def has_next(peekable: more_itertools.peekable) -> bool:
"""Return True if the peekable has a next element."""
try:
peekable.peek()
return True
except StopIteration:
return False
def has_next(peekable: more_itertools.peekable) -> bool:
"""Return True if the peekable has a next element."""
try:
peekable.peek()
return True
except StopIteration:
return False
def _parse_string(json_iterator: peekable) -> str:
result = ''
json_iterator.next() # Skip over opening "
while True:
next_char = json_iterator.next()
if next_char == '"' and not result.endswith('\\'):
break
result += next_char
return result
def _parse_null(json_iterator: peekable):
value = ''
while json_iterator.peek() not in string.whitespace and json_iterator.peek(
) not in (_token_separator, _object_end, _array_end):
value += json_iterator.next()
if value == 'null':
return None
else:
raise ParseError('Invalid string "' + value +
'" found while trying to parse a null value')
def _parse_boolean(json_iterator: peekable) -> bool:
value = ''
while json_iterator.peek() not in string.whitespace and json_iterator.peek(
) not in (_token_separator, _object_end, _array_end):
value += json_iterator.next()
if value == 'true':
return True
elif value == 'false':
return False
else:
raise ParseError('Invalid string "' + value +
'" found while trying to parse a boolean value')
def _take_until(iterable: more_itertools.peekable, predicate):
try:
yield next(iterable)
while not predicate(iterable.peek()):
yield next(iterable)
except StopIteration:
return
def _read_query(cls, lines: peekable):
qls = []
line = lines.peek(None)
while line is not None and not cls._sep_re.match(line):
qls.append(next(lines))
line = lines.peek(None)
# trim lines
while qls and not qls[0].strip():
qls.pop(0)
while qls and not qls[-1].strip():
qls.pop(-1)
if qls or line is not None:
return qls
else:
return None # end of file
def _parse_array(json_iterator: peekable) -> list:
values = []
json_iterator.next() # Skip over opening [
_whitespace_skip(json_iterator)
next_char = json_iterator.peek()
if next_char == _array_end:
json_iterator.next()
return [] # Empty Array
while True:
if next_char == _object_start:
element_value = _parse_object(json_iterator)
elif next_char == _array_start:
element_value = _parse_array(json_iterator)
elif next_char == _string_delimiter:
element_value = _parse_string(json_iterator)
elif next_char in _numeric_start:
element_value = _parse_numeric(json_iterator)
elif next_char in _boolean_start: # JSON defines boolean values as "true" or "false" exclusively
element_value = _parse_boolean(json_iterator)
elif next_char == _null_start: # JSON defines a "null" value
element_value = _parse_null(json_iterator)
values.append(element_value)
_whitespace_skip(json_iterator)
next_char = json_iterator.peek()
if next_char == _array_end:
json_iterator.next()
return values
elif next_char == _token_separator:
next_char = json_iterator.next()
_whitespace_skip(json_iterator)
next_char = json_iterator.peek()
else:
raise ParseError(
'Unexpected character while trying to parse array: "' +
next_char + '"')
def _parse_numeric(json_iterator: peekable) -> numbers.Number:
value = ''
next_char = json_iterator.next()
while True:
value += next_char
next_char = json_iterator.peek()
if next_char in string.whitespace or next_char in (_token_separator,
_object_end,
_array_end):
break
else:
next_char = json_iterator.next()
try:
return int(value)
except ValueError:
try:
return float(value)
except ValueError:
raise ParseError('String ' + value +
' could not be parsed as a number')
def _read_header(cls, lines: peekable):
label = None
errs = []
tx = True
line = lines.peek(None)
while line is not None:
hm = cls._sep_re.match(line)
if hm is None:
break
next(lines) # eat line
line = lines.peek(None)
inst = hm.group('inst')
cm = cls._icode_re.match(inst)
if cm is None:
continue
code = cm.group('code')
args = cm.group('args')
if code == 'step':
label = args
elif code == 'allow':
err = getattr(psycopg2.errorcodes, args.upper())
_log.debug('step allows error %s (%s)', args, err)
errs.append(err)
elif code == 'notx':
_log.debug('chunk will run outside a transaction')
tx = False
else:
_log.error('unrecognized query instruction %s', code)
raise ValueError(f'invalid query instruction {code}')
return ScriptChunk(label=label,
allowed_errors=errs,
src=None,
use_transaction=tx)
def _whitespace_skip(json_iterator: peekable):
while json_iterator.peek() in string.whitespace:
json_iterator.next()
def _parse_object(json_iterator: peekable) -> dict:
next_char = json_iterator.next()
if next_char != _object_start:
raise ParseError(
'Unexpected character while trying to parse object: "' +
next_char + '"')
# Skip over whitespace
_whitespace_skip(json_iterator)
next_char = json_iterator.peek()
if next_char == _object_end:
json_iterator.next()
return {}
tokens = {}
while True:
# At the object level, a valid element follows the form "<element name AS string> : <value>"
if json_iterator.peek() not in (_string_delimiter, _token_separator):
raise ParseError('Unexpected character: "' + next_char + '"')
element_name = _parse_string(json_iterator)
element_value = None
# Advance to the separator and the start of the value
_whitespace_skip(json_iterator)
next_char = json_iterator.peek()
if next_char != _pair_separator:
raise ParseError('Unexpected character while parsing element ' +
element_name + ': "' + next_char + '"')
json_iterator.next()
_whitespace_skip(json_iterator)
# Parse the value element
next_char = json_iterator.peek()
if next_char == _object_start:
element_value = _parse_object(json_iterator)
elif next_char == _array_start:
element_value = _parse_array(json_iterator)
elif next_char == _string_delimiter:
element_value = _parse_string(json_iterator)
elif next_char in _numeric_start:
element_value = _parse_numeric(json_iterator)
elif next_char in _boolean_start: # JSON defines boolean values as "true" or "false" exclusively
element_value = _parse_boolean(json_iterator)
elif next_char == _null_start: # JSON defines a "null" value
element_value = _parse_null(json_iterator)
else: # We've hit something invalid, let's abort
raise ParseError('Unexpected character while parsing element ' +
element_name + ': "' + next_char + '"')
tokens[element_name] = element_value
# Advance the iterator over whitespace, the token separator, whitespace to the start of the next token
_whitespace_skip(json_iterator)
next_char = json_iterator.peek()
if not next_char in (_pair_separator, _object_end, _token_separator):
raise ParseError('Unexpected character while parsing element ' +
element_name + ': "' + next_char + '"')
json_iterator.next()
if next_char == _object_end:
break
_whitespace_skip(json_iterator)
return tokens