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DataBufferHeap.h
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1 //===-- DataBufferHeap.h ----------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef liblldb_DataBufferHeap_h_
10 #define liblldb_DataBufferHeap_h_
11 
13 #include "lldb/lldb-types.h"
14 #include "llvm/ADT/StringRef.h"
15 
16 #include <cstdint>
17 #include <vector>
18 
19 namespace lldb_private {
20 
21 /// \class DataBufferHeap DataBufferHeap.h "lldb/Core/DataBufferHeap.h"
22 /// A subclass of DataBuffer that stores a data buffer on the heap.
23 ///
24 /// This class keeps its data in a heap based buffer that is owned by the
25 /// object. This class is best used to store chunks of data that are created
26 /// or read from sources that can't intelligently and lazily fault new data
27 /// pages in. Large amounts of data that comes from files should probably use
28 /// DataBufferLLVM, which can intelligently determine when memory mapping is
29 /// optimal.
30 class DataBufferHeap : public DataBuffer {
31 public:
32  /// Default constructor
33  ///
34  /// Initializes the heap based buffer with no bytes.
36 
37  /// Construct with size \a n and fill with \a ch.
38  ///
39  /// Initialize this class with \a n bytes and fills the buffer with \a ch.
40  ///
41  /// \param[in] n
42  /// The number of bytes that heap based buffer should contain.
43  ///
44  /// \param[in] ch
45  /// The character to use when filling the buffer initially.
46  DataBufferHeap(lldb::offset_t n, uint8_t ch);
47 
48  /// Construct by making a copy of \a src_len bytes from \a src.
49  ///
50  /// \param[in] src
51  /// A pointer to the data to copy.
52  ///
53  /// \param[in] src_len
54  /// The number of bytes in \a src to copy.
55  DataBufferHeap(const void *src, lldb::offset_t src_len);
56 
57  /// Destructor.
58  ///
59  /// Virtual destructor since this class inherits from a pure virtual base
60  /// class #DataBuffer.
61  ~DataBufferHeap() override;
62 
63  /// \copydoc DataBuffer::GetBytes()
64  uint8_t *GetBytes() override;
65 
66  /// \copydoc DataBuffer::GetBytes() const
67  const uint8_t *GetBytes() const override;
68 
69  /// \copydoc DataBuffer::GetByteSize() const
70  lldb::offset_t GetByteSize() const override;
71 
72  /// Set the number of bytes in the data buffer.
73  ///
74  /// Sets the number of bytes that this object should be able to contain.
75  /// This can be used prior to copying data into the buffer. Note that this
76  /// zero-initializes up to \p byte_size bytes.
77  ///
78  /// \param[in] byte_size
79  /// The new size in bytes that this data buffer should attempt
80  /// to resize itself to.
81  ///
82  /// \return
83  /// The size in bytes after that this heap buffer was
84  /// successfully resized to.
86 
87  /// Makes a copy of the \a src_len bytes in \a src.
88  ///
89  /// Copies the data in \a src into an internal buffer.
90  ///
91  /// \param[in] src
92  /// A pointer to the data to copy.
93  ///
94  /// \param[in] src_len
95  /// The number of bytes in \a src to copy.
96  void CopyData(const void *src, lldb::offset_t src_len);
97  void CopyData(llvm::StringRef src) { CopyData(src.data(), src.size()); }
98 
99  void AppendData(const void *src, uint64_t src_len);
100 
101  void Clear();
102 
103 private:
104  // This object uses a std::vector<uint8_t> to store its data. This takes care
105  // of free the data when the object is deleted.
106  typedef std::vector<uint8_t> buffer_t; ///< Buffer type
107  buffer_t m_data; ///< The heap based buffer where data is stored
108 };
109 
110 } // namespace lldb_private
111 
112 #endif // liblldb_DataBufferHeap_h_
void CopyData(llvm::StringRef src)
Enumerations for broadcasting.
Definition: SBLaunchInfo.h:14
lldb::offset_t SetByteSize(lldb::offset_t byte_size)
Set the number of bytes in the data buffer.
void AppendData(const void *src, uint64_t src_len)
A subclass of DataBuffer that stores a data buffer on the heap.
uint64_t offset_t
Definition: lldb-types.h:87
DataBufferHeap()
Default constructor.
~DataBufferHeap() override
Destructor.
uint8_t * GetBytes() override
lldb::offset_t GetByteSize() const override
void CopyData(const void *src, lldb::offset_t src_len)
Makes a copy of the src_len bytes in src.