Blob.h - mozsearch

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/* -*- 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_Blob_h

#define mozilla_dom_Blob_h

#include "mozilla/dom/BodyConsumer.h"

#include "nsCycleCollectionParticipant.h"

#include "nsCOMPtr.h"

#include "nsWrapperCache.h"

#include "nsWeakReference.h"

class nsIGlobalObject;

class nsIInputStream;

namespace mozilla {

class ErrorResult;

namespace dom {

struct BlobPropertyBag;

class BlobImpl;

class File;

class GlobalObject;

class OwningArrayBufferViewOrArrayBufferOrBlobOrUTF8String;

class Promise;

class ReadableStream;

#define NS_DOM_BLOB_IID                              \

  {                                                  \

    0x648c2a83, 0xbdb1, 0x4a7d, {                    \

      0xb5, 0x0a, 0xca, 0xcd, 0x92, 0x87, 0x45, 0xc2 \

    }                                                \

class Blob : public nsSupportsWeakReference, public nsWrapperCache {

 public:

  NS_DECL_CYCLE_COLLECTING_ISUPPORTS_FINAL

  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(Blob)

  NS_DECLARE_STATIC_IID_ACCESSOR(NS_DOM_BLOB_IID)

  using BlobPart = OwningArrayBufferViewOrArrayBufferOrBlobOrUTF8String;

  // This creates a Blob or a File based on the type of BlobImpl.

  static Blob* Create(nsIGlobalObject* aGlobal, BlobImpl* aImpl);

  static already_AddRefed<Blob> CreateStringBlob(nsIGlobalObject* aGlobal,

                                                 const nsACString& aData,

                                                 const nsAString& aContentType);

  // The returned Blob takes ownership of aMemoryBuffer. aMemoryBuffer will be

  // freed by free so it must be allocated by malloc or something

  // compatible with it.

  static already_AddRefed<Blob> CreateMemoryBlob(nsIGlobalObject* aGlobal,

                                                 void* aMemoryBuffer,

                                                 uint64_t aLength,

                                                 const nsAString& aContentType);

  BlobImpl* Impl() const { return mImpl; }

  bool IsFile() const;

  const nsTArray<RefPtr<BlobImpl>>* GetSubBlobImpls() const;

  // This method returns null if this Blob is not a File; it returns

  // the same object in case this Blob already implements the File interface;

  // otherwise it returns a new File object with the same BlobImpl.

  already_AddRefed<File> ToFile();

  // This method creates a new File object with the given name and the same

  // BlobImpl.

  already_AddRefed<File> ToFile(const nsAString& aName, ErrorResult& aRv) const;

  already_AddRefed<Blob> CreateSlice(uint64_t aStart, uint64_t aLength,

                                     const nsAString& aContentType,

                                     ErrorResult& aRv) const;

  void CreateInputStream(nsIInputStream** aStream, ErrorResult& aRv) const;

  int64_t GetFileId() const;

  // A utility function that enforces the spec constraints on the type of a

  // blob: no codepoints outside the ASCII range (otherwise type becomes empty)

  // and lowercase ASCII only.  We can't just use our existing nsContentUtils

  // ASCII-related helpers because we need the "outside ASCII range" check, and

  // we can't use NS_IsAscii because its definition of "ASCII" (chars all <=

  // 0x7E) differs from the file API definition (which excludes control chars).

  static void MakeValidBlobType(nsAString& aType);

  // WebIDL methods

  nsIGlobalObject* GetParentObject() const { return mGlobal; }

  bool IsMemoryFile() const;

  // Blob constructor

  static already_AddRefed<Blob> Constructor(

      const GlobalObject& aGlobal, const Optional<Sequence<BlobPart>>& aData,

      const BlobPropertyBag& aBag, ErrorResult& aRv);

  JSObject* WrapObject(JSContext* aCx,

                       JS::Handle<JSObject*> aGivenProto) override;

  uint64_t GetSize(ErrorResult& aRv);

  void GetType(nsAString& aType);

  void GetBlobImplType(nsAString& aBlobImplType);

  already_AddRefed<Blob> Slice(const Optional<int64_t>& aStart,

                               const Optional<int64_t>& aEnd,

                               const Optional<nsAString>& aContentType,

                               ErrorResult& aRv);

  size_t GetAllocationSize() const;

  nsresult GetSendInfo(nsIInputStream** aBody, uint64_t* aContentLength,

                       nsACString& aContentType, nsACString& aCharset) const;

  already_AddRefed<ReadableStream> Stream(JSContext* aCx,

                                          ErrorResult& aRv) const;

  already_AddRefed<Promise> Text(ErrorResult& aRv) const;

  already_AddRefed<Promise> ArrayBuffer(ErrorResult& aRv) const;

 protected:

  // File constructor should never be used directly. Use Blob::Create instead.

  Blob(nsIGlobalObject* aGlobal, BlobImpl* aImpl);

  virtual ~Blob();

  virtual bool HasFileInterface() const { return false; }

  already_AddRefed<Promise> ConsumeBody(BodyConsumer::ConsumeType aConsumeType,

                                        ErrorResult& aRv) const;

  // The member is the real backend implementation of this File/Blob.

  // It's thread-safe and not CC-able and it's the only element that is moved

  // between threads.

  // Note: we should not store any other state in this class!

  RefPtr<BlobImpl> mImpl;

 private:

  nsCOMPtr<nsIGlobalObject> mGlobal;

};

NS_DEFINE_STATIC_IID_ACCESSOR(Blob, NS_DOM_BLOB_IID)

// Override BindingJSObjectMallocBytes for blobs to tell the JS GC how much

// memory is held live by the binding object.

size_t BindingJSObjectMallocBytes(Blob* aBlob);

}  // namespace dom

}  // namespace mozilla

inline nsISupports* ToSupports(mozilla::dom::Blob* aBlob) {

  return static_cast<nsISupportsWeakReference*>(aBlob);

#endif  // mozilla_dom_Blob_h