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
12#include "lldb/Utility/DataBuffer.h"
13#include "lldb/lldb-types.h"
14#include "llvm/ADT/StringRef.h"
15
16#include <cstdint>
17#include <vector>
18
19namespace 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.
30class DataBufferHeap : public WritableDataBuffer {
31public:
32 /// Default constructor
33 ///
34 /// Initializes the heap based buffer with no bytes.
35 DataBufferHeap();
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.
88 lldb::offset_t SetByteSize(lldb::offset_t byte_size);
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: src.data(), src_len: 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(ClassID: &ID);
114 }
115 /// }
116
117private:
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
127

source code of lldb/include/lldb/Utility/DataBufferHeap.h