U
e5d� � @ s: d Z ddlZejZG dd� dej�ZG dd� dej�ZdS )z7Internal classes used by the gzip, lzma and bz2 modules� Nc @ s0 e Zd ZdZdd� Zdd� Zdd� Zdd � Zd
S ) �
BaseStreamz Mode-checking helper functions.c C s | j rtd��d S )Nz I/O operation on closed file)�closed�
ValueError��self� r �$/usr/lib64/python3.8/_compression.py�_check_not_closed s z BaseStream._check_not_closedc C s | � � st�d��d S )NzFile not open for reading)�readable�io�UnsupportedOperationr r r r �_check_can_read s zBaseStream._check_can_readc C s | � � st�d��d S )NzFile not open for writing)�writabler r r r r r �_check_can_write s zBaseStream._check_can_writec C s( | � � st�d��| �� s$t�d��d S )Nz3Seeking is only supported on files open for readingz3The underlying file object does not support seeking)r
r r �seekabler r r r �_check_can_seek s
zBaseStream._check_can_seekN)�__name__�
__module__� __qualname__�__doc__r r
r r r r r r r s
r c sj e Zd ZdZdd� Zddd�Z� fdd�Zd d
� Zd d � Zddd�Z dd� Z
e j fdd�Z
dd� Z� ZS )�DecompressReaderz5Adapts the decompressor API to a RawIOBase reader APIc C s dS )NTr r r r r r
$ s zDecompressReader.readabler c K s> || _ d| _d| _d| _|| _|| _| jf | j�| _|| _d S )NFr �����)�_fp�_eof�_pos�_size�_decomp_factory� _decomp_args�
_decompressor�_trailing_error)r �fpZdecomp_factoryZtrailing_errorZ decomp_argsr r r �__init__' s zDecompressReader.__init__c s d | _ t� �� S �N)r �super�closer �� __class__r r r$ ; s zDecompressReader.closec C s
| j �� S r" )r r r r r r r ? s zDecompressReader.seekablec
C sP t |��:}|�d��$}| �t|��}||d t|��< W 5 Q R X W 5 Q R X t|�S )N�B)�
memoryview�cast�read�len)r �bZviewZ byte_view�datar r r �readintoB s $zDecompressReader.readintor c C s� |dk r| � � S |r| jr dS d }| jjr�| jjp<| j�t�}|sDq�| jf | j �| _z| j�
||�}W q� | j k
r� Y q�Y q�X n4| jj r�| j�t�}|s�t
d��nd}| j�
||�}|r"q�q"|s�d| _| j| _dS | jt|�7 _|S )Nr � zACompressed file ended before the end-of-stream marker was reachedT)�readallr r �eofZ unused_datar r* � BUFFER_SIZEr r �
decompressr Z needs_input�EOFErrorr r r+ )r �sizer- Zrawblockr r r r* H s@
��
zDecompressReader.readc C s, | j �d� d| _d| _| jf | j�| _d S )Nr F)r �seekr r r r r r r r r �_rewindr s zDecompressReader._rewindc C s� |t jkr nR|t jkr"| j| }n<|t jkrP| jdk rD| �t j�rDq6| j| }ntd� |���|| jk rr| �
� n
|| j8 }|dkr�| �t t j|��}|s�q�|t |�8 }q|| jS )Nr z Invalid value for whence: {})
r �SEEK_SET�SEEK_CURr �SEEK_ENDr r* �DEFAULT_BUFFER_SIZEr �formatr7 �minr+ )r �offset�whencer- r r r r6 x s&
zDecompressReader.seekc C s | j S )z!Return the current file position.)r r r r r �tell� s zDecompressReader.tell)r )r )r r r r r
r! r$ r r. r* r7 r r8 r6 r@ �
__classcell__r r r% r r ! s
* r )r r r; r2 �BufferedIOBaser � RawIOBaser r r r r � s