Class CMemoryFile

Nested Relationships

Nested Types

Class Documentation

class CMemoryFile

Shared memory file handler class.

Public Functions

CMemoryFile()

Constructor.

~CMemoryFile()

Destructor.

bool Create(const char *name_, bool create_, size_t len_ = 0, bool auto_sanitizing_ = false)

Create a new memory file.

Parameters:

  • name_ – Unique file name.

  • create_ – Add file to system if not exists.

  • len_ – Number of bytes to allocate (only if create_ == true).

Returns:

true if it succeeds, false if it fails.

bool Destroy(bool remove_)

Delete the associated memory file from system.

Parameters:

remove_ – Remove file from system.

Returns:

true if it succeeds, false if it fails.

bool GetReadAccess(int timeout_)

Get memory file read access.

Parameters:

timeout_ – The timeout in ms for access via mutex.

Returns:

true if file exists and could be opened with read access.

bool ReleaseReadAccess()

Release the read access.

Returns:

true if it succeeds, false if it fails.

size_t GetReadAddress(const void *&buf_, size_t len_)

Get payload buffer pointer from an opened memory file for reading.

Parameters:

  • buf_ – The destination address.

  • len_ – Expected length of the available payload.

Returns:

Number of available bytes (or zero if it fails).

size_t Read(void *buf_, size_t len_, size_t offset_)

Read bytes from an opened memory file.

Parameters:

  • buf_ – The destination address.

  • len_ – The length of the allocated memory (has to be allocated by caller).

  • offset_ – The offset where to start reading.

Returns:

Number of copied bytes (or zero if it fails).

bool GetWriteAccess(int timeout_)

Get memory file write access.

Parameters:

timeout_ – The timeout in ms for access via mutex.

Returns:

true if file exists and could be opened with read/write access.

bool ReleaseWriteAccess()

Release the write access.

Returns:

true if it succeeds, false if it fails.

size_t GetWriteAddress(void *&buf_, size_t len_)

Get payload buffer pointer from an opened memory file for writing.

Parameters:

  • buf_ – The destination address.

  • len_ – Expected length of the available payload.

Returns:

Number of available bytes (or zero if it fails).

size_t WriteBuffer(const void *buf_, size_t len_, size_t offset_)

Write bytes to the memory file.

Parameters:

  • buf_ – The source address.

  • len_ – The number of bytes to write.

  • offset_ – The offset for writing the data.

Returns:

Number of bytes copied to the memory file.

size_t WritePayload(CPayloadWriter &payload_, size_t len_, size_t offset_, bool force_full_write_ = false)

Apply payload on the memory file.

Parameters:

  • payload_ – The payload.

  • len_ – The number of bytes to write.

  • offset_ – The offset for writing the data.

  • force_full_write_ – Force full write action.

Returns:

Number of bytes accessed (len if succeeded otherwise zero).

inline size_t MaxDataSize() const

Maximum data size of the whole memory file.

Returns:

The size of the data object.

inline size_t CurDataSize() const

Size of the stored data object (can be smaller than the size of the available data size.

Returns:

The size of the data object.

inline bool IsCreated() const
inline std::string Name() const
inline bool IsOpened() const
inline bool HasReadAccess() const
inline bool HasWriteAccess() const

Protected Types

enum class access_state

Values:

enumerator closed
enumerator read_access
enumerator write_access

Protected Functions

bool GetAccess(int timeout_)

Protected Attributes

bool m_created
bool m_auto_sanitizing
bool m_payload_initialized
access_state m_access_state
std::string m_name
SInternalHeader m_header
SMemFileInfo m_memfile_info
CNamedMutex m_memfile_mutex
struct SInternalHeader

Public Members

std::uint16_t int_hdr_size = sizeof(SInternalHeader)
std::array<std::uint8_t, 2> _reserved_0 = {}
std::uint32_t cur_data_size = 0
std::uint32_t max_data_size = 0