[BlobAsync] Disk support for blob storage

storage/browser/blob/blob_flattener.cc

+// TODO: Insert description here. (generated by dmurph)
+
+#include "storage/browser/blob/blob_flattener.h"
+
+#include <utility>
+
+#include "storage/browser/blob/blob_async_transport_request_builder.h"
+#include "storage/browser/blob/blob_data_builder.h"
+#include "storage/browser/blob/blob_storage_context.h"
+#include "storage/browser/blob/blob_storage_registry.h"
+#include "storage/browser/blob/shareable_blob_data_item.h"
+
+namespace storage {
+namespace {
+using ItemCopyEntry = BlobStorageRegistry::ItemCopyEntry;
+
+bool IsBytes(DataElement::Type type) {
+  return type == DataElement::TYPE_BYTES ||
+         type == DataElement::TYPE_BYTES_DESCRIPTION;
+}
+
+}  // namespace
+
+void BlobFlattener::FlattenBlob(
+    const std::string& uuid,
+    InternalBlobData* output_blob,
+    std::vector<BlobStorageRegistry::ItemCopyEntry>* copies_from_built_ref,
+    std::vector<BlobStorageRegistry::ItemCopyEntry>* copies_from_pending_ref,
+    std::map<std::string, BlobSlice> slice_map,
+    const BlobDataBuilder& transportation_result) {
+  const std::vector<scoped_refptr<BlobDataItem>>& transport_items =
+      transportation_result.items_;
+
+  size_t blob_flattening_index_offset = 0;

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

You're not using this for anything?

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

Removed thanks.

+  size_t current_browser_index = 0;
+  for (size_t transport_item_index = 0;
+       transport_item_index < transport_items.size(); transport_item_index++) {
+    scoped_refptr<BlobDataItem> transport_item =
+        transport_items[transport_item_index];
+
+    if (IsBytes(transport_item->type())) {
+      output_blob->AppendSharedBlobItem(
+          uuid,
+          new ShareableBlobDataItem(BlobStorageContext::GetAndIncrementItemId(),
+                                    std::move(transport_item)));
+      current_browser_index++;
+    } else if (transport_item->type() == DataElement::TYPE_BLOB) {
+      BlobSlice& slice = slice_map[transport_item->blob_uuid()];
+      std::vector<BlobStorageRegistry::ItemCopyEntry>* copies =
+          slice.done_building() ? copies_from_built_ref

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

is done_building() her the right thing to do? Or can you just get rid of
done_building completely and instead decide on the type() of the item being
sliced which list to add to? (TYPE_BYTES added to copies_from_built_ref and
TYPE_BYTES_DESCRIPTION added to copies_from_pending_ref)? Or I might be
misunderstanding how this works.

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

I can remove this now, especially because I no longer do the map for blob
slices.

+                                : copies_from_pending_ref;
+      if (slice.has_sliced_first_memory_item()) {
+        copies->push_back(ItemCopyEntry(
+            transport_item->blob_uuid(), slice.first_item_index(),
+            slice.first_item_slice_offset(), current_browser_index,
+            slice.items().front()->item()->length()));
+      }
+
+      for (const auto& shareable_item : slice.items()) {
+        output_blob->AppendSharedBlobItem(uuid, std::move(shareable_item));
+        ++current_browser_index;
+        ++blob_flattening_index_offset;
+      }
+      --blob_flattening_index_offset;
+
+      if (slice.has_sliced_last_memory_item()) {
+        copies->push_back(ItemCopyEntry(
+            transport_item->blob_uuid(), slice.last_item_index(), 0,
+            current_browser_index - 1, slice.items().back()->item()->length()));
+      }
+    } else {
+      output_blob->AppendSharedBlobItem(
+          uuid,
+          new ShareableBlobDataItem(BlobStorageContext::GetAndIncrementItemId(),
+                                    std::move(transport_item)));
+      current_browser_index++;
+    }
+  }
+}
+
+}  // namespace storage