in azure/multiapi/storage/v2017_11_09/blob/baseblobservice.py [0:0]
def _get_blob(
self, container_name, blob_name, snapshot=None, start_range=None,
end_range=None, validate_content=False, lease_id=None, if_modified_since=None,
if_unmodified_since=None, if_match=None, if_none_match=None, timeout=None,
_context=None):
'''
Downloads a blob's content, metadata, and properties. You can also
call this API to read a snapshot. You can specify a range if you don't
need to download the blob in its entirety. If no range is specified,
the full blob will be downloaded.
See get_blob_to_* for high level functions that handle the download
of large blobs with automatic chunking and progress notifications.
:param str container_name:
Name of existing container.
:param str blob_name:
Name of existing blob.
:param str snapshot:
The snapshot parameter is an opaque DateTime value that,
when present, specifies the blob snapshot to retrieve.
:param int start_range:
Start of byte range to use for downloading a section of the blob.
If no end_range is given, all bytes after the start_range will be downloaded.
The start_range and end_range params are inclusive.
Ex: start_range=0, end_range=511 will download first 512 bytes of blob.
:param int end_range:
End of byte range to use for downloading a section of the blob.
If end_range is given, start_range must be provided.
The start_range and end_range params are inclusive.
Ex: start_range=0, end_range=511 will download first 512 bytes of blob.
:param bool validate_content:
When this is set to True and specified together with the Range header,
the service returns the MD5 hash for the range, as long as the range
is less than or equal to 4 MB in size.
:param str lease_id:
Required if the blob has an active lease.
:param datetime if_modified_since:
A DateTime value. Azure expects the date value passed in to be UTC.
If timezone is included, any non-UTC datetimes will be converted to UTC.
If a date is passed in without timezone info, it is assumed to be UTC.
Specify this header to perform the operation only
if the resource has been modified since the specified time.
:param datetime if_unmodified_since:
A DateTime value. Azure expects the date value passed in to be UTC.
If timezone is included, any non-UTC datetimes will be converted to UTC.
If a date is passed in without timezone info, it is assumed to be UTC.
Specify this header to perform the operation only if
the resource has not been modified since the specified date/time.
:param str if_match:
An ETag value, or the wildcard character (*). Specify this header to perform
the operation only if the resource's ETag matches the value specified.
:param str if_none_match:
An ETag value, or the wildcard character (*). Specify this header
to perform the operation only if the resource's ETag does not match
the value specified. Specify the wildcard character (*) to perform
the operation only if the resource does not exist, and fail the
operation if it does exist.
:param int timeout:
The timeout parameter is expressed in seconds.
:return: A Blob with content, properties, and metadata.
:rtype: :class:`~azure.storage.blob.models.Blob`
'''
_validate_not_none('container_name', container_name)
_validate_not_none('blob_name', blob_name)
_validate_decryption_required(self.require_encryption,
self.key_encryption_key,
self.key_resolver_function)
start_offset, end_offset = 0, 0
if self.key_encryption_key is not None or self.key_resolver_function is not None:
if start_range is not None:
# Align the start of the range along a 16 byte block
start_offset = start_range % 16
start_range -= start_offset
# Include an extra 16 bytes for the IV if necessary
# Because of the previous offsetting, start_range will always
# be a multiple of 16.
if start_range > 0:
start_offset += 16
start_range -= 16
if end_range is not None:
# Align the end of the range along a 16 byte block
end_offset = 15 - (end_range % 16)
end_range += end_offset
request = HTTPRequest()
request.method = 'GET'
request.host_locations = self._get_host_locations(secondary=True)
request.path = _get_path(container_name, blob_name)
request.query = {
'snapshot': _to_str(snapshot),
'timeout': _int_to_str(timeout),
}
request.headers = {
'x-ms-lease-id': _to_str(lease_id),
'If-Modified-Since': _datetime_to_utc_string(if_modified_since),
'If-Unmodified-Since': _datetime_to_utc_string(if_unmodified_since),
'If-Match': _to_str(if_match),
'If-None-Match': _to_str(if_none_match),
}
_validate_and_format_range_headers(
request,
start_range,
end_range,
start_range_required=False,
end_range_required=False,
check_content_md5=validate_content)
return self._perform_request(request, _parse_blob,
[blob_name, snapshot, validate_content, self.require_encryption,
self.key_encryption_key, self.key_resolver_function,
start_offset, end_offset],
operation_context=_context)