[BlobStorage] BlobMemoryController & tests

storage/browser/blob/blob_data_item.h

 // Copyright (c) 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef STORAGE_BROWSER_BLOB_BLOB_DATA_ITEM_H_
 #define STORAGE_BROWSER_BLOB_BLOB_DATA_ITEM_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 10 matching lines @@
 
 namespace storage {
 class BlobDataBuilder;
 class BlobStorageContext;
 
 // Ref counted blob item. This class owns the backing data of the blob item. The
 // backing data is immutable, and cannot change after creation. The purpose of
 // this class is to allow the resource to stick around in the snapshot even
 // after the resource was swapped in the blob (either to disk or to memory) by
 // the BlobStorageContext.
-class STORAGE_EXPORT BlobDataItem : public base::RefCounted<BlobDataItem> {
+class STORAGE_EXPORT BlobDataItem
+    : public base::RefCountedThreadSafe<BlobDataItem> {

[michaeln, 2016/09/27 00:09:29]

see comment elsewhere about thread-safe-refcounts

[dmurph, 2016/09/29 00:44:20]

Yes, you're right, I can remove this.

  public:
   // The DataHandle class is used to persist resources that are needed for
   // reading this BlobDataItem. This object will stay around while any reads are
   // pending. If all blobs with this item are deleted or the item is swapped for
   // a different backend version (mem-to-disk or the reverse), then the item
   // will be destructed after all pending reads are complete.
   class STORAGE_EXPORT DataHandle : public base::RefCounted<DataHandle> {
    protected:
     virtual ~DataHandle() = 0;
 
    private:
     friend class base::RefCounted<DataHandle>;
   };
 
+  explicit BlobDataItem(std::unique_ptr<DataElement> item);
+  BlobDataItem(std::unique_ptr<DataElement> item,
+               const scoped_refptr<DataHandle>& data_handle);
+  BlobDataItem(std::unique_ptr<DataElement> item,
+               const scoped_refptr<DataHandle>& data_handle,
+               disk_cache::Entry* entry,
+               int disk_cache_stream_index,
+               int disk_cache_side_stream_index);
+
   DataElement::Type type() const { return item_->type(); }
   const char* bytes() const { return item_->bytes(); }
   const base::FilePath& path() const { return item_->path(); }
   const GURL& filesystem_url() const { return item_->filesystem_url(); }
   const std::string& blob_uuid() const { return item_->blob_uuid(); }
   uint64_t offset() const { return item_->offset(); }
   uint64_t length() const { return item_->length(); }
   const base::Time& expected_modification_time() const {
     return item_->expected_modification_time();
   }
   const DataElement& data_element() const { return *item_; }
   const DataElement* data_element_ptr() const { return item_.get(); }
   DataElement* data_element_ptr() { return item_.get(); }
 
   disk_cache::Entry* disk_cache_entry() const { return disk_cache_entry_; }
   int disk_cache_stream_index() const { return disk_cache_stream_index_; }
   int disk_cache_side_stream_index() const {
     return disk_cache_side_stream_index_;
   }
 
+  const scoped_refptr<DataHandle>& data_handle() const { return data_handle_; }
+
  private:
   friend class BlobDataBuilder;
   friend class BlobStorageContext;
-  friend class base::RefCounted<BlobDataItem>;
+  friend class base::RefCountedThreadSafe<BlobDataItem>;
   friend STORAGE_EXPORT void PrintTo(const BlobDataItem& x, ::std::ostream* os);
 
-  explicit BlobDataItem(std::unique_ptr<DataElement> item);
-  BlobDataItem(std::unique_ptr<DataElement> item,
-               const scoped_refptr<DataHandle>& data_handle);
-  BlobDataItem(std::unique_ptr<DataElement> item,
-               const scoped_refptr<DataHandle>& data_handle,
-               disk_cache::Entry* entry,
-               int disk_cache_stream_index,
-               int disk_cache_side_stream_index);
   virtual ~BlobDataItem();
 
   std::unique_ptr<DataElement> item_;
   scoped_refptr<DataHandle> data_handle_;
 
   // This naked pointer is safe because the scope is protected by the DataHandle
   // instance for disk cache entries during the lifetime of this BlobDataItem.
   disk_cache::Entry* disk_cache_entry_;
   int disk_cache_stream_index_;  // For TYPE_DISK_CACHE_ENTRY.
   int disk_cache_side_stream_index_;  // For TYPE_DISK_CACHE_ENTRY.
 };
 
 STORAGE_EXPORT bool operator==(const BlobDataItem& a, const BlobDataItem& b);
 STORAGE_EXPORT bool operator!=(const BlobDataItem& a, const BlobDataItem& b);
 
 }  // namespace storage
 
 #endif  // STORAGE_BROWSER_BLOB_BLOB_DATA_ITEM_H_