1 // Copyright 2018 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_LOADER_FETCH_DATA_PIPE_BYTES_CONSUMER_H_
6 #define THIRD_PARTY_BLINK_RENDERER_PLATFORM_LOADER_FETCH_DATA_PIPE_BYTES_CONSUMER_H_
7 
8 #include <memory>
9 
10 #include "base/memory/scoped_refptr.h"
11 #include "mojo/public/cpp/system/data_pipe.h"
12 #include "mojo/public/cpp/system/simple_watcher.h"
13 #include "third_party/blink/renderer/platform/heap/handle.h"
14 #include "third_party/blink/renderer/platform/loader/fetch/bytes_consumer.h"
15 #include "third_party/blink/renderer/platform/platform_export.h"
16 #include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
17 
18 namespace base {
19 class SingleThreadTaskRunner;
20 }  // namespace base
21 
22 namespace blink {
23 
24 // An adapter for mojo::DataPipe. As mojo::DataPipe lacks signals completion and
25 // error signals, we define another interface, CompletionNotifier, for the
26 // signals.
27 class PLATFORM_EXPORT DataPipeBytesConsumer final : public BytesConsumer {
28   USING_PRE_FINALIZER(DataPipeBytesConsumer, Dispose);
29 
30  public:
31   class PLATFORM_EXPORT CompletionNotifier final
32       : public GarbageCollected<CompletionNotifier> {
33    public:
CompletionNotifier(DataPipeBytesConsumer * bytes_consumer)34     explicit CompletionNotifier(DataPipeBytesConsumer* bytes_consumer)
35         : bytes_consumer_(bytes_consumer) {}
36 
37     // One of these methods must be called to signal the end of the data
38     // stream.  We cannot assume that the end of the pipe completes the
39     // stream successfully since errors can occur after the last byte is
40     // written into the pipe.
41     void SignalComplete();
42     void SignalError(const BytesConsumer::Error& error);
43     void Trace(Visitor*);
44 
45    private:
46     const WeakMember<DataPipeBytesConsumer> bytes_consumer_;
47   };
48 
49   DataPipeBytesConsumer(scoped_refptr<base::SingleThreadTaskRunner> task_runner,
50                         mojo::ScopedDataPipeConsumerHandle,
51                         CompletionNotifier** notifier);
52   ~DataPipeBytesConsumer() override;
53 
54   Result BeginRead(const char** buffer, size_t* available) override;
55   Result EndRead(size_t read_size) override;
56   mojo::ScopedDataPipeConsumerHandle DrainAsDataPipe() override;
57   void SetClient(BytesConsumer::Client*) override;
58   void ClearClient() override;
59 
60   void Cancel() override;
61   PublicState GetPublicState() const override;
GetError()62   Error GetError() const override {
63     DCHECK(state_ == InternalState::kErrored);
64     return error_;
65   }
DebugName()66   String DebugName() const override { return "DataPipeBytesConsumer"; }
67 
68   void Trace(Visitor*) override;
69 
70  private:
71   bool IsReadableOrWaiting() const;
72   void MaybeClose();
73   void SetError(const Error& error);
74   void Notify(MojoResult);
75   void ClearDataPipe();
76   void SignalComplete();
77   void SignalError(const Error& error);
78   void Dispose();
79 
80   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
81   mojo::ScopedDataPipeConsumerHandle data_pipe_;
82   mojo::SimpleWatcher watcher_;
83   Member<BytesConsumer::Client> client_;
84   InternalState state_ = InternalState::kWaiting;
85   Error error_;
86   bool is_in_two_phase_read_ = false;
87   bool has_pending_notification_ = false;
88   bool has_pending_complete_ = false;
89   bool has_pending_error_ = false;
90   bool completion_signaled_ = false;
91 };
92 
93 }  // namespace blink
94 
95 #endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_LOADER_FETCH_DATA_PIPE_BYTES_CONSUMER_H_
96