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.
5 #ifndef ReadableStreamImpl_h
6 #define ReadableStreamImpl_h
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/dom/DOMArrayBuffer.h"
13 #include "core/streams/ReadableStream.h"
14 #include "wtf/Deque.h"
15 #include "wtf/RefPtr.h"
16 #include "wtf/text/WTFString.h"
20 // We define the default ChunkTypeTraits for frequently used types.
21 template<typename ChunkType>
22 class ReadableStreamChunkTypeTraits { };
25 class ReadableStreamChunkTypeTraits<String> {
27 typedef String HoldType;
28 typedef const String& PassType;
30 static size_t size(const String& value) { return value.length(); }
31 static ScriptValue toScriptValue(ScriptState* scriptState, const HoldType& value)
33 return ScriptValue(scriptState, v8String(scriptState->isolate(), value));
38 class ReadableStreamChunkTypeTraits<DOMArrayBuffer> {
40 typedef RefPtr<DOMArrayBuffer> HoldType;
41 typedef PassRefPtr<DOMArrayBuffer> PassType;
43 static size_t size(const PassType& value) { return value->byteLength(); }
44 static size_t size(const HoldType& value) { return value->byteLength(); }
45 static ScriptValue toScriptValue(ScriptState* scriptState, const HoldType& value)
47 return ScriptValue(scriptState, toV8NoInline(value.get(), scriptState->context()->Global(), scriptState->isolate()));
51 // ReadableStreamImpl<ChunkTypeTraits> is a ReadableStream subtype. It has a
52 // queue whose type depends on ChunkTypeTraits and it implements queue-related
53 // ReadableStream pure virtual methods.
54 template <typename ChunkTypeTraits>
55 class ReadableStreamImpl : public ReadableStream {
57 ReadableStreamImpl(ExecutionContext* executionContext, UnderlyingSource* source)
58 : ReadableStream(executionContext, source)
59 , m_totalQueueSize(0) { }
60 virtual ~ReadableStreamImpl() { }
62 // ReadableStream methods
63 virtual ScriptValue read(ScriptState*, ExceptionState&) override;
65 bool enqueue(typename ChunkTypeTraits::PassType);
67 virtual void trace(Visitor* visitor) override
69 ReadableStream::trace(visitor);
73 // ReadableStream methods
74 virtual bool isQueueEmpty() const override { return m_queue.isEmpty(); }
75 virtual void clearQueue() override
81 Deque<typename ChunkTypeTraits::HoldType> m_queue;
82 size_t m_totalQueueSize;
85 template <typename ChunkTypeTraits>
86 bool ReadableStreamImpl<ChunkTypeTraits>::enqueue(typename ChunkTypeTraits::PassType chunk)
88 size_t size = ChunkTypeTraits::size(chunk);
89 if (!enqueuePreliminaryCheck(size))
91 m_queue.append(chunk);
92 m_totalQueueSize += size;
93 return enqueuePostAction(m_totalQueueSize);
96 template <typename ChunkTypeTraits>
97 ScriptValue ReadableStreamImpl<ChunkTypeTraits>::read(ScriptState* scriptState, ExceptionState& exceptionState)
99 readPreliminaryCheck(exceptionState);
100 if (exceptionState.hadException())
101 return ScriptValue();
102 ASSERT(state() == Readable);
103 ASSERT(!m_queue.isEmpty());
104 typename ChunkTypeTraits::HoldType chunk = m_queue.takeFirst();
105 m_totalQueueSize -= ChunkTypeTraits::size(chunk);
107 return ChunkTypeTraits::toScriptValue(scriptState, chunk);
112 #endif // ReadableStreamImpl_h