summaryrefslogtreecommitdiff
path: root/python/examples/kaitai/vlq_base128_le.py
diff options
context:
space:
mode:
authorXusheng <xusheng@vector35.com>2021-07-01 12:34:30 +0800
committerXusheng Li <xushengli@protonmail.com>2021-07-05 10:11:47 +0800
commit13ff200ba134b8704f37eca99c42b70dab0d17dc (patch)
tree876b3db3c53f704b31152aeaede1f2edc9d27b24 /python/examples/kaitai/vlq_base128_le.py
parent4039a800349dcd587833d3e27d9137e4649818f4 (diff)
Remove snippet and kaitai plugin. Note their individual links.
Diffstat (limited to 'python/examples/kaitai/vlq_base128_le.py')
-rw-r--r--python/examples/kaitai/vlq_base128_le.py108
1 files changed, 0 insertions, 108 deletions
diff --git a/python/examples/kaitai/vlq_base128_le.py b/python/examples/kaitai/vlq_base128_le.py
deleted file mode 100644
index 6fa8d43b..00000000
--- a/python/examples/kaitai/vlq_base128_le.py
+++ /dev/null
@@ -1,108 +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
-
-
-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))
-
-class VlqBase128Le(KaitaiStruct):
- """A variable-length unsigned integer using base128 encoding. 1-byte groups
- consist of 1-bit flag of continuation and 7-bit value chunk, and are ordered
- "least significant group first", i.e. in "little-endian" manner.
-
- This particular encoding is specified and used in:
-
- * DWARF debug file format, where it's dubbed "unsigned LEB128" or "ULEB128".
- http://dwarfstd.org/doc/dwarf-2.0.0.pdf - page 139
- * Google Protocol Buffers, where it's called "Base 128 Varints".
- https://developers.google.com/protocol-buffers/docs/encoding?csw=1#varints
- * Apache Lucene, where it's called "VInt"
- http://lucene.apache.org/core/3_5_0/fileformats.html#VInt
- * Apache Avro uses this as a basis for integer encoding, adding ZigZag on
- top of it for signed ints
- http://avro.apache.org/docs/current/spec.html#binary_encode_primitive
-
- More information on this encoding is available at https://en.wikipedia.org/wiki/LEB128
-
- This particular implementation supports serialized values to up 8 bytes long.
- """
- SEQ_FIELDS = ["groups"]
- 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['groups']['start'] = self._io.pos()
- self.groups = []
- i = 0
- while True:
- if not 'arr' in self._debug['groups']:
- self._debug['groups']['arr'] = []
- self._debug['groups']['arr'].append({'start': self._io.pos()})
- _t_groups = self._root.Group(self._io, self, self._root)
- _t_groups._read()
- _ = _t_groups
- self.groups.append(_)
- self._debug['groups']['arr'][len(self.groups) - 1]['end'] = self._io.pos()
- if not (_.has_next):
- break
- i += 1
- self._debug['groups']['end'] = self._io.pos()
-
- class Group(KaitaiStruct):
- """One byte group, clearly divided into 7-bit "value" chunk and 1-bit "continuation" flag.
- """
- SEQ_FIELDS = ["b"]
- 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['b']['start'] = self._io.pos()
- self.b = self._io.read_u1()
- self._debug['b']['end'] = self._io.pos()
-
- @property
- def has_next(self):
- """If true, then we have more bytes to read."""
- if hasattr(self, '_m_has_next'):
- return self._m_has_next if hasattr(self, '_m_has_next') else None
-
- self._m_has_next = (self.b & 128) != 0
- return self._m_has_next if hasattr(self, '_m_has_next') else None
-
- @property
- def value(self):
- """The 7-bit (base128) numeric value chunk of this group."""
- if hasattr(self, '_m_value'):
- return self._m_value if hasattr(self, '_m_value') else None
-
- self._m_value = (self.b & 127)
- return self._m_value if hasattr(self, '_m_value') else None
-
-
- @property
- def len(self):
- if hasattr(self, '_m_len'):
- return self._m_len if hasattr(self, '_m_len') else None
-
- self._m_len = len(self.groups)
- return self._m_len if hasattr(self, '_m_len') else None
-
- @property
- def value(self):
- """Resulting value as normal integer."""
- if hasattr(self, '_m_value'):
- return self._m_value if hasattr(self, '_m_value') else None
-
- self._m_value = (((((((self.groups[0].value + ((self.groups[1].value << 7) if self.len >= 2 else 0)) + ((self.groups[2].value << 14) if self.len >= 3 else 0)) + ((self.groups[3].value << 21) if self.len >= 4 else 0)) + ((self.groups[4].value << 28) if self.len >= 5 else 0)) + ((self.groups[5].value << 35) if self.len >= 6 else 0)) + ((self.groups[6].value << 42) if self.len >= 7 else 0)) + ((self.groups[7].value << 49) if self.len >= 8 else 0))
- return self._m_value if hasattr(self, '_m_value') else None
-
-