Source code for hcpsdk.pathbuilder

# -*- coding: utf-8 -*-
# The MIT License (MIT)
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# Copyright (c) 2014-2018 Thorsten Simons (sw@snomis.de)
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from posixpath import join
from io import BytesIO
from uuid import uuid1
from xml.etree.ElementTree import ElementTree
from xml.etree.ElementTree import Element
import logging

__all__ = ['PathBuilderError', 'PathBuilder']

logging.getLogger('hcpsdk.pathbuilder').addHandler(logging.NullHandler())


[docs]class PathBuilderError(Exception): """ Used to signal an error during unique object name generation or object name to path mapping. """ def __init__(self, reason): """ :param reason: an error description """ self.args = (reason,)
[docs]class PathBuilder(object): """ Conversion of a filename into a unique object name and a proper path for HCPs needs. Re-conversion of a unique object name to the path where the object can be found in HCP. """ def __init__(self, initialpath='/rest/hcpsdk', annotation=False): """ :param initialpath: the leading part of the path :param annotation: if True, create an XML structure to be used as custom metadata annotation containing a tag with the original filename of the object. """ self.logger = logging.getLogger(__name__ + '.PathBuilder') self.leadingpath = initialpath self.annotation = annotation
[docs] def getunique(self, filename): """ Build a unique path / object name scheme. The path is build from **initialpath** given during class instantiation plus byte 4 and 3 of the UUID in hexadecimal. If **annotation** is True during class instantiation, there will be a third element in the returned tuple, containing an XML structure that can be used as custom metadata annotation for the object. :param filename: the filename to be transformed :return: a tuple consisting of path, unique object name and -eventually- an annotation string. :raises: hcpsdk.pathbuilder.pathbuilderError **Example:** :: >>> from hcpsdk.pathbuilder import PathBuilder >>> p = PathBuilder(initialpath='/rest/mypath', annotation=True) >>> o = p.getunique('testfile.txt') >>> o ('/rest/mypath/b4/ec', '8ac8ecb4-9f1e-11e4-a524-98fe94437d8c', '<?xml version=\'1.0\' encoding=\'utf-8\'?> <hcpsdk_fileobject filename="testfile.txt" path="/rest/mypath/b4/ec" uuid="8ac8ecb4-9f1e-11e4-a524-98fe94437d8c" />') >>> """ try: uuid = str(uuid1()) path = join(self.leadingpath, uuid[6:8], uuid[4:6]) if self.annotation: xml = ElementTree() e = Element('hcpsdk_fileobject', {'filename': filename, 'path': path, 'uuid': uuid}) # noinspection PyProtectedMember xml._setroot(e) with BytesIO() as xmlstring: xml.write(xmlstring, encoding="utf-8", method="xml", xml_declaration=True) annotation = xmlstring.getvalue().decode() except Exception as e: raise PathBuilderError(str(e)) if self.annotation: # noinspection PyUnboundLocalVariable return path, uuid, annotation else: return path, uuid
[docs] def getpath(self, objectname): """ From a unique object name, retrieve the path in which the object was stored. :param objectname: an unique object name :return: the full path to the object (including its name) :raises: hcpsdk.pathbuilder.pathbuilderError **Example:** :: >>> p.getpath('8ac8ecb4-9f1e-11e4-a524-98fe94437d8c') '/rest/mypath/b4/ec/8ac8ecb4-9f1e-11e4-a524-98fe94437d8c' >>> """ try: path = join(self.leadingpath, objectname[6:8], objectname[4:6], objectname) except Exception as e: raise PathBuilderError(str(e)) return path