1 // Copyright (c) 2011 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 BASE_MEMORY_REF_COUNTED_MEMORY_H_
6 #define BASE_MEMORY_REF_COUNTED_MEMORY_H_
12 #include "base/base_export.h"
13 #include "base/compiler_specific.h"
14 #include "base/memory/ref_counted.h"
16 // TODO(erg): The contents of this file should be in a namespace. This would
17 // require touching >100 files in chrome/ though.
19 // A generic interface to memory. This object is reference counted because one
20 // of its two subclasses own the data they carry, and we need to have
21 // heterogeneous containers of these two types of memory.
22 class BASE_EXPORT RefCountedMemory
23 : public base::RefCountedThreadSafe<RefCountedMemory> {
25 // Retrieves a pointer to the beginning of the data we point to. If the data
26 // is empty, this will return NULL.
27 virtual const unsigned char* front() const = 0;
29 // Size of the memory pointed to.
30 virtual size_t size() const = 0;
33 friend class base::RefCountedThreadSafe<RefCountedMemory>;
35 virtual ~RefCountedMemory();
38 // An implementation of RefCountedMemory, where the ref counting does not
40 class BASE_EXPORT RefCountedStaticMemory : public RefCountedMemory {
42 RefCountedStaticMemory()
43 : data_(NULL), length_(0) {}
44 RefCountedStaticMemory(const unsigned char* data, size_t length)
45 : data_(length ? data : NULL), length_(length) {}
47 // Overridden from RefCountedMemory:
48 virtual const unsigned char* front() const OVERRIDE;
49 virtual size_t size() const OVERRIDE;
52 const unsigned char* data_;
55 DISALLOW_COPY_AND_ASSIGN(RefCountedStaticMemory);
58 // An implementation of RefCountedMemory, where we own our the data in a
60 class BASE_EXPORT RefCountedBytes : public RefCountedMemory {
64 // Constructs a RefCountedBytes object by _copying_ from |initializer|.
65 RefCountedBytes(const std::vector<unsigned char>& initializer);
67 // Constructs a RefCountedBytes object by performing a swap. (To non
68 // destructively build a RefCountedBytes, use the constructor that takes a
70 static RefCountedBytes* TakeVector(std::vector<unsigned char>* to_destroy);
72 // Overridden from RefCountedMemory:
73 virtual const unsigned char* front() const OVERRIDE;
74 virtual size_t size() const OVERRIDE;
76 const std::vector<unsigned char>& data() const { return data_; }
77 std::vector<unsigned char>& data() { return data_; }
80 friend class base::RefCountedThreadSafe<RefCountedBytes>;
81 virtual ~RefCountedBytes();
83 std::vector<unsigned char> data_;
85 DISALLOW_COPY_AND_ASSIGN(RefCountedBytes);
90 // An implementation of RefCountedMemory, where the bytes are stored in an STL
91 // string. Use this if your data naturally arrives in that format.
92 class BASE_EXPORT RefCountedString : public RefCountedMemory {
96 // Constructs a RefCountedString object by performing a swap. (To non
97 // destructively build a RefCountedString, use the default constructor and
98 // copy into object->data()).
99 static RefCountedString* TakeString(std::string* to_destroy);
101 // Overridden from RefCountedMemory:
102 virtual const unsigned char* front() const OVERRIDE;
103 virtual size_t size() const OVERRIDE;
105 const std::string& data() const { return data_; }
106 std::string& data() { return data_; }
109 friend class base::RefCountedThreadSafe<RefCountedString>;
110 virtual ~RefCountedString();
114 DISALLOW_COPY_AND_ASSIGN(RefCountedString);
119 #endif // BASE_MEMORY_REF_COUNTED_MEMORY_H_