llvm-project/lldb/include/lldb/Utility/DataBufferHeap.h

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3.6 KiB
C++

//===-- DataBufferHeap.h ----------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef LLDB_UTILITY_DATABUFFERHEAP_H
#define LLDB_UTILITY_DATABUFFERHEAP_H
#include "lldb/Utility/DataBuffer.h"
#include "lldb/lldb-types.h"
#include "llvm/ADT/StringRef.h"
#include <cstdint>
#include <vector>
namespace lldb_private {
/// \class DataBufferHeap DataBufferHeap.h "lldb/Core/DataBufferHeap.h"
/// A subclass of DataBuffer that stores a data buffer on the heap.
///
/// This class keeps its data in a heap based buffer that is owned by the
/// object. This class is best used to store chunks of data that are created
/// or read from sources that can't intelligently and lazily fault new data
/// pages in. Large amounts of data that comes from files should probably use
/// DataBufferLLVM, which can intelligently determine when memory mapping is
/// optimal.
class DataBufferHeap : public DataBuffer {
public:
/// Default constructor
///
/// Initializes the heap based buffer with no bytes.
DataBufferHeap();
/// Construct with size \a n and fill with \a ch.
///
/// Initialize this class with \a n bytes and fills the buffer with \a ch.
///
/// \param[in] n
/// The number of bytes that heap based buffer should contain.
///
/// \param[in] ch
/// The character to use when filling the buffer initially.
DataBufferHeap(lldb::offset_t n, uint8_t ch);
/// Construct by making a copy of \a src_len bytes from \a src.
///
/// \param[in] src
/// A pointer to the data to copy.
///
/// \param[in] src_len
/// The number of bytes in \a src to copy.
DataBufferHeap(const void *src, lldb::offset_t src_len);
/// Destructor.
///
/// Virtual destructor since this class inherits from a pure virtual base
/// class #DataBuffer.
~DataBufferHeap() override;
/// \copydoc DataBuffer::GetBytes()
uint8_t *GetBytes() override;
/// \copydoc DataBuffer::GetBytes() const
const uint8_t *GetBytes() const override;
/// \copydoc DataBuffer::GetByteSize() const
lldb::offset_t GetByteSize() const override;
/// Set the number of bytes in the data buffer.
///
/// Sets the number of bytes that this object should be able to contain.
/// This can be used prior to copying data into the buffer. Note that this
/// zero-initializes up to \p byte_size bytes.
///
/// \param[in] byte_size
/// The new size in bytes that this data buffer should attempt
/// to resize itself to.
///
/// \return
/// The size in bytes after that this heap buffer was
/// successfully resized to.
lldb::offset_t SetByteSize(lldb::offset_t byte_size);
/// Makes a copy of the \a src_len bytes in \a src.
///
/// Copies the data in \a src into an internal buffer.
///
/// \param[in] src
/// A pointer to the data to copy.
///
/// \param[in] src_len
/// The number of bytes in \a src to copy.
void CopyData(const void *src, lldb::offset_t src_len);
void CopyData(llvm::StringRef src) { CopyData(src.data(), src.size()); }
void AppendData(const void *src, uint64_t src_len);
void Clear();
private:
// This object uses a std::vector<uint8_t> to store its data. This takes care
// of free the data when the object is deleted.
typedef std::vector<uint8_t> buffer_t; ///< Buffer type
buffer_t m_data; ///< The heap based buffer where data is stored
};
} // namespace lldb_private
#endif // LLDB_UTILITY_DATABUFFERHEAP_H