dom/streams/ReadableStreamDefaultReader.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim:set ts=2 sw=2 sts=2 et cindent: */
   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_ReadableStreamDefaultReader_h
   8 #define mozilla_dom_ReadableStreamDefaultReader_h
   9
  10 #include "js/TypeDecls.h"
  11 #include "mozilla/Attributes.h"
  12 #include "mozilla/ErrorResult.h"
  13 #include "mozilla/dom/BindingDeclarations.h"
  14 #include "mozilla/dom/ReadableStreamGenericReader.h"
  15 #include "mozilla/dom/ReadRequest.h"
  16 #include "nsCycleCollectionParticipant.h"
  17 #include "nsISupports.h"
  18 #include "nsWrapperCache.h"
  19 #include "mozilla/LinkedList.h"
  20
  21 namespace mozilla::dom {
  22
  23 class Promise;
  24 class ReadableStream;
  25
  26 // https://streams.spec.whatwg.org/#default-reader-read
  27 struct Read_ReadRequest : public ReadRequest {
  28  public:
  29   NS_DECL_ISUPPORTS_INHERITED
  30   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(Read_ReadRequest, ReadRequest)
  31
  32   RefPtr<Promise> mPromise;
  33
  34   explicit Read_ReadRequest(Promise* aPromise) : mPromise(aPromise) {}
  35
  36   void ChunkSteps(JSContext* aCx, JS::Handle<JS::Value> aChunk,
  37                   ErrorResult& aRv) override;
  38
  39   void CloseSteps(JSContext* aCx, ErrorResult& aRv) override;
  40
  41   void ErrorSteps(JSContext* aCx, JS::Handle<JS::Value> e,
  42                   ErrorResult& aRv) override;
  43
  44  protected:
  45   ~Read_ReadRequest() override = default;
  46 };
  47
  48 class ReadableStreamDefaultReader final : public ReadableStreamGenericReader,
  49                                           public nsWrapperCache
  50
  51 {
  52  public:
  53   NS_DECL_ISUPPORTS_INHERITED
  54   NS_DECL_CYCLE_COLLECTION_WRAPPERCACHE_CLASS_INHERITED(
  55       ReadableStreamDefaultReader, ReadableStreamGenericReader)
  56
  57  public:
  58   explicit ReadableStreamDefaultReader(nsISupports* aGlobal);
  59
  60  protected:
  61   ~ReadableStreamDefaultReader() override;
  62
  63  public:
  64   bool IsDefault() override { return true; }
  65   bool IsBYOB() override { return false; }
  66   ReadableStreamDefaultReader* AsDefault() override { return this; }
  67   ReadableStreamBYOBReader* AsBYOB() override {
  68     MOZ_CRASH();
  69     return nullptr;
  70   }
  71
  72   // Public functions to implement other specs
  73   // https://streams.spec.whatwg.org/#other-specs-rs-create
  74
  75   // The following algorithms can be used on arbitrary ReadableStream instances,
  76   // including ones that are created by web developers. They can all fail in
  77   // various operation-specific ways, and these failures should be handled by
  78   // the calling specification.
  79
  80   // https://streams.spec.whatwg.org/#readablestreamdefaultreader-read-a-chunk
  81   MOZ_CAN_RUN_SCRIPT void ReadChunk(JSContext* aCx, ReadRequest& aRequest,
  82                                     ErrorResult& aRv);
  83
  84   // IDL layer functions
  85
  86   JSObject* WrapObject(JSContext* aCx,
  87                        JS::Handle<JSObject*> aGivenProto) override;
  88
  89   // IDL methods
  90
  91   static already_AddRefed<ReadableStreamDefaultReader> Constructor(
  92       const GlobalObject& aGlobal, ReadableStream& stream, ErrorResult& aRv);
  93
  94   MOZ_CAN_RUN_SCRIPT already_AddRefed<Promise> Read(ErrorResult& aRv);
  95
  96   void ReleaseLock(ErrorResult& aRv);
  97
  98   LinkedList<RefPtr<ReadRequest>>& ReadRequests() { return mReadRequests; }
  99
 100  private:
 101   LinkedList<RefPtr<ReadRequest>> mReadRequests = {};
 102 };
 103
 104 namespace streams_abstract {
 105
 106 void SetUpReadableStreamDefaultReader(ReadableStreamDefaultReader* aReader,
 107                                       ReadableStream* aStream,
 108                                       ErrorResult& aRv);
 109
 110 void ReadableStreamDefaultReaderErrorReadRequests(
 111     JSContext* aCx, ReadableStreamDefaultReader* aReader,
 112     JS::Handle<JS::Value> aError, ErrorResult& aRv);
 113
 114 void ReadableStreamDefaultReaderRelease(JSContext* aCx,
 115                                         ReadableStreamDefaultReader* aReader,
 116                                         ErrorResult& aRv);
 117
 118 }  // namespace streams_abstract
 119
 120 }  // namespace mozilla::dom
 121
 122 #endif  // mozilla_dom_ReadableStreamDefaultReader_h