data

Utilities to read and write EO data types.

CHAR_MAX = 253 module-attribute

The maximum value of an EO char (1-byte encoded integer type).

SHORT_MAX = CHAR_MAX * CHAR_MAX module-attribute

The maximum value of an EO short (2-byte encoded integer type).

THREE_MAX = CHAR_MAX * CHAR_MAX * CHAR_MAX module-attribute

The maximum value of an EO three (3-byte encoded integer type).

INT_MAX = CHAR_MAX * CHAR_MAX * CHAR_MAX * CHAR_MAX module-attribute

The maximum value of an EO int (4-byte encoded integer type).

EoReader

Bases: object

A class for reading EO data from a sequence of bytes.

EoReader features a chunked reading mode, which is important for accurate emulation of the official game client.

See documentation for chunked reading: https://github.com/Cirras/eo-protocol/blob/master/docs/chunks.md

Source code in src/eolib/data/eo_reader.py

class EoReader(object):
    """
    A class for reading EO data from a sequence of bytes.

    `EoReader` features a chunked reading mode, which is important for accurate emulation of
    the official game client.

    See documentation for chunked reading:
    https://github.com/Cirras/eo-protocol/blob/master/docs/chunks.md
    """

    _data: memoryview
    _position: int
    _chunked_reading_mode: bool
    _chunk_start: int
    _next_break: int

    def __init__(self, data: bytes):
        """
        Creates a new `EoReader` instance for the specified data.

        Args:
            data (bytes): The byte array containing the input data.
        """
        self._data = memoryview(data)
        self._position = 0
        self._chunked_reading_mode = False
        self._chunk_start = 0
        self._next_break = -1

    def slice(self, index: Optional[int] = None, length: Optional[int] = None) -> "EoReader":
        """
        Creates a new `EoReader` whose input data is a shared subsequence of this reader's
        data.

        The input data of the new reader will start at position `index` in this reader and contain
        up to `length` bytes. The two reader's position and chunked reading mode will be
        independent.

        The new reader's position will be zero, and its chunked reading mode will be false.

        Args:
            index (int, optional): The position in this reader at which the data of the new reader
                will start; must be non-negative. Defaults to the current reader position.
            length (int, optional): The length of the shared subsequence of data to supply to the
                new reader; must be non-negative. Defaults to the length of the remaining data
                starting from `index`.

        Returns:
            EoReader: The new reader.

        Raises:
            ValueError: If `index` or `length` is negative.
        """
        if index is None:
            index = self.position
        if length is None:
            length = max(0, len(self._data) - index)

        if index < 0:
            raise ValueError(f"negative index: {index}")

        if length < 0:
            raise ValueError(f"negative length: {length}")

        begin = max(0, min(len(self._data), index))
        end = begin + min(len(self._data) - begin, length)

        return EoReader(self._data[begin:end])

    def get_byte(self) -> int:
        """
        Reads a raw byte from the input data.

        Returns:
            int: A raw byte.
        """
        return self._read_byte()

    def get_bytes(self, length: int) -> bytearray:
        """
        Reads an array of raw bytes from the input data.

        Args:
            length (int): The number of bytes to read.

        Returns:
            bytearray: An array of raw bytes.
        """
        return self._read_bytes(length)

    def get_char(self) -> int:
        """
        Reads an encoded 1-byte integer from the input data.

        Returns:
            int: A decoded 1-byte integer.
        """
        return decode_number(self._read_bytes(1))

    def get_short(self) -> int:
        """
        Reads an encoded 2-byte integer from the input data.

        Returns:
            int: A decoded 2-byte integer.
        """
        return decode_number(self._read_bytes(2))

    def get_three(self) -> int:
        """
        Reads an encoded 3-byte integer from the input data.

        Returns:
            int: A decoded 3-byte integer.
        """
        return decode_number(self._read_bytes(3))

    def get_int(self) -> int:
        """
        Reads an encoded 4-byte integer from the input data.

        Returns:
            int: A decoded 4-byte integer.
        """
        return decode_number(self._read_bytes(4))

    def get_string(self) -> str:
        """
        Reads a string from the input data.

        Returns:
            str: A string.
        """
        string_bytes = self._read_bytes(self.remaining)
        return self._decode_ansi(string_bytes)

    def get_fixed_string(self, length: int, padded: bool = False) -> str:
        """
        Reads a string with a fixed length from the input data.

        Args:
            length (int): The length of the string.
            padded (bool, optional): True if the string is padded with trailing `0xFF` bytes.

        Returns:
            str: A decoded string.

        Raises:
            ValueError: If the length is negative.
        """
        if length < 0:
            raise ValueError("Negative length")
        bytes_ = self._read_bytes(length)
        if padded:
            bytes_ = self._remove_padding(bytes_)
        return self._decode_ansi(bytes_)

    def get_encoded_string(self) -> str:
        """
        Reads an encoded string from the input data.

        Returns:
            str: A decoded string.
        """
        bytes_ = self._read_bytes(self.remaining)
        decode_string(bytes_)
        return self._decode_ansi(bytes_)

    def get_fixed_encoded_string(self, length: int, padded: bool = False) -> str:
        """
        Reads an encoded string with a fixed length from the input data.

        Args:
            length (int): The length of the string.
            padded (bool, optional): True if the string is padded with trailing `0xFF` bytes.

        Returns:
            str: A decoded string.

        Raises:
            ValueError: If the length is negative.
        """
        if length < 0:
            raise ValueError("Negative length")
        bytes_ = self._read_bytes(length)
        decode_string(bytes_)
        if padded:
            bytes_ = self._remove_padding(bytes_)
        return self._decode_ansi(bytes_)

    @property
    def chunked_reading_mode(self) -> bool:
        """
        bool: Gets or sets the chunked reading mode for the reader.

        In chunked reading mode:
        - The reader will treat `0xFF` bytes as the end of the current chunk.
        - `next_chunk()` can be called to move to the next chunk.
        """
        return self._chunked_reading_mode

    @chunked_reading_mode.setter
    def chunked_reading_mode(self, chunked_reading_mode: bool) -> None:
        self._chunked_reading_mode = chunked_reading_mode
        if self._next_break == -1:
            self._next_break = self._find_next_break_index()

    @property
    def remaining(self) -> int:
        """
        int: If chunked reading mode is enabled, gets the number of bytes remaining in the current
            chunk. Otherwise, gets the total number of bytes remaining in the input data.
        """
        if self.chunked_reading_mode:
            return self._next_break - min(self.position, self._next_break)
        else:
            return len(self._data) - self.position

    def next_chunk(self) -> None:
        """
        Moves the reader position to the start of the next chunk in the input data.

        Raises:
            RuntimeError: If not in chunked reading mode.
        """
        if not self.chunked_reading_mode:
            raise RuntimeError("Not in chunked reading mode.")

        self._position = self._next_break
        if self._position < len(self._data):
            # Skip the break byte
            self._position += 1

        self._chunk_start = self._position
        self._next_break = self._find_next_break_index()

    @property
    def position(self) -> int:
        """
        int: Gets the current position in the input data.
        """
        return self._position

    def _read_byte(self) -> int:
        """
        Reads a raw byte from the input data.

        Returns:
            int: A raw byte.
        """
        if self.remaining > 0:
            byte = self._data[self._position]
            self._position += 1
            return byte
        return 0

    def _read_bytes(self, length) -> bytearray:
        """
        Reads an array of raw bytes from the input data.

        Args:
            length (int): The number of bytes to read.

        Returns:
            bytearray: An array of raw bytes.
        """
        length = min(length, self.remaining)

        result = bytearray(self._data[self._position : self._position + length])
        self._position += length

        return result

    def _find_next_break_index(self) -> int:
        """
        Finds the index of the next break byte (0xFF) in the input data.

        Returns:
            int: The index of the next break byte, or the length of the data if not found.
        """
        for i in range(self._chunk_start, len(self._data)):
            if self._data[i] == 0xFF:
                return i
        return len(self._data)

    @staticmethod
    def _remove_padding(array: bytearray) -> bytearray:
        """
        Removes padding (trailing 0xFF bytes) from a sequence of bytes.

        Args:
            array (bytearray): The sequence of bytes.

        Returns:
            bytearray: The bytes without padding.
        """
        padding_start = array.find(bytes([0xFF]))
        if padding_start != -1:
            return array[:padding_start]
        return array

    @staticmethod
    def _decode_ansi(bytes: bytearray) -> str:
        """
        Decodes windows-1252 bytes to a string.

        Args:
            bytes (bytearray): The sequence of bytes to decode.

        Returns:
            str: The decoded string.
        """
        return bytes.decode('windows-1252', 'replace')

chunked_reading_mode: bool property writable

bool: Gets or sets the chunked reading mode for the reader.

In chunked reading mode: - The reader will treat 0xFF bytes as the end of the current chunk. - next_chunk() can be called to move to the next chunk.

remaining: int property

If chunked reading mode is enabled, gets the number of bytes remaining in the current

chunk. Otherwise, gets the total number of bytes remaining in the input data.

position: int property

int: Gets the current position in the input data.

__init__(data)

Creates a new EoReader instance for the specified data.

Parameters:

Name	Type	Description	Default
data	bytes	The byte array containing the input data.	required

Source code in src/eolib/data/eo_reader.py

def __init__(self, data: bytes):
    """
    Creates a new `EoReader` instance for the specified data.

    Args:
        data (bytes): The byte array containing the input data.
    """
    self._data = memoryview(data)
    self._position = 0
    self._chunked_reading_mode = False
    self._chunk_start = 0
    self._next_break = -1

slice(index=None, length=None)

Creates a new EoReader whose input data is a shared subsequence of this reader's data.

The input data of the new reader will start at position index in this reader and contain up to length bytes. The two reader's position and chunked reading mode will be independent.

The new reader's position will be zero, and its chunked reading mode will be false.

Parameters:

Name	Type	Description	Default
index	int	The position in this reader at which the data of the new reader will start; must be non-negative. Defaults to the current reader position.	None
length	int	The length of the shared subsequence of data to supply to the new reader; must be non-negative. Defaults to the length of the remaining data starting from index.	None

Returns:

Name	Type	Description
EoReader	EoReader	The new reader.

Raises:

Type	Description
ValueError	If index or length is negative.

Source code in src/eolib/data/eo_reader.py

def slice(self, index: Optional[int] = None, length: Optional[int] = None) -> "EoReader":
    """
    Creates a new `EoReader` whose input data is a shared subsequence of this reader's
    data.

    The input data of the new reader will start at position `index` in this reader and contain
    up to `length` bytes. The two reader's position and chunked reading mode will be
    independent.

    The new reader's position will be zero, and its chunked reading mode will be false.

    Args:
        index (int, optional): The position in this reader at which the data of the new reader
            will start; must be non-negative. Defaults to the current reader position.
        length (int, optional): The length of the shared subsequence of data to supply to the
            new reader; must be non-negative. Defaults to the length of the remaining data
            starting from `index`.

    Returns:
        EoReader: The new reader.

    Raises:
        ValueError: If `index` or `length` is negative.
    """
    if index is None:
        index = self.position
    if length is None:
        length = max(0, len(self._data) - index)

    if index < 0:
        raise ValueError(f"negative index: {index}")

    if length < 0:
        raise ValueError(f"negative length: {length}")

    begin = max(0, min(len(self._data), index))
    end = begin + min(len(self._data) - begin, length)

    return EoReader(self._data[begin:end])

get_byte()

Reads a raw byte from the input data.

Returns:

Name	Type	Description
int	int	A raw byte.

Source code in src/eolib/data/eo_reader.py

def get_byte(self) -> int:
    """
    Reads a raw byte from the input data.

    Returns:
        int: A raw byte.
    """
    return self._read_byte()

get_bytes(length)

Reads an array of raw bytes from the input data.

Parameters:

Name	Type	Description	Default
length	int	The number of bytes to read.	required

Returns:

Name	Type	Description
bytearray	bytearray	An array of raw bytes.

Source code in src/eolib/data/eo_reader.py

def get_bytes(self, length: int) -> bytearray:
    """
    Reads an array of raw bytes from the input data.

    Args:
        length (int): The number of bytes to read.

    Returns:
        bytearray: An array of raw bytes.
    """
    return self._read_bytes(length)

get_char()

Reads an encoded 1-byte integer from the input data.

Returns:

Name	Type	Description
int	int	A decoded 1-byte integer.

Source code in src/eolib/data/eo_reader.py

def get_char(self) -> int:
    """
    Reads an encoded 1-byte integer from the input data.

    Returns:
        int: A decoded 1-byte integer.
    """
    return decode_number(self._read_bytes(1))

get_short()

Reads an encoded 2-byte integer from the input data.

Returns:

Name	Type	Description
int	int	A decoded 2-byte integer.

Source code in src/eolib/data/eo_reader.py

def get_short(self) -> int:
    """
    Reads an encoded 2-byte integer from the input data.

    Returns:
        int: A decoded 2-byte integer.
    """
    return decode_number(self._read_bytes(2))

get_three()

Reads an encoded 3-byte integer from the input data.

Returns:

Name	Type	Description
int	int	A decoded 3-byte integer.

Source code in src/eolib/data/eo_reader.py

def get_three(self) -> int:
    """
    Reads an encoded 3-byte integer from the input data.

    Returns:
        int: A decoded 3-byte integer.
    """
    return decode_number(self._read_bytes(3))

get_int()

Reads an encoded 4-byte integer from the input data.

Returns:

Name	Type	Description
int	int	A decoded 4-byte integer.

Source code in src/eolib/data/eo_reader.py

def get_int(self) -> int:
    """
    Reads an encoded 4-byte integer from the input data.

    Returns:
        int: A decoded 4-byte integer.
    """
    return decode_number(self._read_bytes(4))

get_string()

Reads a string from the input data.

Returns:

Name	Type	Description
str	str	A string.

Source code in src/eolib/data/eo_reader.py

def get_string(self) -> str:
    """
    Reads a string from the input data.

    Returns:
        str: A string.
    """
    string_bytes = self._read_bytes(self.remaining)
    return self._decode_ansi(string_bytes)

get_fixed_string(length, padded=False)

Reads a string with a fixed length from the input data.

Parameters:

Name	Type	Description	Default
length	int	The length of the string.	required
padded	bool	True if the string is padded with trailing 0xFF bytes.	False

Returns:

Name	Type	Description
str	str	A decoded string.

Raises:

Type	Description
ValueError	If the length is negative.

Source code in src/eolib/data/eo_reader.py

def get_fixed_string(self, length: int, padded: bool = False) -> str:
    """
    Reads a string with a fixed length from the input data.

    Args:
        length (int): The length of the string.
        padded (bool, optional): True if the string is padded with trailing `0xFF` bytes.

    Returns:
        str: A decoded string.

    Raises:
        ValueError: If the length is negative.
    """
    if length < 0:
        raise ValueError("Negative length")
    bytes_ = self._read_bytes(length)
    if padded:
        bytes_ = self._remove_padding(bytes_)
    return self._decode_ansi(bytes_)

get_encoded_string()

Reads an encoded string from the input data.

Returns:

Name	Type	Description
str	str	A decoded string.

Source code in src/eolib/data/eo_reader.py

def get_encoded_string(self) -> str:
    """
    Reads an encoded string from the input data.

    Returns:
        str: A decoded string.
    """
    bytes_ = self._read_bytes(self.remaining)
    decode_string(bytes_)
    return self._decode_ansi(bytes_)

get_fixed_encoded_string(length, padded=False)

Reads an encoded string with a fixed length from the input data.

Parameters:

Name	Type	Description	Default
length	int	The length of the string.	required
padded	bool	True if the string is padded with trailing 0xFF bytes.	False

Returns:

Name	Type	Description
str	str	A decoded string.

Raises:

Type	Description
ValueError	If the length is negative.

Source code in src/eolib/data/eo_reader.py

def get_fixed_encoded_string(self, length: int, padded: bool = False) -> str:
    """
    Reads an encoded string with a fixed length from the input data.

    Args:
        length (int): The length of the string.
        padded (bool, optional): True if the string is padded with trailing `0xFF` bytes.

    Returns:
        str: A decoded string.

    Raises:
        ValueError: If the length is negative.
    """
    if length < 0:
        raise ValueError("Negative length")
    bytes_ = self._read_bytes(length)
    decode_string(bytes_)
    if padded:
        bytes_ = self._remove_padding(bytes_)
    return self._decode_ansi(bytes_)

next_chunk()

Moves the reader position to the start of the next chunk in the input data.

Raises:

Type	Description
RuntimeError	If not in chunked reading mode.

Source code in src/eolib/data/eo_reader.py

def next_chunk(self) -> None:
    """
    Moves the reader position to the start of the next chunk in the input data.

    Raises:
        RuntimeError: If not in chunked reading mode.
    """
    if not self.chunked_reading_mode:
        raise RuntimeError("Not in chunked reading mode.")

    self._position = self._next_break
    if self._position < len(self._data):
        # Skip the break byte
        self._position += 1

    self._chunk_start = self._position
    self._next_break = self._find_next_break_index()

EoWriter

Source code in src/eolib/data/eo_writer.py

class EoWriter:
    def __init__(self):
        self.data = bytearray()
        self._string_sanitization_mode = False

    def add_byte(self, value: int) -> None:
        """
        Adds a raw byte to the writer data.

        Args:
            value (int): The byte to add.

        Raises:
            ValueError: If the value is above `0xFF`.
        """
        self._check_number_size(value, 0xFF)
        self.data.append(value)

    def add_bytes(self, bytes: bytes) -> None:
        """
        Adds raw bytes to the writer data.

        Args:
            bytes (bytes): The bytes to add.
        """
        self.data.extend(bytes)

    def add_char(self, number: int) -> None:
        """
        Adds an encoded 1-byte integer to the writer data.

        Args:
            number (int): The number to encode and add.

        Raises:
            ValueError: If the value is not below `CHAR_MAX`.
        """
        self._check_number_size(number, CHAR_MAX - 1)
        number_bytes = encode_number(number)
        self._add_bytes_with_length(number_bytes, 1)

    def add_short(self, number: int) -> None:
        """
        Adds an encoded 2-byte integer to the writer data.

        Args:
            number (int): The number to encode and add.

        Raises:
            ValueError: If the value is not below `SHORT_MAX`.
        """
        self._check_number_size(number, SHORT_MAX - 1)
        number_bytes = encode_number(number)
        self._add_bytes_with_length(number_bytes, 2)

    def add_three(self, number: int) -> None:
        """
        Adds an encoded 3-byte integer to the writer data.

        Args:
            number (int): The number to encode and add.

        Raises:
            ValueError: If the value is not below `THREE_MAX`.
        """
        self._check_number_size(number, THREE_MAX - 1)
        number_bytes = encode_number(number)
        self._add_bytes_with_length(number_bytes, 3)

    def add_int(self, number: int) -> None:
        """
        Adds an encoded 4-byte integer to the writer data.

        Args:
            number (int): The number to encode and add.

        Raises:
            ValueError: If the value is not below `INT_MAX`.
        """
        self._check_number_size(number, INT_MAX - 1)
        number_bytes = encode_number(number)
        self._add_bytes_with_length(number_bytes, 4)

    def add_string(self, string: str) -> None:
        """
        Adds a string to the writer data.

        Args:
            string (str): The string to be added.
        """
        string_bytes = self._encode_ansi(string)
        self._sanitize_string(string_bytes)
        self.add_bytes(string_bytes)

    def add_fixed_string(self, string: str, length: int, padded: bool = False) -> None:
        """
        Adds a fixed-length string to the writer data.

        Args:
            string (str): The string to be added.
            length (int): The expected length of the string.
            padded (bool, optional): True if the string should be padded to the length with
                trailing `0xFF` bytes. Defaults to False.
        """
        self._check_string_length(string, length, padded)
        string_bytes = self._encode_ansi(string)
        self._sanitize_string(string_bytes)
        if padded:
            string_bytes = self._add_padding(string_bytes, length)
        self.add_bytes(string_bytes)

    def add_encoded_string(self, string: str) -> None:
        """
        Adds an encoded string to the writer data.

        Args:
            string (str): The string to be encoded and added.
        """
        string_bytes = self._encode_ansi(string)
        self._sanitize_string(string_bytes)
        encode_string(string_bytes)
        self.add_bytes(string_bytes)

    def add_fixed_encoded_string(self, string: str, length: int, padded: bool = False) -> None:
        """
        Adds a fixed-length encoded string to the writer data.

        Args:
            string (str): The string to be encoded and added.
            length (int): The expected length of the string.
            padded (bool, optional): True if the string should be padded to the length with
                trailing `0xFF` bytes. Defaults to False.
        """
        self._check_string_length(string, length, padded)
        string_bytes = self._encode_ansi(string)
        self._sanitize_string(string_bytes)
        if padded:
            string_bytes = self._add_padding(string_bytes, length)
        encode_string(string_bytes)
        self.add_bytes(string_bytes)

    @property
    def string_sanitization_mode(self) -> bool:
        """
        Gets the string sanitization mode for the writer.

        Returns:
            bool: True if string sanitization is enabled.
        """
        return self._string_sanitization_mode

    @string_sanitization_mode.setter
    def string_sanitization_mode(self, string_sanitization_mode: bool) -> None:
        self._string_sanitization_mode = string_sanitization_mode

    def to_bytearray(self) -> bytearray:
        """
        Gets the writer data as a byte array.

        Returns:
            bytearray: A copy of the writer data as a byte array.
        """
        return self.data.copy()

    def __len__(self) -> int:
        """
        Gets the length of the writer data.

        Returns:
            int: The length of the writer data.
        """
        return len(self.data)

    def _add_bytes_with_length(self, bytes: bytes, bytes_length: int) -> None:
        """
        Adds raw bytes with a specified length to the writer data.

        Args:
            bytes (bytes): The bytes to add.
            bytes_length (int): The number of bytes to add.
        """
        self.data.extend(bytes[:bytes_length])

    def _sanitize_string(self, bytes: bytearray) -> None:
        if self.string_sanitization_mode:
            for i in range(len(bytes)):
                if bytes[i] == 0xFF:  # 'ÿ'
                    bytes[i] = 0x79  # 'y'

    @staticmethod
    def _check_number_size(number: int, max_value: int) -> None:
        if number > max_value:
            raise ValueError(f"Value {number} exceeds maximum of {max_value}.")

    @staticmethod
    def _add_padding(bytes: bytearray, length: int) -> bytearray:
        if len(bytes) == length:
            return bytes

        result = bytearray(length)
        result[: len(bytes)] = bytes
        result[len(bytes) :] = bytearray([0xFF] * (length - len(bytes)))

        return result

    @staticmethod
    def _check_string_length(string: str, length: int, padded: bool) -> None:
        if padded:
            if length >= len(string):
                return
            raise ValueError(f'Padded string "{string}" is too large for a length of {length}.')

        if len(string) != length:
            raise ValueError(f'String "{string}" does not have expected length of {length}.')

    @staticmethod
    def _encode_ansi(string: str) -> bytearray:
        """
        Encodes string to windows-1252 bytes.

        Args:
            string (str): The string to encode.

        Returns:
            bytearray: The encoded string.
        """
        return bytearray(string, 'windows-1252', 'replace')

data = bytearray() instance-attribute

string_sanitization_mode: bool property writable

Gets the string sanitization mode for the writer.

Returns:

Name	Type	Description
bool	bool	True if string sanitization is enabled.

__init__()

Source code in src/eolib/data/eo_writer.py

def __init__(self):
    self.data = bytearray()
    self._string_sanitization_mode = False

add_byte(value)

Adds a raw byte to the writer data.

Parameters:

Name	Type	Description	Default
value	int	The byte to add.	required

Raises:

Type	Description
ValueError	If the value is above 0xFF.

Source code in src/eolib/data/eo_writer.py

def add_byte(self, value: int) -> None:
    """
    Adds a raw byte to the writer data.

    Args:
        value (int): The byte to add.

    Raises:
        ValueError: If the value is above `0xFF`.
    """
    self._check_number_size(value, 0xFF)
    self.data.append(value)

add_bytes(bytes)

Adds raw bytes to the writer data.

Parameters:

Name	Type	Description	Default
bytes	bytes	The bytes to add.	required

Source code in src/eolib/data/eo_writer.py

def add_bytes(self, bytes: bytes) -> None:
    """
    Adds raw bytes to the writer data.

    Args:
        bytes (bytes): The bytes to add.
    """
    self.data.extend(bytes)

add_char(number)

Adds an encoded 1-byte integer to the writer data.

Parameters:

Name	Type	Description	Default
number	int	The number to encode and add.	required

Raises:

Type	Description
ValueError	If the value is not below CHAR_MAX.

Source code in src/eolib/data/eo_writer.py

def add_char(self, number: int) -> None:
    """
    Adds an encoded 1-byte integer to the writer data.

    Args:
        number (int): The number to encode and add.

    Raises:
        ValueError: If the value is not below `CHAR_MAX`.
    """
    self._check_number_size(number, CHAR_MAX - 1)
    number_bytes = encode_number(number)
    self._add_bytes_with_length(number_bytes, 1)

add_short(number)

Adds an encoded 2-byte integer to the writer data.

Parameters:

Name	Type	Description	Default
number	int	The number to encode and add.	required

Raises:

Type	Description
ValueError	If the value is not below SHORT_MAX.

Source code in src/eolib/data/eo_writer.py

def add_short(self, number: int) -> None:
    """
    Adds an encoded 2-byte integer to the writer data.

    Args:
        number (int): The number to encode and add.

    Raises:
        ValueError: If the value is not below `SHORT_MAX`.
    """
    self._check_number_size(number, SHORT_MAX - 1)
    number_bytes = encode_number(number)
    self._add_bytes_with_length(number_bytes, 2)

add_three(number)

Adds an encoded 3-byte integer to the writer data.

Parameters:

Name	Type	Description	Default
number	int	The number to encode and add.	required

Raises:

Type	Description
ValueError	If the value is not below THREE_MAX.

Source code in src/eolib/data/eo_writer.py

def add_three(self, number: int) -> None:
    """
    Adds an encoded 3-byte integer to the writer data.

    Args:
        number (int): The number to encode and add.

    Raises:
        ValueError: If the value is not below `THREE_MAX`.
    """
    self._check_number_size(number, THREE_MAX - 1)
    number_bytes = encode_number(number)
    self._add_bytes_with_length(number_bytes, 3)

add_int(number)

Adds an encoded 4-byte integer to the writer data.

Parameters:

Name	Type	Description	Default
number	int	The number to encode and add.	required

Raises:

Type	Description
ValueError	If the value is not below INT_MAX.

Source code in src/eolib/data/eo_writer.py

def add_int(self, number: int) -> None:
    """
    Adds an encoded 4-byte integer to the writer data.

    Args:
        number (int): The number to encode and add.

    Raises:
        ValueError: If the value is not below `INT_MAX`.
    """
    self._check_number_size(number, INT_MAX - 1)
    number_bytes = encode_number(number)
    self._add_bytes_with_length(number_bytes, 4)

add_string(string)

Adds a string to the writer data.

Parameters:

Name	Type	Description	Default
string	str	The string to be added.	required

Source code in src/eolib/data/eo_writer.py

def add_string(self, string: str) -> None:
    """
    Adds a string to the writer data.

    Args:
        string (str): The string to be added.
    """
    string_bytes = self._encode_ansi(string)
    self._sanitize_string(string_bytes)
    self.add_bytes(string_bytes)

add_fixed_string(string, length, padded=False)

Adds a fixed-length string to the writer data.

Parameters:

Name	Type	Description	Default
string	str	The string to be added.	required
length	int	The expected length of the string.	required
padded	bool	True if the string should be padded to the length with trailing 0xFF bytes. Defaults to False.	False

Source code in src/eolib/data/eo_writer.py

def add_fixed_string(self, string: str, length: int, padded: bool = False) -> None:
    """
    Adds a fixed-length string to the writer data.

    Args:
        string (str): The string to be added.
        length (int): The expected length of the string.
        padded (bool, optional): True if the string should be padded to the length with
            trailing `0xFF` bytes. Defaults to False.
    """
    self._check_string_length(string, length, padded)
    string_bytes = self._encode_ansi(string)
    self._sanitize_string(string_bytes)
    if padded:
        string_bytes = self._add_padding(string_bytes, length)
    self.add_bytes(string_bytes)

add_encoded_string(string)

Adds an encoded string to the writer data.

Parameters:

Name	Type	Description	Default
string	str	The string to be encoded and added.	required

Source code in src/eolib/data/eo_writer.py

def add_encoded_string(self, string: str) -> None:
    """
    Adds an encoded string to the writer data.

    Args:
        string (str): The string to be encoded and added.
    """
    string_bytes = self._encode_ansi(string)
    self._sanitize_string(string_bytes)
    encode_string(string_bytes)
    self.add_bytes(string_bytes)

add_fixed_encoded_string(string, length, padded=False)

Adds a fixed-length encoded string to the writer data.

Parameters:

Name	Type	Description	Default
string	str	The string to be encoded and added.	required
length	int	The expected length of the string.	required
padded	bool	True if the string should be padded to the length with trailing 0xFF bytes. Defaults to False.	False

Source code in src/eolib/data/eo_writer.py

def add_fixed_encoded_string(self, string: str, length: int, padded: bool = False) -> None:
    """
    Adds a fixed-length encoded string to the writer data.

    Args:
        string (str): The string to be encoded and added.
        length (int): The expected length of the string.
        padded (bool, optional): True if the string should be padded to the length with
            trailing `0xFF` bytes. Defaults to False.
    """
    self._check_string_length(string, length, padded)
    string_bytes = self._encode_ansi(string)
    self._sanitize_string(string_bytes)
    if padded:
        string_bytes = self._add_padding(string_bytes, length)
    encode_string(string_bytes)
    self.add_bytes(string_bytes)

to_bytearray()

Gets the writer data as a byte array.

Returns:

Name	Type	Description
bytearray	bytearray	A copy of the writer data as a byte array.

Source code in src/eolib/data/eo_writer.py

def to_bytearray(self) -> bytearray:
    """
    Gets the writer data as a byte array.

    Returns:
        bytearray: A copy of the writer data as a byte array.
    """
    return self.data.copy()

__len__()

Gets the length of the writer data.

Returns:

Name	Type	Description
int	int	The length of the writer data.

Source code in src/eolib/data/eo_writer.py

def __len__(self) -> int:
    """
    Gets the length of the writer data.

    Returns:
        int: The length of the writer data.
    """
    return len(self.data)

decode_number(encoded_number)

Decodes a number from a sequence of bytes.

Parameters:

Name	Type	Description	Default
encoded_number	bytes	The sequence of bytes to decode.	required

Returns:

Name	Type	Description
int	int	The decoded number.

Source code in src/eolib/data/number_encoding_utils.py

def decode_number(encoded_number: bytes) -> int:
    """
    Decodes a number from a sequence of bytes.

    Args:
        encoded_number (bytes): The sequence of bytes to decode.

    Returns:
        int: The decoded number.
    """
    result = 0
    length = min(len(encoded_number), 4)

    for i in range(length):
        value = encoded_number[i]

        if value == 0xFE:
            break

        value -= 1

        if i == 0:
            result += value
        elif i == 1:
            result += CHAR_MAX * value
        elif i == 2:
            result += SHORT_MAX * value
        elif i == 3:
            result += THREE_MAX * value

    return result

decode_string(bytes)

Decodes a string by reversing the bytes and then inverting them.

This is an in-place operation.

Parameters:

Name	Type	Description	Default
bytes	bytearray	The byte array to decode.	required

Source code in src/eolib/data/string_encoding_utils.py

def decode_string(bytes: bytearray) -> None:
    """
    Decodes a string by reversing the bytes and then inverting them.

    This is an in-place operation.

    Args:
        bytes (bytearray): The byte array to decode.
    """
    bytes.reverse()
    _invert_characters(bytes)

encode_number(number)

Encodes a number to a sequence of bytes.

Parameters:

Name	Type	Description	Default
number	int	The number to encode.	required

Returns:

Name	Type	Description
bytes	bytes	The encoded sequence of bytes.

Source code in src/eolib/data/number_encoding_utils.py

def encode_number(number: int) -> bytes:
    """
    Encodes a number to a sequence of bytes.

    Args:
        number (int): The number to encode.

    Returns:
        bytes: The encoded sequence of bytes.
    """
    value = number
    d = 0xFE
    if number >= THREE_MAX:
        d = value // THREE_MAX + 1
        value = value % THREE_MAX

    c = 0xFE
    if number >= SHORT_MAX:
        c = value // SHORT_MAX + 1
        value = value % SHORT_MAX

    b = 0xFE
    if number >= CHAR_MAX:
        b = value // CHAR_MAX + 1
        value = value % CHAR_MAX

    a = value + 1

    return bytes([a, b, c, d])

encode_string(bytes)

Encodes a string by inverting the bytes and then reversing them.

This is an in-place operation.

Parameters:

Name	Type	Description	Default
bytes	bytearray	The byte array to encode.	required

Source code in src/eolib/data/string_encoding_utils.py

def encode_string(bytes: bytearray) -> None:
    """
    Encodes a string by inverting the bytes and then reversing them.

    This is an in-place operation.

    Args:
        bytes (bytearray): The byte array to encode.
    """
    _invert_characters(bytes)
    bytes.reverse()