forked from LBRYCommunity/lbry-sdk
127 lines
3 KiB
Python
127 lines
3 KiB
Python
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import struct
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from io import BytesIO
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class BCDataStream:
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def __init__(self, data=None):
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self.data = BytesIO(data)
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@property
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def is_at_beginning(self):
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return self.data.tell() == 0
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def reset(self):
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self.data.seek(0)
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def get_bytes(self):
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return self.data.getvalue()
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def read(self, size):
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return self.data.read(size)
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def write(self, data):
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self.data.write(data)
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def write_many(self, many):
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self.data.writelines(many)
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def read_string(self):
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return self.read(self.read_compact_size())
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def write_string(self, s):
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self.write_compact_size(len(s))
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self.write(s)
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def read_compact_size(self):
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size = self.read_uint8()
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if size < 253:
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return size
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if size == 253:
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return self.read_uint16()
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elif size == 254:
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return self.read_uint32()
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elif size == 255:
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return self.read_uint64()
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def write_compact_size(self, size):
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if size < 253:
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self.write_uint8(size)
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elif size <= 0xFFFF:
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self.write_uint8(253)
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self.write_uint16(size)
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elif size <= 0xFFFFFFFF:
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self.write_uint8(254)
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self.write_uint32(size)
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else:
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self.write_uint8(255)
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self.write_uint64(size)
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def read_boolean(self):
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return self.read_uint8() != 0
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def write_boolean(self, val):
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return self.write_uint8(1 if val else 0)
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int8 = struct.Struct('b')
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uint8 = struct.Struct('B')
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int16 = struct.Struct('<h')
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uint16 = struct.Struct('<H')
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int32 = struct.Struct('<i')
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uint32 = struct.Struct('<I')
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int64 = struct.Struct('<q')
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uint64 = struct.Struct('<Q')
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def _read_struct(self, fmt):
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value = self.read(fmt.size)
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if len(value) > 0:
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return fmt.unpack(value)[0]
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def read_int8(self):
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return self._read_struct(self.int8)
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def read_uint8(self):
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return self._read_struct(self.uint8)
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def read_int16(self):
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return self._read_struct(self.int16)
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def read_uint16(self):
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return self._read_struct(self.uint16)
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def read_int32(self):
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return self._read_struct(self.int32)
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def read_uint32(self):
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return self._read_struct(self.uint32)
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def read_int64(self):
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return self._read_struct(self.int64)
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def read_uint64(self):
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return self._read_struct(self.uint64)
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def write_int8(self, val):
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self.write(self.int8.pack(val))
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def write_uint8(self, val):
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self.write(self.uint8.pack(val))
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def write_int16(self, val):
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self.write(self.int16.pack(val))
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def write_uint16(self, val):
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self.write(self.uint16.pack(val))
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def write_int32(self, val):
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self.write(self.int32.pack(val))
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def write_uint32(self, val):
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self.write(self.uint32.pack(val))
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def write_int64(self, val):
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self.write(self.int64.pack(val))
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def write_uint64(self, val):
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self.write(self.uint64.pack(val))
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