//===-- DataEncoder.h -------------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef liblldb_DataEncoder_h_
#define liblldb_DataEncoder_h_
#if defined(__cplusplus)
#include "lldb/lldb-defines.h" // for DISALLOW_COPY_AND_ASSIGN
#include "lldb/lldb-enumerations.h" // for ByteOrder
#include "lldb/lldb-forward.h" // for DataBufferSP
#include "lldb/lldb-types.h" // for addr_t
#include <stddef.h> // for size_t
#include <stdint.h>
namespace lldb_private {
//----------------------------------------------------------------------
/// @class DataEncoder DataEncoder.h "lldb/Core/DataEncoder.h"
/// @brief An binary data encoding class.
///
/// DataEncoder is a class that can encode binary data (swapping if needed)
/// to a data buffer. The data buffer can be caller owned, or can be
/// shared data that can be shared between multiple DataEncoder or
/// DataEncoder instances.
///
/// @see DataBuffer
//----------------------------------------------------------------------
class DataEncoder {
public:
//------------------------------------------------------------------
/// Default constructor.
///
/// Initialize all members to a default empty state.
//------------------------------------------------------------------
DataEncoder();
//------------------------------------------------------------------
/// Construct with a buffer that is owned by the caller.
///
/// This constructor allows us to use data that is owned by the
/// caller. The data must stay around as long as this object is
/// valid.
///
/// @param[in] data
/// A pointer to caller owned data.
///
/// @param[in] data_length
/// The length in bytes of \a data.
///
/// @param[in] byte_order
/// A byte order of the data that we are extracting from.
///
/// @param[in] addr_size
/// A new address byte size value.
//------------------------------------------------------------------
DataEncoder(void *data, uint32_t data_length, lldb::ByteOrder byte_order,
uint8_t addr_size);
//------------------------------------------------------------------
/// Construct with shared data.
///
/// Copies the data shared pointer which adds a reference to the
/// contained in \a data_sp. The shared data reference is reference
/// counted to ensure the data lives as long as anyone still has a
/// valid shared pointer to the data in \a data_sp.
///
/// @param[in] data_sp
/// A shared pointer to data.
///
/// @param[in] byte_order
/// A byte order of the data that we are extracting from.
///
/// @param[in] addr_size
/// A new address byte size value.
//------------------------------------------------------------------
DataEncoder(const lldb::DataBufferSP &data_sp, lldb::ByteOrder byte_order,
uint8_t addr_size);
//------------------------------------------------------------------
/// Destructor
///
/// If this object contains a valid shared data reference, the
/// reference count on the data will be decremented, and if zero,
/// the data will be freed.
//------------------------------------------------------------------
~DataEncoder();
//------------------------------------------------------------------
/// Clears the object state.
///
/// Clears the object contents back to a default invalid state, and
/// release any references to shared data that this object may
/// contain.
//------------------------------------------------------------------
void Clear();
//------------------------------------------------------------------
/// Get the current address size.
///
/// Return the size in bytes of any address values this object will
/// extract.
///
/// @return
/// The size in bytes of address values that will be extracted.
//------------------------------------------------------------------
uint8_t GetAddressByteSize() const { return m_addr_size; }
//------------------------------------------------------------------
/// Get the number of bytes contained in this object.
///
/// @return
/// The total number of bytes of data this object refers to.
//------------------------------------------------------------------
size_t GetByteSize() const { return m_end - m_start; }
//------------------------------------------------------------------
/// Get the data end pointer.
///
/// @return
/// Returns a pointer to the next byte contained in this
/// object's data, or NULL of there is no data in this object.
//------------------------------------------------------------------
uint8_t *GetDataEnd() { return m_end; }
const uint8_t *GetDataEnd() const { return m_end; }
//------------------------------------------------------------------
/// Get the shared data offset.
///
/// Get the offset of the first byte of data in the shared data (if
/// any).
///
/// @return
/// If this object contains shared data, this function returns
/// the offset in bytes into that shared data, zero otherwise.
//------------------------------------------------------------------
size_t GetSharedDataOffset() const;
//------------------------------------------------------------------
/// Get the current byte order value.
///
/// @return
/// The current byte order value from this object's internal
/// state.
//------------------------------------------------------------------
lldb::ByteOrder GetByteOrder() const { return m_byte_order; }
//------------------------------------------------------------------
/// Get the data start pointer.
///
/// @return
/// Returns a pointer to the first byte contained in this
/// object's data, or NULL of there is no data in this object.
//------------------------------------------------------------------
uint8_t *GetDataStart() { return m_start; }
const uint8_t *GetDataStart() const { return m_start; }
//------------------------------------------------------------------
/// Encode unsigned integer values into the data at \a offset.
///
/// @param[in] offset
/// The offset within the contained data at which to put the
/// data.
///
/// @param[in] value
/// The value to encode into the data.
///
/// @return
/// The next offset in the bytes of this data if the data
/// was successfully encoded, UINT32_MAX if the encoding failed.
//------------------------------------------------------------------
uint32_t PutU8(uint32_t offset, uint8_t value);
uint32_t PutU16(uint32_t offset, uint16_t value);
uint32_t PutU32(uint32_t offset, uint32_t value);
uint32_t PutU64(uint32_t offset, uint64_t value);
//------------------------------------------------------------------
/// Encode an unsigned integer of size \a byte_size to \a offset.
///
/// Encode a single integer value at \a offset and return the offset
/// that follows the newly encoded integer when the data is successfully
/// encoded into the existing data. There must be enough room in the
/// data, else UINT32_MAX will be returned to indicate that encoding
/// failed.
///
/// @param[in] offset
/// The offset within the contained data at which to put the
/// encoded integer.
///
/// @param[in] byte_size
/// The size in byte of the integer to encode.
///
/// @param[in] value
/// The integer value to write. The least significant bytes of
/// the integer value will be written if the size is less than
/// 8 bytes.
///
/// @return
/// The next offset in the bytes of this data if the integer
/// was successfully encoded, UINT32_MAX if the encoding failed.
//------------------------------------------------------------------
uint32_t PutMaxU64(uint32_t offset, uint32_t byte_size, uint64_t value);
//------------------------------------------------------------------
/// Encode an arbitrary number of bytes.
///
/// @param[in] offset
/// The offset in bytes into the contained data at which to
/// start encoding.
///
/// @param[in] src
/// The buffer that contains the bytes to encode.
///
/// @param[in] src_len
/// The number of bytes to encode.
///
/// @return
/// The next valid offset within data if the put operation
/// was successful, else UINT32_MAX to indicate the put failed.
//------------------------------------------------------------------
uint32_t PutData(uint32_t offset, const void *src, uint32_t src_len);
//------------------------------------------------------------------
/// Encode an address in the existing buffer at \a offset bytes into
/// the buffer.
///
/// Encode a single address (honoring the m_addr_size member) to
/// the data and return the next offset where subsequent data would
/// go.
/// pointed to by \a offset_ptr. The size of the extracted address
/// comes from the \a m_addr_size member variable and should be
/// set correctly prior to extracting any address values.
///
/// @param[in,out] offset_ptr
/// A pointer to an offset within the data that will be advanced
/// by the appropriate number of bytes if the value is extracted
/// correctly. If the offset is out of bounds or there are not
/// enough bytes to extract this value, the offset will be left
/// unmodified.
///
/// @return
/// The next valid offset within data if the put operation
/// was successful, else UINT32_MAX to indicate the put failed.
//------------------------------------------------------------------
uint32_t PutAddress(uint32_t offset, lldb::addr_t addr);
//------------------------------------------------------------------
/// Put a C string to \a offset.
///
/// Encodes a C string into the existing data including the
/// terminating
///
/// @param[in,out] offset_ptr
/// A pointer to an offset within the data that will be advanced
/// by the appropriate number of bytes if the value is extracted
/// correctly. If the offset is out of bounds or there are not
/// enough bytes to extract this value, the offset will be left
/// unmodified.
///
/// @return
/// A pointer to the C string value in the data. If the offset
/// pointed to by \a offset_ptr is out of bounds, or if the
/// offset plus the length of the C string is out of bounds,
/// NULL will be returned.
//------------------------------------------------------------------
uint32_t PutCString(uint32_t offset_ptr, const char *cstr);
lldb::DataBufferSP &GetSharedDataBuffer() { return m_data_sp; }
//------------------------------------------------------------------
/// Set the address byte size.
///
/// Set the size in bytes that will be used when extracting any
/// address and pointer values from data contained in this object.
///
/// @param[in] addr_size
/// The size in bytes to use when extracting addresses.
//------------------------------------------------------------------
void SetAddressByteSize(uint8_t addr_size) { m_addr_size = addr_size; }
//------------------------------------------------------------------
/// Set data with a buffer that is caller owned.
///
/// Use data that is owned by the caller when extracting values.
/// The data must stay around as long as this object, or any object
/// that copies a subset of this object's data, is valid. If \a
/// bytes is NULL, or \a length is zero, this object will contain
/// no data.
///
/// @param[in] bytes
/// A pointer to caller owned data.
///
/// @param[in] length
/// The length in bytes of \a bytes.
///
/// @param[in] byte_order
/// A byte order of the data that we are extracting from.
///
/// @return
/// The number of bytes that this object now contains.
//------------------------------------------------------------------
uint32_t SetData(void *bytes, uint32_t length, lldb::ByteOrder byte_order);
//------------------------------------------------------------------
/// Adopt a subset of shared data in \a data_sp.
///
/// Copies the data shared pointer which adds a reference to the
/// contained in \a data_sp. The shared data reference is reference
/// counted to ensure the data lives as long as anyone still has a
/// valid shared pointer to the data in \a data_sp. The byte order
/// and address byte size settings remain the same. If
/// \a offset is not a valid offset in \a data_sp, then no reference
/// to the shared data will be added. If there are not \a length
/// bytes available in \a data starting at \a offset, the length
/// will be truncated to contains as many bytes as possible.
///
/// @param[in] data_sp
/// A shared pointer to data.
///
/// @param[in] offset
/// The offset into \a data_sp at which the subset starts.
///
/// @param[in] length
/// The length in bytes of the subset of \a data_sp.
///
/// @return
/// The number of bytes that this object now contains.
//------------------------------------------------------------------
uint32_t SetData(const lldb::DataBufferSP &data_sp, uint32_t offset = 0,
uint32_t length = UINT32_MAX);
//------------------------------------------------------------------
/// Set the byte_order value.
///
/// Sets the byte order of the data to extract. Extracted values
/// will be swapped if necessary when decoding.
///
/// @param[in] byte_order
/// The byte order value to use when extracting data.
//------------------------------------------------------------------
void SetByteOrder(lldb::ByteOrder byte_order) { m_byte_order = byte_order; }
//------------------------------------------------------------------
/// Test the validity of \a offset.
///
/// @return
/// \b true if \a offset is a valid offset into the data in this
/// object, \b false otherwise.
//------------------------------------------------------------------
bool ValidOffset(uint32_t offset) const { return offset < GetByteSize(); }
//------------------------------------------------------------------
/// Test the availability of \a length bytes of data from \a offset.
///
/// @return
/// \b true if \a offset is a valid offset and there are \a
/// length bytes available at that offset, \b false otherwise.
//------------------------------------------------------------------
bool ValidOffsetForDataOfSize(uint32_t offset, uint32_t length) const {
return length <= BytesLeft(offset);
}
uint32_t BytesLeft(uint32_t offset) const {
const uint32_t size = GetByteSize();
if (size > offset)
return size - offset;
return 0;
}
protected:
//------------------------------------------------------------------
// Member variables
//------------------------------------------------------------------
uint8_t *m_start; ///< A pointer to the first byte of data.
uint8_t *m_end; ///< A pointer to the byte that is past the end of the data.
lldb::ByteOrder
m_byte_order; ///< The byte order of the data we are extracting from.
uint8_t m_addr_size; ///< The address size to use when extracting pointers or
/// addresses
mutable lldb::DataBufferSP m_data_sp; ///< The shared pointer to data that can
/// be shared among multiple instances
private:
DISALLOW_COPY_AND_ASSIGN(DataEncoder);
};
} // namespace lldb_private
#endif // #if defined (__cplusplus)
#endif // #ifndef liblldb_DataEncoder_h_
