1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
|
"""
Manages external references in the YAML tree using the `JSON Reference
standard <http://tools.ietf.org/html/draft-pbryan-zyp-json-ref-03>`__
and `JSON Pointer standard <http://tools.ietf.org/html/rfc6901>`__.
"""
import weakref
from collections.abc import Sequence
from contextlib import suppress
import numpy as np
from . import generic_io, treeutil, util
from .util import _patched_urllib_parse
__all__ = ["Reference", "find_references", "make_reference", "resolve_fragment", "resolve_references"]
def resolve_fragment(tree, pointer):
"""
Resolve a JSON Pointer within the tree.
"""
pointer = pointer.lstrip("/")
parts = _patched_urllib_parse.unquote(pointer).split("/") if pointer else []
for part in parts:
part_ = part.replace("~1", "/").replace("~0", "~")
if isinstance(tree, Sequence):
# Array indexes should be turned into integers
with suppress(ValueError):
part_ = int(part_)
try:
tree = tree[part_]
except (TypeError, LookupError) as err:
msg = f"Unresolvable reference: '{pointer}'"
raise ValueError(msg) from err
return tree
class Reference:
def __init__(self, uri, base_uri=None, asdffile=None, target=None):
self._uri = uri
if asdffile is not None:
self._asdffile = weakref.ref(asdffile)
self._base_uri = base_uri
self._target = target
def _get_target(self, **kwargs):
if self._target is None:
base_uri = self._base_uri
if base_uri is None:
base_uri = self._asdffile().uri
uri = generic_io.resolve_uri(base_uri, self._uri)
asdffile = self._asdffile().open_external(uri, **kwargs)
parts = _patched_urllib_parse.urlparse(self._uri)
fragment = parts.fragment
self._target = resolve_fragment(asdffile.tree, fragment)
return self._target
def __repr__(self):
# repr alone should not force loading of the reference
if self._target is None:
return f"<Reference (unloaded) to '{self._uri}'>"
return f"<Reference to {self._target!r}>"
def __str__(self):
# str alone should not force loading of the reference
if self._target is None:
return f"<Reference (unloaded) to '{self._uri}'>"
return str(self._target)
def __len__(self):
return len(self._get_target())
def __getattr__(self, attr):
if attr == "_tag":
return None
try:
return getattr(self._get_target(), attr)
except Exception as err:
msg = f"No attribute '{attr}'"
raise AttributeError(msg) from err
def __getitem__(self, item):
return self._get_target()[item]
def __setitem__(self, item, val):
self._get_target()[item] = val
def __array__(self):
return np.asarray(self._get_target())
def __call__(self, **kwargs):
return self._get_target(**kwargs)
def __contains__(self, item):
return item in self._get_target()
def find_references(tree, ctx):
"""
Find all of the JSON references in the tree, and convert them into
`Reference` objects.
"""
def do_find(tree):
if isinstance(tree, dict) and "$ref" in tree:
return Reference(tree["$ref"], asdffile=ctx)
return tree
return treeutil.walk_and_modify(tree, do_find)
def resolve_references(tree, ctx, **kwargs):
"""
Resolve all of the references in the tree, by loading the external
data and inserting it directly into the tree.
"""
def do_resolve(tree):
if isinstance(tree, Reference):
return tree(**kwargs)
return tree
tree = find_references(tree, ctx)
return treeutil.walk_and_modify(tree, do_resolve)
def make_reference(asdffile, path):
"""
Make a reference to a subtree of the given ASDF file.
Parameters
----------
asdffile : AsdfFile
path : list of str and int, optional
The parts of the path pointing to an item in this tree.
If omitted, points to the root of the tree.
Returns
-------
reference : reference.Reference
A reference object.
"""
path_str = "/".join(x.replace("~", "~0").replace("/", "~1") for x in path)
target = resolve_fragment(asdffile.tree, path_str)
if asdffile.uri is None:
msg = "Can not make a reference to a AsdfFile without an associated URI."
raise ValueError(msg)
base_uri = util.get_base_uri(asdffile.uri)
uri = base_uri + "#" + path_str
return Reference(uri, target=target)
|
