[go: nahoru, domu]

blob: 08400ecf467a9c13a6dcb4045ed307b703513523 [file] [log] [blame]
// Copyright (c) 2010 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 BASE_REF_COUNTED_MEMORY_H_
#define BASE_REF_COUNTED_MEMORY_H_
#pragma once
#include <vector>
#include "base/ref_counted.h"
// TODO(erg): The contents of this file should be in a namespace. This would
// require touching >100 files in chrome/ though.
// A generic interface to memory. This object is reference counted because one
// of its two subclasses own the data they carry, and we need to have
// heterogeneous containers of these two types of memory.
class RefCountedMemory : public base::RefCountedThreadSafe<RefCountedMemory> {
public:
// Retrieves a pointer to the beginning of the data we point to. If the data
// is empty, this will return NULL.
virtual const unsigned char* front() const = 0;
// Size of the memory pointed to.
virtual size_t size() const = 0;
protected:
friend class base::RefCountedThreadSafe<RefCountedMemory>;
RefCountedMemory();
virtual ~RefCountedMemory();
};
// An implementation of RefCountedMemory, where the ref counting does not
// matter.
class RefCountedStaticMemory : public RefCountedMemory {
public:
RefCountedStaticMemory()
: data_(NULL), length_(0) {}
RefCountedStaticMemory(const unsigned char* data, size_t length)
: data_(data), length_(length) {}
virtual const unsigned char* front() const;
virtual size_t size() const;
private:
const unsigned char* data_;
size_t length_;
DISALLOW_COPY_AND_ASSIGN(RefCountedStaticMemory);
};
// An implementation of RefCountedMemory, where we own our the data in a
// vector.
class RefCountedBytes : public RefCountedMemory {
public:
// Constructs a RefCountedBytes object by performing a swap. (To non
// destructively build a RefCountedBytes, use the constructor that takes a
// vector.)
static RefCountedBytes* TakeVector(std::vector<unsigned char>* to_destroy);
RefCountedBytes();
// Constructs a RefCountedBytes object by _copying_ from |initializer|.
RefCountedBytes(const std::vector<unsigned char>& initializer);
virtual const unsigned char* front() const;
virtual size_t size() const;
std::vector<unsigned char> data;
protected:
friend class base::RefCountedThreadSafe<RefCountedBytes>;
virtual ~RefCountedBytes();
private:
DISALLOW_COPY_AND_ASSIGN(RefCountedBytes);
};
#endif // BASE_REF_COUNTED_MEMORY_H_