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//===-- DataBuffer.h --------------------------------------------*- C++ -*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#if defined(__cplusplus)
#include <cstdint>
#include <cstring>
#include "lldb/lldb-types.h"
#include "llvm/ADT/ArrayRef.h"
namespace lldb_private {
/// \class DataBuffer DataBuffer.h "lldb/Core/DataBuffer.h"
/// A pure virtual protocol class for abstracted data buffers.
/// DataBuffer is an abstract class that gets packaged into a shared pointer
/// that can use to implement various ways to store data (on the heap, memory
/// mapped, cached inferior memory). It gets used by DataExtractor so many
/// DataExtractor objects can share the same data and sub-ranges of that
/// shared data, and the last object that contains a reference to the shared
/// data will free it.
/// Subclasses can implement as many different constructors or member
/// functions that allow data to be stored in the object's buffer prior to
/// handing the shared data to clients that use these buffers.
/// All subclasses must override all of the pure virtual functions as they are
/// used by clients to access the data. Having a common interface allows
/// different ways of storing data, yet using it in one common way.
/// This class currently expects all data to be available without any extra
/// calls being made, but we can modify it to optionally get data on demand
/// with some extra function calls to load the data before it gets accessed.
class DataBuffer {
/// Destructor
/// The destructor is virtual as other classes will inherit from this class
/// and be downcast to the DataBuffer pure virtual interface. The virtual
/// destructor ensures that destructing the base class will destruct the
/// class that inherited from it correctly.
virtual ~DataBuffer() = default;
/// Get a pointer to the data.
/// \return
/// A pointer to the bytes owned by this object, or NULL if the
/// object contains no bytes.
virtual uint8_t *GetBytes() = 0;
/// Get a const pointer to the data.
/// \return
/// A const pointer to the bytes owned by this object, or NULL
/// if the object contains no bytes.
virtual const uint8_t *GetBytes() const = 0;
/// Get the number of bytes in the data buffer.
/// \return
/// The number of bytes this object currently contains.
virtual lldb::offset_t GetByteSize() const = 0;
llvm::ArrayRef<uint8_t> GetData() const {
return llvm::ArrayRef<uint8_t>(GetBytes(), GetByteSize());
llvm::MutableArrayRef<uint8_t> GetData() {
return llvm::MutableArrayRef<uint8_t>(GetBytes(), GetByteSize());
class DataBufferUnowned : public DataBuffer {
DataBufferUnowned(uint8_t *bytes, lldb::offset_t size)
: m_bytes(bytes), m_size(size) {}
uint8_t *GetBytes() override { return m_bytes; }
const uint8_t *GetBytes() const override { return m_bytes; }
lldb::offset_t GetByteSize() const override { return m_size; }
uint8_t *m_bytes;
lldb::offset_t m_size;
} // namespace lldb_private
#endif /// #if defined(__cplusplus)