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