Source code for girder.utility.path

# -*- coding: utf-8 -*-
"""This module contains utility methods for parsing girder path strings."""

import re
from ..constants import AccessType
from ..exceptions import AccessException, GirderException, ValidationException
from ..exceptions import ResourcePathNotFound
from .model_importer import ModelImporter
from girder.models.collection import Collection
from girder.models.user import User

# Expose the ResourcePathNotFound exception as its original name
NotFoundException = ResourcePathNotFound

[docs]def encode(token): """Escape special characters in a token for path representation. :param str token: The token to encode :return: The encoded string :rtype: str """ return token.replace('\\', '\\\\').replace('/', '\\-')
[docs]def decode(token): """Un-escape special characters in a token from a path representation. :param str token: The token to decode :return: The decoded string :rtype: str """ return token.replace('\\-', '/').replace('\\\\', '\\')
[docs]def split(path): """Split an encoded path string into decoded tokens. :param str path: An encoded path string :return: A list of decoded tokens :rtype: `list` """ # It would be better to split by the regex `(?<!\\)(?>\\\\)*/`, # but python does't support atomic grouping. :( chunks = path.split('/') processed = [chunks[0]] # matches an odd number of backslashes at the end of the string escape = re.compile(r'(?<!\\)(?:\\\\)*\\$') # Loop through the chunks and check if any of the forward slashes was # escaped. for chunk in chunks[1:]: if[-1]): # join the chunks processed[-1] = processed[-1] + '/' + chunk else: # append a new token processed.append(chunk) # now decode all of the tokens and return return [decode(token) for token in processed]
[docs]def join(tokens): """Join a list of tokens into an encoded path string. :param tokens: A list of tokens :return: The encoded path string :rtype: str """ return '/'.join([encode(token) for token in tokens])
[docs]def lookUpToken(token, parentType, parent): """ Find a particular child resource by name or throw an exception. :param token: the name of the child resource to find :param parentType: the type of the parent to search :param parent: the parent resource :returns: the child resource """ # (model name, mask, search filter) searchTable = ( ('folder', parentType in ('user', 'collection', 'folder'), { 'name': token, 'parentId': parent['_id'], 'parentCollection': parentType }), ('item', parentType == 'folder', {'name': token, 'folderId': parent['_id']}), ('file', parentType == 'item', {'name': token, 'itemId': parent['_id']}), ) for candidateModel, mask, filterObject in searchTable: if not mask: continue candidateChild = ModelImporter.model(candidateModel).findOne(filterObject) if candidateChild is not None: return candidateChild, candidateModel # if no folder, item, or file matches, give up raise ResourcePathNotFound('Child resource not found: %s(%s)->%s' % ( parentType, parent.get('name', parent.get('_id')), token))
[docs]def lookUpPath(path, user=None, filter=True, force=False): """ Look up a resource in the data hierarchy by path. :param path: path of the resource :param user: user with correct privileges to access path :param filter: Whether the returned model should be filtered. :type filter: bool :param force: if True, don't validate the access. :type force: bool """ path = path.lstrip('/') pathArray = split(path) model = pathArray[0] if model == 'user': username = pathArray[1] parent = User().findOne({'login': username}) if parent is None: raise ResourcePathNotFound('User not found: %s' % username) elif model == 'collection': collectionName = pathArray[1] parent = Collection().findOne({'name': collectionName}) if parent is None: raise ResourcePathNotFound('Collection not found: %s' % collectionName) else: raise ValidationException('Invalid path format') try: document = parent if not force: ModelImporter.model(model).requireAccess(document, user) for token in pathArray[2:]: document, model = lookUpToken(token, model, document) if not force: ModelImporter.model(model).requireAccess(document, user) except (ValidationException, AccessException): # We should not distinguish the response between access and validation errors so that # adversarial users cannot discover the existence of data they don't have access to by # looking up a path. raise ResourcePathNotFound('Path not found: %s' % path) if filter: document = ModelImporter.model(model).filter(document, user) return { 'model': model, 'document': document }
[docs]def getResourceName(type, doc): """ Get the name of a resource that can be put in a path, :param type: the resource model type. :type type: str :param doc: the resource document. :type doc: dict :return: the name of the resource. :rtype: str """ if type == 'user': return doc['login'] elif type in ('file', 'item', 'folder', 'user', 'collection'): return doc['name'] else: raise GirderException('Invalid resource type.')
[docs]def getResourcePath(type, doc, user=None, force=False): """ Get the path for a resource. :param type: the resource model type. :type type: str :param doc: the resource document. :type doc: dict :param user: user with correct privileges to access path :type user: dict or None :param force: if True, don't validate the access. :type force: bool :return: the path to the resource. :rtype: str """ path = [] while True: path.insert(0, getResourceName(type, doc)) if type == 'file': parentModel = 'item' parentId = doc['itemId'] elif type == 'item': parentModel = 'folder' parentId = doc['folderId'] elif type == 'folder': parentModel = doc['parentCollection'] parentId = doc['parentId'] else: break doc = ModelImporter.model(parentModel).load( id=parentId, user=user, level=AccessType.READ, force=force) type = parentModel path.insert(0, type) return '/' + join(path)