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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 LLDB_UTILITY_DATABUFFERHEAP_H
10 #define LLDB_UTILITY_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.
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  /// Construct by making a copy of a DataBuffer.
58  ///
59  /// \param[in] data_buffer
60  /// A read only data buffer to copy.
61  DataBufferHeap(const DataBuffer &data_buffer);
62 
63  /// Destructor.
64  ///
65  /// Virtual destructor since this class inherits from a pure virtual base
66  /// class #DataBuffer.
67  ~DataBufferHeap() override;
68 
69  /// \copydoc DataBuffer::GetBytes() const
70  const uint8_t *GetBytesImpl() const override;
71 
72  /// \copydoc DataBuffer::GetByteSize() const
73  lldb::offset_t GetByteSize() const override;
74 
75  /// Set the number of bytes in the data buffer.
76  ///
77  /// Sets the number of bytes that this object should be able to contain.
78  /// This can be used prior to copying data into the buffer. Note that this
79  /// zero-initializes up to \p byte_size bytes.
80  ///
81  /// \param[in] byte_size
82  /// The new size in bytes that this data buffer should attempt
83  /// to resize itself to.
84  ///
85  /// \return
86  /// The size in bytes after this heap buffer was resized. If
87  /// the resize failed the size will remain unchanged.
89 
90  /// Makes a copy of the \a src_len bytes in \a src.
91  ///
92  /// Copies the data in \a src into an internal buffer.
93  ///
94  /// \param[in] src
95  /// A pointer to the data to copy.
96  ///
97  /// \param[in] src_len
98  /// The number of bytes in \a src to copy.
99  void CopyData(const void *src, lldb::offset_t src_len);
100  void CopyData(llvm::StringRef src) { CopyData(src.data(), src.size()); }
101 
102  void AppendData(const void *src, uint64_t src_len);
103 
104  void Clear();
105 
106  /// LLVM RTTI support.
107  /// {
108  static char ID;
109  bool isA(const void *ClassID) const override {
110  return ClassID == &ID || WritableDataBuffer::isA(ClassID);
111  }
112  static bool classof(const DataBuffer *data_buffer) {
113  return data_buffer->isA(&ID);
114  }
115  /// }
116 
117 private:
118  // This object uses a std::vector<uint8_t> to store its data. This takes care
119  // of free the data when the object is deleted.
120  typedef std::vector<uint8_t> buffer_t; ///< Buffer type
121  buffer_t m_data; ///< The heap based buffer where data is stored
122 };
123 
124 } // namespace lldb_private
125 
126 #endif // LLDB_UTILITY_DATABUFFERHEAP_H
lldb_private::DataBufferHeap::GetByteSize
lldb::offset_t GetByteSize() const override
Definition: DataBufferHeap.cpp:43
lldb_private::DataBufferHeap::AppendData
void AppendData(const void *src, uint64_t src_len)
Definition: DataBufferHeap.cpp:61
lldb_private::DataBufferHeap::SetByteSize
lldb::offset_t SetByteSize(lldb::offset_t byte_size)
Set the number of bytes in the data buffer.
Definition: DataBufferHeap.cpp:47
lldb_private::DataBufferHeap::CopyData
void CopyData(const void *src, lldb::offset_t src_len)
Makes a copy of the src_len bytes in src.
Definition: DataBufferHeap.cpp:53
lldb_private::DataBufferHeap::GetBytesImpl
const uint8_t * GetBytesImpl() const override
Definition: DataBufferHeap.cpp:38
lldb::offset_t
uint64_t offset_t
Definition: lldb-types.h:87
lldb_private::DataBufferHeap::ID
static char ID
LLVM RTTI support.
Definition: DataBufferHeap.h:108
lldb_private::DataBufferHeap::isA
bool isA(const void *ClassID) const override
Definition: DataBufferHeap.h:109
lldb_private::DataBufferHeap::buffer_t
std::vector< uint8_t > buffer_t
}
Definition: DataBufferHeap.h:120
DataBuffer
lldb_private::DataBufferHeap::~DataBufferHeap
~DataBufferHeap() override
Destructor.
lldb_private::DataBufferHeap::classof
static bool classof(const DataBuffer *data_buffer)
Definition: DataBufferHeap.h:112
lldb_private::DataBufferHeap::Clear
void Clear()
Definition: DataBufferHeap.cpp:66
lldb-types.h
WritableDataBuffer
lldb_private::DataBufferHeap::m_data
buffer_t m_data
The heap based buffer where data is stored.
Definition: DataBufferHeap.h:121
lldb_private::DataBufferHeap::DataBufferHeap
DataBufferHeap()
Default constructor.
Definition: DataBufferHeap.cpp:15
lldb_private
A class that represents a running process on the host machine.
Definition: SBCommandInterpreterRunOptions.h:16
DataBuffer.h
lldb_private::DataBufferHeap
Definition: DataBufferHeap.h:30
lldb_private::DataBufferHeap::CopyData
void CopyData(llvm::StringRef src)
Definition: DataBufferHeap.h:100