def get_throttling_plan(js: str):
"""Extract the "throttling plan".
The "throttling plan" is a list of tuples used for calling functions
in the c array. The first element of the tuple is the index of the
function to call, and any remaining elements of the tuple are arguments
to pass to that function.
:param str js:
The contents of the base.js asset file.
:returns:
The full function code for computing the throttlign parameter.
"""
raw_code = get_throttling_function_code(js)
transform_start = r"try{"
plan_regex = re.compile(transform_start)
match = plan_regex.search(raw_code)
transform_plan_raw = find_object_from_startpoint(raw_code,
match.span()[1] - 1)
# Steps are either c[x](c[y]) or c[x](c[y],c[z])
step_start = r"c\[(\d+)\]\(c\[(\d+)\](,c(\[(\d+)\]))?\)"
step_regex = re.compile(step_start)
matches = step_regex.findall(transform_plan_raw)
transform_steps = []
for match in matches:
if match[4] != '':
transform_steps.append((match[0], match[1], match[4]))
else:
transform_steps.append((match[0], match[1]))
return transform_steps
def get_throttling_function_code(js: str) -> str:
"""Extract the raw code for the throttling function.
:param str js:
The contents of the base.js asset file.
:rtype: str
:returns:
The name of the function used to compute the throttling parameter.
"""
# Begin by extracting the correct function name
name = re.escape(get_throttling_function_name(js))
# Identify where the function is defined
pattern_start = r"%s=function\(\w\)" % name
regex = re.compile(pattern_start)
match = regex.search(js)
# Extract the code within curly braces for the function itself, and merge any split lines
code_lines_list = find_object_from_startpoint(js, match.span()[1]).split('\n')
joined_lines = "".join(code_lines_list)
# Prepend function definition (e.g. `Dea=function(a)`)
return match.group(0) + joined_lines
def get_throttling_function_array(js: str) -> List[Any]:
"""Extract the "c" array.
:param str js:
The contents of the base.js asset file.
:returns:
The array of various integers, arrays, and functions.
"""
raw_code = get_throttling_function_code(js)
array_start = r",c=\["
array_regex = re.compile(array_start)
match = array_regex.search(raw_code)
array_raw = find_object_from_startpoint(raw_code, match.span()[1] - 1)
str_array = throttling_array_split(array_raw)
converted_array = []
for el in str_array:
try:
converted_array.append(int(el))
continue
except ValueError:
# Not an integer value.
pass
if el == 'null':
converted_array.append(None)
continue
if el.startswith('"') and el.endswith('"'):
# Convert e.g. '"abcdef"' to string without quotation marks, 'abcdef'
converted_array.append(el[1:-1])
continue
if el.startswith('function'):
mapper = (
(r"{for\(\w=\(\w%\w\.length\+\w\.length\)%\w\.length;\w--;\)\w\.unshift\(\w.pop\(\)\)}",
throttling_unshift), # noqa:E501
(r"{\w\.reverse\(\)}", throttling_reverse),
(r"{\w\.push\(\w\)}", throttling_push),
(r";var\s\w=\w\[0\];\w\[0\]=\w\[\w\];\w\[\w\]=\w}",
throttling_swap),
(r"case\s\d+", throttling_cipher_function),
(r"\w\.splice\(0,1,\w\.splice\(\w,1,\w\[0\]\)\[0\]\)",
throttling_nested_splice), # noqa:E501
(r";\w\.splice\(\w,1\)}", js_splice),
(r"\w\.splice\(-\w\)\.reverse\(\)\.forEach\(function\(\w\){\w\.unshift\(\w\)}\)",
throttling_prepend), # noqa:E501
(r"for\(var \w=\w\.length;\w;\)\w\.push\(\w\.splice\(--\w,1\)\[0\]\)}",
throttling_reverse), # noqa:E501
)
found = False
for pattern, fn in mapper:
if re.search(pattern, el):
converted_array.append(fn)
found = True
if found:
continue
converted_array.append(el)
# Replace null elements with array itself
for i in range(len(converted_array)):
if converted_array[i] is None:
converted_array[i] = converted_array
return converted_array