Add a string serializer
[ton] / don / __init__.py
index ac70fdb..6f8bf47 100644 (file)
@@ -1,5 +1,329 @@
-import don.binary as binary
-import don.string as string
+import binascii
+import collections
+import struct
+
+VOID = 0x00
+TRUE = 0x01
+FALSE = 0x02
+BOOL = (TRUE, FALSE)
+INT8 = 0x10
+INT16 = 0x11
+INT32 = 0x12
+INT64 = 0x13
+FLOAT = 0x20
+DOUBLE = 0x21
+BINARY = 0x30
+UTF8 = 0x31
+UTF16 = 0x32
+UTF32 = 0x33
+LIST = 0x40
+DICTIONARY = 0x41
+
+DEFAULT_INTEGER_ENCODING = INT32
+DEFAULT_DECIMAL_ENCODING = DOUBLE
+DEFAULT_STRING_ENCODING = UTF8
+
+TaggedObject = collections.namedtuple('TaggedObject', ['tag', 'value'])
+
+_TYPES_TO_TAGS = {
+    int: DEFAULT_INTEGER_ENCODING,
+    float: DEFAULT_DECIMAL_ENCODING,
+    bytes: BINARY,
+    str: DEFAULT_STRING_ENCODING,
+    list: LIST,
+    dict: DICTIONARY,
+    collections.OrderedDict: DICTIONARY,
+}
+
+def _tag(o):
+    if isinstance(o, TaggedObject):
+        return o
+
+    if o is None:
+        return TaggedObject(tag = VOID, value = o)
+
+    if o is True:
+        return TaggedObject(tag = TRUE, value = o)
+
+    if o is False:
+        return TaggedObject(tag = FALSE, value = o)
+
+    return TaggedObject(tag = _TYPES_TO_TAGS[type(o)], value = o)
+
+def _binary_serialize_tag_only_type(o):
+    return b''
+
+def _pack_format_string_to_binary_serializer(pfs):
+    def serializer(i):
+        return struct.pack(pfs, i)
+    return serializer
+
+def _encoder_to_binary_serializer(e):
+    def serializer(s):
+        encoded = e(s)
+        return struct.pack('!I', len(encoded)) + encoded
+    return serializer
+
+def _binary_serialize_list(items):
+    # TODO Enforce that items are all the same type
+    items = [_tag(i) for i in items]
+
+    if len(items) == 0:
+        item_tag = VOID
+    else:
+        item_tag = items[0].tag
+
+    item_serializer = _BINARY_SERIALIZERS[item_tag]
+    items = [item_serializer(i.value) for i in items]
+    item_length = len(items)
+    items = b''.join(items)
+    byte_length = len(items)
+    return struct.pack('!BII', item_tag, byte_length, item_length) + items
+
+def _binary_serialize_dict(d):
+    item_length = 0
+    serialized = b''
+
+    key_serializer = _BINARY_SERIALIZERS[UTF8]
+
+    for key, value in d.items():
+        assert isinstance(key, str)
+        item_length += 1
+        serialized += key_serializer(key) + _binary_serialize(value)
+
+    byte_length = len(serialized)
+    return struct.pack('!II', byte_length, item_length) + serialized
+
+_BINARY_SERIALIZERS = {
+    VOID: _binary_serialize_tag_only_type,
+    TRUE: _binary_serialize_tag_only_type,
+    FALSE: _binary_serialize_tag_only_type,
+    INT8: _pack_format_string_to_binary_serializer('!b'),
+    INT16: _pack_format_string_to_binary_serializer('!h'),
+    INT32: _pack_format_string_to_binary_serializer('!i'),
+    FLOAT: _pack_format_string_to_binary_serializer('!f'),
+    DOUBLE: _pack_format_string_to_binary_serializer('!d'),
+    BINARY: _encoder_to_binary_serializer(lambda b: b),
+    UTF8: _encoder_to_binary_serializer(lambda s: s.encode('utf-8')),
+    UTF16: _encoder_to_binary_serializer(lambda s: s.encode('utf-16')),
+    UTF32: _encoder_to_binary_serializer(lambda s: s.encode('utf-32')),
+    LIST: _binary_serialize_list,
+    DICTIONARY: _binary_serialize_dict,
+}
+
+def _binary_serialize(o):
+    o = _tag(o)
+    return struct.pack('!B', o.tag) + _BINARY_SERIALIZERS[o.tag](o.value)
+
+ParseResult = collections.namedtuple(
+    'ParseResult',
+    [
+        'success',
+        'value',
+        'remaining',
+    ],
+)
+
+_FAILED_PARSE_RESULT = ParseResult(success = False, value = None, remaining = None)
+
+_BYTE_SIZES_TO_UNPACK_FORMATS = {
+    1: '!b',
+    2: '!h',
+    4: '!i',
+    8: '!q',
+}
+
+def make_integer_parser(size_in_bytes):
+    unpack_format = _BYTE_SIZES_TO_UNPACK_FORMATS[size_in_bytes]
+
+    def integer_parser(source):
+        value = struct.unpack(unpack_format, source[:size_in_bytes])[0]
+        remaining = source[size_in_bytes:]
+
+        return ParseResult(success = True, value = value, remaining = remaining)
+
+    return integer_parser
+
+def binary64_parser(source):
+    return ParseResult(
+        success = True,
+        value = struct.unpack('!d', source[:8])[0],
+        remaining = source[8:],
+    )
+
+def make_string_parser(decoder):
+    def string_parser(source):
+        length = struct.unpack('!I', source[:4])[0]
+        source = source[4:]
+        return ParseResult(
+            success = True,
+            value = decoder(source[:length]),
+            remaining = source[length:],
+        )
+
+    return string_parser
+
+def _list_parser(source):
+    tag = source[0]
+    parser = _TAGS_TO_PARSERS[tag]
+
+    source = source[1:]
+    byte_length, items_length = struct.unpack('!II', source[:8])
+    source = source[8:]
+
+    remaining = source[byte_length:]
+    source = source[:byte_length]
+
+    def item_iterator(source):
+        count = 0
+
+        while len(source) > 0:
+            parse_result = parser(source)
+
+            if parse_result.success:
+                count += 1
+                yield parse_result.value
+                source = parse_result.remaining
+
+        assert count == items_length
+    
+    return ParseResult(
+        success = True,
+        value = item_iterator(source),
+        remaining = remaining,
+    )
+
+def dictionary_parser(source):
+    key_parser = _TAGS_TO_PARSERS[UTF8]
+
+    byte_length, item_length = struct.unpack('!II', source[:8])
+    source = source[8:]
+
+    remaining = source[byte_length:]
+    source = source[:byte_length]
+
+    def kvp_iterator(source):
+        count = 0
+
+        while len(source) > 0:
+            count += 1
+            key_parse_result = key_parser(source)
+            key, source = key_parse_result.value, key_parse_result.remaining
+            value_parse_result = _object_parser(source)
+            value, source = value_parse_result.value, value_parse_result.remaining
+
+            yield key, value
+
+        assert count == item_length
+
+    return ParseResult(
+        success = True,
+        value = collections.OrderedDict(kvp_iterator(source)),
+        remaining = remaining,
+    )
+
+
+_TAGS_TO_PARSERS = {
+    VOID: lambda r: ParseResult(True, None, r),
+    TRUE: lambda r: ParseResult(True, True, r),
+    FALSE: lambda r: ParseResult(True, False, r),
+    INT8: make_integer_parser(1),
+    INT16: make_integer_parser(2),
+    INT32: make_integer_parser(4),
+    INT64: make_integer_parser(8),
+    DOUBLE: binary64_parser,
+    BINARY: make_string_parser(lambda b : b),
+    UTF8: make_string_parser(lambda b : b.decode('utf-8')),
+    UTF16: make_string_parser(lambda b : b.decode('utf-16')),
+    UTF32: make_string_parser(lambda b : b.decode('utf-32')),
+    LIST: _list_parser,
+    DICTIONARY: dictionary_parser,
+}
+
+def _object_parser(source):
+    return _TAGS_TO_PARSERS[source[0]](source[1:])
+
+def _parse(parser, source, consume_all = True):
+    result = parser(source)
+
+    if result.success and result.remaining == b'':
+        return result.value
+
+    raise Exception('Unparsed trailing bytes: {}'.format(result.remaining))
+
+def _binary_deserialize(b):
+    return _parse(_object_parser, b)
+
+def _integer_size_to_string_serializer(integer_size):
+    minimum = -(2 ** (integer_size - 1))
+    maximum = 2 ** (integer_size - 1) - 1
+    
+    def serializer(integer):
+        assert minimum <= integer and integer <= maximum
+        return '{}i{}'.format(integer, integer_size)
+
+    return serializer
+
+def _serialize_float(f):
+    return '{}f'.format(f)
+
+def _serialize_double(d):
+    return '{}d'.format(d)
+
+def _serialize_binary(b):
+    return '"{}"b'.format(binascii.hexlify(b).decode('ascii'))
+
+def _utf_encoding_to_serializer(utf_encoding):
+    def serializer(s):
+        return '"{}"{}'.format(s, utf_encoding)
+
+    return serializer
+
+def _string_serialize_list(l):
+    return '[{}]'.format(', '.join(map(_string_serialize, l)))
+
+def _string_serialize_dictionary(d):
+    def serialize_kvp(kvp):
+        return _string_serialize(kvp[0]) + ': ' + _string_serialize(kvp[1])
+    return '{ ' + ', '.join(map(serialize_kvp, d.items())) + ' }'
+
+_STRING_SERIALIZERS = {
+    VOID: lambda o: 'null',
+    TRUE: lambda o: 'true',
+    FALSE: lambda o: 'false',
+    INT8: _integer_size_to_string_serializer(8),
+    INT16: _integer_size_to_string_serializer(16),
+    INT32: _integer_size_to_string_serializer(32),
+    INT64: _integer_size_to_string_serializer(64),
+    FLOAT: _serialize_float,
+    DOUBLE: _serialize_double,
+    BINARY: _serialize_binary,
+    UTF8: _utf_encoding_to_serializer('utf8'),
+    UTF16: _utf_encoding_to_serializer('utf16'),
+    UTF32: _utf_encoding_to_serializer('utf32'),
+    LIST: _string_serialize_list,
+    DICTIONARY: _string_serialize_dictionary,
+}
+
+def _string_serialize(o):
+    o = _tag(o)
+    
+    return _STRING_SERIALIZERS[o.tag](o.value)
+
+def _string_deserialize(o):
+    pass
+
+Serializer = collections.namedtuple('Serializer', ['serialize', 'deserialize'])
+
+binary = Serializer(
+    serialize = _binary_serialize,
+    deserialize = _binary_deserialize,
+)
+
+string = Serializer(
+    serialize = _string_serialize,
+    deserialize = _string_deserialize,
+)
 
 def binary_to_string(b):
     return string.serialize(binary.deserialize(b))