[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..4f0bddffb79c2aefb48fbff0dfa84587000b3da9 100644
--- a/storage/browser/blob/blob_storage_registry.h
+++ b/storage/browser/blob/blob_storage_registry.h
@@ -16,6 +16,8 @@
 #include "base/containers/scoped_ptr_hash_map.h"
 #include "base/macros.h"
 #include "storage/browser/blob/internal_blob_data.h"
+#include "storage/browser/blob/blob_data_handle.h"
+#include "storage/browser/blob/blob_memory_controller.h"
 #include "storage/browser/storage_browser_export.h"
 #include "storage/common/blob_storage/blob_storage_constants.h"
 
@@ -48,30 +50,54 @@ class STORAGE_EXPORT BlobStorageRegistry {
     BROKEN
   };
 
+  struct STORAGE_EXPORT ItemCopyEntry {
+    ItemCopyEntry() {}
+    ItemCopyEntry(std::string uuid,
+                  size_t source_item_index,
+                  size_t source_item_offset,
+                  size_t dest_item_index,
+                  size_t size)
+        : uuid(uuid),
+          source_item_index(source_item_index),
+          source_item_offset(source_item_offset),
+          dest_item_index(dest_item_index),
+          size(size) {}
+
+    std::string uuid;
+
+    size_t source_item_index = 0;

[Marijn Kruisselbrink, 2016/06/29 22:42:21]

Would it be any cleaner/simpler if instead of uuid + item_indices you stored a
scoped_refptr<ShareableBlobDataItem> directly in ItemCopyEntry?

[dmurph, 2016/07/06 23:44:29]

hmmmmmmmm yeah probably ;)

+    size_t source_item_offset = 0;
+    size_t dest_item_index = 0;
+    size_t size = 0;
+  };
+
   struct STORAGE_EXPORT Entry {
-    size_t refcount;
-    BlobState state;
+    size_t refcount = 1;
+    BlobState state = BlobState::PENDING;
     std::vector<BlobConstructedCallback> 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
+    InternalBlobData data;
+    bool waiting_until_user_population = false;
 
+    // Metadata
     std::string content_type;
     std::string content_disposition;
 
-    Entry() = delete;
-    Entry(int refcount, BlobState state);
-    ~Entry();
+    bool can_fit_copies = true;
+    BlobMemoryController::PendingContructionEntry pending_copies_memory_entry;
+    std::vector<ItemCopyEntry> copies_from_built_reference;
+    std::vector<ItemCopyEntry> copies_to_when_built;

[michaeln, 2016/07/07 20:05:22]

How many of these fields are only relevant when the blob is PENDING?

 
-    // 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();