Bug 1321261 - create dom/file for File APIs, r=qdot

dom/file/MutableBlobStorage.h

@@ -0,0 +1,98 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_MutableBlobStorage_h
+#define mozilla_dom_MutableBlobStorage_h
+
+#include "mozilla/RefPtr.h"
+#include "prio.h"
+
+namespace mozilla {
+namespace dom {
+
+class Blob;
+class BlobImpl;
+class MutableBlobStorage;
+
+class MutableBlobStorageCallback
+{
+public:
+  NS_IMETHOD_(MozExternalRefCountType) AddRef(void) = 0;
+
+  NS_IMETHOD_(MozExternalRefCountType) Release(void) = 0;
+
+  virtual void BlobStoreCompleted(MutableBlobStorage* aBlobStorage,
+                                  Blob* aBlob,
+                                  nsresult aRv) = 0;
+};
+
+// This class is main-thread only.
+class MutableBlobStorage final
+{
+public:
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(MutableBlobStorage);
+
+  enum MutableBlobStorageType
+  {
+    eOnlyInMemory,
+    eCouldBeInTemporaryFile,
+  };
+
+  explicit MutableBlobStorage(MutableBlobStorageType aType);
+
+  nsresult Append(const void* aData, uint32_t aLength);
+
+  // This method can be called just once.
+  // The callback will be called when the Blob is ready.
+  // The return value is the total size of the blob, when created.
+  uint64_t GetBlobWhenReady(nsISupports* aParent,
+                            const nsACString& aContentType,
+                            MutableBlobStorageCallback* aCallback);
+
+  void TemporaryFileCreated(PRFileDesc* aFD);
+
+  void  CreateBlobAndRespond(already_AddRefed<nsISupports> aParent,
+                             const nsACString& aContentType,
+                             already_AddRefed<MutableBlobStorageCallback> aCallback);
+
+  void ErrorPropagated(nsresult aRv);
+
+private:
+  ~MutableBlobStorage();
+
+  bool ExpandBufferSize(uint64_t aSize);
+
+  bool ShouldBeTemporaryStorage(uint64_t aSize) const;
+
+  nsresult MaybeCreateTemporaryFile();
+
+  static nsresult DispatchToIOThread(Runnable* aRunnable);
+
+  // All these variables are touched on the main thread only.
+
+  void* mData;
+  uint64_t mDataLen;
+  uint64_t mDataBufferLen;
+
+  enum StorageState {
+    eKeepInMemory,
+    eInMemory,
+    eWaitingForTemporaryFile,
+    eInTemporaryFile,
+    eClosed
+  };
+
+  StorageState mStorageState;
+
+  PRFileDesc* mFD;
+
+  nsresult mErrorResult;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_MutableBlobStorage_h