# Protocol Buffers - Google's data interchange format
# Copyright 2008 Google Inc. All rights reserved.
# http://code.google.com/p/protobuf/
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above
# copyright notice, this list of conditions and the following disclaimer
# in the documentation and/or other materials provided with the
# distribution.
# * Neither the name of Google Inc. nor the names of its
# contributors may be used to endorse or promote products derived from
# this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
"""Contains routines for printing protocol messages in text format."""
__author__ = 'kenton@google.com (Kenton Varda)'
import cStringIO
import re
from collections import deque
from google.protobuf.internal import type_checkers
from google.protobuf import descriptor
__all__ = [ 'MessageToString', 'PrintMessage', 'PrintField',
'PrintFieldValue', 'Merge' ]
class ParseError(Exception):
"""Thrown in case of ASCII parsing error."""
def MessageToString(message):
out = cStringIO.StringIO()
PrintMessage(message, out)
result = out.getvalue()
out.close()
return result
def PrintMessage(message, out, indent = 0):
for field, value in message.ListFields():
if field.label == descriptor.FieldDescriptor.LABEL_REPEATED:
for element in value:
PrintField(field, element, out, indent)
else:
PrintField(field, value, out, indent)
def PrintField(field, value, out, indent = 0):
"""Print a single field name/value pair. For repeated fields, the value
should be a single element."""
out.write(' ' * indent);
if field.is_extension:
out.write('[')
if (field.containing_type.GetOptions().message_set_wire_format and
field.type == descriptor.FieldDescriptor.TYPE_MESSAGE and
field.message_type == field.extension_scope and
field.label == descriptor.FieldDescriptor.LABEL_OPTIONAL):
out.write(field.message_type.full_name)
else:
out.write(field.full_name)
out.write(']')
elif field.type == descriptor.FieldDescriptor.TYPE_GROUP:
# For groups, use the capitalized name.
out.write(field.message_type.name)
else:
out.write(field.name)
if field.cpp_type != descriptor.FieldDescriptor.CPPTYPE_MESSAGE:
# The colon is optional in this case, but our cross-language golden files
# don't include it.
out.write(': ')
PrintFieldValue(field, value, out, indent)
out.write('\n')
def PrintFieldValue(field, value, out, indent = 0):
"""Print a single field value (not including name). For repeated fields,
the value should be a single element."""
if field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_MESSAGE:
out.write(' {\n')
PrintMessage(value, out, indent + 2)
out.write(' ' * indent + '}')
elif field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_ENUM:
out.write(field.enum_type.values_by_number[value].name)
elif field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_STRING:
out.write('\"')
out.write(_CEscape(value))
out.write('\"')
elif field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_BOOL:
if value:
out.write("true")
else:
out.write("false")
else:
out.write(str(value))
def Merge(text, message):
"""Merges an ASCII representation of a protocol message into a message.
Args:
text: Message ASCII representation.
message: A protocol buffer message to merge into.
Raises:
ParseError: On ASCII parsing problems.
"""
tokenizer = _Tokenizer(text)
while not tokenizer.AtEnd():
_MergeField(tokenizer, message)
def _MergeField(tokenizer, message):
"""Merges a single protocol message field into a message.
Args:
tokenizer: A tokenizer to parse the field name and values.
message: A protocol message to record the data.
Raises:
ParseError: In case of ASCII parsing problems.
"""
message_descriptor = message.DESCRIPTOR
if tokenizer.TryConsume('['):
name = [tokenizer.ConsumeIdentifier()]
while tokenizer.TryConsume('.'):
name.append(tokenizer.ConsumeIdentifier())
name = '.'.join(name)
if not message_descriptor.is_extendable:
raise tokenizer.ParseErrorPreviousToken(
'Message type "%s" does not have extensions.' %
message_descriptor.full_name)
field = message.Extensions._FindExtensionByName(name)
if not field:
raise tokenizer.ParseErrorPreviousToken(
'Extension "%s" not registered.' % name)
elif message_descriptor != field.containing_type:
raise tokenizer.ParseErrorPreviousToken(
'Extension "%s" does not extend message type "%s".' % (
name, message_descriptor.full_name))
tokenizer.Consume(']')
else:
name = tokenizer.ConsumeIdentifier()
field = message_descriptor.fields_by_name.get(name, None)
# Group names are expected to be capitalized as they appear in the
# .proto file, which actually matches their type names, not their field
# names.
if not field:
field = message_descriptor.fields_by_name.get(name.lower(), None)
if field and field.type != descriptor.FieldDescriptor.TYPE_GROUP:
field = None
if (field and field.type == descriptor.FieldDescriptor.TYPE_GROUP and
field.message_type.name != name):
field = None
if not field:
raise tokenizer.ParseErrorPreviousToken(
'Message type "%s" has no field named "%s".' % (
message_descriptor.full_name, name))
if field.cpp_type == descriptor.FieldDescriptor.CPPTYPE_MESSAGE:
tokenizer.TryConsume(':')
if tokenizer.TryConsume('<'):
end_token = '>'
else:
tokenizer.Consume('{')
end_token = '}'
if field.label == descriptor.FieldDescriptor.LABEL_REPEATED:
if field.is_extension:
sub_message = message.Extensions[field].add()
else:
sub_message = getattr(message, field.name).add()
else:
if field.is_extension:
sub_message = message.Extensions[field]
else:
sub_message = getattr(message, field.name)
sub_message.SetInParent()
while not tokenizer.TryConsume(end_token):
if tokenizer.AtEnd():
raise tokenizer.ParseErrorPreviousToken('Expected "%s".' % (end_token))
_MergeField(tokenizer, sub_message)
else:
_MergeScalarField(tokenizer, message, field)
def _MergeScalarField(tokenizer, message, field):
"""Merges a single protocol message scalar field into a message.
Args:
tokenizer: A tokenizer to parse the field value.
message: A protocol message to record the data.
field: The descriptor of the field to be merged.
Raises:
ParseError: In case of ASCII parsing problems.
RuntimeError: On runtime errors.
"""
tokenizer.Consume(':')
value = None
if field.type in (descriptor.FieldDescriptor.TYPE_INT32,
descriptor.FieldDescriptor.TYPE_SINT32,
descriptor.FieldDescriptor.TYPE_SFIXED32):
value = tokenizer.ConsumeInt32()
elif field.type in (descriptor.FieldDescriptor.TYPE_INT64,
descriptor.FieldDescriptor.TYPE_SINT64,
descriptor.FieldDescriptor.TYPE_SFIXED64):
value = tokenizer.ConsumeInt64()
elif field.type in (descriptor.FieldDescriptor.TYPE_UINT32,
descriptor.FieldDescriptor.TYPE_FIXED32):
value = tokenizer.ConsumeUint32()
elif field.type in (descriptor.FieldDescriptor.TYPE_UINT64,
descriptor.FieldDescriptor.TYPE_FIXED64):
value = tokenizer.ConsumeUint64()
elif field.type in (descriptor.FieldDescriptor.TYPE_FLOAT,
descriptor.FieldDescriptor.TYPE_DOUBLE):
value = tokenizer.ConsumeFloat()
elif field.type == descriptor.FieldDescriptor.TYPE_BOOL:
value = tokenizer.ConsumeBool()
elif field.type == descriptor.FieldDescriptor.TYPE_STRING:
value = tokenizer.ConsumeString()
elif field.type == descriptor.FieldDescriptor.TYPE_BYTES:
value = tokenizer.ConsumeByteString()
elif field.type == descriptor.FieldDescriptor.TYPE_ENUM:
# Enum can be specified by a number (the enum value), or by
# a string literal (the enum name).
enum_descriptor = field.enum_type
if tokenizer.LookingAtInteger():
number = tokenizer.ConsumeInt32()
enum_value = enum_descriptor.values_by_number.get(number, None)
if enum_value is None:
raise tokenizer.ParseErrorPreviousToken(
'Enum type "%s" has no value with number %d.' % (
enum_descriptor.full_name, number))
else:
identifier = tokenizer.ConsumeIdentifier()
enum_value = enum_descriptor.values_by_name.get(identifier, None)
if enum_value is None:
raise tokenizer.ParseErrorPreviousToken(
'Enum type "%s" has no value named %s.' % (
enum_descriptor.full_name, identifier))
value = enum_value.number
else:
raise RuntimeError('Unknown field type %d' % field.type)
if field.label == descriptor.FieldDescriptor.LABEL_REPEATED:
if field.is_extension:
message.Extensions[field].append(value)
else:
getattr(message, field.name).append(value)
else:
if field.is_extension:
message.Extensions[field] = value
else:
setattr(message, field.name, value)
class _Tokenizer(object):
"""Protocol buffer ASCII representation tokenizer.
This class handles the lower level string parsing by splitting it into
meaningful tokens.
It was directly ported from the Java protocol buffer API.
"""
_WHITESPACE = re.compile('(\\s|(#.*$))+', re.MULTILINE)
_TOKEN = re.compile(
'[a-zA-Z_][0-9a-zA-Z_+-]*|' # an identifier
'[0-9+-][0-9a-zA-Z_.+-]*|' # a number
'\"([^\"\n\\\\]|\\\\.)*(\"|\\\\?$)|' # a double-quoted string
'\'([^\'\n\\\\]|\\\\.)*(\'|\\\\?$)') # a single-quoted string
_IDENTIFIER = re.compile('\w+')
_INTEGER_CHECKERS = [type_checkers.Uint32ValueChecker(),
type_checkers.Int32ValueChecker(),
type_checkers.Uint64ValueChecker(),
type_checkers.Int64ValueChecker()]
_FLOAT_INFINITY = re.compile('-?inf(inity)?f?', re.IGNORECASE)
_FLOAT_NAN = re.compile("nanf?", re.IGNORECASE)
def __init__(self, text_message):
self._text_message = text_message
self._position = 0
self._line = -1
self._column = 0
self._token_start = None
self.token = ''
self._lines = deque(text_message.split('\n'))
self._current_line = ''
self._previous_line = 0
self._previous_column = 0
self._SkipWhitespace()
self.NextToken()
def AtEnd(self):
"""Checks the end of the text was reached.
Returns:
True iff the end was reached.
"""
return not self._lines and not self._current_line
def _PopLine(self):
while not self._current_line:
if not self._lines:
self._current_line = ''
return
self._line += 1
self._column = 0
self._current_line = self._lines.popleft()
def _SkipWhitespace(self):
while True:
self._PopLine()
match = re.match(self._WHITESPACE, self._current_line)
if not match:
break
length = len(match.group(0))
self._current_line = self._current_line[length:]
self._column += length
def TryConsume(self, token):
"""Tries to consume a given piece of text.
Args:
token: Text to consume.
Returns:
True iff the text was consumed.
"""
if self.token == token:
self.NextToken()
return True
return False
def Consume(self, token):
"""Consumes a piece of text.
Args:
token: Text to consume.
Raises:
ParseError: If the text couldn't be consumed.
"""
if not self.TryConsume(token):
raise self._ParseError('Expected "%s".' % token)
def LookingAtInteger(self):
"""Checks if the current token is an integer.
Returns:
True iff the current token is an integer.
"""
if not self.token:
return False
c = self.token[0]
return (c >= '0' and c <= '9') or c == '-' or c == '+'
def ConsumeIdentifier(self):
"""Consumes protocol message field identifier.
Returns:
Identifier string.
Raises:
ParseError: If an identifier couldn't be consumed.
"""
result = self.token
if not re.match(self._IDENTIFIER, result):
raise self._ParseError('Expected identifier.')
self.NextToken()
return result
def ConsumeInt32(self):
"""Consumes a signed 32bit integer number.
Returns:
The integer parsed.
Raises:
ParseError: If a signed 32bit integer couldn't be consumed.
"""
try:
result = self._ParseInteger(self.token, is_signed=True, is_long=False)
except ValueError, e:
raise self._IntegerParseError(e)
self.NextToken()
return result
def ConsumeUint32(self):
"""Consumes an unsigned 32bit integer number.
Returns:
The integer parsed.
Raises:
ParseError: If an unsigned 32bit integer couldn't be consumed.
"""
try:
result = self._ParseInteger(self.token, is_signed=False, is_long=False)
except ValueError, e:
raise self._IntegerParseError(e)
self.NextToken()
return result
def ConsumeInt64(self):
"""Consumes a signed 64bit integer number.
Returns:
The integer parsed.
Raises:
ParseError: If a signed 64bit integer couldn't be consumed.
"""
try:
result = self._ParseInteger(self.token, is_signed=True, is_long=True)
except ValueError, e:
raise self._IntegerParseError(e)
self.NextToken()
return result
def ConsumeUint64(self):
"""Consumes an unsigned 64bit integer number.
Returns:
The integer parsed.
Raises:
ParseError: If an unsigned 64bit integer couldn't be consumed.
"""
try:
result = self._ParseInteger(self.token, is_signed=False, is_long=True)
except ValueError, e:
raise self._IntegerParseError(e)
self.NextToken()
return result
def ConsumeFloat(self):
"""Consumes an floating point number.
Returns:
The number parsed.
Raises:
ParseError: If a floating point number couldn't be consumed.
"""
text = self.token
if re.match(self._FLOAT_INFINITY, text):
self.NextToken()
if text.startswith('-'):
return float('-inf')
return float('inf')
if re.match(self._FLOAT_NAN, text):
self.NextToken()
return float('nan')
try:
result = float(text)
except ValueError, e:
raise self._FloatParseError(e)
self.NextToken()
return result
def ConsumeBool(self):
"""Consumes a boolean value.
Returns:
The bool parsed.
Raises:
ParseError: If a boolean value couldn't be consumed.
"""
if self.token == 'true':
self.NextToken()
return True
elif self.token == 'false':
self.NextToken()
return False
else:
raise self._ParseError('Expected "true" or "false".')
def ConsumeString(self):
"""Consumes a string value.
Returns:
The string parsed.
Raises:
ParseError: If a string value couldn't be consumed.
"""
return unicode(self.ConsumeByteString(), 'utf-8')
def ConsumeByteString(self):
"""Consumes a byte array value.
Returns:
The array parsed (as a string).
Raises:
ParseError: If a byte array value couldn't be consumed.
"""
list = [self.ConsumeSingleByteString()]
while len(self.token) > 0 and self.token[0] in ('\'', '"'):
list.append(self.ConsumeSingleByteString())
return "".join(list)
def ConsumeSingleByteString(self):
text = self.token
if len(text) < 1 or text[0] not in ('\'', '"'):
raise self._ParseError('Exptected string.')
if len(text) < 2 or text[-1] != text[0]:
raise self._ParseError('String missing ending quote.')
try:
result = _CUnescape(text[1:-1])
except ValueError, e:
raise self._ParseError(str(e))
self.NextToken()
return result
def _ParseInteger(self, text, is_signed=False, is_long=False):
"""Parses an integer.
Args:
text: The text to parse.
is_signed: True if a signed integer must be parsed.
is_long: True if a long integer must be parsed.
Returns:
The integer value.
Raises:
ValueError: Thrown Iff the text is not a valid integer.
"""
pos = 0
if text.startswith('-'):
pos += 1
base = 10
if text.startswith('0x', pos) or text.startswith('0X', pos):
base = 16
elif text.startswith('0', pos):
base = 8
# Do the actual parsing. Exception handling is propagated to caller.
result = int(text, base)
# Check if the integer is sane. Exceptions handled by callers.
checker = self._INTEGER_CHECKERS[2 * int(is_long) + int(is_signed)]
checker.CheckValue(result)
return result
def ParseErrorPreviousToken(self, message):
"""Creates and *returns* a ParseError for the previously read token.
Args:
message: A message to set for the exception.
Returns:
A ParseError instance.
"""
return ParseError('%d:%d : %s' % (
self._previous_line + 1, self._previous_column + 1, message))
def _ParseError(self, message):
"""Creates and *returns* a ParseError for the current token."""
return ParseError('%d:%d : %s' % (
self._line + 1, self._column + 1, message))
def _IntegerParseError(self, e):
return self._ParseError('Couldn\'t parse integer: ' + str(e))
def _FloatParseError(self, e):
return self._ParseError('Couldn\'t parse number: ' + str(e))
def NextToken(self):
"""Reads the next meaningful token."""
self._previous_line = self._line
self._previous_column = self._column
if self.AtEnd():
self.token = ''
return
self._column += len(self.token)
# Make sure there is data to work on.
self._PopLine()
match = re.match(self._TOKEN, self._current_line)
if match:
token = match.group(0)
self._current_line = self._current_line[len(token):]
self.token = token
else:
self.token = self._current_line[0]
self._current_line = self._current_line[1:]
self._SkipWhitespace()
# text.encode('string_escape') does not seem to satisfy our needs as it
# encodes unprintable characters using two-digit hex escapes whereas our
# C++ unescaping function allows hex escapes to be any length. So,
# "\0011".encode('string_escape') ends up being "\\x011", which will be
# decoded in C++ as a single-character string with char code 0x11.
def _CEscape(text):
def escape(c):
o = ord(c)
if o == 10: return r"\n" # optional escape
if o == 13: return r"\r" # optional escape
if o == 9: return r"\t" # optional escape
if o == 39: return r"\'" # optional escape
if o == 34: return r'\"' # necessary escape
if o == 92: return r"\\" # necessary escape
if o >= 127 or o < 32: return "\\%03o" % o # necessary escapes
return c
return "".join([escape(c) for c in text])
_CUNESCAPE_HEX = re.compile('\\\\x([0-9a-fA-F]{2}|[0-9a-f-A-F])')
def _CUnescape(text):
def ReplaceHex(m):
return chr(int(m.group(0)[2:], 16))
# This is required because the 'string_escape' encoding doesn't
# allow single-digit hex escapes (like '\xf').
result = _CUNESCAPE_HEX.sub(ReplaceHex, text)
return result.decode('string_escape')
