; 305 } 306 } 307 308 void EntryImpl::DoomImpl() { 309 if (doomed_ || !backend_.get()) 310 return; 311 312 SetPointerForInvalidEntry(backend_->GetCurrentEntryId()); 313 backend_->InternalDoomEntry(this); 314 } 315 316 int EntryImpl::ReadDataImpl(int index, int offset, IOBuffer* buf, int buf_len, 317 const CompletionCallback& callback) { 318 if (net_log_.IsLogging()) { 319 net_log_.BeginEvent( 320 net::NetLog::TYPE_ENTRY_READ_DATA, 321 CreateNetLogReadWriteDataCallback(index, offset, buf_len, false)); 322 } 323 324 int result = InternalReadData(index, offset, buf, buf_len, callback); 325 326 if (result != net::ERR_IO_PENDING && net_log_.IsLogging()) { 327 net_log_.EndEvent( 328 net::NetLog::TYPE_ENTRY_READ_DATA, 329 CreateNetLogReadWriteCompleteCallback(result)); 330 } 331 return result; 332 } 333 334 int EntryImpl::WriteDataImpl(int index, int offset, IOBuffer* buf, int buf_len, 335 const CompletionCallback& callback, 336 bool truncate) { 337 if (net_log_.IsLogging()) { 338 net_log_.BeginEvent( 339 net::NetLog::TYPE_ENTRY_WRITE_DATA, 340 CreateNetLogReadWriteDataCallback(index, offset, buf_len, truncate)); 341 } 342 343 int result = InternalWriteData(index, offset, buf, buf_len, callback, 344 truncate); 345 346 if (result != net::ERR_IO_PENDING && net_log_.IsLogging()) { 347 net_log_.EndEvent( 348 net::NetLog::TYPE_ENTRY_WRITE_DATA, 349 CreateNetLogReadWriteCompleteCallback(result)); 350 } 351 return result; 352 } 353 354 int EntryImpl::ReadSparseDataImpl(int64 offset, IOBuffer* buf, int buf_len, 355 const CompletionCallback& callback) { 356 DCHECK(node_.Data()->dirty || read_only_); 357 int result = InitSparseData(); 358 if (net::OK != result) 359 return result; 360 361 TimeTicks start = TimeTicks::Now(); 362 result = sparse_->StartIO(SparseControl::kReadOperation, offset, buf, buf_len, 363 callback); 364 ReportIOTime(kSparseRead, start); 365 return result; 366 } 367 368 int EntryImpl::WriteSparseDataImpl(int64 offset, IOBuffer* buf, int buf_len, 369 const CompletionCallback& callback) { 370 DCHECK(node_.Data()->dirty || read_only_); 371 int result = InitSparseData(); 372 if (net::OK != result) 373 return result; 374 375 TimeTicks start = TimeTicks::Now(); 376 result = sparse_->StartIO(SparseControl::kWriteOperation, offset, buf, 377 buf_len, callback); 378 ReportIOTime(kSparseWrite, start); 379 return result; 380 } 381 382 int EntryImpl::GetAvailableRangeImpl(int64 offset, int len, int64* start) { 383 int result = InitSparseData(); 384 if (net::OK != result) 385 return result; 386 387 return sparse_->GetAvailableRange(offset, len, start); 388 } 389 390 void EntryImpl::CancelSparseIOImpl() { 391 if (!sparse_.get()) 392 return; 393 394 sparse_->CancelIO(); 395 } 396 397 int EntryImpl::ReadyForSparseIOImpl(const CompletionCallback& callback) { 398 DCHECK(sparse_.get()); 399 return sparse_->ReadyToUse(callback); 400 } 401 402 uint32 EntryImpl::GetHash() { 403 return entry_.Data()->hash; 404 } 405 406 bool EntryImpl::CreateEntry(Addr node_address, const std::string& key, 407 uint32 hash) { 408 Trace("Create entry In"); 409 EntryStore* entry_store = entry_.Data(); 410 RankingsNode* node = node_.Data(); 411 memset(entry_store, 0, sizeof(EntryStore) * entry_.address().num_blocks()); 412 memset(node, 0, sizeof(RankingsNode)); 413 if (!node_.LazyInit(backend_->File(node_address), node_address)) 414 return false; 415 416 entry_store->rankings_node = node_address.value(); 417 node->contents = entry_.address().value(); 418 419 entry_store->hash = hash; 420 entry_store->creation_time = Time::Now().ToInternalValue(); 421 entry_store->key_len = static_cast<int32>(key.size()); 422 if (entry_store->key_len > kMaxInternalKeyLength) { 423 Addr address(0); 424 if (!CreateBlock(entry_store->key_len + 1, &address)) 425 return false; 426 427 entry_store->long_key = address.value(); 428 File* key_file = GetBackingFile(address, kKeyFileIndex); 429 key_ = key; 430 431 size_t offset = 0; 432 if (address.is_block_file()) 433 offset = address.start_block() * address.BlockSize() + kBlockHeaderSize; 434 435 if (!key_file || !key_file->Write(key.data(), key.size(), offset)) { 436 DeleteData(address, kKeyFileIndex); 437 return false; 438 } 439 440 if (address.is_separate_file()) 441 key_file->SetLength(key.size() + 1); 442 } else { 443 memcpy(entry_store->key, key.data(), key.size()); 444 entry_store->key[key.size()] = '\0'; 445 } 446 backend_->ModifyStorageSize(0, static_cast<int32>(key.size())); 447 CACHE_UMA(COUNTS, "KeySize", 0, static_cast<int32>(key.size())); 448 node->dirty = backend_->GetCurrentEntryId(); 449 Log("Create Entry "); 450 return true; 451 } 452 453 bool EntryImpl::IsSameEntry(const std::string& key, uint32 hash) { 454 if (entry_.Data()->hash != hash || 455 static_cast<size_t>(entry_.Data()->key_len) != key.size()) 456 return false; 457 458 return (key.compare(GetKey()) == 0); 459 } 460 461 void EntryImpl::InternalDoom() { 462 net_log_.AddEvent(net::NetLog::TYPE_ENTRY_DOOM); 463 DCHECK(node_.HasData()); 464 if (!node_.Data()->dirty) { 465 node_.Data()->dirty = backend_->GetCurrentEntryId(); 466 node_.Store(); 467 } 468 doomed_ = true; 469 } 470 471 void EntryImpl::DeleteEntryData(bool everything) { 472 DCHECK(doomed_ || !everything); 473 474 if (GetEntryFlags() & PARENT_ENTRY) { 475 // We have some child entries that must go away. 476 SparseControl::DeleteChildren(this); 477 } 478 479 if (GetDataSize(0)) 480 CACHE_UMA(COUNTS, "DeleteHeader", 0, GetDataSize(0)); 481 if (GetDataSize(1)) 482 CACHE_UMA(COUNTS, "DeleteData", 0, GetDataSize(1)); 483 for (int index = 0; index < kNumStreams; index++) { 484 Addr address(entry_.Data()->data_addr[index]); 485 if (address.is_initialized()) { 486 backend_->ModifyStorageSize(entry_.Data()->data_size[index] - 487 unreported_size_[index], 0); 488 entry_.Data()->data_addr[index] = 0; 489 entry_.Data()->data_size[index] = 0; 490 entry_.Store(); 491 DeleteData(address, index); 492 } 493 } 494 495 if (!everything) 496 return; 497 498 // Remove all traces of this entry. 499 backend_->RemoveEntry(this); 500 501 // Note that at this point node_ and entry_ are just two blocks of data, and 502 // even if they reference each other, nobody should be referencing them. 503 504 Addr address(entry_.Data()->long_key); 505 DeleteData(address, kKeyFileIndex); 506 backend_->ModifyStorageSize(entry_.Data()->key_len, 0); 507 508 backend_->DeleteBlock(entry_.address(), true); 509 entry_.Discard(); 510 511 if (!LeaveRankingsBehind()) { 512 backend_->DeleteBlock(node_.address(), true); 513 node_.Discard(); 514 } 515 } 516 517 CacheAddr EntryImpl::GetNextAddress() { 518 return entry_.Data()->next; 519 } 520 521 void EntryImpl::SetNextAddress(Addr address) { 522 DCHECK_NE(address.value(), entry_.address().value()); 523 entry_.Data()->next = address.value(); 524 bool success = entry_.Store(); 525 DCHECK(success); 526 } 527 528 bool EntryImpl::LoadNodeAddress() { 529 Addr address(entry_.Data()->rankings_node); 530 if (!node_.LazyInit(backend_->File(address), address)) 531 return false; 532 return node_.Load(); 533 } 534 535 bool EntryImpl::Update() { 536 DCHECK(node_.HasData()); 537 538 if (read_only_) 539 return true; 540 541 RankingsNode* rankings = node_.Data(); 542 if (!rankings->dirty) { 543 rankings->dirty = backend_->GetCurrentEntryId(); 544 if (!node_.Store()) 545 return false; 546 } 547 return true; 548 } 549 550 void EntryImpl::SetDirtyFlag(int32 current_id) { 551 DCHECK(node_.HasData()); 552 if (node_.Data()->dirty && current_id != node_.Data()->dirty) 553 dirty_ = true; 554 555 if (!current_id) 556 dirty_ = true; 557 } 558 559 void EntryImpl::SetPointerForInvalidEntry(int32 new_id) { 560 node_.Data()->dirty = new_id; 561 node_.Store(); 562 } 563 564 bool EntryImpl::LeaveRankingsBehind() { 565 return !node_.Data()->contents; 566 } 567 568 // This only includes checks that relate to the first block of the entry (the 569 // first 256 bytes), and values that should be set from the entry creation. 570 // Basically, even if there is something wrong with this entry, we want to see 571 // if it is possible to load the rankings node and delete them together. 572 bool EntryImpl::SanityCheck() { 573 if (!entry_.VerifyHash()) 574 return false; 575 576 EntryStore* stored = entry_.Data(); 577 if (!stored->rankings_node || stored->key_len <= 0) 578 return false; 579 580 if (stored->reuse_count < 0 || stored->refetch_count < 0) 581 return false; 582 583 Addr rankings_addr(stored->rankings_node); 584 if (!rankings_addr.SanityCheckForRankings()) 585 return false; 586 587 Addr next_addr(stored->next); 588 if (next_addr.is_initialized() && !next_addr.SanityCheckForEntryV2()) { 589 STRESS_NOTREACHED(); 590 return false; 591 } 592 STRESS_DCHECK(next_addr.value() != entry_.address().value()); 593 594 if (stored->state > ENTRY_DOOMED || stored->state < ENTRY_NORMAL) 595 return false; 596 597 Addr key_addr(stored->long_key); 598 if ((stored->key_len <= kMaxInternalKeyLength && key_addr.is_initialized()) || 599 (stored->key_len > kMaxInternalKeyLength && !key_addr.is_initialized())) 600 return false; 601 602 if (!key_addr.SanityCheckV2()) 603 return false; 604 605 if (key_addr.is_initialized() && 606 ((stored->key_len < kMaxBlockSize && key_addr.is_separate_file()) || 607 (stored->key_len >= kMaxBlockSize && key_addr.is_block_file()))) 608 return false; 609 610 int num_blocks = NumBlocksForEntry(stored->key_len); 611 if (entry_.address().num_blocks() != num_blocks) 612 return false; 613 614 return true; 615 } 616 617 bool EntryImpl::DataSanityCheck() { 618 EntryStore* stored = entry_.Data(); 619 Addr key_addr(stored->long_key); 620 621 // The key must be NULL terminated. 622 if (!key_addr.is_initialized() && stored->key[stored->key_len]) 623 return false; 624 625 if (stored->hash != base::Hash(GetKey())) 626 return false; 627 628 for (int i = 0; i < kNumStreams; i++) { 629 Addr data_addr(stored->data_addr[i]); 630 int data_size = stored->data_size[i]; 631 if (data_size < 0) 632 return false; 633 if (!data_size && data_addr.is_initialized()) 634 return false; 635 if (!data_addr.SanityCheckV2()) 636 return false; 637 if (!data_size) 638 continue; 639 if (data_size <= kMaxBlockSize && data_addr.is_separate_file()) 640 return false; 641 if (data_size > kMaxBlockSize && data_addr.is_block_file()) 642 return false; 643 } 644 return true; 645 } 646 647 void EntryImpl::FixForDelete() { 648 EntryStore* stored = entry_.Data(); 649 Addr key_addr(stored->long_key); 650 651 if (!key_addr.is_initialized()) 652 stored->key[stored->key_len] = '\0'; 653 654 for (int i = 0; i < kNumStreams; i++) { 655 Addr data_addr(stored->data_addr[i]); 656 int data_size = stored->data_size[i]; 657 if (data_addr.is_initialized()) { 658 if ((data_size <= kMaxBlockSize && data_addr.is_separate_file()) || 659 (data_size > kMaxBlockSize && data_addr.is_block_file()) || 660 !data_addr.SanityCheckV2()) { 661 STRESS_NOTREACHED(); 662 // The address is weird so don't attempt to delete it. 663 stored->data_addr[i] = 0; 664 // In general, trust the stored size as it should be in sync with the 665 // total size tracked by the backend. 666 } 667 } 668 if (data_size < 0) 669 stored->data_size[i] = 0; 670 } 671 entry_.Store(); 672 } 673 674 void EntryImpl::IncrementIoCount() { 675 backend_->IncrementIoCount(); 676 } 677 678 void EntryImpl::DecrementIoCount() { 679 if (backend_.get()) 680 backend_->DecrementIoCount(); 681 } 682 683 void EntryImpl::OnEntryCreated(BackendImpl* backend) { 684 // Just grab a reference to the backround queue. 685 background_queue_ = backend->GetBackgroundQueue(); 686 } 687 688 void EntryImpl::SetTimes(base::Time last_used, base::Time last_modified) { 689 node_.Data()->last_used = last_used.ToInternalValue(); 690 node_.Data()->last_modified = last_modified.ToInternalValue(); 691 node_.set_modified(); 692 } 693 694 void EntryImpl::ReportIOTime(Operation op, const base::TimeTicks& start) { 695 if (!backend_.get()) 696 return; 697 698 switch (op) { 699 case kRead: 700 CACHE_UMA(AGE_MS, "ReadTime", 0, start); 701 break; 702 case kWrite: 703 CACHE_UMA(AGE_MS, "WriteTime", 0, start); 704 break; 705 case kSparseRead: 706 CACHE_UMA(AGE_MS, "SparseReadTime", 0, start); 707 break; 708 case kSparseWrite: 709 CACHE_UMA(AGE_MS, "SparseWriteTime", 0, start); 710 break; 711 case kAsyncIO: 712 CACHE_UMA(AGE_MS, "AsyncIOTime", 0, start); 713 break; 714 case kReadAsync1: 715 CACHE_UMA(AGE_MS, "AsyncReadDispatchTime", 0, start); 716 break; 717 case kWriteAsync1: 718 CACHE_UMA(AGE_MS, "AsyncWriteDispatchTime", 0, start); 719 break; 720 default: 721 NOTREACHED(); 722 } 723 } 724 725 void EntryImpl::BeginLogging(net::NetLog* net_log, bool created) { 726 DCHECK(!net_log_.net_log()); 727 net_log_ = net::BoundNetLog::Make( 728 net_log, net::NetLog::SOURCE_DISK_CACHE_ENTRY); 729 net_log_.BeginEvent( 730 net::NetLog::TYPE_DISK_CACHE_ENTRY_IMPL, 731 CreateNetLogEntryCreationCallback(this, created)); 732 } 733 734 const net::BoundNetLog& EntryImpl::net_log() const { 735 return net_log_; 736 } 737 738 // static 739 int EntryImpl::NumBlocksForEntry(int key_size) { 740 // The longest key that can be stored using one block. 741 int key1_len = 742 static_cast<int>(sizeof(EntryStore) - offsetof(EntryStore, key)); 743 744 if (key_size < key1_len || key_size > kMaxInternalKeyLength) 745 return 1; 746 747 return ((key_size - key1_len) / 256 + 2); 748 } 749 750 // ------------------------------------------------------------------------ 751 752 void EntryImpl::Doom() { 753 if (background_queue_.get()) 754 background_queue_->DoomEntryImpl(this); 755 } 756 757 void EntryImpl::Close() { 758 if (background_queue_.get()) 759 background_queue_->CloseEntryImpl(this); 760 } 761 762 std::string EntryImpl::GetKey() const { 763 CacheEntryBlock* entry = const_cast<CacheEntryBlock*>(&entry_); 764 int key_len = entry->Data()->key_len; 765 if (key_len <= kMaxInternalKeyLength) 766 return std::string(entry->Data()->key); 767 768 // We keep a copy of the key so that we can always return it, even if the 769 // backend is disabled. 770 if (!key_.empty()) 771 return key_; 772 773 Addr address(entry->Data()->long_key); 774 DCHECK(address.is_initialized()); 775 size_t offset = 0; 776 if (address.is_block_file()) 777 offset = address.start_block() * address.BlockSize() + kBlockHeaderSize; 778 779 COMPILE_ASSERT(kNumStreams == kKeyFileIndex, invalid_key_index); 780 File* key_file = const_cast<EntryImpl*>(this)->GetBackingFile(address, 781 kKeyFileIndex); 782 if (!key_file) 783 return std::string(); 784 785 ++key_len; // We store a trailing \0 on disk that we read back below. 786 if (!offset && key_file->GetLength() != static_cast<size_t>(key_len)) 787 return std::string(); 788 789 if (!key_file->Read(WriteInto(&key_, key_len), key_len, offset)) 790 key_.clear(); 791 return key_; 792 } 793 794 Time EntryImpl::GetLastUsed() const { 795 CacheRankingsBlock* node = const_cast<CacheRankingsBlock*>(&node_); 796 return Time::FromInternalValue(node->Data()->last_used); 797 } 798 799 Time EntryImpl::GetLastModified() const { 800 CacheRankingsBlock* node = const_cast<CacheRankingsBlock*>(&node_); 801 return Time::FromInternalValue(node->Data()->last_modified); 802 } 803 804 int32 EntryImpl::GetDataSize(int index) const { 805 if (index < 0 || index >= kNumStreams) 806 return 0; 807 808 CacheEntryBlock* entry = const_cast<CacheEntryBlock*>(&entry_); 809 return entry->Data()->data_size[index]; 810 } 811 812 int EntryImpl::ReadData(int index, int offset, IOBuffer* buf, int buf_len, 813 const CompletionCallback& callback) { 814 if (callback.is_null()) 815 return ReadDataImpl(index, offset, buf, buf_len, callback); 816 817 DCHECK(node_.Data()->dirty || read_only_); 818 if (index < 0 || index >= kNumStreams) 819 return net::ERR_INVALID_ARGUMENT; 820 821 int entry_size = entry_.Data()->data_size[index]; 822 if (offset >= entry_size || offset < 0 || !buf_len) 823 return 0; 824 825 if (buf_len < 0) 826 return net::ERR_INVALID_ARGUMENT; 827 828 if (!background_queue_.get()) 829 return net::ERR_UNEXPECTED; 830 831 background_queue_->ReadData(this, index, offset, buf, buf_len, callback); 832 return net::ERR_IO_PENDING; 833 } 834 835 int EntryImpl::WriteData(int index, int offset, IOBuffer* buf, int buf_len, 836 const CompletionCallback& callback, bool truncate) { 837 if (callback.is_null()) 838 return WriteDataImpl(index, offset, buf, buf_len, callback, truncate); 839 840 DCHECK(node_.Data()->dirty || read_only_); 841 if (index < 0 || index >= kNumStreams) 842 return net::ERR_INVALID_ARGUMENT; 843 844 if (offset < 0 || buf_len < 0) 845 return net::ERR_INVALID_ARGUMENT; 846 847 if (!background_queue_.get()) 848 return net::ERR_UNEXPECTED; 849 850 background_queue_->WriteData(this, index, offset, buf, buf_len, truncate, 851 callback); 852 return net::ERR_IO_PENDING; 853 } 854 855 int EntryImpl::ReadSparseData(int64 offset, IOBuffer* buf, int buf_len, 856 const CompletionCallback& callback) { 857 if (callback.is_null()) 858 return ReadSparseDataImpl(offset, buf, buf_len, callback); 859 860 if (!background_queue_.get()) 861 return net::ERR_UNEXPECTED; 862 863 background_queue_->ReadSparseData(this, offset, buf, buf_len, callback); 864 return net::ERR_IO_PENDING; 865 } 866 867 int EntryImpl::WriteSparseData(int64 offset, IOBuffer* buf, int buf_len, 868 const CompletionCallback& callback) { 869 if (callback.is_null()) 870 return WriteSparseDataImpl(offset, buf, buf_len, callback); 871 872 if (!background_queue_.get()) 873 return net::ERR_UNEXPECTED; 874 875 background_queue_->WriteSparseData(this, offset, buf, buf_len, callback); 876 return net::ERR_IO_PENDING; 877 } 878 879 int EntryImpl::GetAvailableRange(int64 offset, int len, int64* start, 880 const CompletionCallback& callback) { 881 if (!background_queue_.get()) 882 return net::ERR_UNEXPECTED; 883 884 background_queue_->GetAvailableRange(this, offset, len, start, callback); 885 return net::ERR_IO_PENDING; 886 } 887 888 bool EntryImpl::CouldBeSparse() const { 889 if (sparse_.get()) 890 return true; 891 892 scoped_ptr<SparseControl> sparse; 893 sparse.reset(new SparseControl(const_cast<EntryImpl*>(this))); 894 return sparse->CouldBeSparse(); 895 } 896 897 void EntryImpl::CancelSparseIO() { 898 if (background_queue_.get()) 899 background_queue_->CancelSparseIO(this); 900 } 901 902 int EntryImpl::ReadyForSparseIO(const CompletionCallback& callback) { 903 if (!sparse_.get()) 904 return net::OK; 905 906 if (!background_queue_.get()) 907 return net::ERR_UNEXPECTED; 908 909 background_queue_->ReadyForSparseIO(this, callback); 910 return net::ERR_IO_PENDING; 911 } 912 913 // When an entry is deleted from the cache, we clean up all the data associated 914 // with it for two reasons: to simplify the reuse of the block (we know that any 915 // unused block is filled with zeros), and to simplify the handling of write / 916 // read partial information from an entry (don't have to worry about returning 917 // data related to a previous cache entry because the range was not fully 918 // written before). 919 EntryImpl::~EntryImpl() { 920 if (!backend_.get()) { 921 entry_.clear_modified(); 922 node_.clear_modified(); 923 return; 924 } 925 Log("~EntryImpl in"); 926 927 // Save the sparse info to disk. This will generate IO for this entry and 928 // maybe for a child entry, so it is important to do it before deleting this 929 // entry. 930 sparse_.reset(); 931 932 // Remove this entry from the list of open entries. 933 backend_->OnEntryDestroyBegin(entry_.address()); 934 935 if (doomed_) { 936 DeleteEntryData(true); 937 } else { 938 #if defined(NET_BUILD_STRESS_CACHE) 939 SanityCheck(); 940 #endif 941 net_log_.AddEvent(net::NetLog::TYPE_ENTRY_CLOSE); 942 bool ret = true; 943 for (int index = 0; index < kNumStreams; index++) { 944 if (user_buffers_[index].get()) { 945 if (!(ret = Flush(index, 0))) 946 LOG(ERROR) << "Failed to save user data"; 947 } 948 if (unreported_size_[index]) { 949 backend_->ModifyStorageSize( 950 entry_.Data()->data_size[index] - unreported_size_[index], 951 entry_.Data()->data_size[index]); 952 } 953 } 954 955 if (!ret) { 956 // There was a failure writing the actual data. Mark the entry as dirty. 957 int current_id = backend_->GetCurrentEntryId(); 958 node_.Data()->dirty = current_id == 1 ? -1 : current_id - 1; 959 node_.Store(); 960 } else if (node_.HasData() && !dirty_ && node_.Data()->dirty) { 961 node_.Data()->dirty = 0; 962 node_.Store(); 963 } 964 } 965 966 Trace("~EntryImpl out 0x%p", reinterpret_cast<void*>(this)); 967 net_log_.EndEvent(net::NetLog::TYPE_DISK_CACHE_ENTRY_IMPL); 968 backend_->OnEntryDestroyEnd(); 969 } 970 971 // ------------------------------------------------------------------------ 972 973 int EntryImpl::InternalReadData(int index, int offset, 974 IOBuffer* buf, int buf_len, 975 const CompletionCallback& callback) { 976 DCHECK(node_.Data()->dirty || read_only_); 977 DVLOG(2) << "Read from " << index << " at " << offset << " : " << buf_len; 978 if (index < 0 || index >= kNumStreams) 979 return net::ERR_INVALID_ARGUMENT; 980 981 int entry_size = entry_.Data()->data_size[index]; 982 if (offset >= entry_size || offset < 0 || !buf_len) 983 return 0; 984 985 if (buf_len < 0) 986 return net::ERR_INVALID_ARGUMENT; 987 988 if (!backend_.get()) 989 return net::ERR_UNEXPECTED; 990 991 TimeTicks start = TimeTicks::Now(); 992 993 if (offset + buf_len > entry_size) 994 buf_len = entry_size - offset; 995 996 UpdateRank(false); 997 998 backend_->OnEvent(Stats::READ_DATA); 999 backend_->OnRead(buf_len); 1000 1001 Addr address(entry_.Data()->data_addr[index]); 1002 int eof = address.is_initialized() ? entry_size : 0; 1003 if (user_buffers_[index].get() && 1004 user_buffers_[index]->PreRead(eof, offset, &buf_len)) { 1005 // Complete the operation locally. 1006 buf_len = user_buffers_[index]->Read(offset, buf, buf_len); 1007 ReportIOTime(kRead, start); 1008 return buf_len; 1009 } 1010 1011 address.set_value(entry_.Data()->data_addr[index]); 1012 DCHECK(address.is_initialized()); 1013 if (!address.is_initialized()) { 1014 DoomImpl(); 1015 return net::ERR_FAILED; 1016 } 1017 1018 File* file = GetBackingFile(address, index); 1019 if (!file) { 1020 DoomImpl(); 1021 LOG(ERROR) << "No file for " << std::hex << address.value(); 1022 return net::ERR_FILE_NOT_FOUND; 1023 } 1024 1025 size_t file_offset = offset; 1026 if (address.is_block_file()) { 1027 DCHECK_LE(offset + buf_len, kMaxBlockSize); 1028 file_offset += address.start_block() * address.BlockSize() + 1029 kBlockHeaderSize; 1030 } 1031 1032 SyncCallback* io_callback = NULL; 1033 if (!callback.is_null()) { 1034 io_callback = new SyncCallback(this, buf, callback, 1035 net::NetLog::TYPE_ENTRY_READ_DATA); 1036 } 1037 1038 TimeTicks start_async = TimeTicks::Now(); 1039 1040 bool completed; 1041 if (!file->Read(buf->data(), buf_len, file_offset, io_callback, &completed)) { 1042 if (io_callback) 1043 io_callback->Discard(); 1044 DoomImpl(); 1045 return net::ERR_CACHE_READ_FAILURE; 1046 } 1047 1048 if (io_callback && completed) 1049 io_callback->Discard(); 1050 1051 if (io_callback) 1052 ReportIOTime(kReadAsync1, start_async); 1053 1054 ReportIOTime(kRead, start); 1055 return (completed || callback.is_null()) ? buf_len : net::ERR_IO_PENDING; 1056 } 1057 1058 int EntryImpl::InternalWriteData(int index, int offset, 1059 IOBuffer* buf, int buf_len, 1060 const CompletionCallback& callback, 1061 bool truncate) { 1062 DCHECK(node_.Data()->dirty || read_only_); 1063 DVLOG(2) << "Write to " << index << " at " << offset << " : " << buf_len; 1064 if (index < 0 || index >= kNumStreams) 1065 return net::ERR_INVALID_ARGUMENT; 1066 1067 if (offset < 0 || buf_len < 0) 1068 return net::ERR_INVALID_ARGUMENT; 1069 1070 if (!backend_.get()) 1071 return net::ERR_UNEXPECTED; 1072 1073 int max_file_size = backend_->MaxFileSize(); 1074 1075 // offset or buf_len could be negative numbers. 1076 if (offset > max_file_size || buf_len > max_file_size || 1077 offset + buf_len > max_file_size) { 1078 int size = offset + buf_len; 1079 if (size <= max_file_size) 1080 size = kint32max; 1081 backend_->TooMuchStorageRequested(size); 1082 return net::ERR_FAILED; 1083 } 1084 1085 TimeTicks start = TimeTicks::Now(); 1086 1087 // Read the size at this point (it may change inside prepare). 1088 int entry_size = entry_.Data()->data_size[index]; 1089 bool extending = entry_size < offset + buf_len; 1090 truncate = truncate && entry_size > offset + buf_len; 1091 Trace("To PrepareTarget 0x%x", entry_.address().value()); 1092 if (!PrepareTarget(index, offset, buf_len, truncate)) 1093 return net::ERR_FAILED; 1094 1095 Trace("From PrepareTarget 0x%x", entry_.address().value()); 1096 if (extending || truncate) 1097 UpdateSize(index, entry_size, offset + buf_len); 1098 1099 UpdateRank(true); 1100 1101 backend_->OnEvent(Stats::WRITE_DATA); 1102 backend_->OnWrite(buf_len); 1103 1104 if (user_buffers_[index].get()) { 1105 // Complete the operation locally. 1106 user_buffers_[index]->Write(offset, buf, buf_len); 1107 ReportIOTime(kWrite, start); 1108 return buf_len; 1109 } 1110 1111 Addr address(entry_.Data()->data_addr[index]); 1112 if (offset + buf_len == 0) { 1113 if (truncate) { 1114 DCHECK(!address.is_initialized()); 1115 } 1116 return 0; 1117 } 1118 1119 File* file = GetBackingFile(address, index); 1120 if (!file) 1121 return net::ERR_FILE_NOT_FOUND; 1122 1123 size_t file_offset = offset; 1124 if (address.is_block_file()) { 1125 DCHECK_LE(offset + buf_len, kMaxBlockSize); 1126 file_offset += address.start_block() * address.BlockSize() + 1127 kBlockHeaderSize; 1128 } else if (truncate || (extending && !buf_len)) { 1129 if (!file->SetLength(offset + buf_len)) 1130 return net::ERR_FAILED; 1131 } 1132 1133 if (!buf_len) 1134 return 0; 1135 1136 SyncCallback* io_callback = NULL; 1137 if (!callback.is_null()) { 1138 io_callback = new SyncCallback(this, buf, callback, 1139 net::NetLog::TYPE_ENTRY_WRITE_DATA); 1140 } 1141 1142 TimeTicks start_async = TimeTicks::Now(); 1143 1144 bool completed; 1145 if (!file->Write(buf->data(), buf_len, file_offset, io_callback, 1146 &completed)) { 1147 if (io_callback) 1148 io_callback->Discard(); 1149 return net::ERR_CACHE_WRITE_FAILURE; 1150 } 1151 1152 if (io_callback && completed) 1153 io_callback->Discard(); 1154 1155 if (io_callback) 1156 ReportIOTime(kWriteAsync1, start_async); 1157 1158 ReportIOTime(kWrite, start); 1159 return (completed || callback.is_null()) ? buf_len : net::ERR_IO_PENDING; 1160 } 1161 1162 // ------------------------------------------------------------------------ 1163 1164 bool EntryImpl::CreateDataBlock(int index, int size) { 1165 DCHECK(index >= 0 && index < kNumStreams); 1166 1167 Addr address(entry_.Data()->data_addr[index]); 1168 if (!CreateBlock(size, &address)) 1169 return false; 1170 1171 entry_.Data()->data_addr[index] = address.value(); 1172 entry_.Store(); 1173 return true; 1174 } 1175 1176 bool EntryImpl::CreateBlock(int size, Addr* address) { 1177 DCHECK(!address->is_initialized()); 1178 if (!backend_.get()) 1179 return false; 1180 1181 FileType file_type = Addr::RequiredFileType(size); 1182 if (EXTERNAL == file_type) { 1183 if (size > backend_->MaxFileSize()) 1184 return false; 1185 if (!backend_->CreateExternalFile(address)) 1186 return false; 1187 } else { 1188 int num_blocks = Addr::RequiredBlocks(size, file_type); 1189 1190 if (!backend_->CreateBlock(file_type, num_blocks, address)) 1191 return false; 1192 } 1193 return true; 1194 } 1195 1196 // Note that this method may end up modifying a block file so upon return the 1197 // involved block will be free, and could be reused for something else. If there 1198 // is a crash after that point (and maybe before returning to the caller), the 1199 // entry will be left dirty... and at some point it will be discarded; it is 1200 // important that the entry doesn't keep a reference to this address, or we'll 1201 // end up deleting the contents of |address| once again. 1202 void EntryImpl::DeleteData(Addr address, int index) { 1203 DCHECK(backend_.get()); 1204 if (!address.is_initialized()) 1205 return; 1206 if (address.is_separate_file()) { 1207 int failure = !DeleteCacheFile(backend_->GetFileName(address)); 1208 CACHE_UMA(COUNTS, "DeleteFailed", 0, failure); 1209 if (failure) { 1210 LOG(ERROR) << "Failed to delete " << 1211 backend_->GetFileName(address).value() << " from the cache."; 1212 } 1213 if (files_[index].get()) 1214 files_[index] = NULL; // Releases the object. 1215 } else { 1216 backend_->DeleteBlock(address, true); 1217 } 1218 } 1219 1220 void EntryImpl::UpdateRank(bool modified) { 1221 if (!backend_.get()) 1222 return; 1223 1224 if (!doomed_) { 1225 // Everything is handled by the backend. 1226 backend_->UpdateRank(this, modified); 1227 return; 1228 } 1229 1230 Time current = Time::Now(); 1231 node_.Data()->last_used = current.ToInternalValue(); 1232 1233 if (modified) 1234 node_.Data()->last_modified = current.ToInternalValue(); 1235 } 1236 1237 File* EntryImpl::GetBackingFile(Addr address, int index) { 1238 if (!backend_.get()) 1239 return NULL; 1240 1241 File* file; 1242 if (address.is_separate_file()) 1243 file = GetExternalFile(address, index); 1244 else 1245 file = backend_->File(address); 1246 return file; 1247 } 1248 1249 File* EntryImpl::GetExternalFile(Addr address, int index) { 1250 DCHECK(index >= 0 && index <= kKeyFileIndex); 1251 if (!files_[index].get()) { 1252 // For a key file, use mixed mode IO. 1253 scoped_refptr<File> file(new File(kKeyFileIndex == index)); 1254 if (file->Init(backend_->GetFileName(address))) 1255 files_[index].swap(file); 1256 } 1257 return files_[index].get(); 1258 } 1259 1260 // We keep a memory buffer for everything that ends up stored on a block file 1261 // (because we don't know yet the final data size), and for some of the data 1262 // that end up on external files. This function will initialize that memory 1263 // buffer and / or the files needed to store the data. 1264 // 1265 // In general, a buffer may overlap data already stored on disk, and in that 1266 // case, the contents of the buffer are the most accurate. It may also extend 1267 // the file, but we don't want to read from disk just to keep the buffer up to 1268 // date. This means that as soon as there is a chance to get confused about what 1269 // is the most recent version of some part of a file, we'll flush the buffer and 1270 // reuse it for the new data. Keep in mind that the normal use pattern is quite 1271 // simple (write sequentially from the beginning), so we optimize for handling 1272 // that case. 1273 bool EntryImpl::PrepareTarget(int index, int offset, int buf_len, 1274 bool truncate) { 1275 if (truncate) 1276 return HandleTruncation(index, offset, buf_len); 1277 1278 if (!offset && !buf_len) 1279 return true; 1280 1281 Addr address(entry_.Data()->data_addr[index]); 1282 if (address.is_initialized()) { 1283 if (address.is_block_file() && !MoveToLocalBuffer(index)) 1284 return false; 1285 1286 if (!user_buffers_[index].get() && offset < kMaxBlockSize) { 1287 // We are about to create a buffer for the first 16KB, make sure that we 1288 // preserve existing data. 1289 if (!CopyToLocalBuffer(index)) 1290 return false; 1291 } 1292 } 1293 1294 if (!user_buffers_[index].get()) 1295 user_buffers_[index].reset(new UserBuffer(backend_.get())); 1296 1297 return PrepareBuffer(index, offset, buf_len); 1298 } 1299 1300 // We get to this function with some data already stored. If there is a 1301 // truncation that results on data stored internally, we'll explicitly 1302 // handle the case here. 1303 bool EntryImpl::HandleTruncation(int index, int offset, int buf_len) { 1304 Addr address(entry_.Data()->data_addr[index]); 1305 1306 int current_size = entry_.Data()->data_size[index]; 1307 int new_size = offset + buf_len; 1308 1309 if (!new_size) { 1310 // This is by far the most common scenario. 1311 backend_->ModifyStorageSize(current_size - unreported_size_[index], 0); 1312 entry_.Data()->data_addr[index] = 0; 1313 entry_.Data()->data_size[index] = 0; 1314 unreported_size_[index] = 0; 1315 entry_.Store(); 1316 DeleteData(address, index); 1317 1318 user_buffers_[index].reset(); 1319 return true; 1320 } 1321 1322 // We never postpone truncating a file, if there is one, but we may postpone 1323 // telling the backend about the size reduction. 1324 if (user_buffers_[index].get()) { 1325 DCHECK_GE(current_size, user_buffers_[index]->Start()); 1326 if (!address.is_initialized()) { 1327 // There is no overlap between the buffer and disk. 1328 if (new_size > user_buffers_[index]->Start()) { 1329 // Just truncate our buffer. 1330 DCHECK_LT(new_size, user_buffers_[index]->End()); 1331 user_buffers_[index]->Truncate(new_size); 1332 return true; 1333 } 1334 1335 // Just discard our buffer. 1336 user_buffers_[index]->Reset(); 1337 return PrepareBuffer(index, offset, buf_len); 1338 } 1339 1340 // There is some overlap or we need to extend the file before the 1341 // truncation. 1342 if (offset > user_buffers_[index]->Start()) 1343 user_buffers_[index]->Truncate(new_size); 1344 UpdateSize(index, current_size, new_size); 1345 if (!Flush(index, 0)) 1346 return false; 1347 user_buffers_[index].reset(); 1348 } 1349 1350 // We have data somewhere, and it is not in a buffer. 1351 DCHECK(!user_buffers_[index].get()); 1352 DCHECK(address.is_initialized()); 1353 1354 if (new_size > kMaxBlockSize) 1355 return true; // Let the operation go directly to disk. 1356 1357 return ImportSeparateFile(index, offset + buf_len); 1358 } 1359 1360 bool EntryImpl::CopyToLocalBuffer(int index) { 1361 Addr address(entry_.Data()->data_addr[index]); 1362 DCHECK(!user_buffers_[index].get()); 1363 DCHECK(address.is_initialized()); 1364 1365 int len = std::min(entry_.Data()->data_size[index], kMaxBlockSize); 1366 user_buffers_[index].reset(new UserBuffer(backend_.get())); 1367 user_buffers_[index]->Write(len, NULL, 0); 1368 1369 File* file = GetBackingFile(address, index); 1370 int offset = 0; 1371 1372 if (address.is_block_file()) 1373 offset = address.start_block() * address.BlockSize() + kBlockHeaderSize; 1374 1375 if (!file || 1376 !file->Read(user_buffers_[index]->Data(), len, offset, NULL, NULL)) { 1377 user_buffers_[index].reset(); 1378 return false; 1379 } 1380 return true; 1381 } 1382 1383 bool EntryImpl::MoveToLocalBuffer(int index) { 1384 if (!CopyToLocalBuffer(index)) 1385 return false; 1386 1387 Addr address(entry_.Data()->data_addr[index]); 1388 entry_.Data()->data_addr[index] = 0; 1389 entry_.Store(); 1390 DeleteData(address, index); 1391 1392 // If we lose this entry we'll see it as zero sized. 1393 int len = entry_.Data()->data_size[index]; 1394 backend_->ModifyStorageSize(len - unreported_size_[index], 0); 1395 unreported_size_[index] = len; 1396 return true; 1397 } 1398 1399 bool EntryImpl::ImportSeparateFile(int index, int new_size) { 1400 if (entry_.Data()->data_size[index] > new_size) 1401 UpdateSize(index, entry_.Data()->data_size[index], new_size); 1402 1403 return MoveToLocalBuffer(index); 1404 } 1405 1406 bool EntryImpl::PrepareBuffer(int index, int offset, int buf_len) { 1407 DCHECK(user_buffers_[index].get()); 1408 if ((user_buffers_[index]->End() && offset > user_buffers_[index]->End()) || 1409 offset > entry_.Data()->data_size[index]) { 1410 // We are about to extend the buffer or the file (with zeros), so make sure 1411 // that we are not overwriting anything. 1412 Addr address(entry_.Data()->data_addr[index]); 1413 if (address.is_initialized() && address.is_separate_file()) { 1414 if (!Flush(index, 0)) 1415 return false; 1416 // There is an actual file already, and we don't want to keep track of 1417 // its length so we let this operation go straight to disk. 1418 // The only case when a buffer is allowed to extend the file (as in fill 1419 // with zeros before the start) is when there is no file yet to extend. 1420 user_buffers_[index].reset(); 1421 return true; 1422 } 1423 } 1424 1425 if (!user_buffers_[index]->PreWrite(offset, buf_len)) { 1426 if (!Flush(index, offset + buf_len)) 1427 return false; 1428 1429 // Lets try again. 1430 if (offset > user_buffers_[index]->End() || 1431 !user_buffers_[index]->PreWrite(offset, buf_len)) { 1432 // We cannot complete the operation with a buffer. 1433 DCHECK(!user_buffers_[index]->Size()); 1434 DCHECK(!user_buffers_[index]->Start()); 1435 user_buffers_[index].reset(); 1436 } 1437 } 1438 return true; 1439 } 1440 1441 bool EntryImpl::Flush(int index, int min_len) { 1442 Addr address(entry_.Data()->data_addr[index]); 1443 DCHECK(user_buffers_[index].get()); 1444 DCHECK(!address.is_initialized() || address.is_separate_file()); 1445 DVLOG(3) << "Flush"; 1446 1447 int size = std::max(entry_.Data()->data_size[index], min_len); 1448 if (size && !address.is_initialized() && !CreateDataBlock(index, size)) 1449 return false; 1450 1451 if (!entry_.Data()->data_size[index]) { 1452 DCHECK(!user_buffers_[index]->Size()); 1453 return true; 1454 } 1455 1456 address.set_value(entry_.Data()->data_addr[index]); 1457 1458 int len = user_buffers_[index]->Size(); 1459 int offset = user_buffers_[index]->Start(); 1460 if (!len && !offset) 1461 return true; 1462 1463 if (address.is_block_file()) { 1464 DCHECK_EQ(len, entry_.Data()->data_size[index]); 1465 DCHECK(!offset); 1466 offset = address.start_block() * address.BlockSize() + kBlockHeaderSize; 1467 } 1468 1469 File* file = GetBackingFile(address, index); 1470 if (!file) 1471 return false; 1472 1473 if (!file->Write(user_buffers_[index]->Data(), len, offset, NULL, NULL)) 1474 return false; 1475 user_buffers_[index]->Reset(); 1476 1477 return true; 1478 } 1479 1480 void EntryImpl::UpdateSize(int index, int old_size, int new_size) { 1481 if (entry_.Data()->data_size[index] == new_size) 1482 return; 1483 1484 unreported_size_[index] += new_size - old_size; 1485 entry_.Data()->data_size[index] = new_size; 1486 entry_.set_modified(); 1487 } 1488 1489 int EntryImpl::InitSparseData() { 1490 if (sparse_.get()) 1491 return net::OK; 1492 1493 // Use a local variable so that sparse_ never goes from 'valid' to NULL. 1494 scoped_ptr<SparseControl> sparse(new SparseControl(this)); 1495 int result = sparse->Init(); 1496 if (net::OK == result) 1497 sparse_.swap(sparse); 1498 1499 return result; 1500 } 1501 1502 void EntryImpl::SetEntryFlags(uint32 flags) { 1503 entry_.Data()->flags |= flags; 1504 entry_.set_modified(); 1505 } 1506 1507 uint32 EntryImpl::GetEntryFlags() { 1508 return entry_.Data()->flags; 1509 } 1510 1511 void EntryImpl::GetData(int index, char** buffer, Addr* address) { 1512 DCHECK(backend_.get()); 1513 if (user_buffers_[index].get() && user_buffers_[index]->Size() && 1514 !user_buffers_[index]->Start()) { 1515 // The data is already in memory, just copy it and we're done. 1516 int data_len = entry_.Data()->data_size[index]; 1517 if (data_len <= user_buffers_[index]->Size()) { 1518 DCHECK(!user_buffers_[index]->Start()); 1519 *buffer = new char[data_len]; 1520 memcpy(*buffer, user_buffers_[index]->Data(), data_len); 1521 return; 1522 } 1523 } 1524 1525 // Bad news: we'd have to read the info from disk so instead we'll just tell 1526 // the caller where to read from. 1527 *buffer = NULL; 1528 address->set_value(entry_.Data()->data_addr[index]); 1529 if (address->is_initialized()) { 1530 // Prevent us from deleting the block from the backing store. 1531 backend_->ModifyStorageSize(entry_.Data()->data_size[index] - 1532 unreported_size_[index], 0); 1533 entry_.Data()->data_addr[index] = 0; 1534 entry_.Data()->data_size[index] = 0; 1535 } 1536 } 1537 1538 void EntryImpl::Log(const char* msg) { 1539 int dirty = 0; 1540 if (node_.HasData()) { 1541 dirty = node_.Data()->dirty; 1542 } 1543 1544 Trace("%s 0x%p 0x%x 0x%x", msg, reinterpret_cast<void*>(this), 1545 entry_.address().value(), node_.address().value()); 1546 1547 Trace(" data: 0x%x 0x%x 0x%x", entry_.Data()->data_addr[0], 1548 entry_.Data()->data_addr[1], entry_.Data()->long_key); 1549 1550 Trace(" doomed: %d 0x%x", doomed_, dirty); 1551 } 1552 1553 } // namespace disk_cache 1554