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

storage/browser/blob/internal_blob_data.h

+// TODO: Insert description here. (generated by dmurph)

[michaeln, 2015/02/05 22:58:47]

copyright headers please

[dmurph, 2015/02/06 01:32:30]

Done.

+
+#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 {
+
+// This class represents a blob in the BlobStorageContext. The
+// SharableBlobDataItem it contains must not have their refcounts modified
+// anywhere but through storage in this class, as the calls to
+// GetNonsharedMemoryUsage rely on the refcount number referring to the number
+// of blobs that have the given item.
+class InternalBlobData {
+ public:
+  class Builder {

[michaeln, 2015/02/05 22:58:47]

It may be more clear to compose this differently? Either by derivation or
aggregation.

class InternalBD;
class MutableInternalBD : InternalBD;

class InternalBD;
class Builder {
  InternalBD* thing_being_built;
}

As coded InternalBlobData and its inner Builder as essentially the same, they
have the same data members and they have the same methods (with method bodies
being reused in a non-object oriented way in the .cc file). Also the two
different 'builder' classes tripped me up on my first read thru since both kinds
are used in certain methods (and a 2nd builder in this set of classes surprised
me).

[dmurph, 2015/02/06 01:32:30]

Done, let me know what you think.

+   public:
+    Builder();
+    ~Builder();
+
+    void AppendSharedBlobItem(scoped_refptr<ShareableBlobDataItem> item);
+
+    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);
+
+    void set_content_type(const std::string& content_type) {
+      content_type_ = content_type;
+    }
+
+    void set_content_disposition(const std::string& content_disposition) {
+      content_disposition_ = content_disposition;
+    }
+
+   private:
+    friend class InternalBlobData;
+
+    std::string content_type_;
+    std::string content_disposition_;
+    std::vector<scoped_refptr<ShareableBlobDataItem>> items_;
+  };
+
+  ~InternalBlobData();
+
+  // 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;
+
+  size_t GetNonsharedMemoryUsage() const;
+
+ private:
+  friend class BlobStorageContext;
+  // Consumes the items in the builder, leaving it empty.
+  InternalBlobData(scoped_ptr<Builder> builder);
+
+  std::string content_type_;
+  std::string content_disposition_;
+  std::vector<scoped_refptr<ShareableBlobDataItem>> items_;
+
+  DISALLOW_COPY_AND_ASSIGN(InternalBlobData);
+};
+
+}  // namespace storage
+#endif  // STORAGE_BROWSER_BLOB_INTERNAL_BLOB_DATA_H_