Disk cache: Add base files for implementation of file format version 3.

net/disk_cache/v3/entry_impl_v3.cc

Index: net/disk_cache/v3/entry_impl_v3.cc
===================================================================
--- net/disk_cache/v3/entry_impl_v3.cc	(revision 0)
+++ net/disk_cache/v3/entry_impl_v3.cc	(working copy)
@@ -23,60 +23,6 @@
 
 namespace {
 
-// Index for the file used to store the key, if any (files_[kKeyFileIndex]).
-const int kKeyFileIndex = 3;
-
-// This class implements FileIOCallback to buffer the callback from a file IO
-// operation from the actual net class.
-class SyncCallback: public disk_cache::FileIOCallback {
- public:
-  // |end_event_type| is the event type to log on completion.  Logs nothing on
-  // discard, or when the NetLog is not set to log all events.
-  SyncCallback(disk_cache::EntryImpl* entry, net::IOBuffer* buffer,
-               const net::CompletionCallback& callback,
-               net::NetLog::EventType end_event_type)
-      : entry_(entry), callback_(callback), buf_(buffer),
-        start_(TimeTicks::Now()), end_event_type_(end_event_type) {
-    entry->AddRef();
-    entry->IncrementIoCount();
-  }
-  virtual ~SyncCallback() {}
-
-  virtual void OnFileIOComplete(int bytes_copied) OVERRIDE;
-  void Discard();
-
- private:
-  disk_cache::EntryImpl* entry_;
-  net::CompletionCallback callback_;
-  scoped_refptr<net::IOBuffer> buf_;
-  TimeTicks start_;
-  const net::NetLog::EventType end_event_type_;
-
-  DISALLOW_COPY_AND_ASSIGN(SyncCallback);
-};
-
-void SyncCallback::OnFileIOComplete(int bytes_copied) {
-  entry_->DecrementIoCount();
-  if (!callback_.is_null()) {
-    if (entry_->net_log().IsLoggingAllEvents()) {
-      entry_->net_log().EndEvent(
-          end_event_type_,
-          disk_cache::CreateNetLogReadWriteCompleteCallback(bytes_copied));
-    }
-    entry_->ReportIOTime(disk_cache::EntryImpl::kAsyncIO, start_);
-    buf_ = NULL;  // Release the buffer before invoking the callback.
-    callback_.Run(bytes_copied);
-  }
-  entry_->Release();
-  delete this;
-}
-
-void SyncCallback::Discard() {
-  callback_.Reset();
-  buf_ = NULL;
-  OnFileIOComplete(0);
-}
-
 const int kMaxBufferSize = 1024 * 1024;  // 1 MB.
 
 }  // namespace
@@ -95,7 +41,7 @@
     buffer_.reserve(kMaxBlockSize);
   }
   ~UserBuffer() {
-    if (backend_.get())
+    if (backend_)
       backend_->BufferDeleted(capacity() - kMaxBlockSize);
   }
 
@@ -252,7 +198,7 @@
 
 void EntryImpl::UserBuffer::Reset() {
   if (!grow_allowed_) {
-    if (backend_.get())
+    if (backend_)
       backend_->BufferDeleted(capacity() - kMaxBlockSize);
     grow_allowed_ = true;
     std::vector<char> tmp;
@@ -272,7 +218,7 @@
   if (required > limit)
     return false;
 
-  if (!backend_.get())
+  if (!backend_)
     return false;
 
   int to_add = std::max(required - current_size, kMaxBlockSize * 4);
@@ -301,104 +247,6 @@
   }
 }
 
-void EntryImpl::DoomImpl() {
-  if (doomed_ || !backend_.get())
-    return;
-
-  SetPointerForInvalidEntry(backend_->GetCurrentEntryId());
-  backend_->InternalDoomEntry(this);
-}
-
-int EntryImpl::ReadDataImpl(int index, int offset, IOBuffer* buf, int buf_len,
-                            const CompletionCallback& callback) {
-  if (net_log_.IsLoggingAllEvents()) {
-    net_log_.BeginEvent(
-        net::NetLog::TYPE_ENTRY_READ_DATA,
-        CreateNetLogReadWriteDataCallback(index, offset, buf_len, false));
-  }
-
-  int result = InternalReadData(index, offset, buf, buf_len, callback);
-
-  if (result != net::ERR_IO_PENDING && net_log_.IsLoggingAllEvents()) {
-    net_log_.EndEvent(
-        net::NetLog::TYPE_ENTRY_READ_DATA,
-        CreateNetLogReadWriteCompleteCallback(result));
-  }
-  return result;
-}
-
-int EntryImpl::WriteDataImpl(int index, int offset, IOBuffer* buf, int buf_len,
-                             const CompletionCallback& callback,
-                             bool truncate) {
-  if (net_log_.IsLoggingAllEvents()) {
-    net_log_.BeginEvent(
-        net::NetLog::TYPE_ENTRY_WRITE_DATA,
-        CreateNetLogReadWriteDataCallback(index, offset, buf_len, truncate));
-  }
-
-  int result = InternalWriteData(index, offset, buf, buf_len, callback,
-                                 truncate);
-
-  if (result != net::ERR_IO_PENDING && net_log_.IsLoggingAllEvents()) {
-    net_log_.EndEvent(
-        net::NetLog::TYPE_ENTRY_WRITE_DATA,
-        CreateNetLogReadWriteCompleteCallback(result));
-  }
-  return result;
-}
-
-int EntryImpl::ReadSparseDataImpl(int64 offset, IOBuffer* buf, int buf_len,
-                                  const CompletionCallback& callback) {
-  DCHECK(node_.Data()->dirty || read_only_);
-  int result = InitSparseData();
-  if (net::OK != result)
-    return result;
-
-  TimeTicks start = TimeTicks::Now();
-  result = sparse_->StartIO(SparseControl::kReadOperation, offset, buf, buf_len,
-                            callback);
-  ReportIOTime(kSparseRead, start);
-  return result;
-}
-
-int EntryImpl::WriteSparseDataImpl(int64 offset, IOBuffer* buf, int buf_len,
-                                   const CompletionCallback& callback) {
-  DCHECK(node_.Data()->dirty || read_only_);
-  int result = InitSparseData();
-  if (net::OK != result)
-    return result;
-
-  TimeTicks start = TimeTicks::Now();
-  result = sparse_->StartIO(SparseControl::kWriteOperation, offset, buf,
-                            buf_len, callback);
-  ReportIOTime(kSparseWrite, start);
-  return result;
-}
-
-int EntryImpl::GetAvailableRangeImpl(int64 offset, int len, int64* start) {
-  int result = InitSparseData();
-  if (net::OK != result)
-    return result;
-
-  return sparse_->GetAvailableRange(offset, len, start);
-}
-
-void EntryImpl::CancelSparseIOImpl() {
-  if (!sparse_.get())
-    return;
-
-  sparse_->CancelIO();
-}
-
-int EntryImpl::ReadyForSparseIOImpl(const CompletionCallback& callback) {
-  DCHECK(sparse_.get());
-  return sparse_->ReadyToUse(callback);
-}
-
-uint32 EntryImpl::GetHash() {
-  return entry_.Data()->hash;
-}
-
 bool EntryImpl::CreateEntry(Addr node_address, const std::string& key,
                             uint32 hash) {
   Trace("Create entry In");
@@ -446,6 +294,10 @@
   return true;
 }
 
+uint32 EntryImpl::GetHash() {
+  return entry_.Data()->hash;
+}
+
 bool EntryImpl::IsSameEntry(const std::string& key, uint32 hash) {
   if (entry_.Data()->hash != hash ||
       static_cast<size_t>(entry_.Data()->key_len) != key.size())
@@ -464,103 +316,6 @@
   doomed_ = true;
 }
 
-void EntryImpl::DeleteEntryData(bool everything) {
-  DCHECK(doomed_ || !everything);
-
-  if (GetEntryFlags() & PARENT_ENTRY) {
-    // We have some child entries that must go away.
-    SparseControl::DeleteChildren(this);
-  }
-
-  if (GetDataSize(0))
-    CACHE_UMA(COUNTS, "DeleteHeader", 0, GetDataSize(0));
-  if (GetDataSize(1))
-    CACHE_UMA(COUNTS, "DeleteData", 0, GetDataSize(1));
-  for (int index = 0; index < kNumStreams; index++) {
-    Addr address(entry_.Data()->data_addr[index]);
-    if (address.is_initialized()) {
-      backend_->ModifyStorageSize(entry_.Data()->data_size[index] -
-                                      unreported_size_[index], 0);
-      entry_.Data()->data_addr[index] = 0;
-      entry_.Data()->data_size[index] = 0;
-      entry_.Store();
-      DeleteData(address, index);
-    }
-  }
-
-  if (!everything)
-    return;
-
-  // Remove all traces of this entry.
-  backend_->RemoveEntry(this);
-
-  // Note that at this point node_ and entry_ are just two blocks of data, and
-  // even if they reference each other, nobody should be referencing them.
-
-  Addr address(entry_.Data()->long_key);
-  DeleteData(address, kKeyFileIndex);
-  backend_->ModifyStorageSize(entry_.Data()->key_len, 0);
-
-  backend_->DeleteBlock(entry_.address(), true);
-  entry_.Discard();
-
-  if (!LeaveRankingsBehind()) {
-    backend_->DeleteBlock(node_.address(), true);
-    node_.Discard();
-  }
-}
-
-CacheAddr EntryImpl::GetNextAddress() {
-  return entry_.Data()->next;
-}
-
-void EntryImpl::SetNextAddress(Addr address) {
-  DCHECK_NE(address.value(), entry_.address().value());
-  entry_.Data()->next = address.value();
-  bool success = entry_.Store();
-  DCHECK(success);
-}
-
-bool EntryImpl::LoadNodeAddress() {
-  Addr address(entry_.Data()->rankings_node);
-  if (!node_.LazyInit(backend_->File(address), address))
-    return false;
-  return node_.Load();
-}
-
-bool EntryImpl::Update() {
-  DCHECK(node_.HasData());
-
-  if (read_only_)
-    return true;
-
-  RankingsNode* rankings = node_.Data();
-  if (!rankings->dirty) {
-    rankings->dirty = backend_->GetCurrentEntryId();
-    if (!node_.Store())
-      return false;
-  }
-  return true;
-}
-
-void EntryImpl::SetDirtyFlag(int32 current_id) {
-  DCHECK(node_.HasData());
-  if (node_.Data()->dirty && current_id != node_.Data()->dirty)
-    dirty_ = true;
-
-  if (!current_id)
-    dirty_ = true;
-}
-
-void EntryImpl::SetPointerForInvalidEntry(int32 new_id) {
-  node_.Data()->dirty = new_id;
-  node_.Store();
-}
-
-bool EntryImpl::LeaveRankingsBehind() {
-  return !node_.Data()->contents;
-}
-
 // This only includes checks that relate to the first block of the entry (the
 // first 256 bytes), and values that should be set from the entry creation.
 // Basically, even if there is something wrong with this entry, we want to see
@@ -667,57 +422,12 @@
   entry_.Store();
 }
 
-void EntryImpl::IncrementIoCount() {
-  backend_->IncrementIoCount();
-}
-
-void EntryImpl::DecrementIoCount() {
-  if (backend_.get())
-    backend_->DecrementIoCount();
-}
-
-void EntryImpl::OnEntryCreated(BackendImpl* backend) {
-  // Just grab a reference to the backround queue.
-  background_queue_ = backend->GetBackgroundQueue();
-}
-
 void EntryImpl::SetTimes(base::Time last_used, base::Time last_modified) {
   node_.Data()->last_used = last_used.ToInternalValue();
   node_.Data()->last_modified = last_modified.ToInternalValue();
   node_.set_modified();
 }
 
-void EntryImpl::ReportIOTime(Operation op, const base::TimeTicks& start) {
-  if (!backend_.get())
-    return;
-
-  switch (op) {
-    case kRead:
-      CACHE_UMA(AGE_MS, "ReadTime", 0, start);
-      break;
-    case kWrite:
-      CACHE_UMA(AGE_MS, "WriteTime", 0, start);
-      break;
-    case kSparseRead:
-      CACHE_UMA(AGE_MS, "SparseReadTime", 0, start);
-      break;
-    case kSparseWrite:
-      CACHE_UMA(AGE_MS, "SparseWriteTime", 0, start);
-      break;
-    case kAsyncIO:
-      CACHE_UMA(AGE_MS, "AsyncIOTime", 0, start);
-      break;
-    case kReadAsync1:
-      CACHE_UMA(AGE_MS, "AsyncReadDispatchTime", 0, start);
-      break;
-    case kWriteAsync1:
-      CACHE_UMA(AGE_MS, "AsyncWriteDispatchTime", 0, start);
-      break;
-    default:
-      NOTREACHED();
-  }
-}
-
 void EntryImpl::BeginLogging(net::NetLog* net_log, bool created) {
   DCHECK(!net_log_.net_log());
   net_log_ = net::BoundNetLog::Make(
@@ -731,27 +441,23 @@
   return net_log_;
 }
 
-// static
-int EntryImpl::NumBlocksForEntry(int key_size) {
-  // The longest key that can be stored using one block.
-  int key1_len =
-      static_cast<int>(sizeof(EntryStore) - offsetof(EntryStore, key));
-
-  if (key_size < key1_len || key_size > kMaxInternalKeyLength)
-    return 1;
-
-  return ((key_size - key1_len) / 256 + 2);
-}
-
 // ------------------------------------------------------------------------
 
 void EntryImpl::Doom() {
-  if (background_queue_.get())
+  if (background_queue_)
     background_queue_->DoomEntryImpl(this);
 }
 
+void EntryImpl::DoomImpl() {
+  if (doomed_ || !backend_)
+    return;
+
+  SetPointerForInvalidEntry(backend_->GetCurrentEntryId());
+  backend_->InternalDoomEntry(this);
+}
+
 void EntryImpl::Close() {
-  if (background_queue_.get())
+  if (background_queue_)
     background_queue_->CloseEntryImpl(this);
 }
 
@@ -821,13 +527,31 @@
   if (buf_len < 0)
     return net::ERR_INVALID_ARGUMENT;
 
-  if (!background_queue_.get())
+  if (!background_queue_)
     return net::ERR_UNEXPECTED;
 
   background_queue_->ReadData(this, index, offset, buf, buf_len, callback);
   return net::ERR_IO_PENDING;
 }
 
+int EntryImpl::ReadDataImpl(int index, int offset, IOBuffer* buf, int buf_len,
+                            const CompletionCallback& callback) {
+  if (net_log_.IsLoggingAllEvents()) {
+    net_log_.BeginEvent(
+        net::NetLog::TYPE_ENTRY_READ_DATA,
+        CreateNetLogReadWriteDataCallback(index, offset, buf_len, false));
+  }
+
+  int result = InternalReadData(index, offset, buf, buf_len, callback);
+
+  if (result != net::ERR_IO_PENDING && net_log_.IsLoggingAllEvents()) {
+    net_log_.EndEvent(
+        net::NetLog::TYPE_ENTRY_READ_DATA,
+        CreateNetLogReadWriteCompleteCallback(result));
+  }
+  return result;
+}
+
 int EntryImpl::WriteData(int index, int offset, IOBuffer* buf, int buf_len,
                          const CompletionCallback& callback, bool truncate) {
   if (callback.is_null())
@@ -840,7 +564,7 @@
   if (offset < 0 || buf_len < 0)
     return net::ERR_INVALID_ARGUMENT;
 
-  if (!background_queue_.get())
+  if (!background_queue_)
     return net::ERR_UNEXPECTED;
 
   background_queue_->WriteData(this, index, offset, buf, buf_len, truncate,
@@ -848,39 +572,95 @@
   return net::ERR_IO_PENDING;
 }
 
+int EntryImpl::WriteDataImpl(int index, int offset, IOBuffer* buf, int buf_len,
+                             const CompletionCallback& callback,
+                             bool truncate) {
+  if (net_log_.IsLoggingAllEvents()) {
+    net_log_.BeginEvent(
+        net::NetLog::TYPE_ENTRY_WRITE_DATA,
+        CreateNetLogReadWriteDataCallback(index, offset, buf_len, truncate));
+  }
+
+  int result = InternalWriteData(index, offset, buf, buf_len, callback,
+                                 truncate);
+
+  if (result != net::ERR_IO_PENDING && net_log_.IsLoggingAllEvents()) {
+    net_log_.EndEvent(
+        net::NetLog::TYPE_ENTRY_WRITE_DATA,
+        CreateNetLogReadWriteCompleteCallback(result));
+  }
+  return result;
+}
+
 int EntryImpl::ReadSparseData(int64 offset, IOBuffer* buf, int buf_len,
                               const CompletionCallback& callback) {
   if (callback.is_null())
     return ReadSparseDataImpl(offset, buf, buf_len, callback);
 
-  if (!background_queue_.get())
+  if (!background_queue_)
     return net::ERR_UNEXPECTED;
 
   background_queue_->ReadSparseData(this, offset, buf, buf_len, callback);
   return net::ERR_IO_PENDING;
 }
 
+int EntryImpl::ReadSparseDataImpl(int64 offset, IOBuffer* buf, int buf_len,
+                                  const CompletionCallback& callback) {
+  DCHECK(node_.Data()->dirty || read_only_);
+  int result = InitSparseData();
+  if (net::OK != result)
+    return result;
+
+  TimeTicks start = TimeTicks::Now();
+  result = sparse_->StartIO(SparseControl::kReadOperation, offset, buf, buf_len,
+                            callback);
+  ReportIOTime(kSparseRead, start);
+  return result;
+}
+
 int EntryImpl::WriteSparseData(int64 offset, IOBuffer* buf, int buf_len,
                                const CompletionCallback& callback) {
   if (callback.is_null())
     return WriteSparseDataImpl(offset, buf, buf_len, callback);
 
-  if (!background_queue_.get())
+  if (!background_queue_)
     return net::ERR_UNEXPECTED;
 
   background_queue_->WriteSparseData(this, offset, buf, buf_len, callback);
   return net::ERR_IO_PENDING;
 }
 
+int EntryImpl::WriteSparseDataImpl(int64 offset, IOBuffer* buf, int buf_len,
+                                   const CompletionCallback& callback) {
+  DCHECK(node_.Data()->dirty || read_only_);
+  int result = InitSparseData();
+  if (net::OK != result)
+    return result;
+
+  TimeTicks start = TimeTicks::Now();
+  result = sparse_->StartIO(SparseControl::kWriteOperation, offset, buf,
+                            buf_len, callback);
+  ReportIOTime(kSparseWrite, start);
+  return result;
+}
+
 int EntryImpl::GetAvailableRange(int64 offset, int len, int64* start,
                                  const CompletionCallback& callback) {
-  if (!background_queue_.get())
+  if (!background_queue_)
     return net::ERR_UNEXPECTED;
 
   background_queue_->GetAvailableRange(this, offset, len, start, callback);
   return net::ERR_IO_PENDING;
 }
 
+int EntryImpl::GetAvailableRangeImpl(int64 offset, int len, int64* start) {
+  int result = InitSparseData();
+  if (net::OK != result)
+    return result;
+
+  return sparse_->GetAvailableRange(offset, len, start);
+}
+
 bool EntryImpl::CouldBeSparse() const {
   if (sparse_.get())
     return true;
@@ -891,21 +671,35 @@
 }
 
 void EntryImpl::CancelSparseIO() {
-  if (background_queue_.get())
+  if (background_queue_)
     background_queue_->CancelSparseIO(this);
 }
 
+void EntryImpl::CancelSparseIOImpl() {
+  if (!sparse_.get())
+    return;
+
+  sparse_->CancelIO();
+}
+
 int EntryImpl::ReadyForSparseIO(const CompletionCallback& callback) {
   if (!sparse_.get())
     return net::OK;
 
-  if (!background_queue_.get())
+  if (!background_queue_)
     return net::ERR_UNEXPECTED;
 
   background_queue_->ReadyForSparseIO(this, callback);
   return net::ERR_IO_PENDING;
 }
 
+int EntryImpl::ReadyForSparseIOImpl(const CompletionCallback& callback) {
+  DCHECK(sparse_.get());
+  return sparse_->ReadyToUse(callback);
+}
+
+// ------------------------------------------------------------------------
+
 // When an entry is deleted from the cache, we clean up all the data associated
 // with it for two reasons: to simplify the reuse of the block (we know that any
 // unused block is filled with zeros), and to simplify the handling of write /
@@ -913,7 +707,7 @@
 // data related to a previous cache entry because the range was not fully
 // written before).
 EntryImpl::~EntryImpl() {
-  if (!backend_.get()) {
+  if (!backend_) {
     entry_.clear_modified();
     node_.clear_modified();
     return;
@@ -964,8 +758,6 @@
   backend_->OnEntryDestroyEnd();
 }
 
-// ------------------------------------------------------------------------
-
 int EntryImpl::InternalReadData(int index, int offset,
                                 IOBuffer* buf, int buf_len,
                                 const CompletionCallback& callback) {
@@ -981,7 +773,7 @@
   if (buf_len < 0)
     return net::ERR_INVALID_ARGUMENT;
 
-  if (!backend_.get())
+  if (!backend_)
     return net::ERR_UNEXPECTED;
 
   TimeTicks start = TimeTicks::Now();
@@ -1063,7 +855,7 @@
   if (offset < 0 || buf_len < 0)
     return net::ERR_INVALID_ARGUMENT;
 
-  if (!backend_.get())
+  if (!backend_)
     return net::ERR_UNEXPECTED;
 
   int max_file_size = backend_->MaxFileSize();
@@ -1171,7 +963,7 @@
 
 bool EntryImpl::CreateBlock(int size, Addr* address) {
   DCHECK(!address->is_initialized());
-  if (!backend_.get())
+  if (!backend_)
     return false;
 
   FileType file_type = Addr::RequiredFileType(size);
@@ -1196,7 +988,7 @@
 // important that the entry doesn't keep a reference to this address, or we'll
 // end up deleting the contents of |address| once again.
 void EntryImpl::DeleteData(Addr address, int index) {
-  DCHECK(backend_.get());
+  DCHECK(backend_);
   if (!address.is_initialized())
     return;
   if (address.is_separate_file()) {
@@ -1206,7 +998,7 @@
       LOG(ERROR) << "Failed to delete " <<
           backend_->GetFileName(address).value() << " from the cache.";
     }
-    if (files_[index].get())
+    if (files_[index])
       files_[index] = NULL;  // Releases the object.
   } else {
     backend_->DeleteBlock(address, true);
@@ -1214,7 +1006,7 @@
 }
 
 void EntryImpl::UpdateRank(bool modified) {
-  if (!backend_.get())
+  if (!backend_)
     return;
 
   if (!doomed_) {
@@ -1230,27 +1022,50 @@
     node_.Data()->last_modified = current.ToInternalValue();
 }
 
-File* EntryImpl::GetBackingFile(Addr address, int index) {
-  if (!backend_.get())
-    return NULL;
+void EntryImpl::DeleteEntryData(bool everything) {
+  DCHECK(doomed_ || !everything);
 
-  File* file;
-  if (address.is_separate_file())
-    file = GetExternalFile(address, index);
-  else
-    file = backend_->File(address);
-  return file;
-}
+  if (GetEntryFlags() & PARENT_ENTRY) {
+    // We have some child entries that must go away.
+    SparseControl::DeleteChildren(this);
+  }
 
-File* EntryImpl::GetExternalFile(Addr address, int index) {
-  DCHECK(index >= 0 && index <= kKeyFileIndex);
-  if (!files_[index].get()) {
-    // For a key file, use mixed mode IO.
-    scoped_refptr<File> file(new File(kKeyFileIndex == index));
-    if (file->Init(backend_->GetFileName(address)))
-      files_[index].swap(file);
+  if (GetDataSize(0))
+    CACHE_UMA(COUNTS, "DeleteHeader", 0, GetDataSize(0));
+  if (GetDataSize(1))
+    CACHE_UMA(COUNTS, "DeleteData", 0, GetDataSize(1));
+  for (int index = 0; index < kNumStreams; index++) {
+    Addr address(entry_.Data()->data_addr[index]);
+    if (address.is_initialized()) {
+      backend_->ModifyStorageSize(entry_.Data()->data_size[index] -
+                                      unreported_size_[index], 0);
+      entry_.Data()->data_addr[index] = 0;
+      entry_.Data()->data_size[index] = 0;
+      entry_.Store();
+      DeleteData(address, index);
+    }
   }
-  return files_[index].get();
+
+  if (!everything)
+    return;
+
+  // Remove all traces of this entry.
+  backend_->RemoveEntry(this);
+
+  // Note that at this point node_ and entry_ are just two blocks of data, and
+  // even if they reference each other, nobody should be referencing them.
+
+  Addr address(entry_.Data()->long_key);
+  DeleteData(address, kKeyFileIndex);
+  backend_->ModifyStorageSize(entry_.Data()->key_len, 0);
+
+  backend_->DeleteBlock(entry_.address(), true);
+  entry_.Discard();
+
+  if (!LeaveRankingsBehind()) {
+    backend_->DeleteBlock(node_.address(), true);
+    node_.Discard();
+  }
 }
 
 // We keep a memory buffer for everything that ends up stored on a block file
@@ -1505,7 +1320,7 @@
 }
 
 void EntryImpl::GetData(int index, char** buffer, Addr* address) {
-  DCHECK(backend_.get());
+  DCHECK(backend_);
   if (user_buffers_[index].get() && user_buffers_[index]->Size() &&
       !user_buffers_[index]->Start()) {
     // The data is already in memory, just copy it and we're done.
@@ -1531,6 +1346,37 @@
   }
 }
 
+void EntryImpl::ReportIOTime(Operation op, const base::TimeTicks& start) {
+  if (!backend_)
+    return;
+
+  switch (op) {
+    case kRead:
+      CACHE_UMA(AGE_MS, "ReadTime", 0, start);
+      break;
+    case kWrite:
+      CACHE_UMA(AGE_MS, "WriteTime", 0, start);
+      break;
+    case kSparseRead:
+      CACHE_UMA(AGE_MS, "SparseReadTime", 0, start);
+      break;
+    case kSparseWrite:
+      CACHE_UMA(AGE_MS, "SparseWriteTime", 0, start);
+      break;
+    case kAsyncIO:
+      CACHE_UMA(AGE_MS, "AsyncIOTime", 0, start);
+      break;
+    case kReadAsync1:
+      CACHE_UMA(AGE_MS, "AsyncReadDispatchTime", 0, start);
+      break;
+    case kWriteAsync1:
+      CACHE_UMA(AGE_MS, "AsyncWriteDispatchTime", 0, start);
+      break;
+    default:
+      NOTREACHED();
+  }
+}
+
 void EntryImpl::Log(const char* msg) {
   int dirty = 0;
   if (node_.HasData()) {