Refactoring split_args into sub-functions

This commit is contained in:
James Cammarata 2014-07-24 20:00:57 -05:00
parent f0859a6d80
commit b8a4ba26f0

View file

@ -15,6 +15,39 @@
# You should have received a copy of the GNU General Public License
# along with Ansible. If not, see <http://www.gnu.org/licenses/>.
def _get_quote_state(token, quote_char):
'''
the goal of this block is to determine if the quoted string
is unterminated in which case it needs to be put back together
'''
# the char before the current one, used to see if
# the current character is escaped
prev_char = None
for idx, cur_char in enumerate(token):
if idx > 0:
prev_char = token[idx-1]
if cur_char in '"\'':
if quote_char:
if cur_char == quote_char and prev_char != '\\':
quote_char = None
else:
quote_char = cur_char
return quote_char
def _count_jinja2_blocks(token, cur_depth, open_token, close_token):
'''
this function counts the number of opening/closing blocks for a
given opening/closing type and adjusts the current depth for that
block based on the difference
'''
num_open = token.count(open_token)
num_close = token.count(close_token)
if num_open != num_close:
cur_depth += (num_open - num_close)
if cur_depth < 0:
cur_depth = 0
return cur_depth
def split_args(args):
'''
Splits args on whitespace, but intelligently reassembles
@ -24,15 +57,13 @@ def split_args(args):
jinja2 blocks, however this function is/will be used in the
core portions as well before the args are templated.
example input: a=b c=d
example output: dict(a='b', c='d')
example input: a=b c="foo bar"
example output: ['a=b', 'c="foo bar"']
Basically this is a variation shlex that has some more intelligence for
how Ansible needs to use it.
'''
# FIXME: refactoring into smaller functions
# the list of params parsed out of the arg string
# this is going to be the result value when we are donei
params = []
@ -40,9 +71,9 @@ def split_args(args):
# here we encode the args, so we have a uniform charset to
# work with, and split on white space
args = args.encode('utf-8')
items = args.split()
tokens = args.split()
# iterate over the items, and reassemble any that may have been
# iterate over the tokens, and reassemble any that may have been
# split on a space inside a jinja2 block.
# ex if tokens are "{{", "foo", "}}" these go together
@ -50,42 +81,22 @@ def split_args(args):
# to keep track of the state of the parsing, since blocks and quotes
# may be nested within each other.
inside_quotes = False
quote_char = None
split_print_depth = 0
split_block_depth = 0
split_comment_depth = 0
inside_quotes = False
print_depth = 0 # used to count nested jinja2 {{ }} blocks
block_depth = 0 # used to count nested jinja2 {% %} blocks
comment_depth = 0 # used to count nested jinja2 {# #} blocks
# now we loop over each split item, coalescing items if the white space
# now we loop over each split token, coalescing tokens if the white space
# split occurred within quotes or a jinja2 block of some kind
for token in tokens:
for item in items:
item = item.strip()
token = token.strip()
# store the previous quoting state for checking later
was_inside_quotes = inside_quotes
# determine the current quoting state
# the goal of this block is to determine if the quoted string
# is unterminated in which case it needs to be put back together
bc = None # before_char
for i in range(0, len(item)): # use enumerate
c = item[i] # current_char
if i > 0:
bc = item[i-1]
if c in ('"', "'"):
if inside_quotes:
if c == quote_char and bc != '\\':
inside_quotes = False
quote_char = None
else:
inside_quotes = True
quote_char = c
quote_char = _get_quote_state(token, quote_char)
inside_quotes = quote_char is not None
# multiple conditions may append a token to the list of params,
# so we keep track with this flag to make sure it only happens once
@ -93,69 +104,45 @@ def split_args(args):
# it to the end of the last token
appended = False
# if we're inside quotes now, but weren't before, append the item
# if we're inside quotes now, but weren't before, append the token
# to the end of the list, since we'll tack on more to it later
if inside_quotes and not was_inside_quotes:
params.append(item)
appended = True
# otherwise, if we're inside any jinja2 block, inside quotes, or we were
# inside quotes (but aren't now) concat this item to the last param
# FIXME: just or these all together
elif (split_print_depth or split_block_depth or split_comment_depth or inside_quotes or was_inside_quotes):
params[-1] = "%s %s" % (params[-1], item)
# inside quotes (but aren't now) concat this token to the last param
if inside_quotes and not was_inside_quotes:
params.append(token)
appended = True
elif print_depth or block_depth or comment_depth or inside_quotes or was_inside_quotes:
params[-1] = "%s %s" % (params[-1], token)
appended = True
# these variables are used to determine the current depth of each jinja2
# block type, by counting the number of openings and closing tags
# FIXME: assumes Jinja2 seperators aren't changeable (also true elsewhere in ansible ATM)
num_print_open = item.count('{{')
num_print_close = item.count('}}')
num_block_open = item.count('{%')
num_block_close = item.count('%}')
num_comment_open = item.count('{#')
num_comment_close = item.count('#}')
# if the number of paired block tags is not the same, the depth has changed, so we calculate that here
# and may append the current item to the params (if we haven't previously done so)
# FIXME: DRY a bit
if num_print_open != num_print_close:
split_print_depth += (num_print_open - num_print_close)
if not appended:
params.append(item)
# and may append the current token to the params (if we haven't previously done so)
prev_print_depth = print_depth
print_depth = _count_jinja2_blocks(token, print_depth, "{{", "}}")
if print_depth != prev_print_depth and not appended:
params.append(token)
appended = True
if split_print_depth < 0:
split_print_depth = 0
if num_block_open != num_block_close:
split_block_depth += (num_block_open - num_block_close)
if not appended:
params.append(item)
prev_block_depth = block_depth
block_depth = _count_jinja2_blocks(token, block_depth, "{%", "%}")
if block_depth != prev_block_depth and not appended:
params.append(token)
appended = True
if split_block_depth < 0:
split_block_depth = 0
if num_comment_open != num_comment_close:
split_comment_depth += (num_comment_open - num_comment_close)
if not appended:
params.append(item)
prev_comment_depth = comment_depth
comment_depth = _count_jinja2_blocks(token, comment_depth, "{#", "#}")
if comment_depth != prev_comment_depth and not appended:
params.append(token)
appended = True
if split_comment_depth < 0:
split_comment_depth = 0
# finally, if we're at zero depth for all blocks and not inside quotes, and have not
# yet appended anything to the list of params, we do so now
if not (split_print_depth or split_block_depth or split_comment_depth) and not inside_quotes and not appended:
params.append(item)
if not (print_depth or block_depth or comment_depth) and not inside_quotes and not appended:
params.append(token)
# If we're done and things are not at zero depth or we're still inside quotes,
# raise an error to indicate that the args were unbalanced
if (split_print_depth or split_block_depth or split_comment_depth) or inside_quotes:
if print_depth or block_depth or comment_depth or inside_quotes:
raise Exception("error while splitting arguments, either an unbalanced jinja2 block or quotes")
# finally, we decode each param back to the unicode it was in the arg string