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// Copyright 2014 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 TerminatedArray_h
#define TerminatedArray_h
#include "wtf/Allocator.h"
#include "wtf/OwnPtr.h"
#include "wtf/Partitions.h"
namespace WTF {
// TerminatedArray<T> represents a sequence of elements of type T in which each
// element knows whether it is the last element in the sequence or not. For this
// check type T must provide isLastInArray method.
// TerminatedArray<T> can only be constructed by TerminatedArrayBuilder<T>.
template<typename T>
class TerminatedArray {
WTF_MAKE_NONCOPYABLE(TerminatedArray);
public:
T& at(size_t index) { return reinterpret_cast<T*>(this)[index]; }
const T& at(size_t index) const { return reinterpret_cast<const T*>(this)[index]; }
template<typename U>
class iterator_base {
public:
iterator_base& operator++()
{
if (m_val->isLastInArray()) {
m_val = 0;
} else {
++m_val;
}
return *this;
}
U& operator*() const { return *m_val; }
bool operator==(const iterator_base& other) const { return m_val == other.m_val; }
bool operator!=(const iterator_base& other) const { return !(*this == other); }
private:
iterator_base(U* val) : m_val(val) { }
U* m_val;
friend class TerminatedArray;
};
typedef iterator_base<T> iterator;
typedef iterator_base<const T> const_iterator;
iterator begin() { return iterator(reinterpret_cast<T*>(this)); }
const_iterator begin() const { return const_iterator(reinterpret_cast<const T*>(this)); }
iterator end() { return iterator(0); }
const_iterator end() const { return const_iterator(0); }
size_t size() const
{
size_t count = 0;
for (const_iterator it = begin(); it != end(); ++it)
count++;
return count;
}
// Match Allocator semantics to be able to use OwnPtr<TerminatedArray>.
void operator delete(void* p) { ::WTF::Partitions::fastFree(p); }
private:
// Allocator describes how TerminatedArrayBuilder should create new instances
// of TerminateArray and manage their lifetimes.
struct Allocator {
typedef PassOwnPtr<TerminatedArray> PassPtr;
typedef OwnPtr<TerminatedArray> Ptr;
static PassPtr create(size_t capacity)
{
return adoptPtr(static_cast<TerminatedArray*>(WTF::Partitions::fastMalloc(capacity * sizeof(T), WTF_HEAP_PROFILER_TYPE_NAME(T))));
}
static PassPtr resize(PassPtr ptr, size_t capacity)
{
return adoptPtr(static_cast<TerminatedArray*>(WTF::Partitions::fastRealloc(ptr.leakPtr(), capacity * sizeof(T), WTF_HEAP_PROFILER_TYPE_NAME(T))));
}
};
// Prohibit construction. Allocator makes TerminatedArray instances for
// TerminatedArrayBuilder by pointer casting.
TerminatedArray();
template<typename, template <typename> class> friend class TerminatedArrayBuilder;
};
} // namespace WTF
using WTF::TerminatedArray;
#endif // TerminatedArray_h