dom/file/Blob.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_dom_Blob_h
   8 #define mozilla_dom_Blob_h
   9
  10 #include "mozilla/dom/BodyConsumer.h"
  11 #include "nsCycleCollectionParticipant.h"
  12 #include "nsCOMPtr.h"
  13 #include "nsWrapperCache.h"
  14 #include "nsWeakReference.h"
  15
  16 class nsIGlobalObject;
  17 class nsIInputStream;
  18
  19 namespace mozilla {
  20 class ErrorResult;
  21
  22 namespace dom {
  23
  24 struct BlobPropertyBag;
  25 class BlobImpl;
  26 class File;
  27 class GlobalObject;
  28 class OwningArrayBufferViewOrArrayBufferOrBlobOrUTF8String;
  29 class Promise;
  30
  31 class ReadableStream;
  32
  33 #define NS_DOM_BLOB_IID                              \
  34   {                                                  \
  35     0x648c2a83, 0xbdb1, 0x4a7d, {                    \
  36       0xb5, 0x0a, 0xca, 0xcd, 0x92, 0x87, 0x45, 0xc2 \
  37     }                                                \
  38   }
  39
  40 class Blob : public nsSupportsWeakReference, public nsWrapperCache {
  41  public:
  42   NS_DECL_CYCLE_COLLECTING_ISUPPORTS_FINAL
  43   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(Blob)
  44   NS_DECLARE_STATIC_IID_ACCESSOR(NS_DOM_BLOB_IID)
  45
  46   using BlobPart = OwningArrayBufferViewOrArrayBufferOrBlobOrUTF8String;
  47
  48   // This creates a Blob or a File based on the type of BlobImpl.
  49   static Blob* Create(nsIGlobalObject* aGlobal, BlobImpl* aImpl);
  50
  51   static already_AddRefed<Blob> CreateStringBlob(nsIGlobalObject* aGlobal,
  52                                                  const nsACString& aData,
  53                                                  const nsAString& aContentType);
  54
  55   // The returned Blob takes ownership of aMemoryBuffer. aMemoryBuffer will be
  56   // freed by free so it must be allocated by malloc or something
  57   // compatible with it.
  58   static already_AddRefed<Blob> CreateMemoryBlob(nsIGlobalObject* aGlobal,
  59                                                  void* aMemoryBuffer,
  60                                                  uint64_t aLength,
  61                                                  const nsAString& aContentType);
  62
  63   BlobImpl* Impl() const { return mImpl; }
  64
  65   bool IsFile() const;
  66
  67   const nsTArray<RefPtr<BlobImpl>>* GetSubBlobImpls() const;
  68
  69   // This method returns null if this Blob is not a File; it returns
  70   // the same object in case this Blob already implements the File interface;
  71   // otherwise it returns a new File object with the same BlobImpl.
  72   already_AddRefed<File> ToFile();
  73
  74   // This method creates a new File object with the given name and the same
  75   // BlobImpl.
  76   already_AddRefed<File> ToFile(const nsAString& aName, ErrorResult& aRv) const;
  77
  78   already_AddRefed<Blob> CreateSlice(uint64_t aStart, uint64_t aLength,
  79                                      const nsAString& aContentType,
  80                                      ErrorResult& aRv) const;
  81
  82   void CreateInputStream(nsIInputStream** aStream, ErrorResult& aRv) const;
  83
  84   int64_t GetFileId() const;
  85
  86   // A utility function that enforces the spec constraints on the type of a
  87   // blob: no codepoints outside the ASCII range (otherwise type becomes empty)
  88   // and lowercase ASCII only.  We can't just use our existing nsContentUtils
  89   // ASCII-related helpers because we need the "outside ASCII range" check, and
  90   // we can't use NS_IsAscii because its definition of "ASCII" (chars all <=
  91   // 0x7E) differs from the file API definition (which excludes control chars).
  92   static void MakeValidBlobType(nsAString& aType);
  93
  94   // WebIDL methods
  95   nsIGlobalObject* GetParentObject() const { return mGlobal; }
  96
  97   bool IsMemoryFile() const;
  98
  99   // Blob constructor
 100   static already_AddRefed<Blob> Constructor(
 101       const GlobalObject& aGlobal, const Optional<Sequence<BlobPart>>& aData,
 102       const BlobPropertyBag& aBag, ErrorResult& aRv);
 103
 104   JSObject* WrapObject(JSContext* aCx,
 105                        JS::Handle<JSObject*> aGivenProto) override;
 106
 107   uint64_t GetSize(ErrorResult& aRv);
 108
 109   void GetType(nsAString& aType);
 110
 111   void GetBlobImplType(nsAString& aBlobImplType);
 112
 113   already_AddRefed<Blob> Slice(const Optional<int64_t>& aStart,
 114                                const Optional<int64_t>& aEnd,
 115                                const Optional<nsAString>& aContentType,
 116                                ErrorResult& aRv);
 117
 118   size_t GetAllocationSize() const;
 119
 120   nsresult GetSendInfo(nsIInputStream** aBody, uint64_t* aContentLength,
 121                        nsACString& aContentType, nsACString& aCharset) const;
 122
 123   already_AddRefed<ReadableStream> Stream(JSContext* aCx,
 124                                           ErrorResult& aRv) const;
 125   already_AddRefed<Promise> Text(ErrorResult& aRv) const;
 126   already_AddRefed<Promise> ArrayBuffer(ErrorResult& aRv) const;
 127
 128  protected:
 129   // File constructor should never be used directly. Use Blob::Create instead.
 130   Blob(nsIGlobalObject* aGlobal, BlobImpl* aImpl);
 131   virtual ~Blob();
 132
 133   virtual bool HasFileInterface() const { return false; }
 134
 135   already_AddRefed<Promise> ConsumeBody(BodyConsumer::ConsumeType aConsumeType,
 136                                         ErrorResult& aRv) const;
 137
 138   // The member is the real backend implementation of this File/Blob.
 139   // It's thread-safe and not CC-able and it's the only element that is moved
 140   // between threads.
 141   // Note: we should not store any other state in this class!
 142   RefPtr<BlobImpl> mImpl;
 143
 144  private:
 145   nsCOMPtr<nsIGlobalObject> mGlobal;
 146 };
 147
 148 NS_DEFINE_STATIC_IID_ACCESSOR(Blob, NS_DOM_BLOB_IID)
 149
 150 // Override BindingJSObjectMallocBytes for blobs to tell the JS GC how much
 151 // memory is held live by the binding object.
 152 size_t BindingJSObjectMallocBytes(Blob* aBlob);
 153
 154 }  // namespace dom
 155 }  // namespace mozilla
 156
 157 inline nsISupports* ToSupports(mozilla::dom::Blob* aBlob) {
 158   return static_cast<nsISupportsWeakReference*>(aBlob);
 159 }
 160
 161 #endif  // mozilla_dom_Blob_h