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pymclevel/nbt.py
David Vierra 86640ec61a Fixed: Remove self from TAG_Compound's key not found error message
String formatting was taking forever.
2013-01-10 16:04:41 -10:00

562 lines
14 KiB
Python

# vim:set sw=2 sts=2 ts=2:
"""
Named Binary Tag library. Serializes and deserializes TAG_* objects
to and from binary data. Load a Minecraft level by calling nbt.load().
Create your own TAG_* objects and set their values.
Save a TAG_* object to a file or StringIO object.
Read the test functions at the end of the file to get started.
This library requires Numpy. Get it here:
http://new.scipy.org/download.html
Official NBT documentation is here:
http://www.minecraft.net/docs/NBT.txt
Copyright 2010 David Rio Vierra
"""
import collections
import gzip
import itertools
import logging
import struct
import zlib
from cStringIO import StringIO
import numpy
from numpy import array, zeros, fromstring
log = logging.getLogger(__name__)
class NBTFormatError(RuntimeError):
pass
TAG_BYTE = 1
TAG_SHORT = 2
TAG_INT = 3
TAG_LONG = 4
TAG_FLOAT = 5
TAG_DOUBLE = 6
TAG_BYTE_ARRAY = 7
TAG_STRING = 8
TAG_LIST = 9
TAG_COMPOUND = 10
TAG_INT_ARRAY = 11
TAG_SHORT_ARRAY = 12
class TAG_Value(object):
"""Simple values. Subclasses override fmt to change the type and size.
Subclasses may set data_type instead of overriding setValue for automatic data type coercion"""
__slots__ = ('_name', '_value')
def __init__(self, value=0, name=""):
self.value = value
self.name = name
fmt = struct.Struct("b")
tagID = NotImplemented
data_type = NotImplemented
_name = None
_value = None
@property
def value(self):
return self._value
@value.setter
def value(self, newVal):
"""Change the TAG's value. Data types are checked and coerced if needed."""
self._value = self.data_type(newVal)
@property
def name(self):
return self._name
@name.setter
def name(self, newVal):
"""Change the TAG's name. Coerced to a unicode."""
self._name = unicode(newVal)
@classmethod
def load_from(cls, ctx):
data = ctx.data[ctx.offset:]
(value,) = cls.fmt.unpack_from(data)
self = cls(value=value)
ctx.offset += self.fmt.size
return self
def __repr__(self):
return "<%s name=\"%s\" value=%r>" % (str(self.__class__.__name__), self.name, self.value)
def write_tag(self, buf):
buf.write(chr(self.tagID))
def write_name(self, buf):
if self.name is not None:
write_string(self.name, buf)
def write_value(self, buf):
buf.write(self.fmt.pack(self.value))
class TAG_Byte(TAG_Value):
__slots__ = ('_name', '_value')
tagID = TAG_BYTE
fmt = struct.Struct(">b")
data_type = int
class TAG_Short(TAG_Value):
__slots__ = ('_name', '_value')
tagID = TAG_SHORT
fmt = struct.Struct(">h")
data_type = int
class TAG_Int(TAG_Value):
__slots__ = ('_name', '_value')
tagID = TAG_INT
fmt = struct.Struct(">i")
data_type = int
class TAG_Long(TAG_Value):
__slots__ = ('_name', '_value')
tagID = TAG_LONG
fmt = struct.Struct(">q")
data_type = long
class TAG_Float(TAG_Value):
__slots__ = ('_name', '_value')
tagID = TAG_FLOAT
fmt = struct.Struct(">f")
data_type = float
class TAG_Double(TAG_Value):
__slots__ = ('_name', '_value')
tagID = TAG_DOUBLE
fmt = struct.Struct(">d")
data_type = float
class TAG_Byte_Array(TAG_Value):
"""Like a string, but for binary data. Four length bytes instead of
two. Value is a numpy array, and you can change its elements"""
tagID = TAG_BYTE_ARRAY
def __init__(self, value=None, name=""):
if value is None:
value = zeros(0, self.dtype)
self.name = name
self.value = value
def __repr__(self):
return "<%s name=%s length=%d>" % (self.__class__, self.name, len(self.value))
__slots__ = ('_name', '_value')
def data_type(self, value):
return array(value, self.dtype)
dtype = numpy.dtype('uint8')
@classmethod
def load_from(cls, ctx):
data = ctx.data[ctx.offset:]
(string_len,) = TAG_Int.fmt.unpack_from(data)
value = fromstring(data[4:string_len * cls.dtype.itemsize + 4], cls.dtype)
self = cls(value)
ctx.offset += string_len * cls.dtype.itemsize + 4
return self
def write_value(self, buf):
value_str = self.value.tostring()
buf.write(struct.pack(">I%ds" % (len(value_str),), self.value.size, value_str))
class TAG_Int_Array(TAG_Byte_Array):
"""An array of big-endian 32-bit integers"""
tagID = TAG_INT_ARRAY
__slots__ = ('_name', '_value')
dtype = numpy.dtype('>u4')
class TAG_Short_Array(TAG_Int_Array):
"""An array of big-endian 16-bit integers. Not official, but used by some mods."""
tagID = TAG_SHORT_ARRAY
__slots__ = ('_name', '_value')
dtype = numpy.dtype('>u2')
class TAG_String(TAG_Value):
"""String in UTF-8
The value parameter must be a 'unicode' or a UTF-8 encoded 'str'
"""
tagID = TAG_STRING
def __init__(self, value="", name=""):
if name:
self.name = name
self.value = value
_decodeCache = {}
__slots__ = ('_name', '_value')
def data_type(self, value):
if isinstance(value, unicode):
return value
else:
decoded = self._decodeCache.get(value)
if decoded is None:
decoded = value.decode('utf-8')
self._decodeCache[value] = decoded
return decoded
@classmethod
def load_from(cls, ctx):
value = load_string(ctx)
return cls(value)
def write_value(self, buf):
write_string(self._value, buf)
string_len_fmt = struct.Struct(">H")
def load_string(ctx):
data = ctx.data[ctx.offset:]
(string_len,) = string_len_fmt.unpack_from(data)
value = data[2:string_len + 2].tostring()
ctx.offset += string_len + 2
return value
def write_string(string, buf):
encoded = string.encode('utf-8')
buf.write(struct.pack(">h%ds" % (len(encoded),), len(encoded), encoded))
#noinspection PyMissingConstructor
class TAG_Compound(TAG_Value, collections.MutableMapping):
"""A heterogenous list of named tags. Names must be unique within
the TAG_Compound. Add tags to the compound using the subscript
operator []. This will automatically name the tags."""
tagID = TAG_COMPOUND
ALLOW_DUPLICATE_KEYS = False
__slots__ = ('_name', '_value')
def __init__(self, value=None, name=""):
self.value = value or []
self.name = name
def __repr__(self):
return "<%s name='%s' keys=%r>" % (str(self.__class__.__name__), self.name, self.keys())
def data_type(self, val):
for i in val:
self.check_value(i)
return list(val)
def check_value(self, val):
if not isinstance(val, TAG_Value):
raise TypeError("Invalid type for TAG_Compound element: %s" % val.__class__.__name__)
if not val.name:
raise ValueError("Tag needs a name to be inserted into TAG_Compound: %s" % val)
@classmethod
def load_from(cls, ctx):
self = cls()
while ctx.offset < len(ctx.data):
tag_type = ctx.data[ctx.offset]
ctx.offset += 1
if tag_type == 0:
break
tag_name = load_string(ctx)
tag = tag_classes[tag_type].load_from(ctx)
tag.name = tag_name
self._value.append(tag)
return self
def save(self, filename_or_buf=None, compressed=True):
"""
Save the TAG_Compound element to a file. Since this element is the root tag, it can be named.
Pass a filename to save the data to a file. Pass a file-like object (with a read() method)
to write the data to that object. Pass nothing to return the data as a string.
"""
if self.name is None:
self.name = ""
buf = StringIO()
self.write_tag(buf)
self.write_name(buf)
self.write_value(buf)
data = buf.getvalue()
if compressed:
gzio = StringIO()
gz = gzip.GzipFile(fileobj=gzio, mode='wb')
gz.write(data)
gz.close()
data = gzio.getvalue()
if filename_or_buf is None:
return data
if isinstance(filename_or_buf, basestring):
f = file(filename_or_buf, "wb")
f.write(data)
else:
filename_or_buf.write(data)
def write_value(self, buf):
for tag in self.value:
tag.write_tag(buf)
tag.write_name(buf)
tag.write_value(buf)
buf.write("\x00")
# --- collection functions ---
def __getitem__(self, key):
# hits=filter(lambda x: x.name==key, self.value)
# if(len(hits)): return hits[0]
for tag in self.value:
if tag.name == key:
return tag
raise KeyError("Key {0} not found".format(key))
def __iter__(self):
return itertools.imap(lambda x: x.name, self.value)
def __contains__(self, key):
return key in map(lambda x: x.name, self.value)
def __len__(self):
return self.value.__len__()
def __setitem__(self, key, item):
"""Automatically wraps lists and tuples in a TAG_List, and wraps strings
and unicodes in a TAG_String."""
if isinstance(item, (list, tuple)):
item = TAG_List(item)
elif isinstance(item, basestring):
item = TAG_String(item)
item.name = key
self.check_value(item)
# remove any items already named "key".
if not self.ALLOW_DUPLICATE_KEYS:
self._value = filter(lambda x: x.name != key, self._value)
self._value.append(item)
def __delitem__(self, key):
self.value.__delitem__(self.value.index(self[key]))
def add(self, value):
if value.name is None:
raise ValueError("Tag %r must have a name." % value)
self[value.name] = value
def get_all(self, key):
return [v for v in self._value if v.name == key]
class TAG_List(TAG_Value, collections.MutableSequence):
"""A homogenous list of unnamed data of a single TAG_* type.
Once created, the type can only be changed by emptying the list
and adding an element of the new type. If created with no arguments,
returns a list of TAG_Compound
Empty lists in the wild have been seen with type TAG_Byte"""
tagID = 9
def __init__(self, value=None, name="", list_type=TAG_BYTE):
# can be created from a list of tags in value, with an optional
# name, or created from raw tag data, or created with list_type
# taken from a TAG class or instance
self.name = name
self.list_type = list_type
self.value = value or []
__slots__ = ('_name', '_value')
def __repr__(self):
return "<%s name='%s' list_type=%r length=%d>" % (self.__class__.__name__, self.name,
tag_classes[self.list_type],
len(self))
def data_type(self, val):
if val:
self.list_type = val[0].tagID
assert all([x.tagID == self.list_type for x in val])
return list(val)
@classmethod
def load_from(cls, ctx):
self = cls()
self.list_type = ctx.data[ctx.offset]
ctx.offset += 1
(list_length,) = TAG_Int.fmt.unpack_from(ctx.data, ctx.offset)
ctx.offset += TAG_Int.fmt.size
for i in range(list_length):
tag = tag_classes[self.list_type].load_from(ctx)
self.append(tag)
return self
def write_value(self, buf):
buf.write(chr(self.list_type))
buf.write(TAG_Int.fmt.pack(len(self.value)))
for i in self.value:
i.write_value(buf)
def check_tag(self, value):
if value.tagID != self.list_type:
raise TypeError("Invalid type %s for TAG_List(%s)" % (value.__class__, tag_classes[self.list_type]))
# --- collection methods ---
def __iter__(self):
return iter(self.value)
def __contains__(self, tag):
return tag in self.value
def __getitem__(self, index):
return self.value[index]
def __len__(self):
return len(self.value)
def __setitem__(self, index, value):
if isinstance(index, slice):
for tag in value:
self.check_tag(tag)
else:
self.check_tag(value)
self.value[index] = value
def __delitem__(self, index):
del self.value[index]
def insert(self, index, value):
if len(self) == 0:
self.list_type = value.tagID
else:
self.check_tag(value)
value.name = ""
self.value.insert(index, value)
tag_classes = { c.tagID: c for c in (TAG_Byte, TAG_Short, TAG_Int, TAG_Long, TAG_Float, TAG_Double, TAG_String,
TAG_Byte_Array, TAG_List, TAG_Compound, TAG_Int_Array, TAG_Short_Array) }
def gunzip(data):
return gzip.GzipFile(fileobj=StringIO(data)).read()
def try_gunzip(data):
try:
data = gunzip(data)
except IOError, zlib.error:
pass
return data
def load(filename="", buf=None):
"""
Unserialize data from an NBT file and return the root TAG_Compound object. If filename is passed,
reads from the file, otherwise uses data from buf. Buf can be a buffer object with a read() method or a string
containing NBT data.
"""
if filename:
buf = file(filename, "rb")
if hasattr(buf, "read"):
buf = buf.read()
return _load_buffer(try_gunzip(buf))
class load_ctx(object):
pass
def _load_buffer(buf):
if isinstance(buf, str):
buf = fromstring(buf, 'uint8')
data = buf
if not len(data):
raise NBTFormatError("Asked to load root tag of zero length")
tag_type = data[0]
if tag_type != 10:
magic = data[:4]
raise NBTFormatError('Not an NBT file with a root TAG_Compound '
'(file starts with "%s" (0x%08x)' % (magic.tostring(), magic.view(dtype='uint32')))
ctx = load_ctx()
ctx.offset = 1
ctx.data = data
tag_name = load_string(ctx)
tag = TAG_Compound.load_from(ctx)
tag.name = tag_name
return tag
__all__ = [a.__name__ for a in tag_classes.itervalues()] + ["load", "gunzip"]
import nbt_util
TAG_Value.__str__ = nbt_util.nested_string
try:
#noinspection PyUnresolvedReferences
from _nbt import (load, TAG_Byte, TAG_Short, TAG_Int, TAG_Long, TAG_Float, TAG_Double, TAG_String,
TAG_Byte_Array, TAG_List, TAG_Compound, TAG_Int_Array, TAG_Short_Array, NBTFormatError)
except ImportError:
pass