Making the switch to v2

lib/ansible/parsing/splitter.py

@@ -0,0 +1,273 @@
+# (c) 2014 James Cammarata, <jcammarata@ansible.com>
+#
+# This file is part of Ansible
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+
+# Make coding more python3-ish
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+import re
+import codecs
+
+# Decode escapes adapted from rspeer's answer here:
+# http://stackoverflow.com/questions/4020539/process-escape-sequences-in-a-string-in-python
+_HEXCHAR = '[a-fA-F0-9]'
+_ESCAPE_SEQUENCE_RE = re.compile(r'''
+    ( \\U{0}           # 8-digit hex escapes
+    | \\u{1}           # 4-digit hex escapes
+    | \\x{2}           # 2-digit hex escapes
+    | \\[0-7]{{1,3}}   # Octal escapes
+    | \\N\{{[^}}]+\}}  # Unicode characters by name
+    | \\[\\'"abfnrtv]  # Single-character escapes
+    )'''.format(_HEXCHAR*8, _HEXCHAR*4, _HEXCHAR*2), re.UNICODE | re.VERBOSE)
+
+def _decode_escapes(s):
+    def decode_match(match):
+        return codecs.decode(match.group(0), 'unicode-escape')
+
+    return _ESCAPE_SEQUENCE_RE.sub(decode_match, s)
+
+def parse_kv(args, check_raw=False):
+    '''
+    Convert a string of key/value items to a dict. If any free-form params
+    are found and the check_raw option is set to True, they will be added
+    to a new parameter called '_raw_params'. If check_raw is not enabled,
+    they will simply be ignored.
+    '''
+
+    ### FIXME: args should already be a unicode string
+    from ansible.utils.unicode import to_unicode
+    args = to_unicode(args, nonstring='passthru')
+
+    options = {}
+    if args is not None:
+        try:
+            vargs = split_args(args)
+        except ValueError as ve:
+            if 'no closing quotation' in str(ve).lower():
+                raise errors.AnsibleError("error parsing argument string, try quoting the entire line.")
+            else:
+                raise
+
+        raw_params = []
+        for x in vargs:
+            x = _decode_escapes(x)
+            if "=" in x:
+                pos = 0
+                try:
+                    while True:
+                        pos = x.index('=', pos + 1)
+                        if pos > 0 and x[pos - 1] != '\\':
+                            break
+                except ValueError:
+                    # ran out of string, but we must have some escaped equals,
+                    # so replace those and append this to the list of raw params
+                    raw_params.append(x.replace('\\=', '='))
+                    continue
+
+                k = x[:pos]
+                v = x[pos + 1:]
+
+                # only internal variables can start with an underscore, so
+                # we don't allow users to set them directy in arguments
+                if k.startswith('_'):
+                    raise AnsibleError("invalid parameter specified: '%s'" % k)
+
+                # FIXME: make the retrieval of this list of shell/command
+                #        options a function, so the list is centralized
+                if check_raw and k not in ('creates', 'removes', 'chdir', 'executable', 'warn'):
+                    raw_params.append(x)
+                else:
+                    options[k.strip()] = unquote(v.strip())
+            else:
+                raw_params.append(x)
+
+        # recombine the free-form params, if any were found, and assign
+        # them to a special option for use later by the shell/command module
+        if len(raw_params) > 0:
+            options[u'_raw_params'] = ' '.join(raw_params)
+
+    return options
+
+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 '"\'' and prev_char != '\\':
+            if quote_char:
+                if cur_char == quote_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
+    those that may have been split over a jinja2 block or quotes.
+
+    When used in a remote module, we won't ever have to be concerned about
+    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="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.
+    '''
+
+    # the list of params parsed out of the arg string
+    # this is going to be the result value when we are done
+    params = []
+
+    # Initial split on white space
+    args = args.strip()
+    items = args.strip().split('\n')
+
+    # 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
+
+    # These variables are used
+    # to keep track of the state of the parsing, since blocks and quotes
+    # may be nested within each other.
+
+    quote_char = None
+    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 chunk, coalescing tokens if the white space
+    # split occurred within quotes or a jinja2 block of some kind
+    for itemidx,item in enumerate(items):
+
+        # we split on spaces and newlines separately, so that we
+        # can tell which character we split on for reassembly
+        # inside quotation characters
+        tokens = item.strip().split(' ')
+
+        line_continuation = False
+        for idx,token in enumerate(tokens):
+
+            # if we hit a line continuation character, but
+            # we're not inside quotes, ignore it and continue
+            # on to the next token while setting a flag
+            if token == '\\' and not inside_quotes:
+                line_continuation = True
+                continue
+
+            # store the previous quoting state for checking later
+            was_inside_quotes = inside_quotes
+            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
+            # append means add to the end of the list, don't append means concatenate
+            # it to the end of the last token
+            appended = False
+
+            # 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
+            # otherwise, if we're inside any jinja2 block, inside quotes, or we were
+            # 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:
+                if idx == 0 and was_inside_quotes:
+                    params[-1] = "%s%s" % (params[-1], token)
+                elif len(tokens) > 1:
+                    spacer = ''
+                    if idx > 0:
+                        spacer = ' '
+                    params[-1] = "%s%s%s" % (params[-1], spacer, token)
+                else:
+                    params[-1] = "%s\n%s" % (params[-1], token)
+                appended = True
+
+            # 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 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
+
+            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
+
+            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
+
+            # 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 (print_depth or block_depth or comment_depth) and not inside_quotes and not appended and token != '':
+                params.append(token)
+
+        # if this was the last token in the list, and we have more than
+        # one item (meaning we split on newlines), add a newline back here
+        # to preserve the original structure
+        if len(items) > 1 and itemidx != len(items) - 1 and not line_continuation:
+            params[-1] += '\n'
+
+        # always clear the line continuation flag
+        line_continuation = False
+
+    # 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 print_depth or block_depth or comment_depth or inside_quotes:
+        raise Exception("error while splitting arguments, either an unbalanced jinja2 block or quotes")
+
+    return params
+
+def is_quoted(data):
+    return len(data) > 0 and (data[0] == '"' and data[-1] == '"' or data[0] == "'" and data[-1] == "'")
+
+def unquote(data):
+    ''' removes first and last quotes from a string, if the string starts and ends with the same quotes '''
+    if is_quoted(data):
+        return data[1:-1]
+    return data