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 DataBuffer {
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 /// 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.
85 lldb::offset_t SetByteSize(lldb::offset_t byte_size);
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
103private:
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 // LLDB_UTILITY_DATABUFFERHEAP_H
113