blob: 7439e7db3aae832bce5781a3b9d5a828a216b8b3 [file] [log] [blame]
# Copyright 2013 The LUCI Authors. All rights reserved.
# Use of this source code is governed under the Apache License, Version 2.0
# that can be found in the LICENSE file.
"""Methods for producing and consuming JSON."""
import functools
import collections
import contextlib
import json
from recipe_engine import recipe_api
from recipe_engine import util as recipe_util
from recipe_engine import config_types
def dumps(*args, **kwargs):
kwargs['sort_keys'] = True
kwargs.setdefault('default', config_types.json_fixup)
return json.dumps(*args, **kwargs)
class JsonOutputPlaceholder(recipe_util.OutputPlaceholder):
"""JsonOutputPlaceholder is meant to be a placeholder object which, when added
to a step's cmd list, will be replaced by the recipe engine with the path to a
temporary file (e.g. /tmp/tmp4lp1qM) which will exist only for the duration of
the step. Create a JsonOutputPlaceholder by calling the 'output()' method of
the JsonApi.
The step is expected to write JSON data to this file, and when the step is
finished, the file will be read and the JSON parsed back into the recipe, and
will be available as part of the step result.
result = api.step('step name',
['', api.json.output()])
# `result.json.output` is the parsed JSON value.
See the example recipe (./examples/ for some more uses.
def __init__(self, api, add_json_log, name=None, leak_to=None):
assert add_json_log in (True, False, 'on_failure'), (
'add_json_log=%r' % add_json_log)
self.raw = api.m.raw_io.output_text('.json', leak_to=leak_to)
self.add_json_log = add_json_log
super(JsonOutputPlaceholder, self).__init__(name=name)
def backing_file(self):
return self.raw.backing_file
def render(self, test):
return self.raw.render(test)
def result(self, presentation, test):
raw_data = self.raw.result(presentation, test)
valid = False
invalid_error = ''
ret = None
ret = JsonApi.loads(
raw_data, object_pairs_hook=collections.OrderedDict)
valid = True
# TypeError is raised when raw_data is None, which can happen if the json
# file was not created. We then correctly handle this as invalid result.
except (ValueError, TypeError) as ex: # pragma: no cover
invalid_error = str(ex)
if self.add_json_log is True or (
self.add_json_log == 'on_failure' and presentation.status != 'SUCCESS'):
if valid:
with contextlib.closing(recipe_util.StringListIO()) as listio:
json.dump(ret, listio, indent=2, sort_keys=True)
presentation.logs[self.label] = listio.lines
presentation.logs[self.label + ' (invalid)'] = raw_data.splitlines()
presentation.logs[self.label + ' (exception)'] = (
return ret
class JsonApi(recipe_api.RecipeApi):
def __init__(self, **kwargs):
super(JsonApi, self).__init__(**kwargs)
self.dumps = dumps
def loads(data, **kwargs):
"""Works like `json.loads`, but strips out unicode objects (replacing them
with utf8-encoded str objects)."""
return recipe_util.strip_unicode(json.loads(data, **kwargs))
def is_serializable(self, obj):
"""Returns True if the object is JSON-serializable."""
return True
except Exception:
return False
def input(self, data):
"""A placeholder which will expand to a file path containing <data>."""
return self.m.raw_io.input_text(self.dumps(data), '.json')
def output(self, add_json_log=True, name=None, leak_to=None):
"""A placeholder which will expand to '/tmp/file'.
If leak_to is provided, it must be a Path object. This path will be used in
place of a random temporary file, and the file will not be deleted at the
end of the step.
* add_json_log (True|False|'on_failure') - Log a copy of the output json
to a step link named `name`. If this is 'on_failure', only create this
log when the step has a non-SUCCESS status.
return JsonOutputPlaceholder(self, add_json_log, name=name, leak_to=leak_to)
def read(self, name, path, add_json_log=True, output_name=None, **kwargs):
"""Returns a step that reads a JSON file.
This method is deprecated. Use file.read_json instead.
return self.m.python.inline(
import shutil
import sys
shutil.copy(sys.argv[1], sys.argv[2])
self.output(add_json_log=add_json_log, name=output_name)],