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Diffstat (limited to 'base/ref_counted_memory.h')
-rw-r--r-- | base/ref_counted_memory.h | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/base/ref_counted_memory.h b/base/ref_counted_memory.h new file mode 100644 index 0000000..ef05abd --- /dev/null +++ b/base/ref_counted_memory.h @@ -0,0 +1,76 @@ +// Copyright (c) 2009 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_ + +#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: + virtual ~RefCountedMemory() {} + + // Retrieves a pointer to the beginning of the data we point to. + virtual const unsigned char* front() const = 0; + + // Size of the memory pointed to. + virtual size_t size() const = 0; +}; + +// 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 { return data_; } + virtual size_t size() const { return length_; } + + 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* bytes = new RefCountedBytes; + bytes->data.swap(*to_destroy); + return bytes; + } + + RefCountedBytes() {} + + // Constructs a RefCountedBytes object by _copying_ from |initializer|. + RefCountedBytes(const std::vector<unsigned char>& initializer) + : data(initializer) {} + + virtual const unsigned char* front() const { return &data.front(); } + virtual size_t size() const { return data.size(); } + + std::vector<unsigned char> data; + + private: + DISALLOW_COPY_AND_ASSIGN(RefCountedBytes); +}; + +#endif // BASE_REF_COUNTED_MEMORY_H_ |