[Storage] Blob items are now shared between blobs. Ready for disk swap.

storage/browser/blob/internal_blob_data.h

Index: storage/browser/blob/internal_blob_data.h
diff --git a/storage/browser/blob/internal_blob_data.h b/storage/browser/blob/internal_blob_data.h
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+// 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_INTERNAL_BLOB_DATA_H_
+#define STORAGE_BROWSER_BLOB_INTERNAL_BLOB_DATA_H_
+
+#include <string>
+#include <vector>
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "storage/browser/blob/shareable_blob_data_item.h"
+
+namespace storage {
+class ViewBlobInternalsJob;
+
+// This class represents a blob in the BlobStorageContext.  It is constructed
+// using the internal Builder class.
+class InternalBlobData {
+ public:
+  ~InternalBlobData();
+
+ protected:
+  friend class BlobStorageContext;
+  friend class ViewBlobInternalsJob;
+
+  // Removes the given blob uuid from the internal ShareableBlobDataItems.
+  // This is called when this blob is being destroyed.
+  void RemoveBlobFromShareableItems(const std::string& blob_uuid);
+
+  const std::vector<scoped_refptr<ShareableBlobDataItem>>& items() const;
+  const std::string& content_type() const;
+  const std::string& content_disposition() const;
+
+  // Gets the memory used by this blob that is not shared by other blobs.
+  size_t GetNonsharedMemoryUsage() const;
+
+  // Includes memory of items possibly shared with other blobs, or items that
+  // appear multiple times in this blob.
+  size_t GetTotalMemoryUsage() const;
+
+ private:
+  friend class Builder;
+  InternalBlobData();
+
+  std::string content_type_;
+  std::string content_disposition_;
+  std::vector<scoped_refptr<ShareableBlobDataItem>> items_;
+
+  class Builder {
+   public:
+    Builder();
+    ~Builder();
+
+    void AppendSharedBlobItem(scoped_refptr<ShareableBlobDataItem> item);
+    void set_content_type(const std::string& content_type);
+    void set_content_disposition(const std::string& content_disposition);
+
+    // Gets the memory used by this builder that is not shared with other blobs.
+    size_t GetNonsharedMemoryUsage() const;
+
+    // Removes the given blob uuid from the internal ShareableBlobDataItems.
+    // This is called on destruction of the blob if we're still building it.
+    void RemoveBlobFromShareableItems(const std::string& blob_uuid);
+
+    // The builder is invalid after calling this method.
+    scoped_ptr<::storage::InternalBlobData> Build();
+
+   private:
+    scoped_ptr<::storage::InternalBlobData> data_;
+  };
+
+  DISALLOW_COPY_AND_ASSIGN(InternalBlobData);
+};
+
+}  // namespace storage
+#endif  // STORAGE_BROWSER_BLOB_INTERNAL_BLOB_DATA_H_