[BlobAsync] Patch 2: Common Constants

storage/common/blob_storage/blob_item_bytes_request.h

Index: storage/common/blob_storage/blob_item_bytes_request.h
diff --git a/storage/common/blob_storage/blob_item_bytes_request.h b/storage/common/blob_storage/blob_item_bytes_request.h
new file mode 100644
index 0000000000000000000000000000000000000000..8cc7cd96d70ed236822d95b815a112bb3a02b74f
--- /dev/null
+++ b/storage/common/blob_storage/blob_item_bytes_request.h
@@ -0,0 +1,120 @@
+// 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.
+
+#ifndef STORAGE_COMMON_FILEAPI_BLOB_ITEM_BYTES_REQUEST_H_
+#define STORAGE_COMMON_FILEAPI_BLOB_ITEM_BYTES_REQUEST_H_
+
+#include <stdint.h>
+#include <ostream>
+
+#include "base/basictypes.h"
+#include "storage/common/blob_storage/blob_storage_constants.h"
+#include "storage/common/storage_common_export.h"
+
+namespace storage {
+
+// This class is serialized over IPC to request bytes from a blob item.
+struct STORAGE_COMMON_EXPORT BlobItemBytesRequest {
+  // not using std::numeric_limits<T>::max() because of non-C++11 builds.

[kinuko, 2015/10/20 10:06:22]

nit: not -> Not

[dmurph, 2015/10/20 18:28:27]

Done.

+  static const size_t kInvalidIndex = SIZE_MAX;
+  static const uint64_t kInvalidSize = kuint64max;
+
+  static BlobItemBytesRequest CreateIPCRequest(size_t request_number,
+                                               size_t renderer_item_index,
+                                               size_t renderer_item_offset,
+                                               size_t size) {
+    return BlobItemBytesRequest(request_number, IPCBlobItemRequestStrategy::IPC,
+                                renderer_item_index, renderer_item_offset, size,
+                                kInvalidIndex, kInvalidSize);
+  }
+
+  static BlobItemBytesRequest CreateSharedMemoryRequest(
+      size_t request_number,
+      size_t renderer_item_index,
+      size_t renderer_item_offset,
+      size_t size,
+      size_t handle_index,
+      uint64_t handle_offset) {
+    return BlobItemBytesRequest(request_number,
+                                IPCBlobItemRequestStrategy::SHARED_MEMORY,
+                                renderer_item_index, renderer_item_offset, size,
+                                handle_index, handle_offset);
+  }
+
+  static BlobItemBytesRequest CreateFileRequest(size_t request_number,
+                                                size_t renderer_item_index,
+                                                uint64_t renderer_item_offset,
+                                                uint64_t size,
+                                                size_t handle_index,
+                                                uint64_t handle_offset) {
+    return BlobItemBytesRequest(
+        request_number, IPCBlobItemRequestStrategy::FILE, renderer_item_index,
+        renderer_item_offset, size, handle_index, handle_offset);
+  }
+
+  BlobItemBytesRequest()
+      : request_number(kInvalidIndex),
+        transport_strategy(IPCBlobItemRequestStrategy::UNKNOWN),
+        renderer_item_index(kInvalidIndex),
+        renderer_item_offset(kInvalidSize),
+        size(kInvalidSize),
+        handle_index(kInvalidIndex),
+        handle_offset(kInvalidSize) {}
+  ~BlobItemBytesRequest() {}
+
+  BlobItemBytesRequest(size_t request_number,
+                       IPCBlobItemRequestStrategy transport_strategy,
+                       size_t renderer_item_index,
+                       uint64_t renderer_item_offset,
+                       uint64_t size,
+                       size_t handle_index,
+                       uint64_t handle_offset)
+      : request_number(request_number),
+        transport_strategy(transport_strategy),
+        renderer_item_index(renderer_item_index),
+        renderer_item_offset(renderer_item_offset),
+        size(size),
+        handle_index(handle_index),
+        handle_offset(handle_offset) {}
+
+  size_t request_number;

[kinuko, 2015/10/20 10:06:22]

Is request_number something like a seq number for this request? The combination
of size_t type and this name makes it a little difficult for me to guess what
this is for.

[dmurph, 2015/10/20 18:28:27]

Not really, it's used by the blob async transportation system to keep track of
memory requests and responses (we need a separate index, as we can have multiple
requests per renderer item and multiple requests per browser item). I added a
comment to clarify.

+  IPCBlobItemRequestStrategy transport_strategy;
+  size_t renderer_item_index;
+  uint64_t renderer_item_offset;
+  uint64_t size;
+  size_t handle_index;
+  uint64_t handle_offset;
+};
+
+#if defined(UNIT_TEST)
+STORAGE_COMMON_EXPORT inline bool operator==(const BlobItemBytesRequest& a,
+                                             const BlobItemBytesRequest& b) {
+  return a.request_number == b.request_number &&
+         a.transport_strategy == b.transport_strategy &&
+         a.renderer_item_index == b.renderer_item_index &&
+         a.renderer_item_offset == b.renderer_item_offset && a.size == b.size &&
+         a.handle_index == b.handle_index && a.handle_offset == b.handle_offset;
+}
+
+STORAGE_COMMON_EXPORT inline bool operator!=(const BlobItemBytesRequest& a,
+                                             const BlobItemBytesRequest& b) {
+  return !(a == b);
+}
+
+STORAGE_COMMON_EXPORT inline ::std::ostream& operator<<(
+    ::std::ostream& os,
+    const BlobItemBytesRequest& request) {
+  os << "{ request_number: " << request.request_number
+     << ", transport_strategy: " << static_cast<int>(request.transport_strategy)
+     << ", renderer_item_index: " << request.renderer_item_index
+     << ", renderer_item_offset: " << request.renderer_item_offset
+     << ", size: " << request.size << ", handle_index: " << request.handle_index
+     << ", handle_offset: " << request.handle_offset << " }";
+  return os;
+}
+#endif  // defined(UNIT_TEST)
+
+}  // namespace storage
+
+#endif  // STORAGE_COMMON_FILEAPI_BLOB_ITEM_BYTES_REQUEST_H_