[BlobAsync] Disk support for blob storage

storage/browser/blob/blob_storage_registry.h

Index: storage/browser/blob/blob_storage_registry.h
diff --git a/storage/browser/blob/blob_storage_registry.h b/storage/browser/blob/blob_storage_registry.h
index 5211094b61a2bba35c6085525f865e4c2c27d96d..910b5b33c6b878857b44057812ef0e4e5abfa62a 100644
--- a/storage/browser/blob/blob_storage_registry.h
+++ b/storage/browser/blob/blob_storage_registry.h
@@ -15,6 +15,8 @@
 #include "base/callback_forward.h"
 #include "base/containers/scoped_ptr_hash_map.h"
 #include "base/macros.h"
+#include "storage/browser/blob/blob_data_handle.h"
+#include "storage/browser/blob/blob_memory_controller.h"
 #include "storage/browser/blob/internal_blob_data.h"
 #include "storage/browser/storage_browser_export.h"
 #include "storage/common/blob_storage/blob_storage_constants.h"
@@ -32,46 +34,47 @@ namespace storage {
 //   uuid. The user must keep track of these.
 class STORAGE_EXPORT BlobStorageRegistry {
  public:
-  // True means the blob was constructed successfully, and false means that
-  // there was an error, which is reported in the second argument.
-  using BlobConstructedCallback =
-      base::Callback<void(bool, IPCBlobCreationCancelCode)>;
-
-  enum class BlobState {
-    // The blob is pending transportation from the renderer. This is the default
-    // state on entry construction.
-    PENDING,
-    // The blob is complete and can be read from.
-    COMPLETE,
-    // The blob is broken and no longer holds data. This happens when there was
-    // a problem constructing the blob, or we've run out of memory.
-    BROKEN
+  struct STORAGE_EXPORT ItemCopyEntry {
+    ItemCopyEntry(scoped_refptr<ShareableBlobDataItem> source_item,
+                  size_t source_item_offset,
+                  scoped_refptr<ShareableBlobDataItem> dest_item);
+    ~ItemCopyEntry();
+    ItemCopyEntry(const ItemCopyEntry&);
+
+    scoped_refptr<ShareableBlobDataItem> source_item;
+    size_t source_item_offset = 0;
+    scoped_refptr<ShareableBlobDataItem> dest_item;
   };
 
   struct STORAGE_EXPORT Entry {
-    size_t refcount;
-    BlobState state;
-    std::vector<BlobConstructedCallback> build_completion_callbacks;
+    size_t refcount = 0;
+    BlobStatus status = BlobStatus::PENDING;
+    std::vector<BlobStatusCallback> build_completion_callbacks;
 
-    // Only applicable if the state == BROKEN.
-    IPCBlobCreationCancelCode broken_reason =
-        IPCBlobCreationCancelCode::UNKNOWN;
-
-    // data and data_builder are mutually exclusive.
-    std::unique_ptr<InternalBlobData> data;
-    std::unique_ptr<InternalBlobData::Builder> data_builder;
+    // Blob items. During construction these can be

[Marijn Kruisselbrink, 2016/07/12 21:33:07]

"these can be"?

[dmurph, 2016/07/14 01:04:31]

Done.

+    InternalBlobData data;
+    bool waiting_until_user_population = false;
+    BlobStatusCallback ready_for_user_population_callback;
 
+    // Metadata
     std::string content_type;
     std::string content_disposition;
 
-    Entry() = delete;
-    Entry(int refcount, BlobState state);
-    ~Entry();
+    // If the blob is destructed, we don't decrease memory in our manager unless
+    // this is true.
+    bool memory_accounted_for = false;
+    bool can_fit = true;
+    BlobMemoryController::PendingConstructionEntry pending_copies_memory_entry;
+    // These are copies from a referenced blob item to our blob items. Some of
+    // these entries may have changed from bytes to files if they were paged.
+    // We must handle this case.
+    std::vector<ItemCopyEntry> copies;
 
-    // Performs a test-and-set on the state of the given blob. If the state
-    // isn't as expected, we return false. Otherwise we set the new state and
-    // return true.
-    bool TestAndSetState(BlobState expected, BlobState set);
+    std::vector<std::unique_ptr<BlobDataHandle>> dependent_blobs;
+    size_t dependent_blobs_building = 0;
+
+    Entry();
+    ~Entry();
   };
 
   BlobStorageRegistry();