pyzim.cluster.EmptyCluster

class documentation

class EmptyCluster(Cluster):

Constructor: EmptyCluster(zim)

A special type of pyzim.cluster.Cluster that is always empty.

This is used for creating new clusters.

Method	`__init__`	The default constructor.
Method	`get_blob_size`	Get the size of a blob.
Method	`get_content_size`	Return the content size of this cluster.
Method	`get_number_of_blobs`	Return the number of blobs in this cluster.
Method	`get_number_of_offsets`	Return the number of offsets in this cluster.
Method	`get_offset`	Return the offset with the specified index.
Method	`get_total_compressed_size`	Return the total compressed size of the cluster.
Method	`get_total_decompressed_size`	Return the total decompressed size of this cluster.
Method	`get_total_offset_size`	Return the total size of the offsets.
Method	`iter_blob_offsets`	Read the blob offsets, yielding them as an iterator.
Method	`iter_read_blob`	Iteratively read the specified blob.
Method	`read_blob`	Read the entirety of the specified range in the specified blob and return the content.
Method	`read_infobyte`	Read the cluster information byte, returning it.
Method	`read_infobyte_if_needed`	Read and parse the infobyte if this has not yet happened.
Method	`reset`	Reset all internal state except the cluster offset, causing said offset to be read again the next time it is required.
Instance Variable	`compression`	Undocumented
Instance Variable	`is_extended`	Undocumented

Inherited from Cluster:

Method	`generate_infobyte`	Generate the infobyte for this cluster.
Method	`parse_infobyte`	Parse the cluster information byte, setting the attributes of this cluster as necessary.
Instance Variable	`offset`	absolute offset of the cluster
Property	`did_read_infobyte`	True if the infobyte was already read and parsed.
Method	`_get_compressor`	Return a compressor suitable to compress this cluster.
Method	`_get_decompressing_reader`	Return a decompressing reader that can be sued to decompress the content.
Method	`_get_decompressor`	Return a decompressor suitable to decompress this cluster.
Method	`_seek_if_needed`	Seek to the specified position (relative to the cluster start) in the file only if it is needed.
Instance Variable	`_decompressing_reader`	Undocumented
Property	`_pointer_format`	The pointer format.

Inherited from BindableMixIn (via Cluster):

Method	`bind`	Bind this object to a ZIM file.
Method	`unbind`	Unbind this object. Can be called multiple times.
Property	`bound`	Whether this object is bound to a ZIM file or not.
Property	`zim`	The bound ZIM archive, if any is bound. Otherwise None.
Instance Variable	`_zim`	the bound ZIM archive or None

def __init__(self, zim=None): ¶

overrides pyzim.cluster.Cluster.__init__

The default constructor.

def get_blob_size(self, i): ¶

overrides pyzim.cluster.Cluster.get_blob_size

Get the size of a blob.

Parameters
i:`int`	index of blob to get size for

Returns
`int`	the size of the uncompressed blob

Raises
`pyzim.exceptions.BindRequired`	if cluster is unbound
`pyzim.exceptions.BlobNotFound`	if the specified blob does not exists

def get_content_size(self): ¶

overrides pyzim.cluster.Cluster.get_content_size

Return the content size of this cluster.

This is the uncompressed size of the content of this cluster, not including the offsets and infobyte.

Returns
`int`	the size of the content of this cluster

Raises
`pyzim.exceptions.BindRequired`	if cluster is unbound

def get_number_of_blobs(self): ¶

overrides pyzim.cluster.Cluster.get_number_of_blobs

Return the number of blobs in this cluster.

This value differs from the number of offsets in the cluster.

Returns
`int`	the number of blobs in this cluster

Raises
`pyzim.exceptions.BindRequired`	if cluster is unbound

def get_number_of_offsets(self): ¶

overrides pyzim.cluster.Cluster.get_number_of_offsets

Return the number of offsets in this cluster.

This value differs from the number of blobs in the cluster.

Returns
`int`	the number of offsets in this cluster.

Raises
`pyzim.exceptions.BindRequired`	if cluster is unbound

def get_offset(self, i): ¶

overrides pyzim.cluster.Cluster.get_offset

Return the offset with the specified index.

Parameters
i:`int`	index of blob to get offset for

Raises
`IndexError`	if i < 0 or i >= len(offsets)
`pyzim.exceptions.BindRequired`	if cluster is unbound

def get_total_compressed_size(self): ¶

overrides pyzim.cluster.Cluster.get_total_compressed_size

Return the total compressed size of the cluster.

This includes the entirety of the cluster, including the infobyte.

NOTE: this method is horribly inefficient, as it requires decompressing the entire cluster

Returns
`int`	the size of this cluster

Raises
`pyzim.exceptions.BindRequired`	if cluster is unbound

def get_total_decompressed_size(self): ¶

overrides pyzim.cluster.Cluster.get_total_decompressed_size

Return the total decompressed size of this cluster.

This is the uncompressed size of the content of this cluster, including the offsets but not the infobyte.

Returns
`int`	the size of the content of this cluster including offsets

Raises
`pyzim.exceptions.BindRequired`	if cluster is unbound

def get_total_offset_size(self): ¶

overrides pyzim.cluster.Cluster.get_total_offset_size

Return the total size of the offsets.

Returns
`int`	the total size of the offsets in bytes

def iter_blob_offsets(self, blob_numbers=None): ¶

overrides pyzim.cluster.Cluster.iter_blob_offsets

Read the blob offsets, yielding them as an iterator.

The order of blob_numbers does not matter, all offsets are always yielded in regular order (offfset 1, offset 2, ...).

Parameters
blob_numbers:`None` or `list` of `int`	if specified, load only these offsets

Yields
`int`	the offset of each blob in the decompressed body, relative to cluster start

Raises
`pyzim.exceptions.BindRequired`	if cluster is unbound

def iter_read_blob(self, i, buffersize=4096, start=None, end=None): ¶

overrides pyzim.cluster.Cluster.iter_read_blob

Iteratively read the specified blob.

The parameters 'start' and 'end' can be used to specify a range within the blob to read. In this case, both values are interpreted relative to the actual blob start. Similar to how python slices work, the 'start' value will be inclusive and the 'end' value exclusive. If start >= size of the blob, the return value will be b"". If the end lies outside the blob, read only up until the end of the blob.

Parameters
i:`int`	index of blob to read
buffersize:`int`	number of bytes to read at once
start:`None` or `int`	if specified, the offset relative to the start of the blob to start reading from
end:`None` or `int`	if specified, the offset relative to the start of the blob to stop reading at

Yields
`bytes`	chunks of the blob content

Raises
`pyzim.exceptions.BindRequired`	if cluster is unbound
`pyzim.exceptions.BlobNotFound`	if the blob index is out of range

def read_blob(self, i, start=None, end=None): ¶

overrides pyzim.cluster.Cluster.read_blob

Read the entirety of the specified range in the specified blob and return the content.

Parameters
i:`int`	index of blob to read
start:`None` or `int`	if specified, the offset relative to the start of the blob to start reading from
end:`None` or `int`	if specified, the offset relative to the start of the blob to stop reading at

Returns
`bytes`	the content of the blob

Raises
`pyzim.exceptions.BindRequired`	if cluster is unbound
`pyzim.exceptions.BlobNotFound`	if the blob index is out of range

def read_infobyte(self): ¶

overrides pyzim.cluster.Cluster.read_infobyte

Read the cluster information byte, returning it.

Returns
`bytes`	the byte containing cluster information

Raises
`pyzim.exceptions.BindRequired`	if cluster is unbound

def read_infobyte_if_needed(self): ¶

overrides pyzim.cluster.Cluster.read_infobyte_if_needed

Read and parse the infobyte if this has not yet happened.

def reset(self): ¶

overrides pyzim.cluster.Cluster.reset

Reset all internal state except the cluster offset, causing said offset to be read again the next time it is required.

compression = ¶

overrides pyzim.cluster.Cluster.compression

Undocumented

is_extended: bool = ¶

overrides pyzim.cluster.Cluster.is_extended

Undocumented