memory_file_data.py

"""Writes/Reads simple data to/from memory.

Topics:
    * c4d.storage.ByteSeq
    * c4d.storage.MemoryFileStruct
    * c4d.storage.HyperFile
"""
__author__ = "XXX"
__copyright__ = "Copyright (C) 2026 MAXON Computer GmbH"
__license__ = "Apache-2.0 License"
__version__ = "R13"

import c4d


def WriteMemoryFile():
    """Writes data to a memory file.
    
    Returns: 
        The byte sequence or None
    """
    # Creates a MemoryFile, data will be written in
    mfs = c4d.storage.MemoryFileStruct()

    # Sets the memory file ready to be written to
    mfs.SetMemoryWriteMode()

    # Initializes a HyperFile
    file = c4d.storage.HyperFile()

    # Opens the HyperFile, with the MemoryFile used
    if not file.Open(0, mfs, c4d.FILEOPEN_WRITE, c4d.FILEDIALOG_NONE):
        raise RuntimeError("Failed to open the HyperFile.")

    # Writes a string to the memory file
    file.WriteString("MemoryFileStruct Example")

    # Writes an integer to the memory file
    file.WriteInt32(1214)

    if c4d.GetC4DVersion() > 22600:
        # Writes an byte array to the memory file
        file.WriteMemory(bytearray("Bytes Array data", "utf-8"))

    # Closes the file
    file.Close()

    # Returns the memory file data (the byte sequence)
    return mfs.GetData()[0]


def ReadMemoryFile(data):
    """Reads data from a memory file.

    Args:
        data: the byte sequence to read
    """
    # Creates a MemoryFile, data will be read in
    mfs = c4d.storage.MemoryFileStruct()

    # Sets the memory file ready to be read from
    mfs.SetMemoryReadMode(data, len(data))

    file = c4d.storage.HyperFile()
    # Opens the memory file and set it ready for reading
    if not file.Open(0, mfs, c4d.FILEOPEN_READ, c4d.FILEDIALOG_NONE):
        raise RuntimeError("Failed to open the HyperFile.")

    # Reads the string from the memory file
    value = file.ReadString()
    print("The string value is :", value)

    # Reads the int from the memory file
    value = file.ReadInt32()
    print("The int value is :", value)

    if c4d.GetC4DVersion() > 22600:
        # Reads the bytes from the memory file
        value = file.ReadMemory()
        print("The memory value is :", value)

    # Closes file
    file.Close()


def main():
    # Write data in a MemoryFile and get the byte sequence
    bytes = WriteMemoryFile()

    # Read data from the byte sequence
    ReadMemoryFile(bytes)


if __name__ == '__main__':
    main()