@@ -391,6 +391,7 @@ ALL_LOCAL += flake8-check
# E128 continuation line under-indented for visual indent
# E129 visually indented line with same indent as next logical line
# E131 continuation line unaligned for hanging indent
+# E203 whitespace before ':'
# E722 do not use bare except, specify exception instead
# W503 line break before binary operator
# W504 line break after binary operator
@@ -403,7 +404,7 @@ ALL_LOCAL += flake8-check
# H233 Python 3.x incompatible use of print operator
# H238 old style class declaration, use new style (inherit from `object`)
FLAKE8_SELECT = H231,H232,H233,H238
-FLAKE8_IGNORE = E121,E123,E125,E126,E127,E128,E129,E131,E722,W503,W504,F811,D,H,I
+FLAKE8_IGNORE = E121,E123,E125,E126,E127,E128,E129,E131,E203,E722,W503,W504,F811,D,H,I
flake8-check: $(FLAKE8_PYFILES)
$(FLAKE8_WERROR)$(AM_V_GEN) \
src='$^' && \
@@ -16,7 +16,6 @@ ovs_pyfiles = \
python/ovs/compat/sortedcontainers/sorteddict.py \
python/ovs/compat/sortedcontainers/sortedset.py \
python/ovs/daemon.py \
- python/ovs/fcntl_win.py \
python/ovs/db/__init__.py \
python/ovs/db/custom_index.py \
python/ovs/db/data.py \
@@ -26,6 +25,10 @@ ovs_pyfiles = \
python/ovs/db/schema.py \
python/ovs/db/types.py \
python/ovs/fatal_signal.py \
+ python/ovs/fcntl_win.py \
+ python/ovs/flow/__init__.py \
+ python/ovs/flow/decoders.py \
+ python/ovs/flow/kv.py \
python/ovs/json.py \
python/ovs/jsonrpc.py \
python/ovs/ovsuuid.py \
@@ -42,6 +45,7 @@ ovs_pyfiles = \
python/ovs/version.py \
python/ovs/vlog.py \
python/ovs/winutils.py
+
# These python files are used at build time but not runtime,
# so they are not installed.
EXTRA_DIST += \
new file mode 100644
new file mode 100644
@@ -0,0 +1,18 @@
+"""Defines helpful decoders that can be used to decode information from the
+flows.
+
+A decoder is generally a callable that accepts a string and returns the value
+object.
+"""
+
+
+def decode_default(value):
+ """Default decoder.
+
+ It tries to convert into an integer value and, if it fails, just
+ returns the string.
+ """
+ try:
+ return int(value, 0)
+ except ValueError:
+ return value
new file mode 100644
@@ -0,0 +1,314 @@
+"""Common helper classes for flow Key-Value parsing."""
+
+import functools
+import re
+
+from ovs.flow.decoders import decode_default
+
+
+class ParseError(RuntimeError):
+ """Exception raised when an error occurs during parsing."""
+
+ pass
+
+
+class KeyMetadata(object):
+ """Class for keeping key metadata.
+
+ Attributes:
+ kpos (int): The position of the keyword in the parent string.
+ vpos (int): The position of the value in the parent string.
+ kstring (string): The keyword string as found in the flow string.
+ vstring (string): The value as found in the flow string.
+ delim (string): Optional, the string used as delimiter between the key
+ and the value.
+ end_delim (string): Optional, the string used as end delimiter
+ """
+
+ def __init__(self, kpos, vpos, kstring, vstring, delim="", end_delim=""):
+ """Constructor."""
+ self.kpos = kpos
+ self.vpos = vpos
+ self.kstring = kstring
+ self.vstring = vstring
+ self.delim = delim
+ self.end_delim = end_delim
+
+ def __str__(self):
+ return "key: [{},{}), val:[{}, {})".format(
+ self.kpos,
+ self.kpos + len(self.kstring),
+ self.vpos,
+ self.vpos + len(self.vstring),
+ )
+
+ def __repr__(self):
+ return "{}('{}')".format(self.__class__.__name__, self)
+
+
+class KeyValue(object):
+ """Class for keeping key-value data.
+
+ Attributes:
+ key (str): The key string.
+ value (any): The value data.
+ meta (KeyMetadata): The key metadata.
+ """
+
+ def __init__(self, key, value, meta=None):
+ """Constructor."""
+ self.key = key
+ self.value = value
+ self.meta = meta
+
+ def __str__(self):
+ return "{}: {} ({})".format(self.key, str(self.value), str(self.meta))
+
+ def __repr__(self):
+ return "{}('{}')".format(self.__class__.__name__, self)
+
+
+class KVDecoders(object):
+ """KVDecoders class is used by KVParser to select how to decode the value
+ of a specific keyword.
+
+ A decoder is simply a function that accepts a value string and returns
+ the value objects to be stored.
+ The returned value may be of any type.
+
+ Decoders may return a KeyValue instance to indicate that the keyword should
+ also be modified to match the one provided in the returned KeyValue.
+
+ The decoder to be used will be selected using the key as an index. If not
+ found, the default decoder will be used. If free keys are found (i.e:
+ keys without a value), the default_free decoder will be used. For that
+ reason, the default_free decoder, must return both the key and value to be
+ stored.
+
+ Args:
+ decoders (dict): Optional; A dictionary of decoders indexed by keyword.
+ default (callable): Optional; A decoder used if a match is not found in
+ configured decoders. If not provided, the default behavior is to
+ try to decode the value into an integer and, if that fails,
+ just return the string as-is.
+ default_free (callable): Optional; The decoder used if a match is not
+ found in configured decoders and it's a free value (e.g:
+ a value without a key) Defaults to returning the free value as
+ keyword and "True" as value.
+ The callable must accept a string and return a key-value pair.
+ """
+
+ def __init__(self, decoders=None, default=None, default_free=None):
+ self._decoders = decoders or dict()
+ self._default = default or decode_default
+ self._default_free = default_free or self._default_free_decoder
+
+ def decode(self, keyword, value_str):
+ """Decode a keyword and value.
+
+ Args:
+ keyword (str): The keyword whose value is to be decoded.
+ value_str (str): The value string.
+
+ Returns:
+ The key (str) and value(any) to be stored.
+ """
+
+ decoder = self._decoders.get(keyword)
+ if decoder:
+ result = decoder(value_str)
+ if isinstance(result, KeyValue):
+ keyword = result.key
+ value = result.value
+ else:
+ value = result
+
+ return keyword, value
+ else:
+ if value_str:
+ return keyword, self._default(value_str)
+ else:
+ return self._default_free(keyword)
+
+ @staticmethod
+ def _default_free_decoder(key):
+ """Default decoder for free keywords."""
+ return key, True
+
+
+delim_pattern = re.compile(r"(\(|=|:|,|\n|\r|\t)")
+parenthesis = re.compile(r"(\(|\))")
+end_pattern = re.compile(r"( |,|\n|\r|\t)")
+separators = (" ", ",")
+end_of_string = (",", "\n", "\t", "\r", "")
+
+
+class KVParser(object):
+ """KVParser parses a string looking for key-value pairs.
+
+ Args:
+ string (str): The string to parse.
+ decoders (KVDecoders): Optional; the KVDecoders instance to use.
+ """
+
+ def __init__(self, string, decoders=None):
+ """Constructor."""
+ self._decoders = decoders or KVDecoders()
+ self._keyval = list()
+ self._string = string
+
+ def keys(self):
+ return list(kv.key for kv in self._keyval)
+
+ def kv(self):
+ return self._keyval
+
+ def __iter__(self):
+ return iter(self._keyval)
+
+ def parse(self):
+ """Parse the key-value pairs in string.
+
+ The input string is assumed to contain a list of comma (or space)
+ separated key-value pairs.
+
+ Key-values pairs can have multiple different delimiters, eg:
+ "key1:value1,key2=value2,key3(value3)".
+
+ Also, we can stumble upon a "free" keywords, e.g:
+ "key1=value1,key2=value2,free_keyword".
+ We consider this as keys without a value.
+
+ So, to parse the string we do the following until the end of the
+ string is found:
+
+ 1 - Skip any leading comma's or spaces.
+ 2 - Find the next delimiter (or end_of_string character).
+ 3 - Depending on the delimiter, obtain the key and the value.
+ For instance, if the delimiter is "(", find the next matching
+ ")".
+ 4 - Use the KVDecoders to decode the key-value.
+ 5 - Store the KeyValue object with the corresponding metadata.
+
+ Raises:
+ ParseError if any parsing error occurs.
+ """
+ kpos = 0
+ while kpos < len(self._string) and self._string[kpos] != "\n":
+ keyword = ""
+ delimiter = ""
+ rest = ""
+
+ # 1. Skip separator characters.
+ if self._string[kpos] in separators:
+ kpos += 1
+ continue
+
+ # 2. Find the next delimiter or end of string character.
+ try:
+ keyword, delimiter, rest = delim_pattern.split(
+ self._string[kpos:], 1
+ )
+ except ValueError:
+ keyword = self._string[kpos:] # Free keyword
+
+ # 3. Extract the value from the rest of the string.
+ value_str = ""
+ vpos = kpos + len(keyword) + 1
+ end_delimiter = ""
+
+ if delimiter in ("=", ":"):
+ # If the delimiter is ':' or '=', the end of the value is the
+ # end of the string or a ', '.
+ value_parts = end_pattern.split(rest, 1)
+ value_str = value_parts[0]
+ next_kpos = vpos + len(value_str)
+
+ elif delimiter == "(":
+ # Find matching ")".
+ level = 1
+ index = 0
+ value_parts = parenthesis.split(rest)
+ for val in value_parts:
+ if val == "(":
+ level += 1
+ elif val == ")":
+ level -= 1
+ index += len(val)
+ if level == 0:
+ break
+
+ if level != 0:
+ raise ParseError(
+ "Error parsing string {}: "
+ "Failed to find matching ')' in {}".format(
+ self._string, rest
+ )
+ )
+
+ value_str = rest[: index - 1]
+ next_kpos = vpos + len(value_str) + 1
+ end_delimiter = ")"
+
+ # Exceptionally, if after the () we find -> {}, do not treat
+ # the content of the parenthesis as the value, consider
+ # ({})->{} as the string value.
+ if index < len(rest) - 2 and rest[index : index + 2] == "->":
+ extra_val = rest[index + 2 :].split(",")[0]
+ value_str = "({})->{}".format(value_str, extra_val)
+ # remove the first "(".
+ vpos -= 1
+ next_kpos = vpos + len(value_str)
+ end_delimiter = ""
+
+ elif delimiter in end_of_string:
+ # Key without a value.
+ next_kpos = kpos + len(keyword)
+ vpos = -1
+
+ # 4. Use KVDecoders to decode the key-value.
+ try:
+ key, val = self._decoders.decode(keyword, value_str)
+ except Exception as e:
+ raise ParseError(
+ "Error parsing key-value ({}, {})".format(
+ keyword, value_str
+ )
+ ) from e
+
+ # Store the KeyValue object with the corresponding metadata.
+ meta = KeyMetadata(
+ kpos=kpos,
+ vpos=vpos,
+ kstring=keyword,
+ vstring=value_str,
+ delim=delimiter,
+ end_delim=end_delimiter,
+ )
+
+ self._keyval.append(KeyValue(key, val, meta))
+
+ kpos = next_kpos
+
+
+def decode_nested_kv(decoders, value):
+ """A key-value decoder that extracts nested key-value pairs and returns
+ them in a dictionary.
+
+ Args:
+ decoders (KVDecoders): The KVDecoders to use.
+ value (str): The value string to decode.
+ """
+ if not value:
+ # Mark as flag
+ return True
+
+ parser = KVParser(value, decoders)
+ parser.parse()
+ return {kv.key: kv.value for kv in parser.kv()}
+
+
+def nested_kv_decoder(decoders=None):
+ """Helper function that creates a nested kv decoder with given
+ KVDecoders."""
+ return functools.partial(decode_nested_kv, decoders)
@@ -71,7 +71,7 @@ setup_args = dict(
author='Open vSwitch',
author_email='dev@openvswitch.org',
packages=['ovs', 'ovs.compat', 'ovs.compat.sortedcontainers',
- 'ovs.db', 'ovs.unixctl'],
+ 'ovs.db', 'ovs.unixctl', 'ovs.flow'],
keywords=['openvswitch', 'ovs', 'OVSDB'],
license='Apache 2.0',
classifiers=[