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