1 // Copyright 2014 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 ReadableStreamImpl_h
6 #define ReadableStreamImpl_h
7
8 #include "bindings/core/v8/ExceptionState.h"
9 #include "bindings/core/v8/ScriptState.h"
10 #include "bindings/core/v8/ScriptValue.h"
11 #include "bindings/core/v8/V8Binding.h"
12 #include "core/streams/ReadableStream.h"
13 #include "wtf/ArrayBuffer.h"
14 #include "wtf/Deque.h"
15 #include "wtf/Forward.h"
16 #include "wtf/OwnPtr.h"
17 #include "wtf/RefPtr.h"
18 #include "wtf/text/WTFString.h"
19
20 namespace blink {
21
22 // We define the default ChunkTypeTraits for frequently used types.
23 template<typename ChunkType>
24 class ReadableStreamChunkTypeTraits { };
25
26 template<>
27 class ReadableStreamChunkTypeTraits<String> {
28 public:
29 typedef String HoldType;
30 typedef const String& PassType;
31
size(const String & value)32 static size_t size(const String& value) { return value.length(); }
toScriptValue(ScriptState * scriptState,const HoldType & value)33 static ScriptValue toScriptValue(ScriptState* scriptState, const HoldType& value)
34 {
35 return ScriptValue(scriptState, v8String(scriptState->isolate(), value));
36 }
37 };
38
39 template<>
40 class ReadableStreamChunkTypeTraits<ArrayBuffer> {
41 public:
42 typedef RefPtr<ArrayBuffer> HoldType;
43 typedef PassRefPtr<ArrayBuffer> PassType;
44
size(const PassType & value)45 static size_t size(const PassType& value) { return value->byteLength(); }
size(const HoldType & value)46 static size_t size(const HoldType& value) { return value->byteLength(); }
toScriptValue(ScriptState * scriptState,const HoldType & value)47 static ScriptValue toScriptValue(ScriptState* scriptState, const HoldType& value)
48 {
49 return ScriptValue(scriptState, toV8NoInline(value.get(), scriptState->context()->Global(), scriptState->isolate()));
50 }
51 };
52
53 // ReadableStreamImpl<ChunkTypeTraits> is a ReadableStream subtype. It has a
54 // queue whose type depends on ChunkTypeTraits and it implements queue-related
55 // ReadableStream pure virtual methods.
56 template <typename ChunkTypeTraits>
57 class ReadableStreamImpl : public ReadableStream {
58 public:
ReadableStreamImpl(ExecutionContext * executionContext,UnderlyingSource * source)59 ReadableStreamImpl(ExecutionContext* executionContext, UnderlyingSource* source)
60 : ReadableStream(executionContext, source)
61 , m_totalQueueSize(0) { }
~ReadableStreamImpl()62 virtual ~ReadableStreamImpl() { }
63
64 // ReadableStream methods
65 virtual ScriptValue read(ScriptState*, ExceptionState&) OVERRIDE;
66
67 bool enqueue(typename ChunkTypeTraits::PassType);
68
trace(Visitor * visitor)69 virtual void trace(Visitor* visitor) OVERRIDE
70 {
71 ReadableStream::trace(visitor);
72 }
73
74 private:
75 // ReadableStream methods
isQueueEmpty()76 virtual bool isQueueEmpty() const OVERRIDE { return m_queue.isEmpty(); }
clearQueue()77 virtual void clearQueue() OVERRIDE
78 {
79 m_queue.clear();
80 m_totalQueueSize = 0;
81 }
82
83 Deque<typename ChunkTypeTraits::HoldType> m_queue;
84 size_t m_totalQueueSize;
85 };
86
87 template <typename ChunkTypeTraits>
enqueue(typename ChunkTypeTraits::PassType chunk)88 bool ReadableStreamImpl<ChunkTypeTraits>::enqueue(typename ChunkTypeTraits::PassType chunk)
89 {
90 size_t size = ChunkTypeTraits::size(chunk);
91 if (!enqueuePreliminaryCheck(size))
92 return false;
93 m_queue.append(chunk);
94 m_totalQueueSize += size;
95 return enqueuePostAction(m_totalQueueSize);
96 }
97
98 template <typename ChunkTypeTraits>
read(ScriptState * scriptState,ExceptionState & exceptionState)99 ScriptValue ReadableStreamImpl<ChunkTypeTraits>::read(ScriptState* scriptState, ExceptionState& exceptionState)
100 {
101 readPreliminaryCheck(exceptionState);
102 if (exceptionState.hadException())
103 return ScriptValue();
104 ASSERT(state() == Readable);
105 ASSERT(!m_queue.isEmpty());
106 typename ChunkTypeTraits::HoldType chunk = m_queue.takeFirst();
107 m_totalQueueSize -= ChunkTypeTraits::size(chunk);
108 readPostAction();
109 return ChunkTypeTraits::toScriptValue(scriptState, chunk);
110 }
111
112 } // namespace blink
113
114 #endif // ReadableStreamImpl_h
115
116