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| author | Xusheng <xusheng@vector35.com> | 2021-07-01 12:34:30 +0800 |
|---|---|---|
| committer | Xusheng Li <xushengli@protonmail.com> | 2021-07-05 10:11:47 +0800 |
| commit | 13ff200ba134b8704f37eca99c42b70dab0d17dc (patch) | |
| tree | 876b3db3c53f704b31152aeaede1f2edc9d27b24 /python/examples/kaitai/google_protobuf.py | |
| parent | 4039a800349dcd587833d3e27d9137e4649818f4 (diff) | |
Remove snippet and kaitai plugin. Note their individual links.
Diffstat (limited to 'python/examples/kaitai/google_protobuf.py')
| -rw-r--r-- | python/examples/kaitai/google_protobuf.py | 150 |
1 files changed, 0 insertions, 150 deletions
diff --git a/python/examples/kaitai/google_protobuf.py b/python/examples/kaitai/google_protobuf.py deleted file mode 100644 index 74d8020e..00000000 --- a/python/examples/kaitai/google_protobuf.py +++ /dev/null @@ -1,150 +0,0 @@ -# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild - -from pkg_resources import parse_version -from .kaitaistruct import __version__ as ks_version, KaitaiStruct, KaitaiStream, BytesIO -import collections -from enum import Enum - - -if parse_version(ks_version) < parse_version('0.7'): - raise Exception("Incompatible Kaitai Struct Python API: 0.7 or later is required, but you have %s" % (ks_version)) - -from .vlq_base128_le import VlqBase128Le -class GoogleProtobuf(KaitaiStruct): - """Google Protocol Buffers (AKA protobuf) is a popular data - serialization scheme used for communication protocols, data storage, - etc. There are implementations are available for almost every - popular language. The focus points of this scheme are brevity (data - is encoded in a very size-efficient manner) and extensibility (one - can add keys to the structure, while keeping it readable in previous - version of software). - - Protobuf uses semi-self-describing encoding scheme for its - messages. It means that it is possible to parse overall structure of - the message (skipping over fields one can't understand), but to - fully understand the message, one needs a protocol definition file - (`.proto`). To be specific: - - * "Keys" in key-value pairs provided in the message are identified - only with an integer "field tag". `.proto` file provides info on - which symbolic field names these field tags map to. - * "Keys" also provide something called "wire type". It's not a data - type in its common sense (i.e. you can't, for example, distinguish - `sint32` vs `uint32` vs some enum, or `string` from `bytes`), but - it's enough information to determine how many bytes to - parse. Interpretation of the value should be done according to the - type specified in `.proto` file. - * There's no direct information on which fields are optional / - required, which fields may be repeated or constitute a map, what - restrictions are placed on fields usage in a single message, what - are the fields' default values, etc, etc. - - .. seealso:: - Source - https://developers.google.com/protocol-buffers/docs/encoding - """ - SEQ_FIELDS = ["pairs"] - def __init__(self, _io, _parent=None, _root=None): - self._io = _io - self._parent = _parent - self._root = _root if _root else self - self._debug = collections.defaultdict(dict) - - def _read(self): - self._debug['pairs']['start'] = self._io.pos() - self.pairs = [] - i = 0 - while not self._io.is_eof(): - if not 'arr' in self._debug['pairs']: - self._debug['pairs']['arr'] = [] - self._debug['pairs']['arr'].append({'start': self._io.pos()}) - _t_pairs = self._root.Pair(self._io, self, self._root) - _t_pairs._read() - self.pairs.append(_t_pairs) - self._debug['pairs']['arr'][len(self.pairs) - 1]['end'] = self._io.pos() - i += 1 - - self._debug['pairs']['end'] = self._io.pos() - - class Pair(KaitaiStruct): - """Key-value pair.""" - - class WireTypes(Enum): - varint = 0 - bit_64 = 1 - len_delimited = 2 - group_start = 3 - group_end = 4 - bit_32 = 5 - SEQ_FIELDS = ["key", "value"] - def __init__(self, _io, _parent=None, _root=None): - self._io = _io - self._parent = _parent - self._root = _root if _root else self - self._debug = collections.defaultdict(dict) - - def _read(self): - self._debug['key']['start'] = self._io.pos() - self.key = VlqBase128Le(self._io) - self.key._read() - self._debug['key']['end'] = self._io.pos() - self._debug['value']['start'] = self._io.pos() - _on = self.wire_type - if _on == self._root.Pair.WireTypes.varint: - self.value = VlqBase128Le(self._io) - self.value._read() - elif _on == self._root.Pair.WireTypes.len_delimited: - self.value = self._root.DelimitedBytes(self._io, self, self._root) - self.value._read() - elif _on == self._root.Pair.WireTypes.bit_64: - self.value = self._io.read_u8le() - elif _on == self._root.Pair.WireTypes.bit_32: - self.value = self._io.read_u4le() - self._debug['value']['end'] = self._io.pos() - - @property - def wire_type(self): - """"Wire type" is a part of the "key" that carries enough - information to parse value from the wire, i.e. read correct - amount of bytes, but there's not enough informaton to - interprete in unambiguously. For example, one can't clearly - distinguish 64-bit fixed-sized integers from 64-bit floats, - signed zigzag-encoded varints from regular unsigned varints, - arbitrary bytes from UTF-8 encoded strings, etc. - """ - if hasattr(self, '_m_wire_type'): - return self._m_wire_type if hasattr(self, '_m_wire_type') else None - - self._m_wire_type = KaitaiStream.resolve_enum(self._root.Pair.WireTypes, (self.key.value & 7)) - return self._m_wire_type if hasattr(self, '_m_wire_type') else None - - @property - def field_tag(self): - """Identifies a field of protocol. One can look up symbolic - field name in a `.proto` file by this field tag. - """ - if hasattr(self, '_m_field_tag'): - return self._m_field_tag if hasattr(self, '_m_field_tag') else None - - self._m_field_tag = (self.key.value >> 3) - return self._m_field_tag if hasattr(self, '_m_field_tag') else None - - - class DelimitedBytes(KaitaiStruct): - SEQ_FIELDS = ["len", "body"] - def __init__(self, _io, _parent=None, _root=None): - self._io = _io - self._parent = _parent - self._root = _root if _root else self - self._debug = collections.defaultdict(dict) - - def _read(self): - self._debug['len']['start'] = self._io.pos() - self.len = VlqBase128Le(self._io) - self.len._read() - self._debug['len']['end'] = self._io.pos() - self._debug['body']['start'] = self._io.pos() - self.body = self._io.read_bytes(self.len.value) - self._debug['body']['end'] = self._io.pos() - - - |
