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 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. 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(); 102 103 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 // LLDB_UTILITY_DATABUFFERHEAP_H 113