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

storage/browser/blob/internal_blob_data.cc

Index: storage/browser/blob/internal_blob_data.cc
diff --git a/storage/browser/blob/internal_blob_data.cc b/storage/browser/blob/internal_blob_data.cc
new file mode 100644
index 0000000000000000000000000000000000000000..8107765c847c707d9e9bc2ad48d681b048470f53
--- /dev/null
+++ b/storage/browser/blob/internal_blob_data.cc
@@ -0,0 +1,110 @@
+// Copyright 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.
+
+#include "storage/browser/blob/internal_blob_data.h"
+
+#include "base/containers/hash_tables.h"
+#include "base/metrics/histogram.h"
+#include "storage/browser/blob/blob_data_item.h"
+#include "storage/common/data_element.h"
+
+namespace storage {
+
+InternalBlobData::Builder::Builder() : data_(new InternalBlobData()) {
+}
+InternalBlobData::Builder::~Builder() {
+}
+
+void InternalBlobData::Builder::AppendSharedBlobItem(
+    scoped_refptr<ShareableBlobDataItem> item) {
+  DCHECK(item);
+  DCHECK(data_);
+  data_->items_.push_back(item);
+}
+
+void InternalBlobData::Builder::RemoveBlobFromShareableItems(
+    const std::string& blob_uuid) {
+  DCHECK(data_);
+  data_->RemoveBlobFromShareableItems(blob_uuid);
+}
+
+void InternalBlobData::Builder::set_content_type(
+    const std::string& content_type) {
+  DCHECK(data_);
+  data_->content_type_ = content_type;
+}
+
+void InternalBlobData::Builder::set_content_disposition(
+    const std::string& content_disposition) {
+  DCHECK(data_);
+  data_->content_disposition_ = content_disposition;
+}
+
+size_t InternalBlobData::Builder::GetNonsharedMemoryUsage() const {
+  DCHECK(data_);
+  return data_->GetUnsharedMemoryUsage();
+}
+
+scoped_ptr<InternalBlobData> InternalBlobData::Builder::Build() {
+  DCHECK(data_);
+  return data_.Pass();
+}
+
+InternalBlobData::InternalBlobData() {
+}
+
+InternalBlobData::~InternalBlobData() {
+}
+
+const std::vector<scoped_refptr<ShareableBlobDataItem>>&
+InternalBlobData::items() const {
+  return items_;
+}
+const std::string& InternalBlobData::content_type() const {
+  return content_type_;
+}
+const std::string& InternalBlobData::content_disposition() const {
+  return content_disposition_;
+}
+
+void InternalBlobData::RemoveBlobFromShareableItems(
+    const std::string& blob_uuid) {
+  for (auto& data_item : items_) {
+    data_item->referencing_blobs().erase(blob_uuid);
+  }
+}
+
+size_t InternalBlobData::GetUnsharedMemoryUsage() const {
+  size_t memory = 0;
+  base::hash_set<void*> seen_items;
+  for (const auto& data_item : items_) {
+    if (data_item->item()->type() != DataElement::TYPE_BYTES ||
+        data_item->referencing_blobs().size() > 1 ||
+        seen_items.find(data_item.get()) != seen_items.end()) {
+      continue;
+    }
+    memory += data_item->item()->length();
+    seen_items.insert(data_item.get());
+  }
+  return memory;
+}
+
+void InternalBlobData::GetMemoryUsage(size_t* total_memory,
+                                      size_t* unshared_memory) {
+  *total_memory = 0;
+  *unshared_memory = 0;
+  base::hash_set<void*> seen_items;
+  for (const auto& data_item : items_) {
+    if (data_item->item()->type() == DataElement::TYPE_BYTES) {
+      *total_memory += data_item->item()->length();
+      if (data_item->referencing_blobs().size() == 1 ||
+          seen_items.find(data_item.get()) == seen_items.end()) {
+        *unshared_memory += data_item->item()->length();
+        seen_items.insert(data_item.get());
+      }
+    }
+  }
+}
+
+}  // namespace storage