bluetooth: WIP Advertising Data

third_party/WebKit/Source/modules/bluetooth/ManufacturerDataMap.h

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef ManufacturerDataMap_h
+#define ManufacturerDataMap_h
+
+#include "bindings/core/v8/Maplike.h"
+#include "bindings/core/v8/ScriptWrappable.h"
+#include "core/dom/DOMArrayBuffer.h"
+#include "platform/heap/Handle.h"
+
+namespace blink {
+
+class ExceptionState;
+class ScriptState;
+
+class ManufacturerDataMap final
+    : public GarbageCollected<ManufacturerDataMap>
+    , public ScriptWrappable
+    , public Maplike<unsigned short, RefPtr<DOMArrayBuffer>> {
+    DEFINE_WRAPPERTYPEINFO();
+public:
+    using MapEntry = std::pair<unsigned short, RefPtr<DOMArrayBuffer>>;
+
+    explicit ManufacturerDataMap()
+        : m_entries()
+        , m_keys()
+    {
+    }
+
+    // IDL attributes / methods
+    size_t size() const { return m_keys.size(); };
+
+    DEFINE_INLINE_TRACE()
+    {
+        visitor->trace(m_keys);
+        visitor->trace(m_entries);
+    }
+
+private:
+    // Required by the Iterable interface.
+    IterationSource* startIteration(ScriptState*, ExceptionState&) override
+    {
+        return new MapIterationSource(this);
+    }
+
+    // Required by the Maplike interface.
+    bool getMapEntry(ScriptState*, const unsigned short& key, RefPtr<DOMArrayBuffer>& value, ExceptionState&) override
+    {
+        auto it = m_keys.find(key);
+        if (it == m_keys.end()) {
+            return false;
+        }
+        value = m_entries[it->value].second;
+        return true;
+    }
+
+    // Map requires that the values are iterated over in the same order they
+    // were added so we keep a vector of the entries.
+    HeapVector<std::pair<unsigned short, RefPtr<DOMArrayBuffer>>> m_entries;
+    // Map requires sublinear access times so we keep a map of Company
+    // Identifier codes to the indices of the entries in the vector.
+    HeapHashMap<unsigned short, int> m_keys;
+
+    // Class used by Iterable to access the entries in the map.
+    // Note: This template class relies on the fact that m_map.m_entries will
+    // never be modified once it is created.
+    class MapIterationSource final : public PairIterable<unsigned short, RefPtr<DOMArrayBuffer>>::IterationSource {
+    public:
+        MapIterationSource(ManufacturerDataMap* map)
+            : m_map(map)
+            , m_current(0)
+        {
+        }
+
+        // Required by the IterationSource interface.
+        bool next(ScriptState*, unsigned short& key, RefPtr<DOMArrayBuffer>& value, ExceptionState&) override
+        {
+            if (m_current >= m_map->size()) {
+                return false;
+            }
+            const MapEntry& entry = m_map->m_entries[m_current];
+            key = entry.first;
+            value = entry.second;
+            m_current++;
+            return true;
+        }
+
+        DEFINE_INLINE_TRACE()
+        {
+            visitor->trace(m_map);
+        }
+    private:
+        // m_map needs to be kept alive while Javascript holds an iterator to it,
+        // so we make it a member.
+        const Member<ManufacturerDataMap> m_map;
+        size_t m_current;
+    };
+};
+
+} // namespace blink
+
+#endif // ManufacturerDataMap_h